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2009 Element 3 pool
492 / 600 questions need explanations
18.0% complete
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A capacitor is sometimes placed in series with the primary of a power transformer to:
  • Improve the power factor. (74% chose this)
  • Improve output voltage regulation. (13% chose this)
  • Rectify the primary windings. (7% chose this)
  • None of these. (6% chose this)
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To couple energy into and out of a waveguide use:
  • Wide copper sheeting. (6% chose this)
  • A thin piece of wire as an antenna. (70% chose this)
  • An LC circuit. (8% chose this)
  • Capacitive coupling. (16% chose this)
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On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on?
  • There is probably a defect in the system causing the carrier to be transmitted. (68% chose this)
  • One of the sidebands is missing. (11% chose this)
  • Both sidebands are being transmitting. (8% chose this)
  • The operation is normal. (13% chose this)
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Which of the following is a required component of an Instrument Landing System (ILS)?
  • Altimeter: shows aircraft height above sea-level. (5% chose this)
  • Localizer: shows aircraft deviation horizontally from center of runway. (75% chose this)
  • VHF Communications: provide communications to aircraft. (8% chose this)
  • Distance Measuring Equipment: shows aircraft distance to VORTAC station. (12% chose this)
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The tachometer of a building’s elevator circuit experiences interference caused by the radio system nearby. What is a common potential “fix” for the problem?
  • Replace the tachometer of the elevator. (3% chose this)
  • Add a .01 µF capacitor across the motor/tachometer leads. (69% chose this)
  • Add a 200 µF capacity across the motor/tachometer leads. (12% chose this)
  • Add an isolating resistor in series with the motor leads. (16% chose this)
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How does the modulation index of a phase-modulated emission vary with RF carrier frequency?
  • It does not depend on the RF carrier frequency. (62% chose this)
  • Modulation index increases as the RF carrier frequency increases. (17% chose this)
  • It varies with the square root of the RF carrier frequency. (3% chose this)
  • It decreases as the RF carrier frequency increases. (17% chose this)
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What are the three terminals of a TRIAC?
  • Emitter, base 1, and base 2. (19% chose this)
  • Base, emitter, and collector. (12% chose this)
  • Gate, source, and sink. (8% chose this)
  • Gate, anode 1, and anode 2. (61% chose this)
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What is the purpose of not putting sharp corners on the ground leads within a building?
  • No reason. (2% chose this)
  • It is easier to install. (3% chose this)
  • Lightning will jump off of the ground lead because it is not able to make sharp bends. (93% chose this)
  • Ground leads should always be made to look good in an installation, including the use of sharp bends in the corners. (2% chose this)
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What factors should be considered when selecting an intermediate frequency?
  • Cross-modulation distortion and interference. (19% chose this)
  • Interference to other services. (5% chose this)
  • Image rejection and selectivity. (69% chose this)
  • Noise figure and distortion. (7% chose this)
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What portion of a microprocessor circuit is the pulse generator?
  • Clock (89% chose this)
  • RAM (0% chose this)
  • ROM (3% chose this)
  • PLL (8% chose this)
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What kind of input signal could be used to test the amplitude linearity of a single-sideband phone transmitter while viewing the output on an oscilloscope?
  • Whistling in the microphone. (6% chose this)
  • An audio frequency sine wave. (14% chose this)
  • A two-tone audio-frequency sine wave. (77% chose this)
  • An audio frequency square wave. (3% chose this)
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What might occur in a receiver if excessive amounts of signal energy overdrive the mixer circuit?
  • Automatic limiting occurs. (6% chose this)
  • Mixer blanking occurs. (4% chose this)
  • Spurious mixer products are generated. (78% chose this)
  • The mixer circuit becomes unstable and drifts. (11% chose this)
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What happens to reactive power in a circuit that has both inductors and capacitors?
  • It is dissipated as heat in the circuit. (11% chose this)
  • It alternates between magnetic and electric fields and is not dissipated. (78% chose this)
  • It is dissipated as inductive and capacitive fields. (9% chose this)
  • It is dissipated as kinetic energy within the circuit. (2% chose this)
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In which frequency band does a search and rescue transponder operate?
  • 9 GHz (68% chose this)
  • 3 GHz (5% chose this)
  • S-band (6% chose this)
  • 406 MHz (22% chose this)
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What is the purpose of a series multiplier resistor used with a voltmeter?
  • It is used to increase the voltage-indicating range of the voltmeter. (83% chose this)
  • A multiplier resistor is not used with a voltmeter. (6% chose this)
  • It is used to decrease the voltage-indicating range of the voltmeter. (6% chose this)
  • It is used to increase the current-indicating range of an ammeter, not a voltmeter. (5% chose this)
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What might contribute to apparent low voltage on marine SSB transmitting?
  • Blown red fuse. (2% chose this)
  • Too much grounding. (6% chose this)
  • Blown black negative fuse. (65% chose this)
  • Antenna mismatch. (27% chose this)
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What is an advantage of using a trap antenna?
  • It may be used for multiband operation. (73% chose this)
  • It has high directivity in the high-frequency bands. (9% chose this)
  • It has high gain. (10% chose this)
  • It minimizes harmonic radiation. (8% chose this)
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Too much gain in a VHF receiver front end could result in this:
  • Local signals become weaker. (1% chose this)
  • Difficult to match receiver impedances. (6% chose this)
  • Dramatic increase in receiver current. (5% chose this)
  • Susceptibility of intermodulation interference from nearby transmitters. (88% chose this)
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In Figure 3H17, the block labeled 4 would indicate that this schematic is most likely a/an:
  • Audio amplifier. (16% chose this)
  • Shipboard RADAR. (4% chose this)
  • SSB radio transmitter. (77% chose this)
  • Wireless LAN (local area network) computer. (3% chose this)
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Which of the following devices acts as two SCRs connected back to back, but facing in opposite directions and sharing a common gate?
  • JFET. (1% chose this)
  • Dual-gate MOSFET. (10% chose this)
  • DIAC. (4% chose this)
  • TRIAC. (86% chose this)
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How can an FM-phone signal be produced in a transmitter?
  • By modulating the supply voltage to a class-B amplifier. (6% chose this)
  • By modulating the supply voltage to a class-C amplifier. (26% chose this)
  • By using a balanced modulator. (20% chose this)
  • By feeding the audio directly to the oscillator. (48% chose this)
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What is the definition of detection in a radio receiver?
  • The process of masking out the intelligence on a received carrier to make an S-meter operational. (7% chose this)
  • The recovery of intelligence from the modulated RF signal. (81% chose this)
  • The modulation of a carrier. (4% chose this)
  • The mixing of noise with the received signal. (8% chose this)
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What pulse width and repetition rate should you use at long ranges?
  • Narrow pulse width and slow repetition rate. (9% chose this)
  • Narrow pulse width and fast repetition rate. (13% chose this)
  • Wide pulse width and fast repetition rate. (5% chose this)
  • Wide pulse width and slow repetition rate. (73% chose this)
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A 1-watt, 10-volt Zener diode with the following characteristics: Imin. = 5 mA; Imax. = 95 mA; and Z = 8 ohms, is to be used as part of a voltage regulator in a 20-V power supply. Approximately what size current-limiting resistor would be used to set its bias to the midpoint of its operating range?
  • 100 ohms. (20% chose this)
  • 200 ohms. (52% chose this)
  • 1 kilohms. (11% chose this)
  • 2 kilohms. (17% chose this)
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What frequency synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter?
  • A direct digital synthesizer. (54% chose this)
  • Phase-locked-loop synthesizer. (37% chose this)
  • A diode-switching matrix synthesizer. (5% chose this)
  • A hybrid synthesizer. (5% chose this)
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An emitter-follower amplifier has:
  • More voltage gain than common emitter or common base. (30% chose this)
  • More power gain than common emitter or common base. (10% chose this)
  • Lowest input impedance of the three amplifier configurations. (5% chose this)
  • More current gain than common emitter or common base. (55% chose this)
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Sites having multiple transmitting antennas must include antennas with more than _______% of the maximum permissible power density exposure limit when evaluating RF site exposure.
  • Any (4% chose this)
  • 5 (77% chose this)
  • 1 (7% chose this)
  • 12.5 (13% chose this)
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What is the approximate ratio of peak envelope power to average power during normal voice modulation peak in a single-sideband phone signal?
  • 2.5 to 1. (75% chose this)
  • 1 to 1. (5% chose this)
  • 25 to 1. (16% chose this)
  • 100 to 1. (3% chose this)
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Halving the cross-sectional area of a conductor will:
  • Not affect the resistance. (4% chose this)
  • Quarter the resistance. (3% chose this)
  • Double the resistance. (84% chose this)
  • Halve the resistance. (10% chose this)
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What is the term used to express the amount of electrical energy stored in an electrostatic field?
  • Joules. (78% chose this)
  • Coulombs. (10% chose this)
  • Watts. (9% chose this)
  • Volts. (3% chose this)
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A good crystal band-pass filter for a single-sideband phone would be?
  • 5 KHz. (23% chose this)
  • 2.1 KHz. (57% chose this)
  • 500 Hz. (5% chose this)
  • 15 KHz. (15% chose this)
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What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated?
  • Amplifier desensitization. (3% chose this)
  • Neutralization. (10% chose this)
  • Adjacent channel interference. (7% chose this)
  • Intermodulation interference. (80% chose this)
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Assuming a power source to have a fixed value of internal resistance, maximum power will be transferred to the load when:
  • The load impedance is greater than the source impedance. (8% chose this)
  • The load impedance equals the internal impedance of the source. (84% chose this)
  • The load impedance is less than the source impedance. (5% chose this)
  • The fixed values of internal impedance are not relative to the power source. (3% chose this)
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What occurs if the load is removed from an operating series DC motor?
  • It will stop running. (5% chose this)
  • Speed will increase slightly. (18% chose this)
  • No change occurs. (3% chose this)
  • It will accelerate until it falls apart. (74% chose this)
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In a negative-logic circuit, what level is used to represent a logic 0?
  • Low level. (26% chose this)
  • Positive-transition level. (2% chose this)
  • Negative-transition level. (5% chose this)
  • High level. (67% chose this)
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In a regulated power supply, what type of component will most likely be used to establish a reference voltage?
  • Tunnel Diode. (7% chose this)
  • Battery. (3% chose this)
  • Pass Transistor. (2% chose this)
  • Zener Diode. (88% chose this)
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What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels?
  • Frequency hopping. (76% chose this)
  • Direct sequence. (1% chose this)
  • Time-domain frequency modulation. (18% chose this)
  • Frequency compandored spread spectrum. (5% chose this)
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Why is the Colpitts oscillator circuit commonly used in a VFO (variable frequency oscillator)?
  • It can be phase locked. (12% chose this)
  • It can be remotely tuned. (7% chose this)
  • It is stable. (72% chose this)
  • It has little or no effect on the crystal’s stability. (9% chose this)
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The ATR box:
  • Prevents the received signal from entering the transmitter. (53% chose this)
  • Protects the receiver from strong RADAR signals. (2% chose this)
  • Turns off the receiver when the transmitter is on. (12% chose this)
  • All of the above. (33% chose this)
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In rectangular coordinates, what is the impedance of a network composed of a 0.1-microhenry inductor in series with a 30-ohm resistor, at 5 MHz?
  • 30 -j3 (17% chose this)
  • 3 +j30 (9% chose this)
  • 3 -j30 (4% chose this)
  • 30 +j3 (71% chose this)
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In what radio stage is the image frequency normally rejected?
  • RF. (51% chose this)
  • IF. (32% chose this)
  • LO. (4% chose this)
  • Detector. (14% chose this)
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What is the main function of the COSPAS-SARSAT satellite system?
  • Monitor 121.5 MHz for voice distress calls. (7% chose this)
  • Monitor 406 MHz for distress calls from EPIRBs. (82% chose this)
  • Monitor 1635 MHz for coded distress calls. (2% chose this)
  • Monitor 2197.5 kHz for hexadecimal coded DSC distress messages. (9% chose this)
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In an NMEA 2000 device, a load equivalence number (LEN) of 1 is equivalent to how much current consumption?
  • 50 mA (55% chose this)
  • 10 mA (15% chose this)
  • 25 mA (17% chose this)
  • 5 mA (13% chose this)
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How many individual memory cells would be contained in a memory IC that has 4 data bus input/output pins and 4 address pins for connection to the address bus?
  • 8 (6% chose this)
  • 16 (26% chose this)
  • 32 (6% chose this)
  • 64 (63% chose this)
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In what stage of a VHF receiver would a low noise amplifier be most advantageous?
  • IF stage. (12% chose this)
  • Front end RF stage. (76% chose this)
  • Audio stage. (10% chose this)
  • Power supply. (2% chose this)
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When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?
  • CODECs are used to digitize the voice signal. (75% chose this)
  • Noise-blanking must be selected by the operator. (6% chose this)
  • The voice signal must be compressed to fit into the allowed bandwidth. (18% chose this)
  • The voice signal will be expanded at the receiving terminal. (2% chose this)
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What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies?
  • Tunnel diode. (9% chose this)
  • Varactor diode. (71% chose this)
  • Silicon-controlled rectifier. (5% chose this)
  • Zener diode. (15% chose this)
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What is the orbiting altitude of the Iridium satellite communications system?
  • 22,184 miles. (27% chose this)
  • 11,492 miles. (13% chose this)
  • 4,686 miles. (2% chose this)
  • 485 miles. (58% chose this)
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What stage determines the maximum frequency response of an oscilloscope?
  • Time base. (22% chose this)
  • Horizontal sweep. (31% chose this)
  • Power supply. (2% chose this)
  • Vertical amplifier. (45% chose this)
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What type of antenna is used in an aircraft’s Instrument Landing System (ILS) glideslope installation?
  • A vertically polarized antenna that radiates an omnidirectional antenna pattern. (12% chose this)
  • A balanced loop reception antenna. (33% chose this)
  • A folded dipole reception antenna. (46% chose this)
  • An electronically steerable phased-array antenna that radiates a directional antenna pattern. (9% chose this)
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What is one common use for PIN diodes?
  • Constant current source. (5% chose this)
  • RF switch. (77% chose this)
  • Constant voltage source. (1% chose this)
  • RF rectifier. (16% chose this)
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A radio frequency device that allows RF energy to pass through in one direction with very little loss but absorbs RF power in the opposite direction is a:
  • Circulator. (10% chose this)
  • Wave trap. (15% chose this)
  • Multiplexer. (4% chose this)
  • Isolator. (71% chose this)
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Which is the code used for SITOR-A and -B transmissions?
  • The 5 bit baudot telex code. (4% chose this)
  • Each character consists of 7 bits with 3 “zeros” and 4 “ones”. (11% chose this)
  • Each character consists of 7 bits with 4 “zeros” and 3 “ones”. (57% chose this)
  • Each character has 7 bits of data and 3 bits for error correction. (28% chose this)
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The expression “voltage regulation” as it applies to a shunt-wound DC generator operating at a constant frequency refers to:
  • Voltage fluctuations from load to no-load. (73% chose this)
  • Voltage output efficiency. (12% chose this)
  • Voltage in the secondary compared to the primary. (12% chose this)
  • Rotor winding voltage ratio (2% chose this)
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Skin effect is the phenomenon where:
  • RF current flows in a thin layer of the conductor, closer to the surface, as frequency increases. (85% chose this)
  • RF current flows in a thin layer of the conductor, closer to the surface, as frequency decreases. (8% chose this)
  • Thermal effects on the surface of the conductor increase the impedance. (5% chose this)
  • Thermal effects on the surface of the conductor decrease the impedance. (1% chose this)
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What is a truth table?
  • A list of input combinations and their corresponding outputs that characterizes a digital device’s function. (88% chose this)
  • A table of logic symbols that indicate the high logic states of an op-amp. (4% chose this)
  • A diagram showing logic states when the digital device’s output is true. (4% chose this)
  • A table of logic symbols that indicates the low logic states of an op-amp. (3% chose this)
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Which of the following Ohms Law formulas is incorrect?
  • I = E / R (7% chose this)
  • I = R / E (84% chose this)
  • E = I x R (5% chose this)
  • R = E / I (4% chose this)
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What type of antenna is used in an aircraft’s Instrument Landing System (ILS) marker beacon installation?
  • An electronically steerable phased-array antenna that radiates a directional antenna pattern. (11% chose this)
  • A folded dipole reception antenna. (30% chose this)
  • A balanced loop reception antenna. (39% chose this)
  • A horizontally polarized antenna that radiates an omnidirectional antenna pattern. (20% chose this)
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What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance?
  • Approximately equal to the circuit resistance. (87% chose this)
  • Approximately equal to XL. (4% chose this)
  • Low, as compared to the circuit resistance. (5% chose this)
  • Approximately equal to XC. (3% chose this)
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What are the characteristics of an inverting operational amplifier (op-amp) circuit?
  • It has input and output signals in phase. (8% chose this)
  • Input and output signals are 90 degrees out of phase. (10% chose this)
  • It has input and output signals 180 degrees out of phase. (73% chose this)
  • Input impedance is low while the output impedance is high. (9% chose this)
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A TDMA radio uses what to carry the multiple conversations sequentially?
  • Separate frequencies. (11% chose this)
  • Separate pilot tones. (3% chose this)
  • Separate power levels. (2% chose this)
  • Separate time slots. (84% chose this)
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The amplitude modulated variable phase signal and the frequency modulated reference phase signal of a Very-high-frequency Omnidirectional Range (VOR) station used for aircraft navigation are synchronized so that both signals are in phase with each other at ____________ of the VOR station.
  • 180 degrees South, true bearing position. (3% chose this)
  • 360 degrees North, magnetic bearing position. (76% chose this)
  • 180 degrees South, magnetic bearing position. (2% chose this)
  • 0 degrees North, true bearing position. (19% chose this)
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What is meant by the term noise figure of a communications receiver?
