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Repeaters, calls and nets: three systems, one habit each

Environ 6 min

Les questions restent dans la langue dans laquelle elles ont été publiées.

This topic asks how to get into a repeater, how to open and answer a call, and how a directed net and its written messages are run. Many of the questions are settled by which of those three systems you are in.

Three systems worth carrying in your head

A repeater is a pair of frequencies plus a key: you listen on the frequency it transmits and transmit on the one it listens to, with a separation fixed by convention for each band. Hearing it only proves it is transmitting; being heard needs the right direction and size of that separation and whatever access it demands, so when you cannot get in, walk the layers in order.

LayerWhat sets it
Frequency pairA band convention, above or below the frequency you listen on
AccessA continuous tone under your audio, or a numeric code matching the machine
RoutingOn digital systems, which traffic reaches you is a configuration choice, not a tuning one

Opening a contact has two forms, and the channel decides which. On a shared machine everyone already monitors there is no point inviting the world: name the station you want, then give your own call sign; or, merely advertising your presence, give the callsign of your own station and say you are listening. On an open frequency you invite anyone, identify, then listen. Answering keeps that address-first order, and nobody owns a frequency, so arriving first confers no rank.

A net is a channel with a chairman: the station running it opens proceedings, calls stations in and says who transmits next; you wait to be called unless what you hold is an emergency. Its formal side is a standard written message, and each field of the form has one fixed job.

Where the answers are lost

Try it

Question 80

What is the purpose of the reverse function on a VHF/UHF transceiver?

  1. To reduce power output
  2. To increase power output
  3. To listen on a repeater’s input frequency
  4. To listen on a repeater’s output frequency
Question 92

What is the purpose of a squelch function?

  1. Reduce a CW transmitter's key clicks
  2. Mute the receiver audio when a signal is not present
  3. Eliminate parasitic oscillations in an RF amplifier
  4. Reduce interference from impulse noise
Question 86

How can you join a digital repeater’s “talkgroup”?

  1. Register with the local Frequency Coordinator
  2. Register with the digital repeater control operator
  3. Program your radio with the group’s ID or code
  4. Program your radio with the DTMF tone used by the talkgroup
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Repeaters, calls and nets: three systems, one habit each · Questena