I have a GE clock radio model 60 that was given to me http://www.nostalgiaair.org/pagesbymodel...007714.pdf 17-16 Page 3 is the proper print.
the tubes all test good, and I recapped, checked the resistors and replaced one the voltages all come out ok. The radio plays good until I get these bursts of static which happens with the volume either up or down makes no difference.
I can't seem to find the source I have done the following
replaced all the tubes one at a time
checked for loose connections cold solder joints
cleaned the tuner and checked the plates and it doesn't seem to make a difference as to position
wiggled and tapped everything I can get to.
Do I have a silver mica problem?
I haven't opened the IF's yet that is probably next!
Any help would be appreciated
Sounds like Silver Mica Disease in the IF's.... unfortunately it is getting more common as sets of this vintage age. Do a search and you'll find out more than you ever wanted to know about it
(10-27-2015, 05:22 PM)Eliot Ness Wrote: Sounds like Silver Mica Disease in the IF's.... unfortunately it is getting more common as sets of this vintage age. Do a search and you'll find out more than you ever wanted to know about it
I have disassembled both IF cans the trimmers are of the type where 2 plates are separated by a piece of mica and a screw going through the center. I took all 4 apart and saw no evidence of the silver mica disease the mica looked like a pane of glass nice and clean. I cleaned all 4 assemblies and put them back together, it made no difference. Next I cleaned the ant and osc trimmer on the tuning capacitor. Still have the problem.
Any thoughts or suggestions on where else to look?
Did you clean the tube sockets with DeOxit and the tube pins? There might be some dampness some were let it play for 30-45 minutes and see what happens. Or just call GhostBusters !
Could be a "noisy" resistor which cannot be tested. Can't be all that many, for a few cents apiece, replace 'em. Also, stating the obvious, but anyway for everyone out there, move set to other rooms, see if a dimmer or other "modern" device(s) are contributing to problem.
I have a 60 also, recently acquired, thanks to Epay. I also have the model just a little newer. Only difference I can see is that is uses 35W4 and 50C5 tubes instead of the 35Z5 and 50L6. Have you found the problem yet? Thoughts on the problem: This radio originally used metal tubes in all but the Rectifier and Audio out. Does it have glass tubes instead and could it be a shielding problem? Can you produce the problem by making interference intentionally? Have you tried using a signal tracer to find the source? A bad "NEW" cap? Bad ground? Intermittent and static problems can be miserable! My 2 cents...
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
There are two common modes of failure with the mica caps inside those mini IF cans, sometimes made by K-tran but not always. First is the silver migration problem, where the silver spray starts to migrate towards that brass rivet in the center and cause leakage. Second is that the actual connection between the silver on each side of the sheet and the legs on the IF can become open or intermittent.
I highly recommend ruling everything else out first ahead of the IF cans if you are getting crashes of static, starting with dirty tube sockets, followed by faulty paper caps, resistors, and solder joints. Opening up one of those IF cans and taking the micas out of it is a PITA. If you want to learn about replacing them then you are in luck, shango066 on You Tube has just started a series repairing a radio with this problem, though it's on the FM side.
Regards
Arran
Had to put this aside as I was going nowhere fast. I decided to take a fresh look as to what I checked and replaced and the only thing I didn't do anything to were the mica caps. It only has three so I lift one end on each and check the value the only one that stood out was C-19 220pf it read 315pf not bad but it was out enough to warrant a change so I replaced it and BINGO! that was it I don't think it was so out of speck that caused the static as I think it was breaking down Any thoughts?
I am not sure but I had SMD in my Halli and even if it was not and they were clean...If I had them open I would have replaced them. You cant always see the problem. Mine were ok in one but tainted in the other. Still replaced all 4 and now it will last another 70 years without issue.
I am glad yours works now though. I am going to get one since I like clock radios and recently was given a great AD for one. I may go to the local Staples and have it scanned. If you ant a copy please let me know.
Kirk
(01-24-2016, 01:16 PM)OldRestorer Wrote: I am not sure but I had SMD in my Halli and even if it was not and they were clean...If I had them open I would have replaced them. You cant always see the problem. Mine were ok in one but tainted in the other. Still replaced all 4 and now it will last another 70 years without issue.
I am glad yours works now though. I am going to get one since I like clock radios and recently was given a great AD for one. I may go to the local Staples and have it scanned. If you ant a copy please let me know.
Kirk
Thanks I would, I have the white one also have the one on the bottom of the flyer
Eric
Eric, I wondered if you had made any progress on your model 60? Been reading and watching you tube videos about the silver mica disease. Interesting...
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
I've used a signal tracer to locate the problem. Use it in the rf mode and check the IF transformers. Use it in the audio mode to have a listen after the detector stage.
Happy Hunting!!
Terry
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