  • The level of noise entering the receiver from the antenna. (11% chose this)
  • The relative strength of a received signal 3 kHz removed from the carrier frequency. (2% chose this)
  • The level of noise generated in the front end and succeeding stages of a receiver. (66% chose this)
  • The ability of a receiver to reject unwanted signals at frequencies close to the desired one. (22% chose this)
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A(n) ____ and ____ can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (TDR).
  • Frequency spectrum analyzer, RF generator. (26% chose this)
  • Oscilloscope, pulse generator. (68% chose this)
  • AC millivolt meter, AF generator. (0% chose this)
  • Frequency counter, linear detector. (5% chose this)
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What is a pi-network?
  • A network consisting of a capacitor, resistor and inductor. (11% chose this)
  • The Phase inversion stage. (3% chose this)
  • An enhanced token ring network. (0% chose this)
  • A network consisting of one inductor and two capacitors or two inductors and one capacitor. (86% chose this)
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What does the term “IO” mean within a microprocessor system?
  • Integrated oscillator. (6% chose this)
  • Integer operation. (1% chose this)
  • Input-output. (93% chose this)
  • Internal operation. (1% chose this)
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Gain of a closed-loop op-amp circuit is determined by?
  • The maximum operating frequency divided by the square root of the load impedance. (13% chose this)
  • The op-amp’s external feedback network. (62% chose this)
  • Supply voltage and slew rate. (4% chose this)
  • The op-amp’s internal feedback network. (21% chose this)
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What is the approximate operating current of a light-emitting diode?
  • 20 mA. (79% chose this)
  • 5 mA. (15% chose this)
  • 10 mA. (7% chose this)
  • 400 mA. (0% chose this)
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In Figure 3C5, which capacitor (labeled 1 through 4) is being used as a bypass capacitor?
  • 1 (4% chose this)
  • 2 (6% chose this)
  • 3 (86% chose this)
  • 4 (3% chose this)
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What type of wave is characterized by a rise time significantly faster than the fall time (or vice versa)?
  • Cosine wave. (2% chose this)
  • Square wave. (4% chose this)
  • Sawtooth wave. (92% chose this)
  • Sine wave. (2% chose this)
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How does the COSPAS-SARSAT satellite system determine the position of a ship in distress?
  • By measuring the Doppler shift of the 406 MHz signal taken at several different points in its orbit. (63% chose this)
  • The EPIRB always transmits its position which is relayed by the satellite to the Local User Terminal. (22% chose this)
  • It takes two different satellites to establish an accurate position. (10% chose this)
  • None of the above. (5% chose this)
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Shipboard RADAR is most commonly operated in what band?
  • VHF. (10% chose this)
  • UHF. (10% chose this)
  • SHF. (76% chose this)
  • EHF. (5% chose this)
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The product of the readings of an AC voltmeter and AC ammeter is called:
  • Apparent power. (75% chose this)
  • True power. (19% chose this)
  • Power factor. (5% chose this)
  • Current power. (2% chose this)
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Which network provides the greatest harmonic suppression?
  • L network. (3% chose this)
  • Pi network. (10% chose this)
  • Pi-L network. (84% chose this)
  • Inverse L network. (3% chose this)
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Prior to testing any RADAR system, the operator should first:
  • Check the system grounds. (2% chose this)
  • Assure the display unit is operating normally. (2% chose this)
  • Inform the airport control tower or ship’s master. (5% chose this)
  • Assure no personnel are in front of the antenna. (91% chose this)
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The frequency of an AC signal can be divided electronically by what type of digital circuit?
  • Free-running multivibrator. (6% chose this)
  • Bistable multivibrator. (65% chose this)
  • OR gate. (6% chose this)
  • Astable multivibrator. (23% chose this)
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Which of the following represents the best standing wave ratio (SWR)?
  • 1:1. (91% chose this)
  • 1:1.5. (3% chose this)
  • 1:3. (2% chose this)
  • 1:4. (4% chose this)
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Which of these will be most useful for insulation at UHF frequencies?
  • Rubber. (6% chose this)
  • Mica. (91% chose this)
  • Wax impregnated paper. (3% chose this)
  • Lead. (1% chose this)
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What special type of diode is capable of both amplification and oscillation?
  • Zener diodes. (18% chose this)
  • Point contact diodes. (5% chose this)
  • Tunnel diodes. (65% chose this)
  • Junction diodes. (13% chose this)
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For the logic input levels given in Figure 3E13, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)
  • A is low, B is low and C is high. (7% chose this)
  • A is low, B is high and C is low. (10% chose this)
  • A is high, B is high and C is high. (78% chose this)
  • A is high, B is low and C is low. (5% chose this)
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What is a characteristic of a NAND gate?
  • Produces a logic “0” at its output only when all inputs are logic “0”. (7% chose this)
  • Produces a logic “1” at its output only when all inputs are logic “1”. (15% chose this)
  • Produces a logic “0” at its output if some but not all of its inputs are logic “1”. (9% chose this)
  • Produces a logic “0” at its output only when all inputs are logic “1”. (70% chose this)
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What are the elements of a unijunction transistor?
  • Base 1, base 2, and emitter. (65% chose this)
  • Gate, cathode, and anode. (15% chose this)
  • Gate, base 1, and base 2. (10% chose this)
  • Gate, source, and sink. (10% chose this)
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What is the frequency range of an aircraft’s Very High Frequency (VHF) communications?
  • 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz). (84% chose this)
  • 108.00 MHz to 117.95 MHz. (14% chose this)
  • 329.15 MHz to 335.00 MHz. (1% chose this)
  • 2.000 MHz to 29.999 MHz. (2% chose this)
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What input-amplitude parameter is most valuable in evaluating the signal-handling capability of a Class A amplifier?
  • Average voltage. (5% chose this)
  • RMS voltage. (17% chose this)
  • Peak voltage. (73% chose this)
  • Resting voltage. (5% chose this)
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What device is used to store electrical energy in an electrostatic field?
  • Battery. (1% chose this)
  • Transformer. (1% chose this)
  • Capacitor. (94% chose this)
  • Inductor. (4% chose this)
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In a circuit where the AC voltage and current are out of phase, how can the true power be determined?
  • By multiplying the apparent power times the power factor. (84% chose this)
  • By subtracting the apparent power from the power factor. (1% chose this)
  • By dividing the apparent power by the power factor. (9% chose this)
  • By multiplying the RMS voltage times the RMS current. (6% chose this)
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The deviation ratio is the:
  • Audio modulating frequency to the center carrier frequency. (10% chose this)
  • Maximum carrier frequency deviation to the highest audio modulating frequency. (69% chose this)
  • Carrier center frequency to the audio modulating frequency. (6% chose this)
  • Highest audio modulating frequency to the average audio modulating frequency. (15% chose this)
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Which of the following statements concerning satellite EPIRBs is true?
  • Once activated, these EPIRBs transmit a signal for use in identifying the vessel and for determining the position of the beacon. (86% chose this)
  • The coded signal identifies the nature of the distress situation. (3% chose this)
  • The coded signal only identifies the vessel’s name and port of registry. (2% chose this)
  • If the GMDSS Radio Operator does not program the EPIRB, it will transmit default information such as the follow-on communications frequency and mode. (8% chose this)
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At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna?
  • Equal voltage and current. (7% chose this)
  • Minimum voltage and maximum current. (13% chose this)
  • Maximum voltage and minimum current. (72% chose this)
  • Minimum voltage and minimum current. (8% chose this)
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Which of the following frequency standards is used as a time base standard by field technicians?
  • Quartz Crystal. (21% chose this)
  • Rubidium Standard. (71% chose this)
  • Cesium Beam Standard. (2% chose this)
  • LC Tank Oscillator. (6% chose this)
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Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport. The localizer beam system:
  • Operates within the assigned frequency range of 108.10 to 111.95 GHz. (9% chose this)
  • Produces two amplitude modulated antenna patterns; one pattern above and one pattern below the normal 2.5 degree approach glide path of the aircraft. (4% chose this)
  • Frequencies are automatically tuned-in when the proper glide slope frequency is selected on the aircraft’s Navigation and Communication (NAV/COMM) transceiver. (9% chose this)
  • Produces two amplitude modulated antenna patterns; one pattern with an audio frequency of 90 Hz and one pattern with an audio frequency of 150 Hz, one left of the runway centerline and one right of the runway centerline. (78% chose this)
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What are the two most commonly-used specifications for a junction diode?
  • Maximum forward current and capacitance. (9% chose this)
  • Maximum reverse current and PIV (peak inverse voltage). (6% chose this)
  • Maximum reverse current and capacitance. (0% chose this)
  • Maximum forward current and PIV (peak inverse voltage). (85% chose this)
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An excited 1/2 wavelength antenna produces:
  • Residual fields. (2% chose this)
  • An electro-magnetic field only. (7% chose this)
  • Both electro-magnetic and electro-static fields. (89% chose this)
  • An electro-flux field sometimes. (2% chose this)
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What radio circuit samples analog signals, records and processes them as numbers, then converts them back to analog signals?
  • The pre-emphasis audio stage. (3% chose this)
  • The squelch gate circuit. (2% chose this)
  • The digital signal processing circuit. (91% chose this)
  • The voltage controlled oscillator circuit. (4% chose this)
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Which class of amplifier provides the highest efficiency?
  • Class A. (32% chose this)
  • Class B. (2% chose this)
  • Class C. (52% chose this)
  • Class AB. (13% chose this)
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Given the input levels shown in Figure 3E14 and assuming positive logic devices, what would the output be?
  • A is low, B is high and C is high. (57% chose this)
  • A is high, B is high and C is low. (22% chose this)
  • A is low, B is low and C is high. (13% chose this)
  • None of the above are correct. (7% chose this)
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How can intermodulation interference between two transmitters in close proximity often be reduced or eliminated?
  • By using a Class C final amplifier with high driving power. (3% chose this)
  • By installing a terminated circulator or ferrite isolator in the feed line to the transmitter and duplexer. (68% chose this)
  • By installing a band-pass filter in the antenna feed line. (23% chose this)
  • By installing a low-pass filter in the antenna feed line. (6% chose this)
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To increase the resonant frequency of a 1/4 wavelength antenna:
  • Add a capacitor in series. (54% chose this)
  • Lower capacitor value. (3% chose this)
  • Cut antenna. (9% chose this)
  • Add an inductor. (34% chose this)
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MOSFETs are manufactured with THIS protective device built into their gate to protect the device from static charges and excessive voltages:
  • Schottky diode. (9% chose this)
  • Metal oxide varistor (MOV). (9% chose this)
  • Zener diode. (73% chose this)
  • Tunnel diode. (9% chose this)
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What is the frequency range of an aircraft’s radio altimeter?
  • 962 MHz to 1213 MHz. (30% chose this)
  • 329.15 MHz to 335.00 MHz. (6% chose this)
  • 4250 MHz to 4350 MHz. (45% chose this)
  • 108.00 MHz to 117.95 MHz. (18% chose this)
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What is the meaning of the term “time constant of an RL circuit”? The time required for the:
  • Current in the circuit to build up to 36.8% of the maximum value. (2% chose this)
  • Voltage in the circuit to build up to 63.2% of the maximum value. (31% chose this)
  • Current in the circuit to build up to 63.2% of the maximum value. (63% chose this)
  • Voltage in the circuit to build up to 36.8% of the maximum value. (4% chose this)
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Referred to the fundamental frequency, a shorted stub line attached to the transmission line to absorb even harmonics could have a wavelength of:
  • 1.41 wavelength. (5% chose this)
  • 1/2 wavelength. (11% chose this)
  • 1/4 wavelength. (81% chose this)
  • 1/6 wavelength. (3% chose this)
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Which INMARSAT systems offer High Speed Data at 64/54 kbps?
  • C. (8% chose this)
  • B and C. (21% chose this)
  • Mini-M. (9% chose this)
  • B, M4 and Fleet. (63% chose this)
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A circuit that compares the output of a voltage-controlled oscillator (VCO) to a frequency standard and produces an error voltage that is then used to adjust the capacitance of a varactor diode used to control frequency in that same VCO is called what?
  • Doubly balanced mixer. (1% chose this)
  • Phase-locked loop. (72% chose this)
  • Differential voltage amplifier. (6% chose this)
  • Variable frequency oscillator. (21% chose this)
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A common base amplifier has:
  • More current gain than common emitter or common collector. (36% chose this)
  • More voltage gain than common emitter or common collector. (53% chose this)
  • More power gain than common emitter or common collector. (5% chose this)
  • Highest input impedance of the three amplifier configurations. (5% chose this)
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What is an advantage of a constant-k filter?
  • It has high attenuation of signals at frequencies far removed from the pass band. (67% chose this)
  • It can match impedances over a wide range of frequencies. (27% chose this)
  • It uses elliptic functions. (2% chose this)
  • The ratio of the cutoff frequency to the trap frequency can be varied. (5% chose this)
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In Figure 3D10 with a square wave input what would be the output?
  • 1 (9% chose this)
  • 2 (21% chose this)
  • 3 (63% chose this)
  • 4 (6% chose this)
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Global Positioning Service (GPS) satellite orbiting altitude is:
  • 4,686 miles. (8% chose this)
  • 24,184 miles. (24% chose this)
  • 12,554 miles. (57% chose this)
  • 247 miles. (11% chose this)
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Where would you normally find a low-pass filter in a radio receiver?
  • In the AVC circuit. (7% chose this)
  • In the Oscillator stage. (19% chose this)
  • In the Power Supply. (11% chose this)
  • A and C, but not B. (63% chose this)
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What is used to decrease circuit loading when using an oscilloscope?
  • Dual input amplifiers. (2% chose this)
  • 10:1 divider probe. (82% chose this)
  • Inductive probe. (3% chose this)
  • Resistive probe. (13% chose this)
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The INMARSAT mini-M system is a:
  • Marine SONAR system. (5% chose this)
  • Marine global satellite system. (17% chose this)
  • Marine depth finder. (3% chose this)
  • Satellite system utilizing spot beams to provide for small craft communications. (74% chose this)
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What device is usually used as a stable reference voltage in a linear voltage regulator?
  • Zener diode. (84% chose this)
  • Tunnel diode. (5% chose this)
  • SCR. (5% chose this)
  • Varactor diode. (5% chose this)
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What is a flip-flop circuit? A binary sequential logic element with ___stable states.
  • 1 (7% chose this)
  • 4 (5% chose this)
  • 2 (87% chose this)
  • 8 (1% chose this)
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What radio navigation aid determines the distance from an aircraft to a selected VORTAC station by measuring the length of time the radio signal takes to travel to and from the station?
  • RADAR. (12% chose this)
  • Loran C. (2% chose this)
  • Distance Marking (DM). (3% chose this)
  • Distance Measuring Equipment (DME). (83% chose this)
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Which of the following answers is true?
  • The RF Power reading on a CDMA (code division multiple access) radio will be very accurate on an analog power meter. (16% chose this)
  • The RF Power reading on a CDMA radio is not accurate on an analog power meter. (66% chose this)
  • Power cannot be measured using CDMA modulation. (9% chose this)
  • None of the above. (9% chose this)
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What tolerance off of plumb should a single base station radio rack be installed?
  • No tolerance allowed. (11% chose this)
  • Just outside the bubble on a level. (7% chose this)
  • All the way to one end. (4% chose this)
  • Just inside the bubble on a level. (78% chose this)
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What is the impedance of a network composed of a 100-picofarad capacitor in parallel with a 4000-ohm resistor, at 500 KHz? Specify your answer in polar coordinates.
  • 2490 ohms, /51.5 degrees (15% chose this)
  • 4000 ohms, /38.5 degrees (16% chose this)
  • 5112 ohms, /-38.5 degrees (8% chose this)
  • 2490 ohms, /-51.5 degrees (61% chose this)
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After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?
  • 86.5 % (23% chose this)
  • 13.5 % (58% chose this)
  • 63.2 % (9% chose this)
  • 36.8 % (10% chose this)
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What does the vertical axis of a spectrum analyzer display?
  • Amplitude. (78% chose this)
  • Duration. (0% chose this)
  • Frequency. (19% chose this)
  • Time. (3% chose this)
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Why must you never look directly into a fiber optic cable?
  • High power light waves can burn the skin surrounding the eye. (2% chose this)
  • An active fiber signal may burn the retina and infra-red light cannot be seen. (97% chose this)
  • The end is easy to break. (1% chose this)
  • The signal is red and you can see it. (0% chose this)
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What is the basic unit of electrical power?
  • Ohm. (0% chose this)
  • Watt. (93% chose this)
  • Volt. (3% chose this)
  • Ampere. (4% chose this)
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What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?
  • Time domain reflectometer. (22% chose this)
  • Wattmeter. (11% chose this)
  • DMM. (5% chose this)
  • Frequency domain reflectometer. (62% chose this)
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What type of wire connects an SSB automatic tuner to an insulated backstay?
  • RG8U. (5% chose this)
  • RG213. (2% chose this)
  • 16-gauge two-conductor. (8% chose this)
  • GTO-15 high-voltage cable. (85% chose this)
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What might occur in NMEA 2000 network topology if one device in line should fail?
  • The system shuts down until the device is removed. (7% chose this)
  • Other electronics after the failed device will be inoperable. (6% chose this)
  • The main fuse on the backbone may open. (2% chose this)
  • There will be no interruption to all other devices. (85% chose this)
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What is the term for the out-of-phase power associated with inductors and capacitors?
  • Effective power. (5% chose this)
  • True power. (3% chose this)
  • Peak envelope power. (5% chose this)
  • Reactive power. (87% chose this)
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What principle allows multiple conversations to be able to share one radio channel on a GSM channel?
  • Frequency Division Multiplex. (13% chose this)
  • Double sideband. (8% chose this)
  • Time Division Multiplex. (74% chose this)
  • None of the above. (5% chose this)
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What is the purpose or function of the RADAR duplexer/circulator? It is a/an:
  • Coupling device that is used in the transition from a rectangular waveguide to a circular waveguide. (6% chose this)
  • Electronic switch that allows the use of one antenna for both transmission and reception. (79% chose this)
  • Modified length of waveguide that is used to sample a portion of the transmitted energy for testing purposes. (8% chose this)
  • Dual section coupling device that allows the use of a magnetron as a transmitter. (7% chose this)
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What is the time constant of a circuit having a 100-microfarad capacitor and a 470-kilohm resistor in series?
