Try this for a very simple explanation. Moe Szylak is standing in the street in front of his bar. Homer stands on the roof of the bar. Barney stands in the alley at the back of the bar. Moe wants to yell a message to Barney, but Barney cannot hear Moe because they are too far apart. So Moe yells his message up to Homer, and Homer then yells the message to Barney. There you go - simple as Duff! (Oh yaaaaah!)
If that explaination was too simple for you - then please step up to the plate and take a swing at the following explanation.
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The best way to understand radio repeaters is to think of two boxes sitting on the top of a hill. In box A we have a radio RECEIVER that picks up messages from/on radio frequency (freq) A. In box B we have a radio transmitter that sends out radio messages on/via freq B. There is a wire that runs FROM box A TO box B. Whenever box A picks up a message on freq A, it immediately sends it down the wire TO box B. Box B then instantaneously transmits that radio message out over freq B. This is the simple and magical explaination of the workings of a radio repeater.
If this is not clear - let me rephrase it a little. The receiver in box A listens for messages on frequency A continuously. When it starts to pick up a message, it immediately starts pumping it down the line to box B. When box B starts getting the message via the line, it immediately starts to send that message out via frequency B.
Capiche? [Bart : "I understood everything up to the 'Capiche' part"]
With this knowledge you can better handle jammers, stuck microphones, and various types of radio failures.
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POP QUIZ TIME
1. What frequency would a police car transmit on to access the repeater?
2. What frequency would an ambulance listen on to receive messages from the repeater?
3. What frequency would a fire rig transmit on to talk on "direct" or "talkaround" or "fireground"?
4. How is your dispatch center linked to the repeater? Via telephone line? via microwave link? via radio link?
5. Can your dispatcher receive and transmit messages at the same time when using the repeater?
If you have any trouble answering these questions, I would suggest that you contact a radio man, a ham radio operator, or a "radio smart" person for the answers!
A ADDITIONAL THOUGHT - May 29, 1999 - When you learn the information shown above, it gives you the power/ability to respond to/ameliorate problems within your radio system. Unlike problems which might occur with computers, radio consoles, or heavy mechanical equipment - problems with radio systems can often be handled by an intelligent dispatcher or radio operator.
Take care - happy radioing! by PWS
The URL for this item is www.geocities.com/CapeCanaveral/3327/repeaters.html
Written Up - July 1998
Reviewed - May 1999 - Cleaned Up (~HTML changes) - 14 Dec 00 - rewritten 19 May 2001