When there is radio interference, whether intentional or unintentional, you can use radio direction finding to track down the interfering noise source. This can be a directional antenna or some other means of determining where the offender is located. After you have a direction from two locations you can pinpoint where to go to find your culprit.

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Tags: troubleshooting noise and interference definitions activities arrl chapter 6 arrl module 14

A hidden transmitter hunt, also known as a "Fox Hunt", involves having a hidden transmitter (the "fox") that transmits periodically while other operators attempt to find it. The simplest way to do this is to watch the signal strength meter on your radio while rotating a directional antenna to find out from which direction the signal is the strongest.

A calibrated SWR (Standing Wave Ratio) meter might be helpful for tuning your antenna, but for a fox hunt you may actually want an out of tune antenna -- since it wouldn't receive as well, it would be easier to see where the signal is coming from =)

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Tags: directional antenna activities arrl chapter 6 arrl module 14

Contests are a very popular and fun use of HF. During a contest, all operators participating keep a log of what stations they have contacted and rather than having a conversation with them will exchange the minimum information required to confirm the contact and for the contest rules with as many stations as possible for the duration of the contest.

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Tags: activities arrl chapter 6 arrl module 14

Since the purpose of a radio contest is to see how many stations you can contact during the duration of a contest, the most important things are to make sure that both stations have accurately recorded the identification of the stations (so you should certainly not use only two letters of your call) and that you don't take more of their time than necessary, thus slowing them down (and so you shouldn't work the station more than once).

Always be brief, but also be concise and complete.

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Tags: activities best practices arrl chapter 6 arrl module 14

A Grid Locator, also known as a Grid Square, is basically a shorthand for location based on latitude and longitude. For more information visit http://www.arrl.org/grid- squares

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Tags: definitions arrl chapter 6 arrl module 14

IRLP: Internet Radio Linking Project DTMF: Dual Tone - Multi Frequency

DTMF is the generic term for Touch-Tone, which is a registered trademark of ATT. Your touch-tone® phone is technically a DTMF generator that produces DTMF tones as you press the buttons.

Communicating with an IRLP node requires the keying of DTMF signals, sent manually by key pad or automatically.

A repeater could require CTCSS (Continuous Tone-Coded Squelch System) or DCS (Digital Code Squelch) to communicate with it, regardless of IRLP, but IRLP itself does not depend on CTCSS or DCS tones.

Also, some repeaters require a special password that you send along with the DTMF signals, but the IRLP access is still accomplished by using DTMF signals.

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Tags: arrl chapter 5 arrl module 10

Think of Voice Over Internet Protocol (VoIP) as Vonage or Skype. You're using the Internet to send the audio signal (voice) from a receiver (or a computer) to another radio or another computer for transmission through a radio

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Tags: arrl chapter 6 arrl module 15

IRLP is one of several projects used for linking repeaters and other systems across the internet.

Amateurs use DTMF tones (phone keypad) on a radio to send control codes to the repeater to link or unlink with another repeater or node.

Similar technologies include EchoLink, AllStar, and Icom's D-Star network.

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Tags: arrl chapter 6 arrl module 15

The FCC rulebook provides guidelines for what is allowed, and local coordinators keep track of which repeaters are using which frequencies in which location in order to avoid interference between different nodes in the same area. None of those three sources would provide any definite information about what technologies or features a specific repeater has.

The best place to find information such as a list of active nodes that use VoIP is from an actively maintained repeater directory. A Repeater Directory is a list that someone (company, club, community, etc) maintains of repeaters that has information such as what features are on the repeater, who owns it, callsign, etc.

There are many repeater directories, both on paper and on the internet, such as here and here.

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Tags: frequencies repeater arrl chapter 6 arrl module 15

Echolink is a system of Internet-connected repeaters that can be connected to with client software and used to receive and transmit on amateur radio bands (VHF and UHF). It is essentially a method of remotely controlling a station, so when using it you are the control operator of whichever station you are using.

Since you can't legally be a control operator of an amateur station without a license, whether control is remote or local, you must register your call sign and provide proof of license to use the network.

The other options describe things that are not required to use Echolink. Any licensed amateur radio operator can use Echolink and register for a login. But keep in mind you are still responsible for your actions and must still ensure that you do not violate any regulations when using it. This is particularly important to keep in mind when connecting to repeaters in other countries where you may or may not be allowed to operate a station!

Echolink clients are available for desktop/laptop operating systems, and less sophisticated clients are available for use on mobile devices.

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Tags: arrl chapter 6 arrl module 15

In computer terms a gateway is the name of a device that connects two different networks together; a router is a type of gateway. Thus, a station that connects a packet radio network to the Internet is also a gateway.

A digipeater is a station that receives packets and then retransmits them; it's the only distractor that would make any sense, but it has nothing to do with the Internet, though it is possible for a digipeater to also be a gateway.

Repeaters simultaneously retransmit signals on another frequency and are used for voice operation; beacons transmit some form of information periodically. Neither has anything to do with packet radio.

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Tags: repeater digital modes arrl chapter 5 arrl module 12