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2950 receive not right

Posted: Saturday 23rd Sep 2006, 2:39
by Grasshopper
I stated in the "Shout out" section that I am returning to the hobby after 5 years of absence. I ended up taking the 2950 out of my truck, because it wasn't working right, and put the 148GTL back in. That was about a year before I took all my equipment and packed it away.
Now I want to reinstall the 2950 into my Jeep. The problem is with the RX. The volume level would fad out. I would need to have the radio set at full volume. Then the sound quality would be compromised, very distorted. I also remember that if I hit the bottom of the radio it would come back for awhile. Not the best way to do a repair, I know.
After some time it was worse so I pull it out and put the Cobra back in.
Does anyone know what could have caused this behavier? Any ideas would be greatly apreciated. I really want to use this radio again. Even if I bring it somewhere to get repaired, I at least, want to know what is going on so I don't get ripped off. 73s, John.

Posted: Saturday 23rd Sep 2006, 3:45
by moonshinner
Have you tryed an ext. speaker could be a bad int. speaker. :?: 73

Posted: Saturday 23rd Sep 2006, 9:25
by The Defpom
If hitting the radio gets it to work the problem is most likely to be a cracked trace or bad solder joint, most probably on the audio amp IC.

The IC is bolted onto the side of the radio as it used the chassis as a heatsink, if the side rails are pulled by a mounting bracket it can put stress on the soldered points on the IC, which can break the traces, so it may be a pretty easy repair.

Posted: Saturday 23rd Sep 2006, 9:32
by Grasshopper
That's good news!!!! I hope it is an easy fix. It even sounds like I could do the repair myself. I have modified maney radios, with the use of books. I am only an ametur, by no means am I an expert. But, it does seem like I accually might be able to do this myself. Thanks a lot for your help. 73s, John.

Posted: Saturday 23rd Sep 2006, 14:13
by kwc
You may want to check all of the chassis ground connections around the outside edge of the main circuit board for poor or cracked solder joints. The early 2950's were notorious for bad grounds. My 2950 had a similar problem and I found one of the ground connections had gone bad.

Posted: Tuesday 26th Sep 2006, 14:48
by thetnhillbilly
I think I remember someone with that radio having the same problem. The problem showed up after they had modified the radio and in doing so replaced the ceramic insulator with a mica (or mabey vice versa), anyway once they went back to the stock spec insulator the problem went away. If memory serves me, but you know how that can go.

Posted: Wednesday 27th Sep 2006, 4:39
by Grasshopper
Oh, yes, I do know how that goes. I haven't used the radio in about 5 years and had to try to remember what was wrong with it. :lol:

Posted: Tuesday 6th Feb 2007, 10:15
by SoCal392
well, my 2950 used to do the same thing. the first time it happened, i found that the ext. spkr switch that turns off the internal spkr was'nt making contact because of residue buildup. second time, was a simple case of the pcb screws being rattled loose. hope this helps

Posted: Wednesday 7th Feb 2007, 0:05
by Grasshopper
I forgot about this post. Thanks for the info. The problem still exsists. I haven't had time to take a look at the radio like I wanted. I've been busy buying old trucks. :lol: I have two 1967 F350's and a 1971 F100. I've been making one good F350 from two not so good ones. Maybe I'll have time before spring, to look at the radio. Thanks again, I'll keep your suggestion in mind.

P.S. I have a 1972 Royce that I'll be putting into the F100. Should be cool, I like old school.