More of a "What if"...

[fchrist16]

Say MURS and GMRS was able to be cross-band linked, like 2m and 70cm is.

One would have a repeater setup, using GM300's and 1 CDM1250, on 151.820 + .040 offset (randomized) and 462.5625 + 5.00 offset (randomized again). That would have the VHF repeater as 151.820/151.880 and UHF as 462.5625/467.5625. Now run those two setups on two different peaks, e.g. North side of Crater Lake and South side, with the same PL (since it's the same "system").

The end result...

North Side VHF-TX is 151.820//RX on 151.880// PL 131.8 -- GM300
North Side UHF-TX is 462.5625//RX on 467.5625// PL 131.8 -- GM300

South Side VHF-TX is 151.880//RX on 151.820// PL 131.8 -- CDM1250
South Side UHF-TX is 467.5625//RX on 462.5625// PL 131.8 -- GM300

Now with that in mind, using the same "cheap RICK" controller on both sides, the minute someone keys up the whole system hangs in an infinite loop.


Now if we switched only the VHF side and kept the UHF side the same, as noted below, would it still hang?

North Side VHF-TX is 151.820//RX on 151.880
North Side UHF-TX is 467.5625//RX on 462.5625

South Side VHF-TX is 151.820//RX on 151.880
South Side UHF-TX is 462.5625//RX on 467.5625


I'm attempting something similar but literally in the 2m/70cm bands as a backup for our local club, but for now I'm using a dummy load on the setup, so as to not interfere with normal ops. This is all tested with a VHF and UHF handheld (XTS5000-UHF and HT1000-VHF) in two different rooms so as to not have any feedback or desense going on.

Your hypothetical, or reality, thoughts are greatly appreciated.

Regards,

-Frank C.

[Jim202]

Say MURS and GMRS was able to be cross-band linked, like 2m and 70cm is.

One would have a repeater setup, using GM300's and 1 CDM1250, on 151.820 + .040 offset (randomized) and 462.5625 + 5.00 offset (randomized again). That would have the VHF repeater as 151.820/151.880 and UHF as 462.5625/467.5625. Now run those two setups on two different peaks, e.g. North side of Crater Lake and South side, with the same PL (since it's the same "system").

The end result...

North Side VHF-TX is 151.820//RX on 151.880// PL 131.8 -- GM300
North Side UHF-TX is 462.5625//RX on 467.5625// PL 131.8 -- GM300

South Side VHF-TX is 151.880//RX on 151.820// PL 131.8 -- CDM1250
South Side UHF-TX is 467.5625//RX on 462.5625// PL 131.8 -- GM300

Now with that in mind, using the same "cheap RICK" controller on both sides, the minute someone keys up the whole system hangs in an infinite loop.


Now if we switched only the VHF side and kept the UHF side the same, as noted below, would it still hang?

North Side VHF-TX is 151.820//RX on 151.880
North Side UHF-TX is 467.5625//RX on 462.5625

South Side VHF-TX is 151.820//RX on 151.880
South Side UHF-TX is 462.5625//RX on 467.5625


I'm attempting something similar but literally in the 2m/70cm bands as a backup for our local club, but for now I'm using a dummy load on the setup, so as to not interfere with normal ops. This is all tested with a VHF and UHF handheld (XTS5000-UHF and HT1000-VHF) in two different rooms so as to not have any feedback or desense going on.

Your hypothetical, or reality, thoughts are greatly appreciated.

Regards,

-Frank C.

You can't link 2 repeater systems by using a receiver on the output as the input to the second site. It will lock
up as you have stated. The only way this will work is to have some sort of link connection between the sites
and using the RX input of each of the systems, not the output. The link connection can be a wireline, microwave
or a radio link using another set of frequencies. This is done all the time in public safety systems.

Jim

[Bill_G]

Yes Frank - Your first setup is definitely a noise maker, and your second setup is poorman's vhf simulcast repeater tied together by a full duplex uhf link. How well it works depends on the terrain and separation between the two vhf footprints. The possibility for a mess is very high if there is a lot of overlap. If you used a common vhf input freq with different vhf output freqs, then it would behave well, serve a large area, and not be mutually destructive.

[fchrist16]

Thanks Bill and Jim!

Bill, would sharing both a common vhf and uhf input frequency but different outputs work just as well?

Regards,

-Frank C.

[Bill_G]

No. You would lose your link between the two sites. You could do it simplex. That would give it first come first serve priority and cut your costs. But, if you use split channels to get full duplex, the freqs need to line up tx to rx.

[fchrist16]

I was thinking of using simplex, since that's what I'm used too with these sort of setups, but they want to keep the VHF and UHF repeaters on air if the Main sites were to go down, these would act as backup temp's...

Making repeaters out of GM300's like this is confusing for me, then add the crossband and it's super confusing.

Bill if you want to PM me for more help/details, etc it would be greatly appreciated.

EDIT: I think I have it now. I'm about to take all the equipment out into the field for testing. I'll report back with results.

UPDATE EDIT: Still don't have it. I think tomorrow I'll be stopping by HRO, a guy there seems to know Moto gear and can be hands on with me, unless something else pops up here...

Regards,

-Frank C.

[Will]

You may NOT have any repeaters on FRS frequencies... Period..

"North Side UHF-TX is 462.5625//RX on 467.5625// PL 131.8 -- GM300

South Side UHF-TX is 467.5625//RX on 462.5625// PL 131.8 -- GM300"

[fchrist16]

You may NOT have any repeaters on FRS frequencies... Period..

"North Side UHF-TX is 462.5625//RX on 467.5625// PL 131.8 -- GM300

South Side UHF-TX is 467.5625//RX on 462.5625// PL 131.8 -- GM300"

Read what I write..."Say MURS and GMRS was able to be cross-band linked, like 2m and 70cm is."

Regards,

-Frank C.

[akardam]

Let's not have any radio-police action here, shall we? It's up to the OP to ensure that he's following all applicable FCC rules and regs.

That having been said, I'm curious if having subscribers on both VHF and UHF is a solid requirement, or if you could go all VHF and link on UHF, or vice versa?

[fchrist16]

I would think that having subscribers on both VHF and UHF is not always a good idea, but having a UHF link between two setups is a good idea regardless.

Regards,

-Frank C.