Batboard

I'm trying to interface a LinkComm controller with IRLP node to the
MTR2000. Currently I'm using the configuration shown on RepeaterBuilder.com


Everything is working fine, except I would like the IRLP audio coming in on
the External PTT to have PL tone, just like the repeater audio. I have
tried to connect an external CTCSS encoder to add PL to the audio. When I
do this the MTR2000 does not seem to like it. The PL deviation level either
winds up too low or too high causing a buzz.

We run several repeaters using MSF5000's & Quantars. I been able to
successfully interface to these units but cannot solve the problem with the
MTR2000.

Thanks for your time!

I was involved doing the installation that we later wrote up and posted to Repeater-Builder.
Listed there under "operational quirks" it pretty well describes the issue that you are having.
The only fix I have heard of is do exactly what Motorola does as stated on Repeater-Builder.
They have the interface made by Zetron, but that section is really just a summing amp.
It consists of an LM358N dual op amp and the components to go along with it.
It is just a matter of "mixing" the Mic audio, and a PL generator then feeding the mixed signal into the
backplane connector of your MTR on the correct pin at the appropriate levels and with out an impedance
mismatch that causes distortion.
You might find the schematic or maybe get it from Zetron or maybe Motorola.
Zetrons part number for the interface is 702-9895
Motorola calls it CDN9895A
I have installed several of them on MTR's when using an external controller in addition to the
internal features programmed into the station.

Your other option is to Function Tone the PTT with wireline control.

Your audio then can be match and the station will self generate the PL.

You do need the wireline card though.

CoM

First...Thanks Everyone for your replys....I appreciate your time.

I visited Repeater Builders again and found the new article with the Zetron interface. The article I had was an older one from Repeater Builder. Right now I'm looking into the Zetron interface, which I think will solve my problem.

One question I did have was the REC Audio on the Euro connector. I am feeding the audio into a LinkComm Controller which is a high Z input and an OpAmp. I noticed when I adjust the LinkComm receiver audio level it seems to affect the deviation of the transmitted audio. Is there any special interfacing which needs to be done with the MTR2000 audio from the Euro connector?

Thank You Again...SCJohnie....