  • 4700 seconds. (3% chose this)
  • 470 seconds. (5% chose this)
  • 47 seconds. (82% chose this)
  • 0.47 seconds. (10% chose this)
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When would it be more desirable to use an m-derived filter over a constant-k filter?
  • When the response must be maximally flat at one frequency. (5% chose this)
  • When the number of components must be minimized. (2% chose this)
  • When high power levels must be filtered. (2% chose this)
  • When you need more attenuation at a certain frequency that is too close to the cut-off frequency for a constant-k filter. (91% chose this)
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What are the directional characteristics of the INMARSAT-C SES antenna?
  • Highly directional parabolic antenna requiring stabilization. (14% chose this)
  • Wide beam width in a cardioid pattern off the front of the antenna. (10% chose this)
  • Very narrow beam width straight-up from the top of the antenna. (8% chose this)
  • Omnidirectional. (68% chose this)
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Which one of these filters can be used in micro-miniature electronic circuits?
  • High power transmitter cavity. (5% chose this)
  • Receiver SAW IF filter. (85% chose this)
  • Floppy disk controller. (3% chose this)
  • Internet DSL to telephone line filter. (8% chose this)
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What is the primary purpose of the final IF amplifier stage in a receiver?
  • Dynamic response. (15% chose this)
  • Gain. (67% chose this)
  • Noise figure performance. (9% chose this)
  • Bypass undesired signals. (10% chose this)
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Which of the following logic gates will provide an active high out when both inputs are active high?
  • NAND. (2% chose this)
  • NOR. (3% chose this)
  • AND. (94% chose this)
  • XOR. (0% chose this)
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What is the purpose of de-emphasis in the receiver audio stage?
  • When coupled with the transmitter pre-emphasis, flat audio is achieved. (12% chose this)
  • When coupled with the transmitter pre-emphasis, flat audio and noise reduction is received. (73% chose this)
  • No purpose is achieved. (4% chose this)
  • To conserve bandwidth by squelching no-audio periods in the transmission. (11% chose this)
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By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak voltage value?
  • 0.707 (12% chose this)
  • 0.9 (21% chose this)
  • 1.414 (66% chose this)
  • 3.14 (1% chose this)
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What determines the visible color radiated by an LED junction?
  • The color of a lens in an eyepiece. (7% chose this)
  • The amount of voltage across the device. (2% chose this)
  • The amount of current through the device. (5% chose this)
  • The materials used to construct the device. (86% chose this)
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The beta cutoff frequency of a bipolar transistor is the frequency at which:
  • Base current gain has increased to 0.707 of maximum. (29% chose this)
  • Emitter current gain has decreased to 0.707 of maximum. (49% chose this)
  • Collector current gain has decreased to 0.707. (19% chose this)
  • Gate current gain has decreased to 0.707. (4% chose this)
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Digital signal processing (DSP) of RADAR signals (compared with analog) causes:
  • Improved display graphics. (10% chose this)
  • Improved weak signal or target enhancement. (72% chose this)
  • Less interference with SONAR systems. (3% chose this)
  • Less interference with other radio communications equipment. (15% chose this)
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What integrated circuit device converts an analog signal to a digital signal?
  • DAC (12% chose this)
  • DCC (0% chose this)
  • ADC (88% chose this)
  • CDC (0% chose this)
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What spectral impurity components might be generated by a phase-locked-loop synthesizer?
  • Spurs at discrete frequencies. (38% chose this)
  • Random spurs which gradually drift up in frequency. (9% chose this)
  • Broadband noise. (44% chose this)
  • Digital conversion noise. (9% chose this)
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How should shielding be grounded on an NMEA 0183 data line?
  • Unterminated at both ends. (1% chose this)
  • Terminated to ground at the talker and unterminated at the listener. (69% chose this)
  • Unterminated at the talker and terminated at the listener. (3% chose this)
  • Terminated at both the talker and listener. (28% chose this)
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What are the three terminals of a bipolar transistor?
  • Cathode, plate and grid. (1% chose this)
  • Base, collector and emitter. (89% chose this)
  • Gate, source and sink. (7% chose this)
  • Input, output and ground. (2% chose this)
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What is the function of a decade counter digital IC?
  • Decode a decimal number for display on a seven-segment LED display. (6% chose this)
  • Produce one output pulse for every ten input pulses. (82% chose this)
  • Produce ten output pulses for every input pulse. (10% chose this)
  • Add two decimal numbers. (2% chose this)
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What will occur when a non-linear amplifier is used with a single-sideband phone transmitter?
  • Reduced amplifier efficiency. (6% chose this)
  • Increased intelligibility. (6% chose this)
  • Sideband inversion. (3% chose this)
  • Distortion. (85% chose this)
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How do you compute true power (power dissipated in the circuit) in a circuit where AC voltage and current are out of phase?
  • Multiply RMS voltage times RMS current. (15% chose this)
  • Subtract apparent power from the power factor. (3% chose this)
  • Divide apparent power by the power factor. (10% chose this)
  • Multiply apparent power times the power factor. (72% chose this)
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What will occur if an amplifier input signal coupling capacitor fails open?
  • No amplification will occur, with DC within the circuit measuring normal. (75% chose this)
  • Improper biasing will occur within the amplifier stage. (5% chose this)
  • Oscillation and thermal runaway may occur. (11% chose this)
  • An AC hum will appear on the circuit output. (9% chose this)
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Which of the following op-amp circuits is operated open-loop?
  • Non-inverting amp.er. (6% chose this)
  • Inverting amp. (18% chose this)
  • Active filt (4% chose this)
  • Comparator. (72% chose this)
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In the term “ARPA RADAR,” ARPA is the acronym for which of the following?
  • Automatic RADAR Plotting Aid. (77% chose this)
  • Automatic RADAR Positioning Angle. (18% chose this)
  • American RADAR Programmers Association. (3% chose this)
  • Authorized RADAR Programmer and Administrator. (3% chose this)
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What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?
  • It is increased. (24% chose this)
  • It is decreased. (70% chose this)
  • No change occurs. (4% chose this)
  • It becomes flat. (2% chose this)
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What is the description of an optocoupler?
  • A resistor and a capacitor. (0% chose this)
  • Two light sources modulated onto a mirrored surface. (1% chose this)
  • An LED and a photosensitive device. (97% chose this)
  • An amplitude modulated beam encoder. (1% chose this)
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What class of amplifier is distinguished by the presence of output throughout the entire signal cycle and the input never goes into the cutoff region?
  • Class A. (81% chose this)
  • Class B. (5% chose this)
  • Class C. (11% chose this)
  • Class D. (3% chose this)
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There is an improper impedance match between a 30 watt transmitter and the antenna, with 5 watts reflected. How much power is actually radiated?
  • 35 watts. (4% chose this)
  • 30 watts. (7% chose this)
  • 25 watts. (86% chose this)
  • 20 watts. (3% chose this)
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The majority of airborne Distance Measuring Equipment systems automatically tune their transmitter and receiver frequencies to the paired __ / __ channel.
  • VOR/marker beacon. (3% chose this)
  • VOR/LOC. (82% chose this)
  • Marker beacon/glideslope. (8% chose this)
  • LOC/glideslope. (8% chose this)
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Which of the following groups is correct for listing common materials in order of descending conductivity?
  • Silver, copper, aluminum, iron, and lead. (88% chose this)
  • Lead, iron, silver, aluminum, and copper. (5% chose this)
  • Iron, silver, aluminum, copper, and silver. (3% chose this)
  • Silver, aluminum, iron, lead, and copper. (5% chose this)
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What is the process of detection in a radio diode detector circuit?
  • Breakdown of the Zener voltage. (8% chose this)
  • Mixing with noise in the transition region of the diode. (5% chose this)
  • Rectification and filtering of RF. (74% chose this)
  • The change of reactance in the diode with respect to frequency. (14% chose this)
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When a lead-acid storage battery is being charged, a harmful effect to humans is:
  • Internal plate sulfation may occur under constant charging. (6% chose this)
  • Emission of oxygen. (1% chose this)
  • Emission of chlorine gas. (8% chose this)
  • Emission of hydrogen gas. (85% chose this)
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What is the definition of the term “receiver desensitizing”?
  • A burst of noise when the squelch is set too low. (1% chose this)
  • A reduction in receiver sensitivity because of a strong signal on a nearby frequency. (88% chose this)
  • A burst of noise when the squelch is set too high. (1% chose this)
  • A reduction in receiver sensitivity when the AF gain control is turned down. (11% chose this)
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What determines the velocity factor in a transmission line?
  • The termination impedance. (7% chose this)
  • The line length. (8% chose this)
  • Dielectrics in the line. (75% chose this)
  • The center conductor resistivity. (11% chose this)
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Which class of amplifier has an operating angle of more than 180 degrees but less than 360 degrees when driven by a sine wave signal?
  • Class A. (3% chose this)
  • Class B. (15% chose this)
  • Class C. (9% chose this)
  • Class AB. (73% chose this)
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What is the channel spacing used for VHF marine radio?
  • 10 kHz. (14% chose this)
  • 12.5 kHz. (16% chose this)
  • 20 kHz. (4% chose this)
  • 25 kHz. (66% chose this)
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What is the meaning of the term “time constant of an RC circuit”? The time required to charge the capacitor in the circuit to:
  • 23.7% of the supply voltage. (3% chose this)
  • 36.8% of the supply voltage. (5% chose this)
  • 57.3% of the supply voltage. (3% chose this)
  • 63.2% of the supply voltage. (90% chose this)
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Which statement best describes the code used for GMDSS-DSC transmissions?
  • A 10 bit error correcting code starting with bits of data followed by a 3 bit error correcting code. (65% chose this)
  • A 10 bit error correcting code starting with a 3 bit error correcting code followed by 7 bits of data. (14% chose this)
  • An 8 bit code with 7 bits of data followed by a single parity bit. (18% chose this)
  • A 7 bit code that is transmitted twice for error correction. (3% chose this)
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What will produce a magnetic field?
  • A DC source not connected to a circuit. (2% chose this)
  • The presence of a voltage across a capacitor. (0% chose this)
  • A current flowing through a conductor. (95% chose this)
  • The force that drives current through a resistor. (3% chose this)
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Corrosion resulting from electric current flow between dissimilar metals is called:
  • Electrolysis. (10% chose this)
  • Stray current corrosion. (1% chose this)
  • Oxygen starvation corrosion. (0% chose this)
  • Galvanic corrosion. (89% chose this)
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Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in FCC Part 1, OET Bulletin 65) for “controlled” environments, are averaged over _______ minutes, while “uncontrolled” RF environments are averaged over ______ minutes.
  • 6, 30. (60% chose this)
  • 30, 6. (21% chose this)
  • 1, 15. (7% chose this)
  • 15, 1. (12% chose this)
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In an FM-phone signal, what is the term for the maximum deviation from the carrier frequency divided by the maximum audio modulating frequency?
  • Deviation index. (12% chose this)
  • Modulation index. (19% chose this)
  • Deviation ratio. (55% chose this)
  • Modulation ratio. (14% chose this)
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Which of the following describes the INMARSAT Satellite system?
  • AOR at 35° W, POR-E at 165° W, POR-W at 155° E and IOR at 56.5° E. (5% chose this)
  • AOR-E at 25° W, AOR-W at 85° W, POR at 175° W and IOR at 56.5° E. (11% chose this)
  • AOR-E at 15.5° W, AOR-W at 54° W, POR at 178° E and IOR at 64.5° E. (75% chose this)
  • AOR at 40° W, POR at 178° W, IOR-E at 109° E and IOR-W at 46° E. (9% chose this)
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How many GPS satellites are normally in operation?
  • 8 (8% chose this)
  • 18 (4% chose this)
  • 24 (75% chose this)
  • 36 (13% chose this)
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What happens to the conductivity of photoconductive material when light shines on it?
  • It increases. (90% chose this)
  • It decreases. (7% chose this)
  • It stays the same. (1% chose this)
  • It becomes temperature dependent. (2% chose this)
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A “hot gas bonder” is used:
  • To apply solder to the iron tip while it is heating the component. (8% chose this)
  • For non-contact melting of solder. (76% chose this)
  • To allow soldering both sides of the PC board simultaneously. (10% chose this)
  • To cure LCA adhesives. (6% chose this)
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What are three major oscillator circuits found in radio equipment?
  • Taft, Pierce, and negative feedback. (1% chose this)
  • Colpitts, Hartley, and Taft. (4% chose this)
  • Taft, Hartley, and Pierce. (4% chose this)
  • Colpitts, Hartley, and Pierce. (91% chose this)
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What wave form would appear on the voltage outputs at the collectors of an astable, multivibrator, common-emitter stage?
  • Sine wave. (9% chose this)
  • Sawtooth wave. (22% chose this)
  • Square wave. (59% chose this)
  • Half-wave pulses. (10% chose this)
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What conditions exists when a transistor is operating in saturation?
  • The base-emitter junction and collector-base junction are both forward biased. (63% chose this)
  • The base-emitter junction and collector-base junction are both reverse biased. (4% chose this)
  • The base-emitter junction is reverse biased and the collector-base junction is forward biased. (9% chose this)
  • The base-emitter junction is forward biased and the collector-base junction is reverse biased. (25% chose this)
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What test instrument can be used to display spurious signals in the output of a radio transmitter?
  • A spectrum analyzer. (91% chose this)
  • A wattmeter. (2% chose this)
  • A logic analyzer. (1% chose this)
  • A time domain reflectometer. (6% chose this)
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What circuit might contain a SCR?
  • Filament circuit of a tube radio receiver. (11% chose this)
  • A light-dimming circuit. (84% chose this)
  • Shunt across a transformer primary. (2% chose this)
  • Bypass capacitor circuit to ground. (3% chose this)
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What are the transmit and receive frequencies of an aircraft’s mode C transponder operating in the Air Traffic Control RADAR Beacon System (ATCRBS)?
  • Transmit at 1090 MHz, and receive at 1030 MHz (51% chose this)
  • Transmit at 1030 kHz, and receive at 1090 kHz (12% chose this)
  • Transmit at 1090 kHz, and receive at 1030 kHz (13% chose this)
  • Transmit at 1030 MHz, and receive at 1090 MHz (24% chose this)
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How should the signal from a Search And Rescue RADAR Transponder appear on a RADAR display?
  • A series of dashes. (7% chose this)
  • A series of spirals all originating from the range and bearing of the SART. (5% chose this)
  • A series of twenty dashes. (2% chose this)
  • A series of 12 equally spaced dots. (86% chose this)
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An electrical relay is a:
  • Current limiting device. (4% chose this)
  • Device used for supplying 3 or more voltages to a circuit. (2% chose this)
  • Component used mainly with HF audio amplifiers. (1% chose this)
  • Remotely controlled switching device. (93% chose this)
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What type of antenna or pickup device is used to extract the RADAR signal from the wave guide?
  • J-hook. (76% chose this)
  • K-hook. (4% chose this)
  • Folded dipole. (11% chose this)
  • Circulator. (8% chose this)
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What is the range of voltage ratings available in Zener diodes?
  • 1.2 volts to 7 volts. (6% chose this)
  • 2.4 volts to 200 volts and above. (83% chose this)
  • 3 volts to 2000 volts. (4% chose this)
  • 1.2 volts to 5.6 volts. (6% chose this)
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What happens to the beamwidth of an antenna as the gain is increased? The beamwidth:
  • Increases geometrically as the gain is increased. (12% chose this)
  • Increases arithmetically as the gain is increased. (11% chose this)
  • Is essentially unaffected by the gain of the antenna. (6% chose this)
  • Decreases as the gain is increased. (72% chose this)
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In a single-sideband phone signal, what determines the PEP-to-average power ratio?
  • The frequency of the modulating signal. (14% chose this)
  • The degree of carrier suppression. (6% chose this)
  • The speech characteristics. (71% chose this)
  • The amplifier power. (8% chose this)
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What is the description of an optoisolator?
  • An LED and a photosensitive device. (91% chose this)
  • A P-N junction that develops an excess positive charge when exposed to light. (7% chose this)
  • An LED and a capacitor. (1% chose this)
  • An LED and a lithium battery cell. (0% chose this)
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What is the modulation index of a FM phone transmitter producing a maximum carrier deviation of 6 kHz when modulated with a 2 kHz modulating frequency?
  • 3 (94% chose this)
  • 6,000 (1% chose this)
  • 2,000 (4% chose this)
  • 1 (1% chose this)
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After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?
  • 36.8 % (4% chose this)
  • 63.2 % (17% chose this)
  • 86.5 % (76% chose this)
  • 95 % (3% chose this)
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What capacity in amperes does a storage battery need to be in order to operate a 50 watt transmitter for 6 hours? Assume a continuous transmitter load of 70% of the key-locked demand of 40 A, and an emergency light load of 1.5 A.
  • 100 ampere-hours. (8% chose this)
  • 177 ampere-hours. (70% chose this)
  • 249 ampere-hours. (19% chose this)
  • None of these. (3% chose this)
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What is the advantage of a GaAsFET preamplifier in a modern VHF radio receiver?
  • Increased selectivity and flat gain. (13% chose this)
  • Low gain but high selectivity. (4% chose this)
  • High gain and low noise floor. (80% chose this)
  • High gain with high noise floor. (3% chose this)
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Given the combined DC input voltages, what would the output voltage be in the circuit shown in Figure 3D7?
  • 150 mV (11% chose this)
  • 5.5 V (15% chose this)
  • -15 mv (3% chose this)
  • -5.5 V (71% chose this)
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What describes a diode junction that is forward biased?
  • It is a high impedance. (19% chose this)
  • It conducts very little current. (2% chose this)
  • It is a low impedance. (73% chose this)
  • It is an open circuit. (5% chose this)
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An R-S flip-flop is capable of doing all of the following except:
  • Accept data input into R-S inputs with CLK initiated. (5% chose this)
  • Accept data input into PRE and CLR inputs without CLK being initiated. (14% chose this)
  • Refuse to accept synchronous data if asynchronous data is being input at same time. (15% chose this)
  • Operate in toggle mode with R-S inputs held constant and CLK initiated. (66% chose this)
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In a direct digital synthesizer, what are the unwanted components on its output?
