Batboard

I am looking to link two separate repeaters (both UHF GR1225s) that are on separate frequencies. I have heard three suggestions:

1. Use two additional two-way radios, one at each site, on simplex to link the two repeaters
2. Use two additional radios, one at each site to listen to the output of the remote site, and relay it to the local repeater
3. Similar to #2, Use two additional radios, one at each site to transmit local audio on the input frequency of the remote site

The GR1225s do not have a controller (other than the built-in function) so however I do this , it would have to be supportable in this configuration and either through the mic socket or the accessory connector.

For cost and power considerations I would like to use some cheap HTs for the linking (the two repeaters are not too distant, the issue is terrain blocking an isolated area). But, would consider used mobile gear as well.

Any/All ideas welcomed.

Do you have network access at either site? Do you have LOS between the sites where you can put up an unlicensed microwave hop?

I have done both 1 & 2, using stock GR1225's and CDM radios. Straight forward hookup using the accessory connectors.

motorola_otaku wrote:Do you have network access at either site? Do you have LOS between the sites where you can put up an unlicensed microwave hop?

No network access. But LOS is a possibility. Can you suggest some microwave systems? I might also be able to use 2.4 gHz wifi gear.

wavetar wrote:I have done both 1 & 2, using stock GR1225's and CDM radios. Straight forward hookup using the accessory connectors.

Thanks. Would a Maxtrac work? And, do you have a schematic for the cables or us therva part number?

Or, maybe an M1225?

berkinet wrote:

motorola_otaku wrote:Do you have network access at either site? Do you have LOS between the sites where you can put up an unlicensed microwave hop?

No network access. But LOS is a possibility. Can you suggest some microwave systems? I might also be able to use 2.4 gHz wifi gear.

Ubiquity NanoBeam NBE-M5-16. 5.8 GHz license-free and super-easy to set up. If you have clear LOS you can just point them in the general direction of each other and they'll work.

Once you get a network hop up and running there are myriad ways to send audio over IP. CIsco routers with E&M cards are my preferred method but TELEX IP-223s work equally well.

berkinet wrote:

wavetar wrote:I have done both 1 & 2, using stock GR1225's and CDM radios. Straight forward hookup using the accessory connectors.

Thanks. Would a Maxtrac work? And, do you have a schematic for the cables or us therva part number?

Any 16-pin model that allows configuration of the accessory pins will do. I'm sure the cable pinouts are posted here in a hundred different places, but off the top of my head:

GR1225 Maxtrac/CDM/M1225
7 ground <---> 7 ground
11 RX Audio <---> 2 Aux Mic In
8 COR <---> 3 PTT
3 PTT <---> 8 COR
2 Aux Mic In <---> 11 RX Audio

Pin 8 is typically the only one that requires programming config to active low and you can choose carrier or carrier with PL/DPL. The others are either hard coded, or defaulted to what I indicate. Also recommend you either use a common power supply for both radios, or connect the chassis of the radios together with a 10 gauge wire or better.

Thanks to @wavetar & @motorola_otaku You have both given me a number of ways to go. It may be a while before this gets implemented, but I can now start looking for equipment and planning a path forward.