T200 – Repeater Basics and Operating Practices

So, you have a shiny new radio in your hand. Now what do you do?

As a Technician, most of your communications with a 2 meter or 70 centimeter FM radio will be through a FM repeater. FM Repeaters are used to extend the range of your radio. To use your radio on a FM repeater you are going to need some information on how to set up your radio.

Repeater Basics & Operations:

A repeater is a radio system using a higher power transmitter usually placed at a location with some height. A great location for a repeater is a radio tower or tall building.

Here is how the repeater system works: Your radio transmits to the repeater on a certain frequency. If you are in range of the repeater, it picks up your signal and starts retransmitting your audio on another frequency. Other radios in range of the repeater who are “listening” to the repeater will pick up your audio on their radio. When you are finished talking, your radio will be “listening” to the repeater. The other party will transmit to the repeater and it will retransmit their audio. You will be able to hear them on your radio. The advantage of using a repeater is that it usually is a higher power radio and its antenna has a height advantage. You and another ham may not be in radio range with each other, but you can still communicate if the two of you are in range of the repeater.

Let’s see how our friend Jason KC5HWB explains it:

There are three basic details you need to know in order to talk to others via a repeater: Frequency, Offset, and Access Tone. If you have these three details, you should be able to communicate through most analog repeaters.

Repeater Frequency

This is the transmit frequency of the repeater. You will set your radio’s receiver to the repeater frequency so you can pick up the repeaters transmissions.

Repeater Offset

You will often hear the term Repeater Offset. This is the difference between the repeater’s transmit and receive frequencies. For 2 meter repeaters the offset frequency is usually +/- 600kHz from the Repeater Frequency. For 70cm repeaters the offset is usually +/- 5.0 MHz the Repeater Frequency.

Example: Our main two meter repeater (K5RWK) has a frequency of 147.120 MHz with an offset of +600 kHz.

This means that you set your radio’s receiver to 147.12 Mhz and set the radio’s transmitter to 147.72 Mhz. (147.12Mhz + 600Khz) You will be transmitting on 147.72 Mhz and listening on 147.12 Mhz.

Repeater Access Tone / PL Tone or Continuous Tone Coded Squelch System (CTCSS)

Most repeaters look for an access tone while listening for a signal. You need to set your radio to transmit the access tone when you key the transmitter of your radio. Repeaters use access tones to help keep stray signals not intended for the repeater from “keying” the repeater.

Example: The RWK Repeaters use 110.9 Hz CTCSS tones for access. You need to set your radio to transmit a continuous tone at 110.9Hz when you want to talk through the repeater.

A very handy URL for obtaining repeater details is www.repeaterbook.com and install the repeaterbook app on your smartphone.

Repeater Etiquette

When wanting to talk to someone on the HF bands, the common practice is to call CQ on a frequency. That is not the preferred method of calling on a repeater. Here are some good manners for talking on a repeater.

Calling Out

When calling out to talk to anyone on a repeater, one usually says their call sign and says something like “listening” or “monitoring this frequency”.

Example: “KG5WRY listening.” or “KG5WRY monitoring this frequency”.

Answering a call

To answer someone calling out on a repeater, you usually say “their call sign, this is (your callsign)”.
Example:  You hear KD4C calling out on the repeater. He says, “KD4C listening”.  You respond, “KD4C this is KG5WRY good afternoon”.

Finishing a conversation

When you are finished with the conversation, you can say your call sign and “listening” if you want to talk to someone else, or if you are done talking for a while you can say “Call sign Clear.

Example “KG5WRY clear”.

Remember that the FCC wants you to identify yourself every 10 minutes and at the finish of your conversation.

Joining another conversation

If you are listening to a conversation between other hams on a repeater and want to join the conversation, the polite method of joining the conversation is to wait for a break in the conversation. When you find a break in the conversation key your radio and say your call sign. The other party will either ask you to join in on the conversation or ask you to hold off for a minute, then ask you to join in.

Example:

I hear a conversation on the repeater and I want to join in. I wait for a break in the conversation. When I hear a break in the conversation, I key my transmitter and say KG5WRY. I wait for a response from the other party.

Don’t forget to pause once in a while during a conversation to give others a chance to join the party.

Emergency Communications

If you have a true emergency you may break in a conversation at any time. Emergency traffic always takes precedence. If you have an emergency, don’t wait, break into the conversation by keying your transmitter and saying, “BREAK BREAK EMERGENCY.” Others should stop their conversation and ask how they can help you.  If you hear an emergency call, you should do the same.

Simplex Operations:

A ham using a HT can directly communicate with another ham if the transceivers are within range of each other and both radios are on the same frequency.  Each ham takes turns transmitting to the other ham. This mode of communication is called simplex operation.  HT radios can effectively transmit in to other radios for a couple of miles, depending upon the terrain. Lots of trees and buildings can dramatically shorten the communications range. (This is why we use repeaters.)

The 2 meter simplex frequencies for hams is 146.400-146.595 MHz with 145.520 MHz as the National Simplex Calling Frequency.  In Texas, the frequencies are divided into 20 kHz channels. So in Texas, the simplex frequencies are:

146.400, 146.420, 146.440, 146.460, 146.480, 146.500, 146.520, 146.540, 146.560, 146.580, 146.600, 147.400, 147.420, 147.440, 147.480, 147.500, 147.520, 147.540, 147.560, 147.580.

As said earlier, to talk to someone in simplex mode, both transmit and receive frequencies must be the same. If you are trying to randomly talk to someone in simplex mode, you can switch to 146.520 MHz (VHF national call Frequency) and push the transmit button and say something like, “This is (your call sign) listening for any station on simplex.”  Take your finger off of the PTT button and listen for a reply.  Wait a few seconds and repeat the call if nothing is heard. If you do not make contact after several calls and want to end the calling session, finish the session by pressing the transmit button and say something like “Nothing heard, (your call sign) Clear.” The FCC requires you to end your transmission session by identifying yourself by your call sign.  If you make contact, then make arrangements to move to another simplex frequency so others can use 146.520 to make contact.

What Radio Do I Need?

Many new Hams purchase an inexpensive hand held transceiver to start their amateur radio journey. The $30 Handy-Talkie (HT) may be your first radio purchase, but it is guaranteed not be the last.

What Antenna Do I Need?

Most HT-type radios come with an attached flexible antenna, sometimes called a “rubber duck”. This antenna is fine for very short range, but is a compromise of short, flexible, cheap and performance. Many hams choose to replace the “stock” antenna with a better antenna with better performance. If you use your HT in your car or at your home, you will probably want to add an external antenna outside your car and/or house. An external antenna with get you much better communication range and signal quality.

Any Other Equipment?

In addition to basic HT-type radios, many hams choose to install “mobile” radios in their vehicles and also inside their houses (using a separate 12V power supply). These radios have higher power output and better receivers and will work much better in a car/house environment.

The 2 Meter Band Plan

It’s important to learn what happens where in the 2M band. This isn’t codified by the FCC but rather general agreement between operators, so that things work and people don’t get upset.

If you know the basics of the Two Meter Bandplan, you will easily understand “what happens where”.