  • Broadband noise. (24% chose this)
  • Spurs at discrete frequencies. (54% chose this)
  • Digital conversion noise. (19% chose this)
  • Nyquist limit noise pulses. (2% chose this)
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On runway approach, an ILS Localizer shows:
  • Deviation left or right of runway center line. (94% chose this)
  • Deviation up and down from ground speed. (2% chose this)
  • Deviation percentage from authorized ground speed. (3% chose this)
  • Wind speed along runway. (1% chose this)
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What does the term “BCD” mean?
  • Binaural coded digit. (7% chose this)
  • Bit count decimal. (3% chose this)
  • Binary coded decimal. (90% chose this)
  • Broad course digit. (0% chose this)
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What is the common method for determining the exact sensitivity specification of a receiver?
  • Measure the recovered audio for 12 dB of SINAD. (74% chose this)
  • Measure the recovered audio for 10 dB of quieting. (10% chose this)
  • Measure the recovered audio for 10 dB of SINAD. (11% chose this)
  • Measure the recovered audio for 25 dB of quieting. (5% chose this)
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The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications?
  • Regular-Pulse Excited (RPE). (59% chose this)
  • Code-Excited Linear Predictive (CLEP). (11% chose this)
  • Multi-Pulse Excited (MPE). (23% chose this)
  • Linear Excited Code (LEC). (7% chose this)
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In which oscillator circuit would you find a quartz crystal?
  • Hartley. (6% chose this)
  • Pierce (65% chose this)
  • Colpitts. (17% chose this)
  • All of the above. (12% chose this)
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What is the principal characteristic of a tunnel diode?
  • High forward resistance. (9% chose this)
  • Very high PIV(peak inverse voltage). (20% chose this)
  • Negative resistance region. (56% chose this)
  • High forward current rating. (15% chose this)
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What is a 1/2 digit on a DMM?
  • Smaller physical readout on the left side of the display. (5% chose this)
  • Partial extended accuracy on lower part of the range. (80% chose this)
  • Smaller physical readout on the right side. (8% chose this)
  • Does not apply to DMMs. (7% chose this)
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What is the easiest voltage amplitude to measure by viewing a pure sine wave signal on an oscilloscope?
  • Peak-to-peak. (91% chose this)
  • RMS. (6% chose this)
  • Average. (3% chose this)
  • DC. (1% chose this)
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What type of wire would connect an SSB automatic tuner to an insulated backstay?
  • GTO-15 high-voltage cable. (87% chose this)
  • RG8U. (4% chose this)
  • RG213. (3% chose this)
  • 16-gauge two-conductor. (7% chose this)
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What is the relative dielectric constant for air?
  • 1 (87% chose this)
  • 2 (5% chose this)
  • 4 (2% chose this)
  • 0 (7% chose this)
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What is the frequency range of an aircraft’s Automatic Direction Finding (ADF) equipment?
  • 190 kHz to 1750 kHz. (44% chose this)
  • 190 MHz to 1750 MHz. (16% chose this)
  • 108.10 MHz to 111.95 MHz. (26% chose this)
  • 108.00 MHz to 117.95 MHz. (14% chose this)
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What is the primary purpose of the first IF amplifier stage in a receiver?
  • Noise figure performance. (14% chose this)
  • Tune out cross-modulation distortion. (9% chose this)
  • Dynamic response. (10% chose this)
  • Selectivity. (67% chose this)
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How much gain should be used in the RF amplifier stage of a receiver?
  • Sufficient gain to allow weak signals to overcome noise generated in the first mixer stage. (87% chose this)
  • As much gain as possible short of self oscillation. (2% chose this)
  • Sufficient gain to keep weak signals below the noise of the first mixer stage. (9% chose this)
  • It depends on the amplification factor of the first IF stage. (2% chose this)
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What is the maximum FM deviation for voice operation of a normal wideband channel on VHF and UHF?
  • 2.5 kHz (20% chose this)
  • 5.0 kHz (65% chose this)
  • 7.5 kHz (5% chose this)
  • 10 kHz (10% chose this)
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What best describes the GPS Satellites orbits?
  • They are in six orbital planes equally spaced and inclined about 55 degrees to the equator. (68% chose this)
  • They are in four orbital planes spaced 90 degrees in a polar orbit. (5% chose this)
  • They are in a geosynchronous orbit equally spaced around the equator. (15% chose this)
  • They are in eight orbital planes at an altitude of approximately 1,000 miles. (12% chose this)
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Choose the only correct statement about an aircraft’s Automatic Direction Finding (ADF) equipment.
  • An aircraft’s ADF transmission exhibits primarily a line-of-sight range to the ground-based target station and will not follow the curvature of the Earth. (15% chose this)
  • Only a single omnidirectional sense antenna is required to receive an NDB transmission and process the signal to calculate the aircraft’s bearing to the selected ground station. (10% chose this)
  • All frequencies in the ADF’s operating range except the commercial standard broadcast stations (550 to 1660 kHz) can be utilized as a navigational Non Directional Beacon (NDB) signal. (8% chose this)
  • An aircraft’s ADF antennas can receive transmissions that are over the Earth’s horizon (sometimes several hundred miles away) since these signals will follow the curvature of the Earth. (67% chose this)
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What is the name of the semiconductor IC that has a fixed pattern of digital data stored in its memory matrix?
  • RAM – Random-Access Memory. (13% chose this)
  • ROM – Read-Only Memory. (80% chose this)
  • Register. (4% chose this)
  • Latch. (2% chose this)
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A receiver selectivity of 10 KHz in the IF circuitry is optimum for what type of signals?
  • Double-sideband AM. (67% chose this)
  • SSB voice. (29% chose this)
  • CW. (2% chose this)
  • FSK RTTY. (2% chose this)
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What is a frequency discriminator in a radio receiver?
  • A circuit for detecting FM signals. (70% chose this)
  • A circuit for filtering two closely adjacent signals. (26% chose this)
  • An automatic band switching circuit. (2% chose this)
  • An FM generator. (2% chose this)
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What metal is usually employed as a sacrificial anode for corrosion control purposes?
  • Platinum bushing. (1% chose this)
  • Lead bar. (7% chose this)
  • Zinc bar. (87% chose this)
  • Brass rod. (4% chose this)
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What is the main underlying operating principle of the Very-high-frequency Omnidirectional Range (VOR) aircraft navigational system?
  • A definite amount of time is required to send and receive a radio signal. (16% chose this)
  • The difference between the peak values of two DC voltages may be used to determine an aircraft’s altitude above a selected VOR station. (3% chose this)
  • A phase difference between two AC voltages may be used to determine an aircraft’s azimuth position in relation to a selected VOR station. (68% chose this)
  • A phase difference between two AC voltages may be used to determine an aircraft’s distance from a selected VOR station. (13% chose this)
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What is the primary purpose of an RF amplifier in a receiver?
  • To provide most of the receiver gain. (37% chose this)
  • To vary the receiver image rejection by utilizing the AGC. (5% chose this)
  • To improve the receiver’s noise figure. (55% chose this)
  • To develop the AGC voltage. (3% chose this)
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What is the approximate magnitude of the impedance of a series R-L-C circuit at resonance?
  • High, as compared to the circuit resistance. (6% chose this)
  • Approximately equal to the circuit resistance. (86% chose this)
  • Approximately equal to XL. (3% chose this)
  • Approximately equal to XC. (4% chose this)
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In addition to duplicating the functions of a mode C transponder, an aircraft’s mode S transponder can also provide:
  • Primary RADAR surveillance capabilities. (6% chose this)
  • Long range lightning detection. (3% chose this)
  • Mid-Air collision avoidance capabilities. (83% chose this)
  • Backup VHF voice communication abilities. (8% chose this)
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In rectangular coordinates, what is the impedance of a network composed of a 1.0-millihenry inductor in series with a 200-ohm resistor, at 30 kHz?
  • 200 - j188 (10% chose this)
  • 200 + j188 (78% chose this)
  • 188 + j200 (8% chose this)
  • 188 - j200 (4% chose this)
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Where is the external feedback network connected to control the gain of a closed-loop op-amp circuit?
  • Between the differential inputs. (4% chose this)
  • From output to the non-inverting input. (20% chose this)
  • From output to the inverting input. (58% chose this)
  • Between the output and the differential inputs. (18% chose this)
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The component or circuit providing the transmitter output power for a RADAR system is the:
  • Thyratron. (3% chose this)
  • SCR. (5% chose this)
  • Klystron. (6% chose this)
  • Magnetron. (86% chose this)
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What is the approximate DC input power to a Class AB RF power amplifier stage in an unmodulated carrier transmitter when the PEP output power is 500 watts?
  • 250 watts. (25% chose this)
  • 600 watts. (6% chose this)
  • 800 watts. (8% chose this)
  • 1000 watts. (62% chose this)
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How many degrees are there in one complete sine wave cycle?
  • 90 degrees. (1% chose this)
  • 270 degrees. (0% chose this)
  • 180 degrees. (5% chose this)
  • 360 degrees. (95% chose this)
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What does the power factor equal in an R-L circuit having a 30 degree phase angle between the voltage and the current?
  • 1.73 (4% chose this)
  • 0.866 (62% chose this)
  • 0.5 (27% chose this)
  • 0.577 (6% chose this)
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The GPS transmitted frequencies are:
  • 1626.5 MHz and 1644.5 MHz. (18% chose this)
  • 1227.6 MHz and 1575.4 MHz. (56% chose this)
  • 2245.4 and 2635.4 MHz. (14% chose this)
  • 946.2 MHz and 1226.6 MHz. (12% chose this)
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What instrument is used to indicate high and low digital voltage states?
  • Ohmmeter. (6% chose this)
  • Logic probe. (89% chose this)
  • Megger. (2% chose this)
  • Signal strength meter. (4% chose this)
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For current to flow in an NPN silicon transistor’s emitter-collector junction, the base must be:
  • At least 0.4 volts positive with respect to the emitter. (3% chose this)
  • At a negative voltage with respect to the emitter. (7% chose this)
  • At least 0.7 volts positive with respect to the emitter. (75% chose this)
  • At least 0.7 volts negative with respect to the emitter. (15% chose this)
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What is the standard scan rate for high-frequency 3 MHz - 23 MHz weather facsimile reception from shore stations?
  • 240 lines per minute. (8% chose this)
  • 120 lines per minute. (71% chose this)
  • 150 lines per second. (6% chose this)
  • 60 lines per second. (16% chose this)
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In rectangular coordinates, what is the impedance of a network composed of a 0.001-microfarad capacitor in series with a 400-ohm resistor, at 500 kHz?
  • 318 - j400 (10% chose this)
  • 400 + j318 (16% chose this)
  • 318 + j400 (7% chose this)
  • 400 - j318 (68% chose this)
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The output of a separately-excited AC generator running at a constant speed can be controlled by:
  • The armature. (7% chose this)
  • The amount of field current. (84% chose this)
  • The brushes. (2% chose this)
  • The exciter. (7% chose this)
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What is the name of the type of modulation in which the modulating signal varies the duration of the transmitted pulse?
  • Amplitude modulation. (3% chose this)
  • Frequency modulation. (9% chose this)
  • Pulse-height modulation. (0% chose this)
  • Pulse-width modulation. (88% chose this)
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What is the meaning of the term “beta” with regard to bipolar transistors? The change of:
  • Base current with respect to emitter current. (29% chose this)
  • Collector current with respect to emitter current. (18% chose this)
  • Collector current with respect to base current. (48% chose this)
  • Base current with respect to gate current. (5% chose this)
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Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?
  • 121.5 MHz. (12% chose this)
  • 243 MHz. (2% chose this)
  • 121.5 and 243 MHz. (9% chose this)
  • 121.5, 243 and 406 MHz. (76% chose this)
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What is the main advantage of using an op-amp audio filter over a passive LC audio filter?
  • Op-amps are largely immune to vibration and temperature change. (5% chose this)
  • Most LC filter manufacturers have retooled to make op-amp filters. (2% chose this)
  • Op-amps are readily available in a wide variety of operational voltages and frequency ranges. (16% chose this)
  • Op-amps exhibit gain rather than insertion loss. (78% chose this)
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What is the common power supply voltage for TTL series integrated circuits?
  • 12 volts. (7% chose this)
  • 13.6 volts. (5% chose this)
  • 1 volt. (3% chose this)
  • 5 volts. (85% chose this)
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How can selectivity be achieved in the front-end circuitry of a communications receiver?
  • By using an audio filter. (5% chose this)
  • By using an additional RF amplifier stage. (9% chose this)
  • By using an additional IF amplifier stage. (8% chose this)
  • By using a preselector. (79% chose this)
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Which type of oscillator circuit is commonly used in a VFO (variable frequency oscillator)?
  • Colpitts. (67% chose this)
  • Pierce. (20% chose this)
  • Hartley. (8% chose this)
  • Negative feedback. (5% chose this)
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How would you calculate the total capacitance of three capacitors in parallel?
  • CT = C1 + C2 / C1 - C2 + C3. (1% chose this)
  • CT = C1 + C2 + C3. (90% chose this)
  • CT = C1 + C2 / C1 x C2 + C3. (1% chose this)
  • CT = 1 / C1+1 / C2 + 1 / C3. (7% chose this)
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What type of antenna is used in an aircraft’s Very High Frequency Omnidirectional Range (VOR) and Localizer (LOC) installations?
  • Vertically polarized antenna that radiates an omnidirectional antenna pattern. (21% chose this)
  • Horizontally polarized omnidirection reception antenna. (47% chose this)
  • Balanced loop transmission antenna. (8% chose this)
  • Folded dipole reception antenna. (24% chose this)
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What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors all in series?
  • 220 seconds. (81% chose this)
  • 55 seconds. (6% chose this)
  • 110 seconds. (3% chose this)
  • 440 seconds. (11% chose this)
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What is the term used to refer to the condition where the signals from a very strong station are superimposed on other signals being received?
  • Intermodulation distortion. (27% chose this)
  • Cross-modulation interference. (66% chose this)
  • Receiver quieting. (0% chose this)
  • Capture effect. (7% chose this)
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What does it mean for a transistor to be cut off?
  • There is no base current. (5% chose this)
  • The transistor is at its Class A operating point. (2% chose this)
  • There is no current between emitter and collector. (77% chose this)
  • There is maximum current between emitter and collector. (16% chose this)
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Good conductors with minimum resistance have what type of electrons?
  • Few free electrons. (5% chose this)
  • No electrons. (1% chose this)
  • Some free electrons. (1% chose this)
  • Many free electrons. (93% chose this)
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A switching electronic voltage regulator:
  • Varies the conduction of a control element in direct proportion to the line voltage or load current. (21% chose this)
  • Provides more than one output voltage. (2% chose this)
  • Switches the control device on or off, with the duty cycle proportional to the line or load conditions. (76% chose this)
  • Gives a ramp voltage at its output. (1% chose this)
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What is the meaning of the term velocity factor of a transmission line?
  • The ratio of the characteristic impedance of the line to the terminating impedance. (8% chose this)
  • The velocity of the wave on the transmission line divided by the velocity of light in a vacuum. (73% chose this)
  • The velocity of the wave on the transmission line multiplied by the velocity of light in a vacuum. (19% chose this)
  • The index of shielding for coaxial cable. (1% chose this)
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What device can be used to determine the performance of a RADAR system at sea?
  • Echo box. (79% chose this)
  • Klystron. (6% chose this)
  • Circulator. (3% chose this)
  • Digital signal processor. (12% chose this)
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What term describes a wide-bandwidth communications system in which the RF carrier varies according to some pre-determined sequence?
  • Spread-spectrum communication. (78% chose this)
  • AMTOR. (1% chose this)
  • SITOR. (6% chose this)
  • Time-domain frequency modulation. (15% chose this)
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Which of the following statements is true?
  • The Signal Repetition character (1001100) is used as a control signal in SITOR-ARQ. (14% chose this)
  • The Idle Signal (a) (0000111) is used for FEC Phasing Signal 1. (58% chose this)
  • The Idle Signal (b) (0011001) is used for FEC Phasing Signal 2. (14% chose this)
  • The Control Signal 1 (0101100) is used to determine the time displacement in SITOR-B. (15% chose this)
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When a RADAR is being operated on the 6 mile range setting what is the most appropriate pulse width and pulse repetition rate?
  • 1.0 μs PW and 500 pps. (21% chose this)
  • 2.0 μs PW and 3,000 pps. (4% chose this)
  • 0.25 μs PW and 1,000 pps. (66% chose this)
  • 0.01 μs PW and 500 pps. (8% chose this)
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What is meant by the term antenna bandwidth?
  • Antenna length divided by the number of elements. (3% chose this)
  • The frequency range over which an antenna can be expected to perform well. (89% chose this)
  • The angle between the half-power radiation points. (1% chose this)
  • The angle formed between two imaginary lines drawn through the ends of the elements. (8% chose this)
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What determines whether a NAVTEX receiver does not print a particular type of message content?
  • The message does not concern your vessel. (10% chose this)
  • The subject indicator matches that programmed for rejection by the operator. (72% chose this)
  • The transmitting station ID covering your area has not been programmed for rejection by the operator. (12% chose this)
  • All messages sent during each broadcast are printed. (6% chose this)
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Which of the following could cause a high standing wave ratio on a transmission line?
  • Excessive modulation. (7% chose this)
  • An increase in output power. (4% chose this)
  • A detuned antenna coupler. (85% chose this)
  • Low power from the transmitter. (5% chose this)
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The rate that the transmitted VOR variable signal rotates is equivalent to how many revolutions per second?
  • 60 (20% chose this)
  • 30 (67% chose this)
  • 2400 (7% chose this)
  • 1800 (6% chose this)
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What services are provided by the Iridium system?
