Spectra PTT Signalling

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BikerScout
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Spectra PTT Signalling

Post by BikerScout »

Ok, I have one that has my radio tech stumped.
I have a T84FWA7HA4AK radio that no matter what the tech turns off the radio broadcasts a either a DTMF or MDC signal at the beginning of the PTT cycle I can't tell which. Even when PTT ID is turned off in MDC Signalling Options and Everything Disabled. He doen't work on spectras very often so he really can't figure it out. The radio is a MLM 6.15 and the head was changed to a A5.
Anyone have any ideas? I will see him again on tuesday.

Bryan
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Post by 911-EMT »

is it only on one mode or on all mode's?
BikerScout
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Post by BikerScout »

It's on all the modes.
jmr061
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Post by jmr061 »

I recall seeing a similiar post a while back. Open up the radio and look for any aftermarket boards being added in. Its possible its GE Star or another non-motorola signalling device.

Jason
BikerScout
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Post by BikerScout »

Funny You should say that. Now that I think of it, It does sound like a GE-Star. I thought that was what I was hearing things. It sounds like this.
http://www.kb9ukd.com/digital/ge-star.wav
Don't know how many times I played those file trying to figure out what I was hearing.
Thanks Jason. I might head outside and pull the radio. Any advise on how to pull it without messing things up?

Bryan
jmr061
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Post by jmr061 »

Disconnect power from it and pull the top cover off with the two torx screws. That give access to the command board. If the add in board is anywhere I would imagine it would be connected to the command board.

Jason
BikerScout
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Post by BikerScout »

Do I just unsolder the wires?

Bryan
jmr061
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Post by jmr061 »

Ive never dealt with one. If there is one there see if you can find a manufacturer name on it. And maybe someone can come up with the install instructions. Hopefully it is as simple as unsoldering the wires but its always possible some chip jumpers, etc were changed.

Did you look to see if there is something there?

Jason
BikerScout
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Post by BikerScout »

Yup, it is sitting right next to the MLM. Looks like someone did a real nice install. I just had to unplug it. I left the wires on since they had a nice connector on the end. If I ever decide to reinstall the board it will be a plug and play option.
I can't wait to let my radio tech know how easy it was to fix. We never opened the radio up to see if anything was installed. Just figured it was software/code plug problems.

Bryan
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Post by kb3jkp »

I want that module!!! lol
BikerScout
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Post by BikerScout »

Here are some pics of that blasted little board that caused me and my radio tech soo much grief. Just to the right of MLM board with all the little wires running to it. All I had to do was unplug it. About One square inch big.

Image
Image
Image

There are some more chips on the bottom with more surface mount components. When I started to pull the double sided tape off it looked like I was leaving a lot of residue. So I just left on.

Bryan
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