repeater frequencies

[dnoyeb]

do repeaters have to use special frequencies, or can they use the basic frequencies? Is there any technical problem with that?

I'm thinking if a group of people were on frequency A, and I had a repeater echoing to B and receiving on C echoing to A, could That work? Is it legal?

 

[mmckenna]

GMRS has 2 sets of 8 channels.

The 462.XXX frequencies are for simplex (radio to radio) use, AND for repeater outputs.
The 467.XXX frequencies are for repeater inputs ONLY.

A radio talks "in" to the repeater on the 467.XXX frequency, and the radio listens on 462.XXX, the repeater output.

So, an example would be:
I have a repeater on a mountain top. The repeater receives the transmissions from my mobile on 467.650. The repeater amplifies that and retransmits that traffic out on 462.650.

A repeater could, technically, listen on one of the 462 frequencies, and retransmit on a different 462 frequency, but that raises a few issues.
1. with such a small separation between the repeater input and the repeater output, you would need some very high end duplexers to handle the separation needed between the repeater input and repeater output.
2. It would tie up two "simplex" or repeater output channels, a needless waste.
3. It's been a while since I read part 95, but there is probably a rule against it.

I'm not quite sure I am comprehending your a-b-c-a question, but let me know if I didn't answer it above.

 

[quarterwave]

Sounds like he is describing (if he even means to) a mirrored repeater system. This is rare, but I did it (with FCC approval) in commercial work once (it's still on the air!). I'll save the technicals for now.

But, I think he is worried his repeater will get repeated. Your explanation of how we have input and outputs designated will answer that. I will also just add that you are not allowed to talk simplex on the GMRS repeater input frequencies, although doing so might be hard to catch or prove.

 

[dnoyeb]

Yea, Im asking a crazy question I know.

Here's the situation. A group of people talk simplex on channel A. I want to talk with them using a repeater from a long way away. Without asking them to use the repeater themselves.

Doable?

 

[quarterwave]

Sure, as long as they are on a 462, your repeater will be 467 in 462 out, so they are in Talkaround or Direct mode and you are using your repeater...just remember you will have more range TO them, and they will have less getting BACK to you, because you are receiving them on a mobile or portable, versus through the repeaters receiver (if repeated). Unless of course you maintain a 462 receiver at the same site....depends on your setup.

This comes down to simplex being X miles range, and repeater being X times 2 (roughly) range.

Oh yeah, you'll want your repeater hang time to be ZERO or your tail will talk over them on simplex if they key up quickly.

 

[dnoyeb]

I should have phrased it differently. I'm mostly interested in the opposite. I think my radio at 4W has typically more power than their bubble wraps do. So what I want is the repeater to pick up their transmissions and rebroadcast so I can get them.

I'm really just getting a better understanding on how these things work. Though if the price was actually <$500 I'd probably do it.

 

[quarterwave]

No, that won't fly. Not by the rules.

You could look at doing a Simplexer...that's a store and forward base station. It records up to xx seconds of what opens it's squelch, and then when the carrier drops, it re-transmits what it recorded. So you hear yourself, but it uses the base station with a high profile antenna to reach out...so for you it would work both ways.

I however don't recommend this setup. "Users" who are non technical will not get used to it and will be talking all over each other, etc.

I hope I don't ignite a simplexer debate as I think we sawed that wood a while back, but it is a technically possible scenario, just not a simple one user-wise.

If this is a regular group, it sounds like you need to put up a real repeater, and then invite those guys to toss bubble packs in favor of real radios and them all of you can enjoy either 4W simplex ops or the repeater for better range.

 

[DaveNF2G]

If this is a regular group, it sounds like you need to put up a real repeater, and then invite those guys to toss bubble packs in favor of real radios and them all of you can enjoy either 4W simplex ops or the repeater for better range.

I'm guessing they will also need to spend the $80 for GMRS licenses.

 

[quarterwave]

Yes. Implied, but not expressed. Sorry.

 

[kc8mln]

Let me toss this out there to the group "for what it's worth" for discussion...

I believe that the GMRS rules do say that you can only operate a repeater on the "repeater pair" frequencies, but does it specifically say that you have to use the same input/output freq?..just wondered about that while I was reading over this thread.

For example, if your input is set at 467.650, but your repeater output is set to 462.625 instead.....you would still be using the approved freq's, but just not in the "tied pairs".....so any input/comment as to if that is permitted, or does it specifically state somewhere in the rules that you MUST operate a gmrs repeater on the designated paired freqs and NOT do any split pairs?

 

[DaveNF2G]

The frequencies are allocated in pairs. Besides that, in a shared service with so few available frequencies, doing non-standard splits is just plain stupid.

 

[kc8mln]

Just figured I'd toss that out there, in my area, other services use non-standard "split pairs"

 

[ecps92]

What band ??

Just figured I'd toss that out there, in my area, other services use non-standard "split pairs"

 

[SteveC0625]

What band ??

There's no standard split on VHF repeater pairs, at least in the PS stuff, unlike the standard 3 or 5 MHz on UHF.

 

[ecps92]

Which is why I am asking the person who made the comment.

However there are Groups who have implemented Non Standard UHF Pairs.

Even have found an active Repeater running 467 Out with 462 in :roll:

There's no standard split on VHF repeater pairs, at least in the PS stuff, unlike the standard 3 or 5 MHz on UHF.