  • Analog voice and Data at 4.8 kbps. (6% chose this)
  • Digital voice and Data at 9.6 kbps. (32% chose this)
  • Digital voice and Data at 2.4 kbps. (55% chose this)
  • Analog voice and Data at 9.6 kbps. (6% chose this)
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What is an important factor in pulse-code modulation using time-division multiplex?
  • Synchronization of transmit and receive clock pulse rates. (83% chose this)
  • Frequency separation. (12% chose this)
  • Overmodulation and undermodulation. (5% chose this)
  • Slight variations in power supply voltage. (1% chose this)
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In Figure 3F15 at what point in the circuit (labeled 1 through 4) could a DC voltmeter be used to monitor signal strength?
  • 1 (15% chose this)
  • 2 (8% chose this)
  • 3 (20% chose this)
  • 4 (57% chose this)
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What services are provided by the INMARSAT-M service?
  • Data and Fax at 4.8 kbps plus e-mail. (6% chose this)
  • Voice at 3 kHz, Fax at 9.6 kbps and Data at 4.8 kbps. (17% chose this)
  • Voice at 6.2 kbps, Data at 2.4 kbps, Fax at 2.4 kbps and e-mail. (61% chose this)
  • Data at 4.8 kbps and Fax at 9.6 kbps plus e-mail. (15% chose this)
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What is the resonant frequency in an electrical circuit?
  • The frequency at which capacitive reactance equals inductive reactance. (94% chose this)
  • The highest frequency that will pass current. (4% chose this)
  • The lowest frequency that will pass current. (1% chose this)
  • The frequency at which power factor is at a minimum. (1% chose this)
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Why are special precautions necessary in handling FET and CMOS devices?
  • They have fragile leads that may break off. (1% chose this)
  • They are susceptible to damage from static charges. (96% chose this)
  • They have micro-welded semiconductor junctions that are susceptible to breakage. (3% chose this)
  • They are light sensitive. (0% chose this)
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What turns ratio does a transformer need in order to match a source impedance of 500 ohms to a load of 10 ohms?
  • 7.1 to 1. (66% chose this)
  • 14.2 to 1. (5% chose this)
  • 50 to 1. (27% chose this)
  • None of these. (1% chose this)
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Which of the following is not part of a MCU processor?
  • RAM (6% chose this)
  • ROM (2% chose this)
  • I/O (5% chose this)
  • Voltage Regulator (87% chose this)
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How many satellites must be received to provide complete position and time?
  • 1 (2% chose this)
  • 2 (5% chose this)
  • 3 (17% chose this)
  • 4 (76% chose this)
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How can a double-sideband phone signal be produced?
  • By using a reactance modulator. (5% chose this)
  • By varying the voltage to the varactor in an oscillator circuit. (15% chose this)
  • By using a phase detector, oscillator, and filter in a feedback loop. (31% chose this)
  • By modulating the supply voltage to a class C amplifier. (49% chose this)
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Using the polar coordinate system, what visual representation would you get of a voltage in a sinewave circuit?
  • To show the reactance which is present. (2% chose this)
  • To graphically represent the AC and DC component. (6% chose this)
  • To display the data on an XY chart. (10% chose this)
  • The plot shows the magnitude and phase angle. (81% chose this)
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Can a P25 radio system be monitored with a scanner?
  • Yes , regardless if it has P25 decoding or not. (6% chose this)
  • No. (6% chose this)
  • Yes, if the scanner has P25 decoding. (82% chose this)
  • Yes, but it must also have P26 decoding. (6% chose this)
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By what factor must the voltage measured in an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?
  • 0.707 (19% chose this)
  • 1.414 (15% chose this)
  • 0.9 (63% chose this)
  • 3.14 (3% chose this)
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In rectangular coordinates, what is the impedance of a network composed of a 10-microhenry inductor in series with a 40-ohm resistor, at 500 MHz?
  • 40 +j31400 (75% chose this)
  • 40 -j31400 (8% chose this)
  • 31400 +j40 (12% chose this)
  • 31400 -j40 (4% chose this)
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What is the reason for the USA-INT control or function?
  • It changes channels that are normally simplex channels into duplex channels. (11% chose this)
  • It changes some channels that are normally duplex channels into simplex channels. (80% chose this)
  • When the control is set to “INT” the range is increased. (7% chose this)
  • None of the above. (2% chose this)
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What is the name of the semiconductor memory IC whose digital data can be written or read, and whose memory word address can be accessed randomly?
  • ROM – Read-Only Memory. (2% chose this)
  • PROM – Programmable Read-Only Memory. (4% chose this)
  • RAM – Random-Access Memory. (90% chose this)
  • EPROM – Electrically Programmable Read-Only Memory. (5% chose this)
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What formula would calculate the total inductance of inductors in series?
  • LT = L1 / L2 (1% chose this)
  • LT = L1 + L2 (93% chose this)
  • LT = 1 / L1 + L2 (3% chose this)
  • LT = 1 / L1 x L2 (3% chose this)
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What condition must exist for a circuit to oscillate? It must:
  • Have a gain of less than 1. (9% chose this)
  • Be neutralized. (7% chose this)
  • Have sufficient negative feedback. (18% chose this)
  • Have sufficient positive feedback. (66% chose this)
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RF exposure from portable radio transceivers may be harmful to the eyes because:
  • Magnetic fields blur vision. (2% chose this)
  • RF heating polarizes the eye lens. (10% chose this)
  • The magnetic field may attract metal particles to the eye. (2% chose this)
  • RF heating may cause cataracts. (87% chose this)
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What is the frequency range of the Distance Measuring Equipment (DME) used to indicate an aircraft’s slant range distance to a selected ground-based navigation station?
  • 108.00 MHz to 117.95 MHz. (22% chose this)
  • 108.10 MHz to 111.95 MHz. (22% chose this)
  • 962 MHz to 1213 MHz. (47% chose this)
  • 329.15 MHz to 335.00 MHz. (9% chose this)
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What instrument may be used to verify proper radio antenna functioning?
  • Digital ohm meter. (2% chose this)
  • Hewlett-Packard frequency meter. (2% chose this)
  • An SWR meter. (93% chose this)
  • Different radio. (3% chose this)
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What factors limit the accuracy, frequency response, and stability of an oscilloscope?
  • Sweep oscillator quality and deflection amplifier bandwidth. (74% chose this)
  • Tube face voltage increments and deflection amplifier voltage. (4% chose this)
  • Sweep oscillator quality and tube face voltage increments. (10% chose this)
  • Deflection amplifier output impedance and tube face frequency increments. (11% chose this)
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Which metal object may be least affected by galvanic corrosion when submerged in seawater?
  • Aluminum outdrive. (4% chose this)
  • Bronze through-hull. (2% chose this)
  • Exposed lead keel. (2% chose this)
  • Stainless steel propeller shaft. (92% chose this)
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What is the photoconductive effect?
  • The conversion of photon energy to electromotive energy. (8% chose this)
  • The increased conductivity of an illuminated semiconductor junction. (87% chose this)
  • The conversion of electromotive energy to photon energy. (3% chose this)
  • The decreased conductivity of an illuminated semiconductor junction. (1% chose this)
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What is a GFI electrical socket used for?
  • To prevent electrical shock by sensing ground path current and shutting the circuit down. (95% chose this)
  • As a gold plated socket. (0% chose this)
  • To prevent children from sticking objects in the socket. (2% chose this)
  • To increase the current capacity of the socket. (3% chose this)
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What is the normal range of pulse widths?
  • .05 μs to 0.1 μs. (7% chose this)
  • .05 μs to 1.0 μs. (70% chose this)
  • 1.0 μs to 3.5 μs. (12% chose this)
  • 2.5 μs to 5.0 μs. (11% chose this)
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Which statement is true regarding the filter output characteristics shown in Figure 3F16?
  • C is a low pass curve and B is a band pass curve. (7% chose this)
  • B is a high pass curve and D is a low pass curve. (9% chose this)
  • A is a high pass curve and B is a low pass curve. (6% chose this)
  • A is a low pass curve and D is a band stop curve. (77% chose this)
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A nickel-cadmium cell has an operating voltage of about:
  • 1.25 volts. (73% chose this)
  • 1.4 volts. (5% chose this)
  • 1.5 volts. (8% chose this)
  • 2.1 volts. (14% chose this)
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What are the distinguishing features of a Chebyshev filter?
  • It has a maximally flat response over its passband. (21% chose this)
  • It only requires inductors. (3% chose this)
  • It allows ripple in the passband. (62% chose this)
  • A filter whose product of the series- and shunt-element impedances is a constant for all frequencies. (14% chose this)
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746 watts, corresponding to the lifting of 550 pounds at the rate of one-foot-per-second, is the equivalent of how much horsepower?
  • One-quarter horsepower. (3% chose this)
  • One-half horsepower. (3% chose this)
  • Three-quarters horsepower. (5% chose this)
  • One horsepower. (90% chose this)
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In Figure 3C4, if a small variable capacitor were installed in place of the dashed line, it would?
  • Increase gain. (14% chose this)
  • Increase parasitic oscillations. (6% chose this)
  • Decrease parasitic oscillations. (74% chose this)
  • Decrease crosstalk. (6% chose this)
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What is the term for the ratio between the largest tolerable receiver input signal and the minimum discernible signal?
  • Intermodulation distortion. (5% chose this)
  • Noise floor. (12% chose this)
  • Noise figure. (9% chose this)
  • Dynamic range. (75% chose this)
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The class B amplifier output is present for what portion of the input cycle?
  • 360 degrees. (1% chose this)
  • Greater than 180 degrees and less than 360 degrees. (25% chose this)
  • Less than 180 degrees. (14% chose this)
  • 180 degrees. (59% chose this)
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Typical airborne HF transmitters usually provide a nominal RF power output to the antenna of ____ watts, compared with ____ watts RF output from a typical VHF transmitter.
  • 10, 50 (10% chose this)
  • 50, 10 (13% chose this)
  • 20, 100 (13% chose this)
  • 100, 20 (64% chose this)
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A perfect (no loss) coaxial cable has 7 dB of reflected power when the input is 5 watts. What is the output of the transmission line?
  • 1 watt. (56% chose this)
  • 1.25 watts. (19% chose this)
  • 2.5 watts. (13% chose this)
  • 5 watts. (12% chose this)
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A power transformer has a primary winding of 200 turns of #24 wire and a secondary winding consisting of 500 turns of the same size wire. When 20 volts are applied to the primary winding, the expected secondary voltage will be:
  • 500 volts. (10% chose this)
  • 25 volts. (5% chose this)
  • 10 volts. (2% chose this)
  • 50 volts. (83% chose this)
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What is an astable multivibrator?
  • A circuit that alternates between two stable states. (26% chose this)
  • A circuit that alternates between a stable state and an unstable state. (15% chose this)
  • A circuit set to block either a 0 pulse or a 1 pulse and pass the other. (3% chose this)
  • A circuit that alternates between two unstable states. (56% chose this)
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A vertical 1/4 wave antenna receives signals:
  • In the microwave band. (4% chose this)
  • In one vertical direction. (6% chose this)
  • In one horizontal direction. (4% chose this)
  • Equally from all horizontal directions. (86% chose this)
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How can a single-sideband phone signal be generated?
  • By driving a product detector with a DSB signal. (5% chose this)
  • By using a reactance modulator followed by a mixer. (9% chose this)
  • By using a loop modulator followed by a mixer. (10% chose this)
  • By using a balanced modulator followed by a filter. (75% chose this)
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How might two similar SCRs be connected to safely distribute the power load of a circuit?
  • In series. (7% chose this)
  • In parallel, same polarity. (17% chose this)
  • In parallel, reverse polarity. (69% chose this)
  • In a combination series and parallel configuration. (7% chose this)
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What is the purpose of a synchro transmitter and receiver?
  • Synchronizes the transmitted and received pulse trains. (16% chose this)
  • Prevents the receiver from operating during the period of the transmitted pulse. (23% chose this)
  • Transmits the angular position of the antenna to the indicator unit. (58% chose this)
  • Keeps the speed of the motor generator constant. (3% chose this)
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When an NPN transistor is operating as a Class A amplifier, the base-emitter junction:
  • And collector-base junction are both forward biased. (31% chose this)
  • And collector-base junction are both reverse biased. (5% chose this)
  • Is reverse biased and the collector-base junction is forward biased. (10% chose this)
  • Is forward biased and the collector-base junction is reverse biased. (54% chose this)
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What is the main underlying operating principle of an aircraft’s Distance Measuring Equipment (DME)?
  • A measurable amount of time is required to send and receive a radio signal through the Earth’s atmosphere. (74% chose this)
  • The difference between the peak values of two DC voltages may be used to determine an aircraft’s distance to another aircraft. (9% chose this)
  • A measurable frequency compression of an AC signal may be used to determine an aircraft’s altitude above the earth. (11% chose this)
  • A phase inversion between two AC voltages may be used to determine an aircraft’s distance to the exit ramp of an airport’s runway. (6% chose this)
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Which of the following is the primary frequency that is used exclusively for NAVTEX broadcasts internationally?
  • 2187.5 kHz. (14% chose this)
  • 4209.5 kHz. (4% chose this)
  • VHF channel 16. (17% chose this)
  • 518 kHz. (65% chose this)
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How can ferrite beads be used to suppress ignition noise? Install them:
  • In the resistive high voltage cable every 2 years. (3% chose this)
  • Between the starter solenoid and the starter motor. (9% chose this)
  • Install them in the primary and secondary ignition leads. (83% chose this)
  • In the antenna lead. (5% chose this)
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What is the time constant of a circuit having a 220-microfarad capacitor and a 1-megohm resistor in parallel?
  • 220 seconds. (79% chose this)
  • 22 seconds. (12% chose this)
  • 2.2 seconds. (2% chose this)
  • 0.22 seconds. (7% chose this)
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Before ground testing an aircraft RADAR, the operator should:
  • Ensure that the area in front of the antenna is clear of other maintenance personnel to avoid radiation hazards. (91% chose this)
  • Be sure the receiver has been properly shielded and grounded. (4% chose this)
  • First test the transmitter connected to a matched load. (3% chose this)
  • Measure power supply voltages to prevent circuit damage. (2% chose this)
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What is the 6th pair color code in a 25 pair switchboard cable as is found in building telecommunications interconnections?
  • Blue/Green, Green/Blue. (20% chose this)
  • Red/Blue, White/Violet. (5% chose this)
  • Red/Blue, Blue/Red. (70% chose this)
  • White/Slate, Slate/White. (4% chose this)
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Which of the following statements about the Iridium system is true?
  • There are 48 spot beams per satellite with a footprint of 30 miles in diameter. (75% chose this)
  • There are 48 satellites in orbit in 4 orbital planes. (10% chose this)
  • The inclination of the orbital planes is 55 degrees. (11% chose this)
  • The orbital period is approximately 85 minutes. (4% chose this)
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What does it mean for a transistor to be fully saturated?
  • The collector current is at its maximum value. (85% chose this)
  • The collector current is at its minimum value. (1% chose this)
  • The transistor’s Alpha is at its maximum value. (5% chose this)
  • The transistor’s Beta is at its maximum value. (10% chose this)
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In Figure 3C5, the 1 μF capacitor is connected to a potentiometer that is used to:
  • Increase gain. (16% chose this)
  • Neutralize amplifier. (4% chose this)
  • Couple. (6% chose this)
  • Adjust tone. (74% chose this)
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Which of the following codes has gained the widest acceptance for exchange of data from one computer to another?
  • Gray. (3% chose this)
  • Baudot. (3% chose this)
  • Morse. (5% chose this)
  • ASCII. (89% chose this)
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In Figure 3B2, what is the voltage drop across R1?
  • 1.2 volts. (8% chose this)
  • 2.4 volts. (8% chose this)
  • 3.7 volts. (6% chose this)
  • 9 volts. (77% chose this)
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A common shipboard RADAR antenna is the:
  • Slotted array. (74% chose this)
  • Dipole. (16% chose this)
  • Stacked Yagi. (4% chose this)
  • Vertical Marconi. (6% chose this)
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Do shorted-stub lightning protectors work at all frequencies?
  • Yes. (11% chose this)
  • No, the short also kills the radio signals. (8% chose this)
  • No, the short enhances the radio signal at the tuned band. (5% chose this)
  • No, only at the tuned frequency band. (76% chose this)
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How many bits of information can be stored in a single flip-flop circuit?
  • 1 (66% chose this)
  • 2 (28% chose this)
  • 3 (1% chose this)
  • 4 (6% chose this)
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What term describes a wide-bandwidth communications system in which the RF carrier frequency varies according to some predetermined sequence?
  • Amplitude compandored single sideband. (1% chose this)
  • SITOR. (9% chose this)
  • Time-domain frequency modulation. (13% chose this)
  • Spread spectrum communication. (77% chose this)
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An NMEA 2000 system with devices in a single location may be powered using this method:
  • Dual mid-powered network. (3% chose this)
  • End-powered network. (71% chose this)
  • Individual devices individually powered. (20% chose this)
  • No 12 volts needed for NMEA 2000 devices. (7% chose this)
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What is the equivalent to the root-mean-square value of an AC voltage?
  • AC voltage is the square root of the average AC value. (2% chose this)
  • The DC voltage causing the same heating in a given resistor at the peak AC voltage. (17% chose this)
  • The AC voltage found by taking the square of the average value of the peak AC voltage. (7% chose this)
  • The DC voltage causing the same heating in a given resistor as the RMS AC voltage of the same value. (73% chose this)
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What is a balanced modulator?
  • An FM modulator that produces a balanced deviation. (11% chose this)
  • A modulator that produces a double sideband, suppressed carrier signal. (60% chose this)
  • A modulator that produces a single sideband, suppressed carrier signal. (20% chose this)
  • A modulator that produces a full carrier signal. (10% chose this)
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What is the term used to refer to a reduction in receiver sensitivity caused by unwanted high-level adjacent channel signals?
  • Desensitizing. (76% chose this)
  • Intermodulation distortion. (20% chose this)
  • Quieting. (3% chose this)
  • Overloading. (1% chose this)
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What are the distinguishing features of a Butterworth filter?
