The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Hey, I have a galaxy dx959 bipolar type that has a strange problem. It is in my car, and it is affected by the ambient air temperature. When it is cold outside, I have no problems, but when it gets warm or hot outside the radio will quit modulating if left on for about 15 minutes. I reheated some of the joints, but that didn't fix it. It has been doing this ever since I bought it. I think that it is strange that it will only act up when the ambient air is warm to hot, in cool to cold weather it won't act up no matter how long I leave the radio on. With spring and then summer around the corner, I'm hoping someone knows the solution.

i had a radio done the same thing....was a crack in the solder...sounds like you have already tried that

I would first try replacing C154 .22u, as this cap can give some strange problems.
When the problem arises, it would be a good idea to try a PA test.
Is the problem the same on SSB?
Let us know how you get on.

Sorry it has taken me so long to update, I don't have internet at the house anymore and things have been hectic too. It is having the same problem on PA. When I opened it up to look for C154, I noticed that it had been changed to another value, and some other components had been changed also. Unfortunatly I haven't had time recently to go through and catalog all the changed parts. I would like to do that, and get your opinion on what mod has been done, before I replace the parts or change back to stock (whichever ends up being best). Rick, thank you so much for your help, and I hope you will be patient with me while I try to find time to get things together.

Working on a dx959...the mic amp chip (4558) output is noisy when cold...better when hot, but not good. 4558 on order, will post results.

4558 was bad. ssb tx shows a substantial increase in average power, pep power remains the same.