Cobra 29 unstable dead key

[Illahe]

Hello all,

Cobra 29 LTD 1993 manufacture date. Dead keys 4 watts when turned on and swings 8-10 pep. After a few moments the dead key drops to 1 watt and it swings 5 watts pep. Any suggestions on troubleshooting the radio are appreciated.

 

[doffo]

Unsure if it will help, but maybe heat related? Possibly a cold solder joint somewhere? Gently push around the board with a plastic tool when it happens to see if the deadkey watts jump back up... Just an idea to try. Otherwise, hoping its not something else more severe.

 

[doffo]

Now that I think about it, My Galaxy 99v does randomly drop power... Comes back randomly. I did try to poke around the board, but it was still acting up. I will need to take a much closer look at each solder joint.

Another Uniden PC66XL radio I bought at auction for a couple dollars wasnt working. It wasnt until one particular solder joint looked a bit off, and after adding a little more solder, receive came in nice and loud. I fixed a couple more PC66XL radios like this.

 

[DTB Radio]

You will want to document signal levels at different points in the transmit circuit chain when the radio is operating properly, then compare them to the ones you see when it falls off. This should narrow the problem down quite a bit.