What Are Ham Radio Repeaters?

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For many HAM operators starting out, the first step is to obtain a license.  If you are good enough, you can take all three tests to obtain the extra license right away.  Most of us though will only obtain the Technician license starting out.

With a Technician license you will only have radio privileges above 30 mHz.  This will give access to the 2 meter band which is a very popular band for those who want to talk to people around town.

A beginner HAM operator might also start out with a simple hand held rig.  A handheld radio when held 6 ft into the air will probably travel about 3.5 miles because the curvature of the earth will eventually get in the way.  So if you have a friend who you want to talk to, you might be able to talk to them if they are no more than 7 miles from you.

So what if you want to talk to someone who is a little bit farther away?  That’s where a repeater comes in very handy.  A repeater is a device that allows you to communicate with people farther away.

How does a ham radio repeater work?

A repeater uses two frequencies.  One for receiving and one for transmitting.  You must have both of these frequencies tuned into your radio to be able to communicate with anyone using a repeater.  The repeater receives your low power signal, processes the audio and then transmits your audio at a much higher power to the world.

A repeater is basically a large antenna that is set up high on a mountain or a building top.  These large antennas are high gain, low loss and are designed to be working continuously.

The antenna is connected to a duplexor.  The duplexor is connected to a receiver which is connected to a controller.  The signal goes from the controller to the transmitter which is connected back to the duplexor.

The duplexor is an electronic device that allows bi-directional signal to live on a single path.  It allows a received signal to get to the receiver from the antenna and also allows the outgoing signal from the transceiver to get to the antenna without the two hearing each other.  This is obviously a very important component of a repeater.

The repeater repeats audio signal almost instantaneously.  If it were only using one frequency, the repeater would not function correctly.  The difference between the receive and transmit frequency is called the repeater’s offset.

So to sum it up, once you have programmed the two frequencies into your radio (allowing you to transmit to and listen to the repeater), you can key your radio and send signal.  The repeater’s antenna picks up the signal, the signal goes to the duplexor.  The duplexor isolates this signal from any outgoing signal.  Once the signal is processed, it goes around to the transceiver and it is broadcast to anyone listening to that repeater.

How to use a ham radio repeater

You might be wondering if there are any repeaters in your area.  The easiest way to find out is to do a quick google search.  Once you find a repeater you are interested in checking out, program the two frequencies into your HAM radio.  The next step is the most important step…


Before you start talking on a repeater frequency always give it a good listen to make sure the channel is open for use.  It would be unfortunate to interrupt someone else’s conversation.

If you’re ready to start a conversation you can key the radio and identify yourself and what repeater you are transmitting through.  So you give your call sign and the frequency you are using.  If you are trying to talk to someone specific, you just have to say their call sign first and then identify your own call sign.

Most HAM’s will keep a log of all of the people they’ve contacted that includes their call sign, name, location and maybe even something memorable about their conversation.  You can do this with pencil and paper or by using online logs specifically intended for HAMs.