42-340 - looking for electronics update/repair - Printable Version
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+--- Thread: 42-340 - looking for electronics update/repair (/showthread.php?tid=13552)
42-340 - looking for electronics update/repair - LET-UT - 11-24-2015
I purchased a beautiful 42-340 a few years ago when I lived in California. The cabinet is pristine, and the radio played well. . . until I shot some electronics cleaner into it. (Yes, I've learned a whole bunch of lessons.)
Anyway, I still have this pristine looking radio but need to find someone who can diagnose and repair whatever I've done. Right now it's just static coming through. At the same time as the diagnosis/repair, I'll happily pay to have it brought up to safe standards with new capacitors and whatever else is needed.
I'm in Northern Utah, just outside of Ogden. Does anyone here know of either a good Utah source, or is there somewhere I should ship my radio to? Thanks in advance. (I can post photos if it's of any help.)
RE: 42-340 - looking for electronics update/repair - Phlogiston - 11-25-2015
I can tell you what is probably wrong with it.
The volume/tone/other controls used in Philcos are often easily damaged by many types of contact cleaner. It actually removes the conductive/resistor coating. Only the plastic safe (green) type of Deoxit should be used - if any is used at all.
RE: 42-340 - looking for electronics update/repair - klondike98 - 11-25-2015
Russ, thanks for that info. I did not know that and have been using the D5 Deoxit. After reading your post I found the following info on the deoxit line on the Craig website. Might be useful http://store.caig.com/s.nl/it.I/id.73/.f
RE: 42-340 - looking for electronics update/repair - klondike98 - 11-25-2015
HI LET_UT
Welcome to the Phorum!
Here are a list of a few radio repair folks that Ron has listed on PhilcoRadio.com
Other folks may have other experiences and post some suggestions for you.
I don't see any Utah based antique radio clubs but there are a number of HAM related folks and often some overlap so you may also be able to connect with someone in the area with some troubleshooting skills. See: http://user.xmission.com/~uarc/other_clubs.html
When you say the radio was recapped does that mean you see some electrolytic caps added under the chassis. If so they may be an old recap and you could be in need of a total recap job.
RE: 42-340 - looking for electronics update/repair - LET-UT - 11-25-2015
It hasn't been recapped yet, I'm thinking it's probably a good idea as part of any repair.
RE: 42-340 - looking for electronics update/repair - klondike98 - 11-25-2015
Ooopps... I was mixing your post with another one regarding the recapping...
RE: 42-340 - looking for electronics update/repair - Arran - 11-27-2015
Testing a volume control, or any other potentiometer, is fairly easy. All that one needs to do is connect an ohm meter across the two outside terminals, with the meter set to the appropriate range, lets say 1,000,000 Ohms, and see what comes up. If the control measures as something close to what it should be, lets say a 500,000 Ohm control measures in at 550,000 or 480,000 ohms, then the resistive element is probably still good.
The next test is connect on Ohm meter lead to the center terminal of the control, and the other to one of the two outside terminals, then to rotate the shaft, and note the resistance measurements as you rotate it, then switch it from one outside terminal to the other. The resistance should change in value fairly smoothly, not abruptly go up or down in value. I should mention that on volume controls the resistance is not usually linear, it has what is called a logarithmic taper meaning that the rate that the resistance changes at the lower end of the control is less then at the top end.
I have not heard of Philco controls having an issue with the resistive material washing away with some solvents, I would think that spraying them with an alcohol based cleaner should be safe enough.
Regards
Arran
RE: 42-340 - looking for electronics update/repair - codefox1 - 11-27-2015
Agree with all. Sometimes, a mechanical problem causes the shaft to "bump" the rotor part just enough to cause a problem. A tiny drop of WD40 allowed to soak into the junction of the shaft with the body and a few dozen gentle back and forth min to max twists can help rule this out. I have not killed a control yet with Deoxit 5, but there's always a first time.
RE: 42-340 - looking for electronics update/repair - LET-UT - 11-28-2015
(11-27-2015, 12:18 AM)Arran Wrote: Testing a volume control, or any other potentiometer, is fairly easy. ...I would think that spraying them with an alcohol based cleaner should be safe enough.
Thank you! I'll give it a try this evening.
RE: 42-340 - It's alive, I tell you, ALIVE! - LET-UT - 12-05-2015
[Video: https://youtu.be/WIkO_mTDl0Y]A wonderful gentleman in out local Odgen Amateur Radio Club took my old Philco and put the breath of life back into it. He called this afternoon and I just picked it up. I'm beside myself with joy as I listen to this old unit. It picks up AM and Shortwave. I was surprised that I was able to pick up Radio Havana Cuba without even putting on a long wire antenna!
Thanks to all for the various suggestions and inputs.
RE: 42-340 - looking for electronics update/repair - Eric Adams - 12-06-2015
The suspense is killing me! What did he do to get it working?
RE: 42-340 - looking for electronics update/repair - LET-UT - 12-06-2015
(12-06-2015, 06:45 AM)Eric Adams Wrote: The suspense is killing me! What did he do to get it working?
You realize you're asking a technical question of quite possible the dumbest man on earth. . . He told me that he pulled the chassis from the case, hooked up the radio to his oscilliscope to see what it was doing, and then applied power when it all looked good. - It started right up for him so he put it all back together. Like I said, he's wonderful, and I'm stupid.
RE: 42-340 - looking for electronics update/repair - Eric Adams - 12-06-2015
Oh
RE: 42-340 - looking for electronics update/repair - LET-UT - 12-08-2015
(12-06-2015, 09:42 PM)Eric Adams Wrote: OhI really wish I could explain what he did, but truthfully, I have no idea. I've been able to listen to it for a couple of days now and am still as giddy as a little kid in a candy store. The whole experience has served to remind me that there are MANY people in this world who are much smarter than I and, and who give of themselves quite freely. I'm very grateful for this man's act of kindness.