VHF MSR2000 to M120 VHF Radio

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Vercomm
Posts: 429
Joined: Mon Apr 12, 2004 7:00 pm

VHF MSR2000 to M120 VHF Radio

Post by Vercomm »

Hi guys,

I have done a couple searches on the MSR2000 and have not found the info I am looking for. I am new to the MSR2000 but have done quite a lot of work with all other kinds of moto repeaters. To tell you the truth I have been a little scared of this unit (so many pins, cards, jumpers etc....). I have a 30watt VHF MSR2000 repeater. I do have the Control & Audio manual and the Station Manual.

This is a working repeater and I want to connect an M120 VHF radio to it. The station has the following:

R1 Audio - TRN9689APR
Squeltch Key - TRN5324APR
DC Transfer TRN5254APR
Station Control Module - TRN5321APR
Line Driver TRN5235APR


Following is a description of how I'd like to have the setup work.

When the MSR receives a signal I'd like to have it output go active low and key up the M120( I'll use Pin 3 on 16 pin). When the M120 receives a signal I'd like the Active low Output of Pin 7 to key up the MSR. I'd like audio to pass both ways.

Should I be using a external controller of some kind or can I use just the MSR and M120.

This MSR has previously had and old crappy phone patch connected to it. On the back plane of the repeater it is connected to the following points:
E1
E2
E7
E8
E12
E16
Pin 20 - R1 Card

Your help is much appreciated.


Jamie
User avatar
Vercomm
Posts: 429
Joined: Mon Apr 12, 2004 7:00 pm

Post by Vercomm »

To correct, not pin 7 of M120 for COR Pin 8!!
George
Posts: 266
Joined: Wed Apr 16, 2003 11:14 am
What radios do you own?: X9000, HT1550XLS, MTS2000, etc

Post by George »

Others may disagree, but the easiest way to go about this is to use a remote adapter on your m120 and give it a 600 ohm level of interface.

You can even use an old remote adapter from an old base station and wire the transmit side into the microphone jack and grab the audio from the 16 pin output.

Wire the line side of the transformer to the line one output from the MSR2000. Get it? You have three windings, one for m120 transmit, one for m120 receive and the last for the phone line.

Set the m120 for a 0db line out at full system deviation.

Set the MSR for 0db in for full system deviation.

Set the MSR for 0db out at full system deviation in.

Okay, that takes care of the audio.

For control, I would look at the print for the squelch gate and see if the points are on the board for a relay. Don't use the relay, but look for a way out of the board on a spare pin. You may have to use a transistor to key the m120. There is a place on the squelch gate to get a signal that will key the transistor and make it follow with the incoming carrier from a mobile.

I don't have a manual in front of me, but you do and you should see a way to do this. There should be a screw that you can get a way to get a cable out of the MSR to the m120.

Now, to key the MSR is a bit of a trick. You need to use the line PTT input. I think this works a bit different than the Micor where you have to add a diode to the dc transfer board to make the audio path open up.

Try grounding the line ptt input and see if you can put a tone in the line 1 input.

This is a great simplification of the process, but it works because I have done this in the past with Micor stations and it works wonderfully. Audio is standard and sounds good and clean.

George
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