The International Telecommunication Union (ITU) is an agency of the United Nations which regulates information and communication technology issues. It is also the global focal point for governments and the private sector in regards to developing networks and services.

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Tags: itu arrl chapter 7 arrl module 15

Since radio frequency energy doesn't simply stop at borders, the use of certain frequencies is governed by what they're being used for in a particular region/territory/location.

The International Telecommunication Union (ITU) divides the world into three regions to manage the global radio spectrum. Each region has its own set of frequency allocations.

Region 1 comprises Europe, Africa, the Middle East west of the Persian Gulf including Iraq, the former Soviet Union and Mongolia.

Region 2 covers the Americas, Greenland and some of the eastern Pacific Islands.

Region 3 contains most of non-former-Soviet-Union Asia, east of and including Iran, and most of Oceania.

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Tags: arrl chapter 7 arrl module 15

As an aid, convert the wavelength to frequency:

\begin{align} f_\text{ (MHz)} = \frac{300}{\lambda _\text{ (meters)}} \end{align}

So in this case: \begin{align} f_\text{ (MHz)} &= \frac{300}{6 \text{ m}} \approx 50 \text{ MHz} \end{align}

52.525 MHz is the only frequency in the 6 meter band.

Note:
The distractor answer 49 MHz is even closer to 6 meters in length, however, is outside of the US amateur 6 meter frequency allocation, which is the range 50.0 MHz - 54.0 MHz. The sub-band 50.0 MHz to 50.1 MHz is restricted to CW (Continuous Wave) only.

Hint: Subtract 1 from the band (6) to come up with 5. Only the correct answer (52.525) starts with a 5.

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Tags: frequencies 6 meter arrl chapter 7 arrl module 15

As an aid, you can convert the frequency (\(f\)) to wavelength in meters (\(\lambda\)) :

\begin{align} \lambda_\text{ (m)} = \frac{300}{f_\text{(MHz)}} \end{align}

(300 is approximately the number of Mm/sec light travels in a vacuum.) So in this case: \begin{align} \lambda_\text{ (m)} &= \frac{300}{146.52 \text{ MHz}} = 2.05 \text{ m} \approx 2 \text{ m} \end{align}

144-148Mhz is the frequency range allocated to ham radio operators in the 2 meter band, with 144.0-144.1 being allocated for CW mode only.

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Tags: frequencies 2 meter arrl chapter 7 arrl module 15

300 / frequency = wavelength in meters. 300 / 443.35 is around .70 (this question is easy to spot if you remember the formula, because 443.35 is the only answer that would give you a value less than 1m). The frequencies allocated to amateur radio in the 70cm band are 420-450Mhz.

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Tags: frequencies 70 cm arrl chapter 7 arrl module 15

One common thread in most frequency related questions on the technician exam is that only one of the answers is even in the given band.

300 / frequency = wavelength in meters. 300 / 1296 = 0.23, or 23cm.

You are allowed a calculator on the exam.

The frequencies 1240-1300MHz are allocated to amateur radio operators in the 23cm band.

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Tags: frequencies 23 cm arrl chapter 7 arrl module 15

We have an equation:

Speed of light (c) = wavelength (lambda) * freq. (f) -> lambda = c / f = (3*10^8) / (223.50 * 10^6) = 300/223.50 = 1.34 m

Normally when the result of the 300 / frequency equation lands over a band, it's considered outside that band. In this case, 1.34 is over 1.25, but it is the closest available answer. You must simply know that the 1.25 meter band is significant.

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Tags: frequencies 1.25 meter arrl chapter 7 arrl module 15

Secondary means that while amateur radio is allowed to use that band, amateurs are not considered the primary user. Therefore amateurs must give priority access to the primary users by not interfering with them.

The answers involving foreign amateur stations are not correct, they are still amateur radio operators, so they aren't protected by this rule. The only proscription on talking to foreign amateur stations is when their country does not allow communications with our country - there aren't many of those, but there are a few.

In the US, digital transmissions are allowed on the entire 70 cm band, so this choice is also not correct.

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All of the choices are correct. Here is each one explained:

1. The frequency you set on a transmitter is actually the carrier frequency which is either at the center of the total bandwidth that you're using (for FM or non-SSB) or at the top or bottom of the bandwidth (for SSB). When you transmit on a frequency, you will actually use a little bit of bandwidth above and/or below that frequency (referred to as deviation) even with a properly calibrated transmitter!

2. Not all transmitters are calibrated perfectly, and so if you set your transmitter exactly on a specific frequency, say the bottom edge of the amateur portion of the band even when using upper sideband (USB), you may actually be transmitting illegally out of band, due to calibration error.

3. Some transmitters may drift a little bit off frequency during transmission as well (due to temperature changes as the radio gets warmer etc).

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On 6 meters, 50.0 - 50.1MHz is allocated to CW mode only. (Morse code)

On 2 meters, 144.0 - 144.1MHz is allocated to CW mode only.

On 1.25 meters, 219.0-220.0 may be used only for Fixed digital message forwarding systems.

Dedicating a small portion of the band, a 100 khz wide sub-band, helps enable the reception of low power signals, such as EME (Earth-Moon-Earth) and propagation beacons, by protecting them from higher bandwidth modes like SSB/FM phone.

Similarly, the dedicated space on 1.25 meters, helps enable the operation of automatically controlled digital message forwarding systems. Reserving that piece of bandwidth from other operations helps prevent interference from other operators, as well as prevents other communications from being interfered with by automatically controlled stations.

For more information, ARRL has published a chart of ham radio bands [PDF].

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Tags: mode-restricted 6 meter 2 meter 1.25 meter arrl chapter 7 arrl module 15

On 6 meters, 50.0 - 50.1MHz is allocated to CW mode only. (Morse code)

On 2 meters, 144.0 - 144.1MHz is allocated to CW mode only.

Dedicating a small portion of the band, a 100 khz wide sub-band, helps enable the reception of low power signals, such as EME (Earth-Moon-Earth) and propagation beacons, by protecting them from higher bandwidth modes like SSB/FM phone.

For more information, ARRL has published a chart of ham radio bands.

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Tags: morse code 2 meter 6 meter mode-restricted arrl chapter 7 arrl module 15

When U.S. stations aboard ships sail around the world, they pass through various ITU regions. It's the regions that determine what frequencies are allowed.

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Whenever there is a part of the band that is reserved for Data it is generally the lowest part, and so it makes sense that the range at the bottom of the 220 MHz range would be for data. In point of fact, all non-data frequencies allowed to ham operators in the 1.25 meter band (222 MHz) are from 222.0 to 225.0 MHz, and that block allows phone and image.

219 to 220MHz is for fixed digital message forwarding systems only.

See the ARRL Frequency Chart for a handy one-page reference to band privileges.

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