Multi-channel repeater operations

[firedog359]

Hello all, I found an old thread on this but it really did not answer my questions. I work for a local hospital and we have 4 repeater pair frequencies that we use, channels 1-4. Plant ops and our police officers work on two channels and we have the other two for other uses. All four channels work off repeater. we are using the 400 MHz business band. This is fairly new system that was a narrowband upgrade from a 2 channel wideband system. I have not actually seen the installation on this system but just as a general question. Can you run 4 repeater pair channels off 1 repeater or do you have to have a repeater for each pair?

 

[rescue161]

You can set this up a bunch of different ways.

Analog:

1) Run one repeater as a "community repeater" with each "channel" having its own PL or DCS tone. This keeps other users from hearing chatter on other channels. This is not an ideal solution as each user has to share the repeater, so if security is using the repeater, then nobody else can use it until security stops talking. It's a major undertaking to train people to share spectrum, so this almost never gets used anymore.

2) Using separate repeaters for each channel. This is a better solution, but as you can imagine, it is more costly. If real estate is scarce, then it becomes even more costly as you'd need transmit combiners and receive multi-couplers.

Digital:
1) Motorola's Capacity+ would be an ideal solution even with one repeater. It acts sort of like a mini-trunking system with no control channel. Depending on usage, you could get away with one repeater (two-time-slots) or you could have two repeaters with four time-slots.

There are a lot of other options. This is just a small sample of the things that could be done. You could look their license up on the FCC database to know exactly what type of modulation they are using.