Batboard

We have three analog repeater sites. The coverage area for all the sites overlap. We are thinking about MotoTrbo. Currently all the repeater sites use the same set of TX/RCV frequencies except the Receive for each repeater is set for different PLs. Subscribers have to change channels depending upon what area of the county they are in so that only one repeater transmits at a time. My question is could MotoTrbo 'Site connect' do something simlar and use the same 'receive' frequency with 3 separate 'transmit' frequencies? I could probably modify my licenses and come up with 4 usable frequencies but coming up with 6 would probably be impossible.

TreyH wrote: My question is could MotoTrbo 'Site connect' do something simlar and use the same 'receive' frequency with 3 separate 'transmit' frequencies? I could probably modify my licenses and come up with 4 usable frequencies but coming up with 6 would probably be impossible.

Yes, you should be able to do what you are asking. You'd need to use a different 'color code' for each site, so the radios will roam effectively.

Todd

If you use the same RX freq at each site, you may have a issue if you use both time slots and you have 2 users transmitting at the same time (on different time slots) in an overlap area.

You may experience RF contention as both signals hit the repeater RX

RFguy wrote:If you use the same RX freq at each site, you may have a issue if you use both time slots and you have 2 users transmitting at the same time (on different time slots) in an overlap area.

You may experience RF contention as both signals hit the repeater RX

This is true, but would also be true in his current analog system (unless the sites are linked for TX somehow, so the users wouldn't likely want to key up at the same time at different sites...wasn't mentioned). Definitely something to be aware of though, as contention sounds completely different in analog as opposed to digital. Maybe consider using only one slot.

Thanks for the replies. Nice to know we can at least make it work and hope for some frequencies down the road to get our 2nd time slot. We may try just two repeaters starting out and see how the coverage goes. Our county is 58 miles east-west and one transmitter at a time is just not working on the subscribers receive side; especially inside buildings.

..forgot to answer that more than 1 user should not be transmitting on the same time slot at a time. I guess we would like it to act like a 'poor man's simulcast' ? but we would still like to utilize that second time slot which would give us a second talk path correct?

Maybe simulcast is the way you should go. If you cannot get two new freq pairs, you will have a mess whether you go Trbo or stay analog. Site connect works quite well. We've built out several systems, and they are very good at unifying coverage. But, physics is physics.

Do all 3 sites overlap? If not, the two 'outer' sites could re-use frequencies, with the 'middle' site having distinct freqs. Just a thought.