  • A filter whose product of the series- and shunt-element impedances is a constant for all frequencies. (19% chose this)
  • It only requires capacitors. (4% chose this)
  • It has a maximally flat response over its passband. (76% chose this)
  • It requires only inductors. (2% chose this)
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What is the frequency range of the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport?
  • 108.10 kHz to 111.95 kHz. (11% chose this)
  • 329.15 MHz to 335.00 MHz. (12% chose this)
  • 329.15 kHz to 335.00 kHz. (4% chose this)
  • 108.10 MHz to 111.95 MHz. (74% chose this)
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What does the term “DAC” refer to in a microprocessor circuit?
  • Dynamic access controller. (2% chose this)
  • Digital to analog converter. (93% chose this)
  • Digital access counter. (3% chose this)
  • Dial analog control. (2% chose this)
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What are the two basic types of junction field-effect transistors?
  • N-channel and P-channel. (84% chose this)
  • High power and low power. (4% chose this)
  • MOSFET and GaAsFET. (11% chose this)
  • Silicon FET and germanium FET. (1% chose this)
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What type of wave is made up of sine waves at the fundamental frequency and all the harmonics?
  • Sawtooth wave. (60% chose this)
  • Square wave. (32% chose this)
  • Sine wave. (8% chose this)
  • Cosine wave. (1% chose this)
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We are looking at a target 25 miles away. When a RADAR is being operated on the 25 mile range setting what is the most appropriate pulse width and pulse repetition rate?
  • 1.0 μs PW and 500 pps. (64% chose this)
  • 0.25 μs PW and 1,000 pps. (21% chose this)
  • 0.01 μs PW and 500 pps. (8% chose this)
  • 0.05 μs PW and 2,000 pps. (7% chose this)
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How can parasitic oscillations be eliminated in a power amplifier?
  • By tuning for maximum SWR. (10% chose this)
  • By tuning for maximum power output. (8% chose this)
  • By neutralization. (69% chose this)
  • By tuning the output. (13% chose this)
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What parameter must be selected when designing an audio filter using an op-amp?
  • Bandpass characteristics. (80% chose this)
  • Desired current gain. (13% chose this)
  • Temperature coefficient. (5% chose this)
  • Output-offset overshoot. (2% chose this)
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What is a pi-L network?
  • A Phase Inverter Load network. (6% chose this)
  • A network consisting of two inductors and two capacitors. (88% chose this)
  • A network with only three discrete parts. (2% chose this)
  • A matching network in which all components are isolated from ground. (4% chose this)
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How could voltage be greater across reactances in series than the applied voltage?
  • Resistance. (5% chose this)
  • Conductance. (11% chose this)
  • Capacitance. (9% chose this)
  • Resonance. (76% chose this)
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A three-terminal regulator:
  • Supplies three voltages with variable current. (5% chose this)
  • Supplies three voltages at a constant current. (13% chose this)
  • Contains a voltage reference, error amplifier, sensing resistors and transistors, and a pass element. (81% chose this)
  • Contains three error amplifiers and sensing transistors. (1% chose this)
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What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value?
  • One time constant. (92% chose this)
  • An exponential period of one. (2% chose this)
  • A time factor of one. (5% chose this)
  • One exponential rate. (1% chose this)
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What do the initials TTL stand for?
  • Resistor-transistor logic. (0% chose this)
  • Transistor-transistor logic. (98% chose this)
  • Diode-transistor logic. (1% chose this)
  • Emitter-coupled logic. (1% chose this)
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What is the definition of a phase-locked loop (PLL) circuit?
  • A servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator. (8% chose this)
  • A circuit also known as a monostable multivibrator. (6% chose this)
  • A circuit consisting of a precision push-pull amplifier with a differential input. (11% chose this)
  • A servo loop consisting of a phase detector, a low-pass filter and voltage-controlled oscillator. (75% chose this)
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The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:
  • Eddy currents. (3% chose this)
  • Hysteresis. (4% chose this)
  • Permeability. (10% chose this)
  • Reluctance. (83% chose this)
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The sequence ARQ, FEC, SFEC best corresponds to which of the following sequences?
  • One-way communications to a single station, one-way communications to all stations, two-way communications. (10% chose this)
  • One-way communications to all stations, two-way communications, one-way communications to a single station. (10% chose this)
  • Two way communications, one-way communications to all stations, one-way communications to a single station. (70% chose this)
  • Two way communications, one-way communications to a single station, one-way communications to all stations. (10% chose this)
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What is the digital signal processing term for noise subtraction circuitry?
  • Adaptive filtering and autocorrelation. (54% chose this)
  • Noise blanking. (18% chose this)
  • Noise limiting. (11% chose this)
  • Auto squelch noise reduction. (17% chose this)
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An AC ammeter indicates:
  • Effective (TRM) values of current. (0% chose this)
  • Effective (RMS) values of current. (82% chose this)
  • Peak values of current. (3% chose this)
  • Average values of current. (15% chose this)
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The permanent magnetic field that surrounds a traveling-wave tube (TWT) is intended to:
  • Provide a means of coupling. (2% chose this)
  • Prevent the electron beam from spreading. (72% chose this)
  • Prevent oscillations. (9% chose this)
  • Prevent spurious oscillations. (17% chose this)
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Why should you not use white or translucent plastic tie wraps on a radio tower?
  • White tie wraps are not FAA approved. (2% chose this)
  • UV radiation from the Sun deteriorates the plastic very quickly. (95% chose this)
  • The white color attracts wasps (2% chose this)
  • The black tie wraps may cause electrolysis. (1% chose this)
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What is the meaning of the term “alpha” with regard to bipolar transistors? The change of:
  • Collector current with respect to base current. (17% chose this)
  • Base current with respect to collector current. (12% chose this)
  • Collector current with respect to gate current. (6% chose this)
  • Collector current with respect to emitter current. (65% chose this)
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In Figure 3B1, what is the voltage drop across R1?
  • 9 volts. (14% chose this)
  • 7 volts. (3% chose this)
  • 5 volts. (73% chose this)
  • 3 volts. (10% chose this)
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When soldering or working with CMOS electronics products or equipment, a wrist strap:
  • Must have less than 100,000 ohms of resistance to prevent static electricity. (86% chose this)
  • Cannot be used when repairing TTL devices. (3% chose this)
  • Must be grounded to a water pipe. (6% chose this)
  • Does not work well in conjunction with anti-static floor mats. (5% chose this)
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What statement best describes the INMARSAT-B services?
  • Voice at 16 kbps, Fax at 14.4 kbps and high-speed Data at 64/54. (63% chose this)
  • Store and forward high speed data at 36/48 kbps. (11% chose this)
  • Voice at 3 kHz, Fax at 9.6 kbps and Data at 4.8 kbps. (17% chose this)
  • Service is available only in areas served by highly directional spot beam antennas. (9% chose this)
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What does the power factor equal in an R-L circuit having a 45 degree phase angle between the voltage and the current?
  • 0.866 (19% chose this)
  • 1.0 (3% chose this)
  • 0.5 (11% chose this)
  • 0.707 (67% chose this)
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How does the gain of a parabolic dish antenna change when the operating frequency is doubled?
  • Gain does not change. (10% chose this)
  • Gain is multiplied by 0.707. (5% chose this)
  • Gain increases 6 dB. (65% chose this)
  • Gain increases 3 dB. (19% chose this)
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What is the voltage range considered to be a valid logic high input in a TTL device operating at 5.0 volts?
  • 2.0 to 5.5 volts. (88% chose this)
  • 1.5 to 3.0 volts. (6% chose this)
  • 1.0 to 1.5 volts. (3% chose this)
  • 5.2 to 34.8 volts. (2% chose this)
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In the op-amp oscillator circuit shown in Figure 3D6, what would be the most noticeable effect if the capacitance of C were suddenly doubled?
  • Frequency would be lower. (68% chose this)
  • Frequency would be higher. (19% chose this)
  • There would be no change. The inputs are reversed, therefore the circuit cannot function. (7% chose this)
  • None of the above. (6% chose this)
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A flip-flop circuit is a binary logic element with how many stable states?
  • 1 (13% chose this)
  • 2 (82% chose this)
  • 4 (3% chose this)
  • 8 (1% chose this)
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What statement is true regarding 406 MHz EPIRB transmissions?
  • Allows immediate voice communications with the RCC. (2% chose this)
  • Coding permits the SAR authorities to know if manually or automatically activated. (7% chose this)
  • Transmits a unique hexadecimal identification number. (80% chose this)
  • Radio Operator programs an I.D. into the SART immediately prior to activation. (11% chose this)
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The voltage produced in a receiving antenna is:
  • Out of phase with the current if connected properly. (9% chose this)
  • Out of phase with the current if cut to 1/3 wavelength. (2% chose this)
  • Variable depending on the station’s SWR. (13% chose this)
  • Always proportional to the received field strength. (77% chose this)
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If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?
  • 70 watts. (10% chose this)
  • 50 watts. (11% chose this)
  • 25 watts. (26% chose this)
  • 6 watts. (53% chose this)
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What is the mixing process in a radio receiver?
  • The elimination of noise in a wideband receiver by phase comparison. (2% chose this)
  • The elimination of noise in a wideband receiver by phase differentiation. (3% chose this)
  • Distortion caused by auroral propagation. (1% chose this)
  • The combination of two signals to produce sum and difference frequencies. (94% chose this)
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What is the characteristic of the current flow within the parallel elements in a parallel R-L-C circuit at resonance?
  • Minimum. (10% chose this)
  • Maximum. (83% chose this)
  • DC. (1% chose this)
  • Zero. (6% chose this)
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What is the purpose of a bypass capacitor?
  • It increases the resonant frequency of the circuit. (7% chose this)
  • It removes direct current from the circuit by shunting DC to ground. (16% chose this)
  • It removes alternating current by providing a low impedance path to ground. (76% chose this)
  • It forms part of an impedance transforming circuit. (1% chose this)
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What does the photoconductive effect in crystalline solids produce a noticeable change in?
  • The capacitance of the solid. (6% chose this)
  • The inductance of the solid. (11% chose this)
  • The specific gravity of the solid. (3% chose this)
  • The resistance of the solid. (81% chose this)
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What is the term used to identify an AC voltage that would cause the same heating in a resistor as a corresponding value of DC voltage?
  • Cosine voltage. (1% chose this)
  • Power factor. (8% chose this)
  • Root mean square (RMS). (85% chose this)
  • Average voltage. (6% chose this)
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What is an L-network?
  • A low power Wi-Fi RF network connection. (2% chose this)
  • A network consisting of an inductor and a capacitor. (83% chose this)
  • A “lossy” network. (3% chose this)
  • A network formed by joining two low pass filters. (12% chose this)
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A power transformer has a single primary winding and three secondary windings producing 5.0 volts, 12.6 volts, and 150 volts. Assuming similar wire sizes, which of the three secondary windings will have the highest measured DC resistance?
  • The 12.6 volt winding. (6% chose this)
  • The 150 volt winding. (79% chose this)
  • The 5.0 volt winding. (11% chose this)
  • All will have equal resistance values. (4% chose this)
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An oscilloscope can be used to accomplish all of the following except:
  • Measure electron flow with the aid of a resistor. (10% chose this)
  • Measure phase difference between two signals. (4% chose this)
  • Measure velocity of light with the aid of a light emitting diode. (81% chose this)
  • Measure electrical voltage. (5% chose this)
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In a pulse-position modulation system, what parameter does the modulating signal vary?
  • The number of pulses per second. (7% chose this)
  • The time at which each pulse occurs. (54% chose this)
  • Both the frequency and amplitude of the pulses. (13% chose this)
  • The duration of the pulses. (25% chose this)
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How does the input impedance of a field-effect transistor compare with that of a bipolar transistor?
  • An FET has high input impedance; a bipolar transistor has low input impedance. (79% chose this)
  • One cannot compare input impedance without first knowing the supply voltage. (2% chose this)
  • An FET has low input impedance; a bipolar transistor has high input impedance. (18% chose this)
  • The input impedance of FETs and bipolar transistors is the same. (1% chose this)
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What type of wave is made up of sine waves of the fundamental frequency and all the odd harmonics?
  • Square. (87% chose this)
  • Sine. (7% chose this)
  • Cosine. (3% chose this)
  • Tangent. (3% chose this)
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Maximum allowable frequency deviation for VHF marine radios is:
  • +/- 5 kHz. (63% chose this)
  • +/- 15 kHz. (10% chose this)
  • +/- 2.5 kHz. (11% chose this)
  • +/- 25 kHz. (16% chose this)
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What would be the maximum current to safely illuminate a LED?
  • 1 amp. (2% chose this)
  • 1 microamp. (2% chose this)
  • 500 milliamps. (7% chose this)
  • 20 mA. (89% chose this)
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What is a frequency standard?
  • A well-known (standard) frequency used for transmitting certain messages. (22% chose this)
  • A device used to produce a highly accurate reference frequency. (69% chose this)
  • A device for accurately measuring frequency to within 1 Hz. (6% chose this)
  • A device used to generate wide-band random frequencies. (2% chose this)
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What is the purpose of a shunt resistor used with an ammeter?
  • A shunt resistor is not used with an ammeter. (3% chose this)
  • It is used to decrease the ampere indicating range of the ammeter. (10% chose this)
  • It is used to increase the ampere indicating range of the ammeter. (76% chose this)
  • It is used to increase the voltage indicating range of the voltmeter, not the ammeter. (11% chose this)
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What is the purpose of a prescaler circuit?
  • Converts the output of a JK flip-flop to that of an RS flip-flop. (5% chose this)
  • Multiplies an HF signal so a low-frequency counter can display the operating frequency. (16% chose this)
  • Prevents oscillation in a low frequency counter circuit. (6% chose this)
  • Divides an HF signal so that a low-frequency counter can display the operating frequency. (74% chose this)
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In a pulse-width modulation system, what parameter does the modulating signal vary?
  • Pulse frequency. (14% chose this)
  • Pulse duration. (78% chose this)
  • Pulse amplitude. (7% chose this)
  • Pulse intensity. (1% chose this)
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What is the limiting condition for sensitivity in a communications receiver?
  • The noise floor of the receiver. (86% chose this)
  • The power supply output ripple. (3% chose this)
  • The two-tone intermodulation distortion. (5% chose this)
  • The input impedance to the detector. (6% chose this)
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What degree of selectivity is desirable in the IF circuitry of a wideband FM phone receiver?
  • 1 kHz. (13% chose this)
  • 2.4 kHz. (19% chose this)
  • 4.2 kHz. (7% chose this)
  • 15 kHz. (61% chose this)
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What is meant by the term modulation index?
  • The ratio between the deviation of a frequency modulated signal and the modulating frequency. (55% chose this)
  • The processor index. (3% chose this)
  • The FM signal-to-noise ratio. (2% chose this)
  • The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency. (41% chose this)
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What device can protect a transmitting station from a direct lightning hit?
  • Lightning protector. (15% chose this)
  • Grounded cabinet. (6% chose this)
  • Short lead in. (3% chose this)
  • There is no device to protect a station from a direct hit from lightning. (76% chose this)
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The resonant frequency of a Hertz antenna can be lowered by:
  • Lowering the frequency of the transmitter. (4% chose this)
  • Placing an inductance in series with the antenna. (76% chose this)
  • Placing a condenser in series with the antenna. (8% chose this)
  • Placing a resistor in series with the antenna. (12% chose this)
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The RADAR range in nautical miles to an object can be found by measuring the elapsed time during a RADAR pulse and dividing this quantity by:
  • 0.87 seconds. (12% chose this)
  • 1.15 µs. (8% chose this)
  • 12.346 µs. (73% chose this)
  • 1.073 µs. (8% chose this)
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What is the characteristic of the current flow in a series R-L-C circuit at resonance?
  • Maximum. (82% chose this)
  • Minimum. (8% chose this)
  • DC. (2% chose this)
  • Zero. (8% chose this)
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How is a frequency counter used?
  • To provide reference points on an analog receiver dial thereby aiding in the alignment of the receiver. (8% chose this)
  • To heterodyne the frequency being measured with a known variable frequency oscillator until zero beat is achieved, thereby indicating the unknown frequency. (14% chose this)
  • To measure the deviation in an FM transmitter in order to determine the percentage of modulation. (12% chose this)
  • To measure the time between events, or the frequency, which is the reciprocal of the time. (65% chose this)
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What circuit interconnects the microprocessor with the memory and input/output system?
  • Control logic bus. (18% chose this)
  • PLL line. (1% chose this)
  • Data bus line. (77% chose this)
  • Directional coupler. (4% chose this)
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What type of signals are used to conduct an SSB two-tone test?
  • Two audio signals of the same frequency, but shifted 90 degrees in phase. (12% chose this)
  • Two non-harmonically related audio signals that are within the modulation band pass of the transmitter. (76% chose this)
  • Two different audio frequency square wave signals of equal amplitude. (4% chose this)
  • Any two audio frequencies as long as they are harmonically related. (8% chose this)
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Which of the following is NOT a precaution that should be taken to ensure the magnetron is not weakened:
  • Keep metal tools away from the magnet. (12% chose this)
  • Do not subject it to excessive heat. (8% chose this)
  • Keep the TR properly tuned. (79% chose this)
  • Do not subject it to shocks and blows. (1% chose this)
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What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generate audio tones?
  • Oscilloscope. (19% chose this)
  • Spectrum analyzer. (20% chose this)
  • Service monitor. (60% chose this)
  • DMM. (1% chose this)
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Some aircraft and avionics equipment operates with a prime power line frequency of 400 Hz. What is the principle advantage of a higher line frequency?
  • 400 Hz power supplies draw less current than 60 Hz supplies allowing more current available for other systems on the aircraft. (7% chose this)
  • A 400 Hz power supply generates less heat and operates much more efficiently than a 60 Hz power supply. (7% chose this)
  • The magnetic devices in a 400 Hz power supply such as transformers, chokes and filters are smaller and lighter than those used in 60 Hz power supplies. (84% chose this)
  • 400 Hz power supplies are much less expensive to produce than power supplies with lower line frequencies. (2% chose this)
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What is a product detector?
