So ladies and gentlemen, i have a new brilliant 2 way radio vox piece for you to read, i know, you don't need to thank me each and every one, just add a social like to the piece of writing to prove your appreciation.
In two way radio systems, poor coverage is a fairly common problem. This can be due to either large obstructions or simply distance between radios.
A repeater is a type of base station which can be used to improve the coverage of a radio system.
PMR radios can be programmed to transmit on one frequency and receive on another. (Semi-duplex.)
A repeater works by receiving a radio signal on one frequency and simultaneously re-transmitting the signal on another frequency. (Duplex.)
For example, a portable radio transmits on 1 and receives on 2.
The repeater picks up the transmission on 1 and simultaneously re-transmits on 2.
Others radio users hear the transmission on 2 and reply on 1.
This channel splitting is done because a two way radio can't transmit and receive on the same frequency at the same time.
Think about it like this... A signal on the receiver causes the transmitter to key up, which transmits on the same frequency as the receiver, which receives the signal and continues to key up the transmitter... It would effectively lock up.
Repeaters are useful in extending radio range. If two users are too far apart to receive each other, a repeater located between them would effectively, hop or bounce the signal.
Repeaters also work well at overcoming "line of sight" limitations.
If two users are on either side of a mountain, the radio signal cannot penetrate the mountain and they are unable to communicate.
Now install a repeater at the top of the mountain. Both radios can now see the repeater's antenna... and communicate. The height of the repeater would also give the added bonus of increased range.
Repeaters do not necessarily have to cover a large area. If there is just a small pocket of poor coverage within a larger system, a low power repeater could be used just to "fill in" the area.
In the UK, repeaters come in types ranging from just a couple of watts up to 25 watts.
Invariably, the repeater transmit power should match that of the mobiles or portables.
If the repeater transmits at 25 watts and the portables are rated at 5 watts, the portables can get into a situation where they can hear the repeater, but are unable to reply due to the power difference... Frustrating!