25 LTD Classic

[kiser sosay]

I have a 25 LTD classic with no tx. I have tryed three different working mic's with no difference.

Here are the symptoms so to speak.

Radio powered on I get recieve but is very very quite, both with internal and external speakers. with I tx nothing it stays on recieve. No led change or anything. Now when I plug the external speaker into the p.a. jack
Then flip the switch to p.a., no voice out of p.a. eithet but the audio level in the speaker comes up to where it should be, as it monitors the band. other than this all other switches function as they should.

I have researched this all over the net to no avail. Any help at all would be appreciated.

 

[Robb]

If it doesn't key the transmit when you hit the push-to-talk switch on the microphone; then the mic is not wired properly. Or one of the wires is broken inside the mic's plug. That has been my experience...

 

[kiser sosay]

I've tryed three different working mic's. So that's not the problem, unless the 25's require a different 4 pin wiring setup.

Which they may be, but I thought the 4 pin wiring was setup up the same as most of the other cobras.

tryed my Astatic 636, Road King 56, and a bad new stock galaxy mic, all work on my other radio's

 

[Robb]

I've tryed three different working mic's. So that's not the problem, unless the 25's require a different 4 pin wiring setup.

Unless they are wired to the Cobra standard - it may not work. Did you try using the same mic from another Cobra radio you have? Or from a Galaxy? Or from a Magnum? Or from a Ranger? Or from a Connex? It is a very common mic wiring - so long as you have and use common radios. Just because it is a 4-pin plug doesn't guarantee that it is automatically the same wiring as the 'other' radio you have. Do you have the stock mic for this radio?

I would also invite you to open up the plug on the end of the mic cable - and see if there isn't a broken wire there. It happens to me all of the time...

Cobra 25LTD
Here is the CBTricks web page for the Cobra 25LTD. It shows the mic wiring for this radio to the stock mic - and Astatic, Turner, and a couple of other mic mfr's...

 

[kiser sosay]

Thank's for the quick response Rob.

Sorry should have mentioned the radios, Galaxy DX959, Cobra 148 NW ST, Cobra 29, Uniden PC76XLW.

I can do a little mods here and there. I'm no tech by any means. That is why I turn to thease forums, and reasearch as much on the net as possible. I was just trying to fix it myself. There are not a lot of shop's around my house. It will probably end up being parts. But would be nice to fix.

 

[Robb]

If the mic that is on the Galaxy 959 doesn't work on the Cobra 25; then the radio may well have a problem.
Glad we got that out of the way.
Someone else can now guide you thru to the next step. Might be the switching diode between the TX/RX circuit. Someone with more experience will say for sure!