  • It provides local oscillations for input to the mixer. (5% chose this)
  • It amplifies and narrows the band-pass frequencies. (11% chose this)
  • It uses a mixing process with a locally generated carrier. (63% chose this)
  • It is used to detect cross-modulation products. (21% chose this)
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If a receiver mixes a 13.8 MHz VFO with a 14.255 MHz receive signal to produce a 455 kHz intermediate frequency signal, what type of interference will a 13.345 MHz signal produce in the receiver?
  • Local oscillator interference. (8% chose this)
  • An image response. (69% chose this)
  • Mixer interference. (10% chose this)
  • Intermediate frequency interference. (13% chose this)
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How might you reduce the inductance of an antenna coil?
  • Add additional turns. (7% chose this)
  • Add more core permeability. (1% chose this)
  • Reduce the number of turns. (90% chose this)
  • Compress the coil turns. (2% chose this)
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Structurally, what are the two main categories of semiconductor diodes?
  • Junction and point contact. (80% chose this)
  • Electrolytic and junction. (18% chose this)
  • Electrolytic and point contact. (2% chose this)
  • Vacuum and point contact. (1% chose this)
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In a linear electronic voltage regulator:
  • The output is a ramp voltage. (5% chose this)
  • The pass transistor switches from the “off” state to the “on”" state. (3% chose this)
  • The control device is switched on or off, with the duty cycle proportional to the line or load conditions. (34% chose this)
  • The conduction of a control element is varied in direct proportion to the line voltage or load current. (58% chose this)
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What class of amplifier is distinguished by the bias being set well beyond cutoff?
  • Class A. (12% chose this)
  • Class C. (67% chose this)
  • Class B. (5% chose this)
  • Class AB. (16% chose this)
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What is a common use of a hot-carrier diode?
  • Balanced inputs in SSB generation. (3% chose this)
  • Variable capacitance in an automatic frequency control circuit. (6% chose this)
  • Constant voltage reference in a power supply. (16% chose this)
  • VHF and UHF mixers and detectors. (74% chose this)
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Nitrogen is placed in transmission lines to:
  • Improve the “skin-effect” of microwaves. (4% chose this)
  • Reduce arcing in the line. (5% chose this)
  • Reduce the standing wave ratio of the line. (6% chose this)
  • Prevent moisture from entering the line. (85% chose this)
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What is the piezoelectric effect?
  • Mechanical vibration of a crystal by the application of a voltage. (87% chose this)
  • Mechanical deformation of a crystal by the application of a magnetic field. (8% chose this)
  • The generation of electrical energy by the application of light. (5% chose this)
  • Reversed conduction states when a P-N junction is exposed to light. (0% chose this)
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TTL inputs left open develop what logic state?
  • A high-logic state. (72% chose this)
  • A low-logic state. (14% chose this)
  • Open inputs on a TTL device are ignored. (6% chose this)
  • Random high- and low-logic states. (9% chose this)
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How can even-order harmonics be reduced or prevented in transmitter amplifier design?
  • By using a push-push amplifier. (8% chose this)
  • By operating class C. (13% chose this)
  • By using a push-pull amplifier. (70% chose this)
  • By operating class AB. (10% chose this)
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What is the voltage range considered to be valid logic low input in a TTL device operating at 5 volts?
  • 2.0 to 5.5 volts. (19% chose this)
  • -2.0 to -5.5 volts. (4% chose this)
  • Zero to 0.8 volts. (75% chose this)
  • 5.2 to 34.8 volts. (2% chose this)
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What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?
  • Output-offset overshoot. (2% chose this)
  • Undesired signals will reach the audio stage. (90% chose this)
  • Thermal-noise distortion. (4% chose this)
  • Filter ringing. (4% chose this)
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A receiver selectivity of 2.4 kHz in the IF circuitry is optimum for what type of signals?
  • CW. (3% chose this)
  • Double-sideband AM voice. (18% chose this)
  • SSB voice. (74% chose this)
  • FSK RTTY. (5% chose this)
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What causes the SART to begin a transmission?
  • When activated manually, it begins radiating immediately. (2% chose this)
  • After being activated the SART responds to RADAR interrogation. (80% chose this)
  • It is either manually or water activated before radiating. (15% chose this)
  • It begins radiating only when keyed by the operator. (2% chose this)
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A common emitter amplifier has:
  • Lower input impedance than a common base. (5% chose this)
  • More voltage gain than a common collector. (79% chose this)
  • Less current gain than a common base. (9% chose this)
  • Less voltage gain than a common collector. (7% chose this)
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What is a characteristic of an OR gate?
  • Produces a logic “1” at its output if any input is logic “1”. (83% chose this)
  • Produces a logic “0” at its output if any input is logic “1”. (6% chose this)
  • Produces a logic “0” at its output if all inputs are logic “1”. (5% chose this)
  • Produces a logic “1” at its output if all inputs are logic “0”. (6% chose this)
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What frequency band is used by the Iridium system for telephone and messaging?
  • 965 - 985 MHz. (13% chose this)
  • 1616 -1626 MHz. (57% chose this)
  • 1855 -1895 MHz. (12% chose this)
  • 2415 - 2435 MHz. (17% chose this)
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Which of the following instruments would be best for checking a TTL logic circuit?
  • VOM. (5% chose this)
  • DMM. (3% chose this)
  • Continuity tester. (2% chose this)
  • Logic probe. (90% chose this)
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Which stage of a receiver primarily establishes its noise figure?
  • The audio stage. (8% chose this)
  • The RF stage. (81% chose this)
  • The IF strip. (6% chose this)
  • The local oscillator. (5% chose this)
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In Figure 3H17, which block diagram symbol (labeled 1 through 4) represents where audio intelligence is inserted?
  • 1 (2% chose this)
  • 2 (77% chose this)
  • 3 (13% chose this)
  • 4 (8% chose this)
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What does a two-tone test illustrate on an oscilloscope?
  • Linearity of a SSB transmitter. (70% chose this)
  • Frequency of the carrier phase shift. (15% chose this)
  • Percentage of frequency modulation. (8% chose this)
  • Sideband suppression. (7% chose this)
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What is one way that voice is transmitted in a pulse-width modulation system?
  • A standard pulse is varied in amplitude by an amount depending on the voice waveform at that instant. (16% chose this)
  • The position of a standard pulse is varied by an amount depending on the voice waveform at that instant. (8% chose this)
  • A standard pulse is varied in duration by an amount depending on the voice waveform at that instant. (63% chose this)
  • The number of standard pulses per second varies depending on the voice waveform at that instant. (13% chose this)
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Which of the following best describes a pulse modulation system?
  • The peak transmitter power is normally much greater than the average power. (70% chose this)
  • Pulse modulation is sometimes used in SSB voice transmitters. (11% chose this)
  • The average power is normally only slightly below the peak power. (11% chose this)
  • The peak power is normally twice as high as the average power. (8% chose this)
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Name two types of spread spectrum systems used in most RF communications applications?
  • AM and FM. (7% chose this)
  • QPSK or QAM. (11% chose this)
  • Direct Sequence and Frequency Hopping. (61% chose this)
  • Frequency Hopping and APSK. (21% chose this)
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To produce a single-sideband suppressed carrier transmission it is necessary to ____ the carrier and to ____ the unwanted sideband.
  • Filter, filter. (8% chose this)
  • Cancel, filter. (69% chose this)
  • Filter, cancel. (20% chose this)
  • Cancel, cancel. (3% chose this)
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What type of antenna is attached to an aircraft’s Mode C transponder installation and used to receive 1030 MHz interrogation signals from the Air Traffic Control Radar Beacon System (ATCRBS)?
  • An electronically steerable phased-array directional antenna. (4% chose this)
  • An L-band monopole blade-type omnidirectional antenna. (60% chose this)
  • A folded dipole reception antenna. (35% chose this)
  • An internally mounted, mechanically rotatable loop antenna. (1% chose this)
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What is facsimile?
  • The transmission of still pictures by slow-scan television. (3% chose this)
  • The transmission of characters by radioteletype that form a picture when printed. (21% chose this)
  • The transmission of printed pictures for permanent display on paper. (75% chose this)
  • The transmission of video by television. (1% chose this)
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A transformer used to step up its input voltage must have:
  • More turns of wire on its primary than on its secondary. (7% chose this)
  • More turns of wire on its secondary than on its primary. (93% chose this)
  • Equal number of primary and secondary turns of wire. (1% chose this)
  • None of the above statements are correct. (0% chose this)
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If the MPE (Maximum Permissible Exposure) power is present, how often must the personnel accessing the affected area be trained and certified?
  • Weekly. (3% chose this)
  • Monthly. (7% chose this)
  • Yearly. (87% chose this)
  • Not at all. (3% chose this)
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What is the name for a microprocessor’s sequence of commands and instructions?
  • Program. (82% chose this)
  • Sequence. (5% chose this)
  • Data string. (8% chose this)
  • Data execution. (5% chose this)
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When repairing circuit board assemblies it is most important to:
  • Use a dental pick to clear plated-through holes. (3% chose this)
  • Bridge broken copper traces with solder. (6% chose this)
  • Wear safety glasses. (86% chose this)
  • Use a holding fixture. (5% chose this)
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What is a monostable multivibrator?
  • A circuit that can be switched momentarily to the opposite binary state and then returns after a set time to its original state. (77% chose this)
  • A “clock” circuit that produces a continuous square wave oscillating between 1 and 0. (8% chose this)
  • A circuit designed to store one bit of data in either the 0 or the 1 configuration. (7% chose this)
  • A circuit that maintains a constant output voltage, regardless of variations in the input voltage. (7% chose this)
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The Distance Measuring Equipment (DME) measures the distance from the aircraft to the DME ground station. This is referred to as:
  • DME bearing. (12% chose this)
  • The slant range. (72% chose this)
  • Glide Slope angle of approach. (14% chose this)
  • Localizer course width. (3% chose this)
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What do the initials CMOS stand for?
  • Common mode oscillating system. (3% chose this)
  • Complementary mica-oxide silicon. (3% chose this)
  • Complementary metal-oxide semiconductor. (89% chose this)
  • Complementary metal-oxide substrate. (4% chose this)
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What is cross-modulation interference?
  • Interference between two transmitters of different modulation type. (18% chose this)
  • Interference caused by audio rectification in the receiver preamp. (2% chose this)
  • Modulation from an unwanted signal heard in addition to the desired signal. (78% chose this)
  • Harmonic distortion of the transmitted signal. (3% chose this)
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What are the principal frequencies that appear at the output of a mixer circuit?
  • Two and four times the original frequency. (1% chose this)
  • The sum, difference and square root of the input frequencies. (10% chose this)
  • The original frequencies and the sum and difference frequencies. (84% chose this)
  • 1.414 and 0.707 times the input frequency. (4% chose this)
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What type of encoding is used in an aircraft’s mode C transponder transmission to a ground station of the Air Traffic Control RADAR Beacon System (ATCRBS)?
  • Differential phase shift keying. (8% chose this)
  • Pulse position modulation. (73% chose this)
  • Doppler effect compressional encryption. (9% chose this)
  • Amplitude modulation at 95%. (10% chose this)
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In Figure 3D9, determine if there is a problem with this regulated power supply and identify the problem.
  • R1 value is too low which would cause excessive base current and instantly destroy TR 1. (7% chose this)
  • D1 and D2 are reversed. The power supply simply would not function. (10% chose this)
  • TR1 is shown as an NPN and must be changed to a PNP. (3% chose this)
  • There is no problem with the circuit. (80% chose this)
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What factors determine the capacitance of a capacitor?
  • Voltage on the plates and distance between the plates. (3% chose this)
  • Voltage on the plates and the dielectric constant of the material between the plates. (2% chose this)
  • Amount of charge on the plates and the dielectric constant of the material between the plates. (13% chose this)
  • Distance between the plates and the dielectric constant of the material between the plates. (83% chose this)
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What does the horizontal axis of a spectrum analyzer display?
  • Amplitude. (15% chose this)
  • Voltage. (2% chose this)
  • Resonance. (3% chose this)
  • Frequency. (80% chose this)
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In a positive-logic circuit, what level is used to represent a logic 1?
  • High level (91% chose this)
  • Low level (4% chose this)
  • Positive-transition level (4% chose this)
  • Negative-transition level (1% chose this)
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What class of amplifier is characterized by conduction for 180 degrees of the input wave?
  • Class A. (9% chose this)
  • Class B. (81% chose this)
  • Class C. (10% chose this)
  • Class D. (1% chose this)
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What is a CODEC?
  • A device to read Morse code. (0% chose this)
  • A computer operated digital encoding compandor. (9% chose this)
  • A coder/decoder IC or circuitry that converts a voice signal into a predetermined digital format for encrypted transmission. (91% chose this)
  • A voice amplitude compression chip. (0% chose this)
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Which class of amplifier has the highest linearity and least distortion?
  • Class A. (73% chose this)
  • Class B. (3% chose this)
  • Class C. (16% chose this)
  • Class AB. (8% chose this)
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What is the ratio of the output frequency to the input frequency of a single-phase full-wave rectifier?
  • 1:1. (19% chose this)
  • 1:2. (8% chose this)
  • 2:1. (72% chose this)
  • None of these. (1% chose this)
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What is the transistor called that is fabricated as two complementary SCRs in parallel with a common gate terminal?
  • TRIAC. (81% chose this)
  • Bilateral SCR. (4% chose this)
  • Unijunction transistor. (9% chose this)
  • Field effect transistor. (7% chose this)
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What is the orbital altitude of INMARSAT Satellites?
  • 16, 436 miles. (5% chose this)
  • 22,177 miles. (70% chose this)
  • 10, 450 miles. (6% chose this)
  • 26,435 miles. (18% chose this)
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What is the description of a square wave?
  • A wave with only 300 degrees in one cycle. (3% chose this)
  • A wave whose periodic function is always negative. (1% chose this)
  • A wave whose periodic function is always positive. (1% chose this)
  • A wave that abruptly changes back and forth between two voltage levels and stays at these levels for equal amounts of time. (95% chose this)
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On an analog wattmeter, what part of the scale is most accurate and how much does that accuracy extend to the rest of the reading scale?
  • The accuracy is only at full scale, and that absolute number reading is carried through to the rest of the range. The upper 1/3 of the meter is the only truly calibrated part. (75% chose this)
  • The accuracy is constant throughout the entire range of the meter. (14% chose this)
  • The accuracy is only there at the upper 5% of the meter, and is not carried through at any other reading. (7% chose this)
  • The accuracy cannot be determined at any reading. (3% chose this)
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Lines drawn from the VOR station in a particular magnetic direction are:
  • Radials. (72% chose this)
  • Quadrants. (3% chose this)
  • Bearings. (16% chose this)
  • Headings. (9% chose this)
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What causes a squelch circuit to function?
  • Presence of noise. (79% chose this)
  • Absence of noise. (5% chose this)
  • Received tones. (9% chose this)
  • Received digital codes. (6% chose this)
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What makes a Digital Coded Squelch work?
  • Noise. (7% chose this)
  • Tones. (15% chose this)
  • Absence of noise. (4% chose this)
  • Digital codes. (74% chose this)
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What is the distinguishing feature of a Class A amplifier?
  • Output for less than 180 degrees of the signal cycle. (9% chose this)
  • Output for the entire 360 degrees of the signal cycle. (81% chose this)
  • Output for more than 180 degrees and less than 360 degrees of the signal cycle. (6% chose this)
  • Output for exactly 180 degrees of the input signal cycle. (5% chose this)
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Which lamps would be lit in the circuit shown in Figure 3D8?
  • 2, 3, 4, 5 and 6. (7% chose this)
  • 5, 6, 8 and 9. (2% chose this)
  • 2, 3, 4, 7 and 8. (84% chose this)
  • 1, 3, 5, 7 and 8. (6% chose this)
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The class C amplifier output is present for what portion of the input cycle?
  • Less than 180 degrees. (57% chose this)
  • Exactly 180 degrees. (11% chose this)
  • 360 degrees. (13% chose this)
  • More than 180 but less than 360 degrees. (19% chose this)
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The class AB amplifier output is present for what portion of the input cycle?
  • Exactly 180 degrees. (6% chose this)
  • 360 degrees (10% chose this)
  • More than 180 but less than 360 degrees. (78% chose this)
  • Less than 180 degrees. (5% chose this)
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What is a common occurrence when voice-testing an SSB aboard a boat?
  • Ammeter fluctuates down with each spoken word. (17% chose this)
  • Voltage panel indicator lamps may glow with each syllable. (72% chose this)
  • Automatic tuner cycles on each syllable. (6% chose this)
  • Minimal voltage drop seen at power source. (5% chose this)
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What is meant by the term radiation resistance of an antenna?
  • Losses in the antenna elements and feed line. (3% chose this)
  • The specific impedance of the antenna. (7% chose this)
  • The resistance in the trap coils to received signals. (3% chose this)
  • An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna. (87% chose this)
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What is an m-derived filter?
  • A filter whose input impedance varies widely over the design bandwidth. (11% chose this)
  • A filter whose product of the series- and shunt-element impedances is a constant for all frequencies. (13% chose this)
  • A filter whose schematic shape is the letter “M”. (2% chose this)
  • A filter that uses a trap to attenuate undesired frequencies too near cutoff for a constant-k filter. (74% chose this)
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An LED facing a photodiode in a light-tight enclosure is commonly known as a/an:
  • Optoisolator. (88% chose this)
  • Seven segment LED. (1% chose this)
  • Optointerrupter. (3% chose this)
  • Infra-red (IR) detector. (8% chose this)
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To lengthen an antenna electrically, add a:
  • Coil. (90% chose this)
  • Resistor. (3% chose this)
  • Battery. (2% chose this)
  • Conduit. (5% chose this)
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What is the normal range of pulse repetition rates?
