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Maxtrac, Tone Adapter, and MC2500

Posted: Sat Jul 14, 2007 3:16 pm
by alex
I'm slowly building up a MC2500 console setup at home for S&G's, and I'm running in to a problem with a C100 remote and a MC2500, hooked to a Maxtrac UHF. I have a set of 4 TNA200's which I will use once my DB15's arrive in the mail, and I have time to put together the cables. In the mean time, the seller was nice enough to kick me a C100 along with the MC2500, so I made a interface cable to run to the Maxtrac. I hooked up a VHF Maxtrac (which was used in a tone remote configuration in a previous life) which worked out of the box it arrived in, no problems. I can key up, monitor, do everything, and it works fine. It's sitting here on my desk cranking right along.

I purchased a UHF Maxtrac the other week at Sussex, and programmed it up, and matched the radio wide settings for pin assignment to "remote" and programed it up on a channel. Upon connecting it to the C100 remote, and the C100 to the MC2500 - I get instant static over the console, but nothing out of the speaker on the radio. Radio receives perfectly on the programmed channel, speaker is quiet.

So what gives? I popped the cover off the maxtrac to see if maybe someone made a discriminator output, or some other hack, but the 16 pin header inside the radio looks clean, and much like every other maxtrac I've pulled apart.

Any ideas? I played with the settings for the console a bit, but I can't make the static go away, and flipping around the dip switches on the C100 is about as useless as trying to drive somewhere without directions.

-Alex

Re: Maxtrac, Tone Adapter, and MC2500

Posted: Sat Jul 14, 2007 3:37 pm
by xmo
If the receive audio is being supplied from pin 11 on the 16 pin connector, look at the position of JU-551.

Pin 11 provides receiver audio output and depends on the position of JU551 on the logic board near the audio output transistors. When JU551 is installed in position A the output is flat (not de-emphasized) and is not muted by the radio squelch. When in position B the output audio is both squelch muted and de-emphasized.

Re: Maxtrac, Tone Adapter, and MC2500

Posted: Sat Jul 14, 2007 5:37 pm
by alex
Sweet man, thanks!

It works perfectly now. I was thinking it would be a get out your soldering iron and go to down, but was nice to see it was just a standard plastic jumper.

Cool!

-Alex