Quantar with External Controller

This forum is for discussions regarding System Infrastructure and Related Equipment. This includes but is not limited to repeaters, base stations, consoles, voters, Voice over IP, system design and implementation, and other related topics.

Moderator: Queue Moderator

Post Reply
MikeOxlong
Posts: 161
Joined: Tue Feb 03, 2004 12:46 pm

Quantar with External Controller

Post by MikeOxlong »

Folks, I'm trying to replace an old analog MSR2000 and custom controller with a Quantar and external controller.

There's nothing fancy on the MSR.

We've got dtmf commands to shut it on and off and dtmf commands to fire up a link radio.

The courtesy tone is a beep during unlinked operation and a boop during link operation.

The controller handles the CW ID.

Pretty simple stuff.

I've got a Quantar sitting here which I'd like to throw into service to convert the repeater to analog/P25 operation.

At this point, it looks like I'll have to keep the internal Quantar controller if I want to repeat P25.

The controller would only be used for linking.

I've got a 4 wire WLIB installed in the Quantar.

Does the P25 raw data appear on the WL out or is it analog only? Hopefully it's only the analog voice which would get passed to the controller.

Is the External PTT still available on the backplane even if the Quantar is still set up as a repeater?

Any advice or gotcha's that I haven't considered?

TIA.
User avatar
Bill_G
Posts: 3087
Joined: Thu Sep 17, 2009 5:00 am

Re: Quantar with External Controller

Post by Bill_G »

Yes. PTT is available on the backplane. Towards the back of the service manual are the drawings showing pin assignments on the variety of connectors. Getting those pins to work is a function of the programming in the RSS, and can be a lengthy discussion.

All P25 repeaters I've seen also had a DigiTAC comparator, and the Quantar wireline board had a modem daughter board to maintain a secure connection to the comparator. I don't know if a Quantar will repeat P25 internally, and I don't know what appears on the line 1 and line 2.
MikeOxlong
Posts: 161
Joined: Tue Feb 03, 2004 12:46 pm

Re: Quantar with External Controller

Post by MikeOxlong »

Bill_G wrote:Yes. PTT is available on the backplane. Towards the back of the service manual are the drawings showing pin assignments on the variety of connectors. Getting those pins to work is a function of the programming in the RSS, and can be a lengthy discussion.
Yup, I know it's available and I've seen the recent thread on it. What I want to know, is if I leave the Quantar setup as a repeater, is that function still available on the backplane?
Bill_G wrote: All P25 repeaters I've seen also had a DigiTAC comparator, and the Quantar wireline board had a modem daughter board to maintain a secure connection to the comparator. I don't know if a Quantar will repeat P25 internally, and I don't know what appears on the line 1 and line 2.
Yes, a Quantar will repeat P25 internally. I've got one working now as a standalone analog/P25 repeater.

The daughterboard was probably a v.24 modem which allowed the P25 data to pass to the comparator.

What I want to add is an external analog controller that will allow control and routing of analog audio between the Quantar and a link radio.
User avatar
Bill_G
Posts: 3087
Joined: Thu Sep 17, 2009 5:00 am

Re: Quantar with External Controller

Post by Bill_G »

I'm sure you're not breaking new ground with this project, but I don't know for certain if a Quantar will do what you ask. You'll probably be able to tell us soon enough. Hopefully you can test bed this in the shop before you accumulate a bunch of windshield time to find out it won't do what you want without some serious McGuivering.
MikeOxlong
Posts: 161
Joined: Tue Feb 03, 2004 12:46 pm

Re: Quantar with External Controller

Post by MikeOxlong »

Plan is to have it fully working on the bench before it gets moved.

It's replacing an msr2k that's already in service so until it's fully working, the msr will continue to plod along.

In reality, I'd prefer to have this as a standalone machine but repeaters pairs are so scarce, I'll have ton reuse an existing pair.
User avatar
xmo
Moderator
Posts: 2549
Joined: Fri Oct 12, 2001 4:00 pm

Re: Quantar with External Controller

Post by xmo »

You can interface a mixed mode Quantar to an external ham controller and have the conrtoller pass analog traffic over the Quantar but the controller won't be able to pass digital traffic in either direction. That means you will have to decide how to deal with the fact that whatever is on the other end of the link won't know if the Quantar is engaged in a digital QSO. Link traffic will either go nowhere or else interrupt the digital QSO.

The ideal thing would be to acquire a DIU and interface it between the Quantar and your repeater / link controller.

With a DIU your controller can voice ID the P25 repeater in digital and you can pass link traffic out through the Quantar in either digital or analog modes as well as pass either digital or analog traffic on the repeater back down the link. You can configure the system to force traffic coming up the link to go out the Quantar in either digital, analog, last active mode, or user selectable [such as by a certain PL on the link]
MikeOxlong
Posts: 161
Joined: Tue Feb 03, 2004 12:46 pm

Re: Quantar with External Controller

Post by MikeOxlong »

Anybody have a DIU real cheap?

The DIU would be the best solution but it would probably cost as much as the Quantar.

Too bad there's not a signal available on the backplane to denote a P25 conversation.

Perhaps two channels with the same frequency but only one has the valid analog PL with a bogus NAC and the other has a bogus PL and valid NAC.

Use a Wildcard table to detect the channel with the valid NAC and trigger an output line as a pseudo digital COS?
User avatar
N4DES
was KS4VT
Posts: 1233
Joined: Thu Dec 25, 2003 7:59 am
What radios do you own?: APX,XTS2500,XTL2500,XTL1500

Re: Quantar with External Controller

Post by N4DES »

Wouldn't it just be easier to put a SAM card in it?
User avatar
xmo
Moderator
Posts: 2549
Joined: Fri Oct 12, 2001 4:00 pm

Re: Quantar with External Controller

Post by xmo »

The Station Access Module would eliminate the need for an external controller and would be the top choice for an integrated 'all-Motorola' solution.

I didn't recommend it because the SAM can be a challenge to program and the cost of a SAM plus RSS for the SAM would be a lot more than a simple linking controller.

The controller choice is a separate consideration from issue of a DIU which would be necessary if there is a requirement to have the link operational for both analog and digital users on the Quantar.
Post Reply

Return to “Base Stations, Repeaters, General Infrastructure”