Linking 2 Quantar's together.

[P25Radio]

What would be the best way to link 2 Quantar repeaters together. Both same freq, same tone out, different tones in. One at my house and one on the mountain. Use 1 as a base remote? Something like the Winsystem has? Ideas please.

 

[buddrousa]

Microwave LINK or T1 something with not much Latency like a Simulcast System.

 

[chief21]

If the intent is to have them both TX at the same time without special infrastructure, I would expect that this would create "interference zones" where the two transmitters are fighting with each other.

 

[P25Radio]

If the intent is to have them both TX at the same time without special infrastructure, I would expect that this would create "interference zones" where the two transmitters are fighting with each other.

You would be right on that factor.

 

[kb4mdz]

Distance between them? Expected or actual coverages? (Are their coverage areas overlapping? A little/A lot?)

Analog only? Or Analog & Digital, switchable?

Simplest analog version would be something like 4 wire with an E&M signalling pair; 6 wire, using the wildcard programming. Assuming you have the correct Wireline card that has all of those functions.

But then how to accomplish that given your distances? I've linked a VHF & a UHF quantars in a cross-band configuration this way, but they were literally side by side in the room. Easy peasey, as the little lizard says.

Any real distance will need to involve either leased Telco lines ($$ to set up thru your telcos, and then recurring monthly rape, errr, rate charges, depending on whether it's one circuit on copper, or thru a T1 link, which probably only makes sense if you have other circuits you need to transport. Or as buddrousa says, a microwave link; assuming Line Of Sight between you.
Running digital? Def. need a IP network connection.

We're better than Radio Shack: You've got questions? We got non- stupid answers, but we might be kinda sarcastic sometimes.

 

[mmckenna]

What would be the best way to link 2 Quantar repeaters together. Both same freq, same tone out, different tones in. One at my house and one on the mountain. Use 1 as a base remote? Something like the Winsystem has? Ideas please.

Linking is the easy part. What you use will depend entirely on what is available at each end.
-Many telco's are getting out of the conditioned copper pair business. I'd recommend not going that route, if they'll even sell it to you.
-Microwave is fine, but it's a lot of bandwidth for the application. Then again, if you have line of sight something like the Ubiquity radios would probably work and be easy on the budget.
-If IP is available at both ends, that would probably be your easiest/cheapest solution. The level of reliability you require will depend on the use. Since this doesn't sound like a public safety application, then standard consumer internet service would probably be good enough.

If these two repeaters are within line of sight of each other, you are going to have no end of headaches trying to get them to play well together on the same transmit frequency. I had to take over maintenance on a system where someone had tried to do that with zero design. It didn't work and we moved them to operate on different frequencies. It's MUCH cheaper than building a simulcast system. Simulcast systems are not easy to set up, and they are not cheap.

 

[P25Radio]

IP is available at both ends.

 

[mmckenna]

JPS makes some nice IP interface gear.

 

[Project25_MASTR]

Running digital? Def. need a IP network connection.

Actually, just a serial network is needed. Now most end up transporting that serial network via IP (originally it was done via V.24 modems on a leased line) for practical purposes. Point to point application, this can be done fairly easily with any serial server setup. Multipoint setups will require the use of a multicast capable serial server.

Interestingly enough, the manual actually goes into detail the configuration for running Quantar's back to back for digital operation (similarly to what we've both done using E&M for analog) with just a null-modem serial cable as the interface.

 

[mikewazowski]

Simplest solution is with a couple of Cisco routers with serial cards if you've got reliable IP between the sites.

Keep an eye out for Cisco 1841's with serial cards installed.

 

[petnrdx]

You will find that the "linking" is the easy part.
If the two transmitters have any areas where they BOTH cover, it will not work unless you set things up for true "simulcast".
Meaning, the transmitters must be held to just a few HZ of each other. So probably GPS sync.
Phase difference of the voice frequency audios arriving in the "overlap"areas must be very close.
The delay difference needs to be a few microseconds different between the two transmitters.
And the audio amplitude needs to be better closer than a few tenths of a dB.
So unless you have VERY stable linking, audio delay equipment and GPS sync of the carriers, its probably not going to work.
That's called sloppy-casting. And usually pretty worthless.
Now if these two transmitters have mutually exclusive coverage areas, the suggestions above might just work.

 

[Project25_MASTR]

You will find that the "linking" is the easy part.
If the two transmitters have any areas where they BOTH cover, it will not work unless you set things up for true "simulcast".
Meaning, the transmitters must be held to just a few HZ of each other. So probably GPS sync.
Phase difference of the voice frequency audios arriving in the "overlap"areas must be very close.
The delay difference needs to be a few microseconds different between the two transmitters.
And the audio amplitude needs to be better closer than a few tenths of a dB.
So unless you have VERY stable linking, audio delay equipment and GPS sync of the carriers, its probably not going to work.
That's called sloppy-casting. And usually pretty worthless.
Now if these two transmitters have mutually exclusive coverage areas, the suggestions above might just work.

Sloppy-cast...I've shivered about that since a PE introduced me to it. Multi-cast (conventional voting scan works great for this) or simulcast correctly.

 

[slicerwizard]

the transmitters must be held to just a few HZ of each other

I think that an error of a few Hertz would be a disaster.

 

[kayn1n32008]

I think that an error of a few Hertz would be a disaster.

Equally important is signal phase with in the intended overlap area...

 

[ff026]

In the Quantar manual there is a section on how to link 2 stations using RA/RT. I did something like that years ago but it was cross banded from a UHF quantar to a Low Band M208 and used a controller to change channels on the M208 and control the rebroadcast from UHF to Low band.

In that section it describes how to link the two stations using the 25 pin connector on the back plane of the Quantar.

 

[petnrdx]

I was being "generous".