  • 2,000 to 4,000 pps. (4% chose this)
  • 1,000 to 3,000 pps. (5% chose this)
  • 500 to 1,000 pps. (12% chose this)
  • 500 to 2,000 pps. (79% chose this)
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Pulse type interference to automobile radio receivers that appears related to the speed of the engine can often be reduced by:
  • Installing resistances in series with spark plug wires. (78% chose this)
  • Using heavy conductors between the starting battery and the starting motor. (6% chose this)
  • Connecting resistances in series with the battery. (7% chose this)
  • Grounding the negative side of the battery. (9% chose this)
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Which piece of required GMDSS equipment is the primary source of transmitting locating signals?
  • Radio Direction Finder (RDF). (6% chose this)
  • A SART transmitting on 406 MHz. (15% chose this)
  • Survival Craft Transceiver. (1% chose this)
  • An EPIRB transmitting on 406 MHz. (79% chose this)
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All directions associated with a VOR station are related to:
  • Magnetic north. (90% chose this)
  • North pole. (5% chose this)
  • North star. (1% chose this)
  • None of these. (5% chose this)
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What are the three general groupings of filters?
  • High-pass, low-pass and band-pass. (78% chose this)
  • Inductive, capacitive and resistive. (2% chose this)
  • Audio, radio and capacitive. (1% chose this)
  • Hartley, Colpitts and Pierce. (19% chose this)
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How many flip-flops are required to divide a signal frequency by 4?
  • 1 (2% chose this)
  • 4 (18% chose this)
  • 8 (13% chose this)
  • 2 (68% chose this)
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When a RADAR is being operated on the 48 mile range setting, what is the most appropriate pulse width (PW) and pulse repetition rate (pps)?
  • 1.0 μs PW and 2,000 pps. (16% chose this)
  • 0.05 μs PW and 2,000 pps. (10% chose this)
  • 2.5 μs PW and 2,500 pps. (10% chose this)
  • 1.0 μs PW and 500 pps. (64% chose this)
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How does a spectrum analyzer differ from a conventional oscilloscope?
  • The oscilloscope is used to display electrical signals while the spectrum analyzer is used to measure ionospheric reflection. (5% chose this)
  • The oscilloscope is used to display electrical signals in the frequency domain while the spectrum analyzer is used to display electrical signals in the time domain. (16% chose this)
  • The oscilloscope is used to display electrical signals in the time domain while the spectrum analyzer is used to display electrical signals in the frequency domain. (76% chose this)
  • The oscilloscope is used for displaying audio frequencies and the spectrum analyzer is used for displaying radio frequencies. (3% chose this)
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Exposure to microwave energy from RADAR or other electronics devices is limited by U.S. Health Department regulations to _______ mW/centimeter.
  • 0.005 (3% chose this)
  • 5.0 (68% chose this)
  • 0.05 (12% chose this)
  • 0.5 (17% chose this)
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What is a characteristic of a NOR gate?
  • Produces a logic “0” at its output only if all inputs are logic “0”. (7% chose this)
  • Produces a logic “1” at its output only if all inputs are logic “1”. (5% chose this)
  • Produces a logic “0” at its output if any or all inputs are logic “1”. (78% chose this)
  • Produces a logic “1” at its output if some but not all of its inputs are logic “1”. (10% chose this)
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A communications technician would perform a modulation-acceptance bandwidth test in order to:
  • Ascertain the audio frequency response of the receiver. (10% chose this)
  • Determine whether the CTCSS in the receiver is operating correctly. (9% chose this)
  • Verify the results from a 12 dB SINAD test. (15% chose this)
  • Determine the effective bandwidth of a communications receiver. (65% chose this)
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With a pure AC signal input to the circuit shown in Figure 3D11, what output wave form would you expect to see on an oscilloscope display?
  • 1 (10% chose this)
  • 2 (65% chose this)
  • 3 (22% chose this)
  • 4 (4% chose this)
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What is the image frequency if the normal channel is 151.000 MHz, the IF is operating at 11.000 MHz, and the LO is at 140.000 MHz?
  • 131.000 MHz. (7% chose this)
  • 129.000 MHz. (72% chose this)
  • 162.000 MHz. (15% chose this)
  • 150.000 MHz. (6% chose this)
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Aviation services use predominantly ____ microphones.
  • Dynamic (69% chose this)
  • Carbon (6% chose this)
  • Condenser (15% chose this)
  • Piezoelectric crystal (10% chose this)
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When INMARSAT-B and INMARSAT-C terminals are compared:
  • INMARSAT-C antennas are small and omni-directional, while INMARSAT-B antennas are larger and directional. (75% chose this)
  • INMARSAT-B antennas are bulkier but omni-directional, while INMARSAT-C antennas are smaller and parabolic, for aiming at the satellite. (10% chose this)
  • INMARSAT-B antennas are parabolic and smaller for higher gain, while INMARSAT-C antennas are larger but omni-directional. (12% chose this)
  • INMARSAT-C antennas are smaller but omni-directional, while INMARSAT-B antennas are parabolic for lower gain. (4% chose this)
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In a microprocessor, what is the meaning of the term “ALU”?
  • Automatic lock/unlock. (3% chose this)
  • Arithmetical logic unit. (93% chose this)
  • Auto latch undo. (2% chose this)
  • Answer local unit. (2% chose this)
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What determines the strength of the magnetic field around a conductor?
  • The resistance divided by the current. (1% chose this)
  • The ratio of the current to the resistance. (4% chose this)
  • The diameter of the conductor. (5% chose this)
  • The amount of current. (90% chose this)
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Which of the following contains a multirange AF voltmeter calibrated in dB and a sharp, internal 1000 Hz bandstop filter, both used in conjunction with each other to perform quieting tests?
  • SINAD meter. (74% chose this)
  • Reflectometer. (13% chose this)
  • Dip meter. (5% chose this)
  • Vector-impedance meter. (8% chose this)
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What is a bistable multivibrator circuit commonly named?
  • AND gate. (0% chose this)
  • OR gate. (2% chose this)
  • Clock. (6% chose this)
  • Flip-flop. (92% chose this)
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What class of fire is one that is caused by an electrical short circuit and what is the preferred substance used to extinguish that type of fire?
  • FE28. (11% chose this)
  • FE29. (7% chose this)
  • FE30. (73% chose this)
  • FE31. (8% chose this)
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What would be the bandwidth of a good crystal lattice band-pass filter for weather facsimile HF (high frequency) reception?
  • 500 Hz at -6 dB. (8% chose this)
  • 6 kHz at -6 dB. (19% chose this)
  • 1 kHz at -6 dB. (52% chose this)
  • 15 kHz at -6 dB. (20% chose this)
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What is meant by the term “night effect” when using an aircraft’s Automatic Direction Finding (ADF) equipment? Night effect refers to the fact that:
  • All Non Directional Beacon (NDB) transmitters are turned-off at dusk and turned-on at dawn. (2% chose this)
  • Non Directional Beacon (NDB) transmissions can bounce-off the Earth’s ionosphere at night and be received at almost any direction. (82% chose this)
  • An aircraft’s ADF transmissions will be slowed at night due to the increased density of the Earth’s atmosphere after sunset. (12% chose this)
  • An aircraft’s ADF antennas usually collect dew moisture after sunset which decreases their effective reception distance from an NDB transmitter. (4% chose this)
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The Distance Measuring Equipment (DME) ground station has a built-in delay between reception of an interrogation and transmission of the reply to allow:
  • Someone to answer the call. (7% chose this)
  • The VOR to make a mechanical hook-up. (9% chose this)
  • Operation at close range. (76% chose this)
  • Clear other traffic for a reply. (8% chose this)
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What is the relationship between current through a resonant circuit and the voltage across the circuit?
  • The current and voltage are 180 degrees out of phase. (10% chose this)
  • The current leads the voltage by 90 degrees. (9% chose this)
  • The voltage and current are in phase. (73% chose this)
  • The voltage leads the current by 90 degrees. (8% chose this)
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In Figure 3C4, which component (labeled 1 through 4) is used to provide a signal ground?
  • 1 (7% chose this)
  • 2 (85% chose this)
  • 3 (6% chose this)
  • 4 (1% chose this)
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What is the modulation type that can be a frequency hopping of one carrier or multiple simultaneous carriers?
  • SSB. (7% chose this)
  • FM. (4% chose this)
  • OFSK. (2% chose this)
  • Spread spectrum. (86% chose this)
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What data language is bi-directional, multi-transmitter, multi-receiver network?
  • NMEA 2000. (80% chose this)
  • NMEA 0181. (4% chose this)
  • NMEA 0182. (6% chose this)
  • NMEA 0183. (10% chose this)
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Which of the following statements concerning SITOR communications is true?
  • ARQ message transmissions are made in data groups consisting of three-character blocks. (66% chose this)
  • ARQ transmissions are acknowledged by the Information Receiving Station only at the end of the message. (18% chose this)
  • ARQ communications rely upon error correction by time diversity transmission and reception. (8% chose this)
  • Forward error correction is an interactive mode. (8% chose this)
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What circuit component must be connected in series to protect an LED?
  • Bypass capacitor to ground. (6% chose this)
  • Electrolytic capacitor. (3% chose this)
  • Series resistor. (89% chose this)
  • Shunt coil in series. (2% chose this)
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If a resistance to which a constant voltage is applied is halved, what power dissipation will result?
  • Double. (81% chose this)
  • Halved. (13% chose this)
  • Quadruple. (3% chose this)
  • Remain the same. (3% chose this)
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What limits the maximum forward current in a junction diode?
  • The peak inverse voltage (PIV). (17% chose this)
  • The junction temperature. (72% chose this)
  • The forward voltage. (7% chose this)
  • The back EMF. (4% chose this)
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What is the frequency range of the marker beacon system used to indicate an aircraft's position during an Instrument Landing System (ILS) approach to an airport's runway?
  • The outer, middle, and inner marker beacons’ UHF frequencies are unique for each ILS equipped airport to provide unambiguous frequency-protected reception areas in the 329.15 to 335.00 MHz range. (8% chose this)
  • The outer marker beacon’s carrier frequency is 400 MHz, the middle marker beacon’s carrier frequency is 1300 MHz, and the inner marker beacon’s carrier frequency is 3000 MHz. (8% chose this)
  • The outer, the middle, and the inner marker beacon’s carrier frequencies are all 75 MHz but the marker beacons are 95% tone-modulated at 400 Hz (outer), 1300 Hz (middle), and 3000 Hz (inner). (75% chose this)
  • The outer, marker beacon’s carrier frequency is 3000 kHz, the middle marker beacon’s carrier frequency is 1300 kHz, and the inner marker beacon’s carrier frequency is 400 kHz. (10% chose this)
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How should the filter bandwidth of a receiver IF section compare with the bandwidth of a received signal?
  • Slightly greater than the received-signal bandwidth. (73% chose this)
  • Approximately half the received-signal bandwidth. (13% chose this)
  • Approximately two times the received-signal bandwidth. (11% chose this)
  • Approximately four times the received-signal bandwidth. (2% chose this)
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What is a characteristic of a NOT gate?
  • Does not allow data transmission when its input is high. (7% chose this)
  • Produces a logic “0” at its output when the input is logic “1” and vice versa. (83% chose this)
  • Allows data transmission only when its input is high. (3% chose this)
  • Produces a logic "1" at its output when the input is logic "1" and vice versa. (6% chose this)
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What is the RMS voltage at a common household electrical power outlet?
  • 331-V AC. (1% chose this)
  • 82.7-V AC. (4% chose this)
  • 165.5-V AC. (15% chose this)
  • 117-V AC. (81% chose this)
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When induced currents produce expanding magnetic fields around conductors in a direction that opposes the original magnetic field, this is known as:
  • Lenz’s law. (85% chose this)
  • Gilbert's law. (5% chose this)
  • Maxwell’s law. (6% chose this)
  • Norton’s law. (4% chose this)
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Why is the value of the radiation resistance of an antenna important?
  • Knowing the radiation resistance makes it possible to match impedances for maximum power transfer. (78% chose this)
  • Knowing the radiation resistance makes it possible to measure the near-field radiation density from transmitting antenna. (12% chose this)
  • The value of the radiation resistance represents the front-to-side ratio of the antenna. (4% chose this)
  • The value of the radiation resistance represents the front-to-back ratio of the antenna. (6% chose this)
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In a microprocessor-controlled two-way radio, a “watchdog” timer:
  • Verifies that the microprocessor is executing the program. (76% chose this)
  • Assures that the transmission is exactly on frequency. (11% chose this)
  • Prevents the transmitter from exceeding allowed power out. (11% chose this)
  • Connects to the system RADAR presentation. (2% chose this)
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Which of the following conditions can render INMARSAT -B communications impossible?
  • An obstruction, such as a mast, causing disruption of the signal between the satellite and the SES antenna when the vessel is steering a certain course. (15% chose this)
  • A satellite whose signal is on a low elevation, below the horizon. (2% chose this)
  • Travel beyond the effective radius of the satellite. (2% chose this)
  • All of these. (82% chose this)
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In a CTCSS controlled FM receiver, the CTCSS tone is filtered out after the:
  • IF stage but before the mixer. (14% chose this)
  • Mixer but before the IF. (6% chose this)
  • IF but before the discriminator. (10% chose this)
  • Discriminator but before the audio section. (71% chose this)
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Conductance takes place in a waveguide:
  • By interelectron delay. (3% chose this)
  • Through electrostatic field reluctance. (3% chose this)
  • In the same manner as a transmission line. (11% chose this)
  • Through electromagnetic and electrostatic fields in the walls of the waveguide. (84% chose this)
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Which three network types are commonly used to match an amplifying device to a transmission line?
  • Pi-C network, pi network and T network. (6% chose this)
  • T network, M network and Z network. (1% chose this)
  • L network, pi network and pi-L network. (84% chose this)
  • L network, pi network and C network. (9% chose this)
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What is a bistable multivibrator circuit?
  • Flip-flop. (89% chose this)
  • AND gate. (2% chose this)
  • OR gate. (2% chose this)
  • Clock. (8% chose this)
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What is the best description for the INMARSAT-C system?
  • It provides slow speed telex and voice service. (6% chose this)
  • It is a store-and-forward system that provides routine and distress communications. (76% chose this)
  • It is a real-time telex system. (3% chose this)
  • It provides world-wide coverage. (14% chose this)
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What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the supply voltage?
  • An exponential rate of one. (1% chose this)
  • One time constant. (95% chose this)
  • One exponential period. (1% chose this)
  • A time factor of one. (3% chose this)
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Which of the 4 groups of metals listed below are the best low-resistance conductors?
  • Gold, silver, and copper. (95% chose this)
  • Stainless steel, bronze, and lead. (2% chose this)
  • Iron, lead, and nickel. (2% chose this)
  • Bronze, zinc, and manganese. (1% chose this)
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The pulse repetition rate (prr) of a RADAR refers to the:
  • Reciprocal of the duty cycle. (3% chose this)
  • Pulse rate of the local oscillator. (13% chose this)
  • Pulse rate of the klystron. (4% chose this)
  • Pulse rate of the magnetron. (79% chose this)
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Which of the following statements concerning SITOR communications is true?
  • Communication is established on the working channel and answerbacks are exchanged before FEC broadcasts can be received. (16% chose this)
  • In the ARQ mode each character is transmitted twice. (12% chose this)
  • Weather broadcasts cannot be made in FEC because sending each character twice would cause the broadcast to be prohibitively long. (3% chose this)
  • Two-way communication with the coast radio station using FEC is not necessary to be able to receive the broadcasts. (69% chose this)
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Should you use a power drill without eye protection?
  • Yes. (3% chose this)
  • No. (96% chose this)
  • It’s okay as long as you keep your face away from the drill bit. (0% chose this)
  • Only in an extreme emergency. (1% chose this)
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What instrument is used to check the signal quality of a single-sideband radio transmission?
  • Field strength meter. (8% chose this)
  • Signal level meter. (9% chose this)
  • Sidetone monitor. (7% chose this)
  • Oscilloscope. (75% chose this)
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For the logic input levels shown in Figure 3E12, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)
  • A is high, B is low and C is low. (4% chose this)
  • A is low, B is high and C is high. (75% chose this)
  • A is high, B is high and C is low. (17% chose this)
  • A is low, B is high and C is low. (3% chose this)
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In Figure 3F15, which block diagram symbol (labeled 1 through 4) is used to represent a local oscillator?
  • 1 (6% chose this)
  • 2 (70% chose this)
  • 3 (5% chose this)
  • 4 (18% chose this)
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Permeability is defined as:
  • The magnetic field created by a conductor wound on a laminated core and carrying current. (6% chose this)
  • The ratio of magnetic flux density in a substance to the magnetizing force that produces it. (82% chose this)
  • Polarized molecular alignment in a ferromagnetic material while under the influence of a magnetizing force. (7% chose this)
  • None of these. (5% chose this)
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What is a sine wave?
  • A constant-voltage, varying-current wave. (3% chose this)
  • A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed. (94% chose this)
  • A wave following the laws of the trigonometric tangent function. (3% chose this)
  • A wave whose polarity changes in a random manner. (0% chose this)
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What pulse width and repetition rate should you use at short ranges?
  • Wide pulse width and fast repetition rate. (9% chose this)
  • Narrow pulse width and slow repetition rate. (8% chose this)
  • Narrow pulse width and fast repetition rates. (78% chose this)
  • Wide pulse width and slow repetition rates. (5% chose this)
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What happens to the conductivity of a photosensitive semiconductor junction when it is illuminated?
  • The junction resistance is unchanged. (1% chose this)
  • The junction resistance decreases. (81% chose this)
  • The junction resistance becomes temperature dependent. (2% chose this)
  • The junction resistance increases (16% chose this)
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Which of the following statements about SSB voice transmissions is correct?
  • They use A3E emission which are produced by modulating the final amplifier. (10% chose this)
  • They use F3E emission which is produced by phase shifting the carrier. (6% chose this)
  • They normally use J3E emissions, which consists of one sideband and a suppressed carrier. (82% chose this)
  • They may use A1A emission to suppress the carrier. (2% chose this)
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