TheUniversalDave1
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FOREWORD...
Last March, I made a terrific mistake which cost me my beloved Philco 41-231. I have since joined the Alabama Historical Radio Society. They have a very well equipped workshop with all the parts you could ever need. They are also a treasure trove of valuable radio knowledge. I have not been to the weekly Saturday meeting since May, so when I go back there this weekend, intreresting things might happen. IF IT AIN'T BROKE DON'T FIX IT! I picked up this lovely 1942 Philco 42-327 at the flea mall today for only $18.00. That's pretty good compared to the prices on ebay. I will be taking it to the AHRS this weekend in hopes of getting it working again.
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« Last Edit: February 25, 2015, 06:32:06 PM by TheUniversalDave1 »
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toomanybulbs
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nice find. so what went so badly wrong with the first one? they usually are not that bad to get playing. its a series heater set with no expensive power transformer to worry about.
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TheUniversalDave1
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I got this radio working. I took it to the AHRS this past Saturday. I replaced the cord, a few capacitors, and one tube, and now it works good. For the first five minutes of operation, the sound comes in crystal clear, but after that, it starts getting weaker until it becomes unlistenable. I have determined this to be a bad audio coupling capacitor, and possibly a bad audio output tube. I will fix those Saturday.
The bad capacitor is No. 40, and the bad tube is 50L6.
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« Last Edit: September 01, 2014, 09:49:02 PM by TheUniversalDave1 »
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ace100w120v
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I'm also into vintage radios though I know nothing about them. I'd like to find a nice old stereo tuner/amplifier sometime.
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TheUniversalDave1
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I forgot about this thread. I got the Philco 42-327 working good, and it has been going strong since I fixed it in September. I replaced the cord, two tubes, five capacitors, and the dial light.
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« Last Edit: February 25, 2015, 06:32:52 PM by TheUniversalDave1 »
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themaritimegirl
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Cool. What happened with the first radio?
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TheUniversalDave1
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I screwed up the first radio. It was working -JUST FINE- and everybody I talked to said I should replace all the capacitors and electrolytics because "they could short." Well, back then, I had not the foggiest idea how to tackle a radio like that, and I ended up smoking something. I am still waiting for a donor radio to get its chassis. And fix it the -RIGHT- way. Now that I have more experience. Now, I have another project. A 1941 Zenith console that needs a little help. I took it to the AHRS, and it took us all morning to get the chassis out. I'll do some recapping and other minor reworking next Saturday. My radio station is back on the air! (For now.) Now, I can enjoy my antique radios! I wish I could put up a picture of the Zenith console, but the 512 KB limit will not allow it.
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« Last Edit: February 25, 2015, 10:33:36 PM by TheUniversalDave1 »
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TheUniversalDave1
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One thing about the Philco is that it is extremely sensitive. I'm talkin', if you look at it hard enough, it needs to be readjusted. It is extremely picky about where you put it. Hopefully, it will like being on top of the Zenith when I fix it.
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TheUniversalDave1
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I got this ARRL The Radio Amateur's Handbook today while working on my Zenith console radio. It goes into extreme detail on electrical theory of all types. There's some pretty brutal math in there. I'm sure it will help me if I take the same path as TheMaritimeMan.
I went to the workshop this morning and started early on my Zenith. I replaced a few small capacitors, and a 16 MFD 475 volt big capacitor. I checked almost all the tubes and put on a new power cord. I then proceed to "smoke test." So I yell "smoke test!" I powered it up slowly on an isolation transformer, and when I got up to about 50 volts, the current jumped way up. We concluded that the circuit is short.
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TheUniversalDave1
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I've been reading The Radio Amateur's Handbook, and I swear to you, I can't put it down! The storyline is GRIPPING!
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ace100w120v
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Cool! A well-known trick with ANY vintage radio (or TV!) is to not plug it straight into 120v at first since caps, etc. could have degraded over the decades it was unused and go bang when powered up for the first time in decades. A rudimentary way around this is to use what's known as a "Dim-bulb tester" in which you wire an incandescent bulb in series with the radio, etc. Start with something like a 15w bulb (or even 7.5w) and if it glows dimmer than it should you're good. Start working your way up in wattage (say, from 15w to 25w to 40w to 60w to 75w to 100w to 150w and so on) and if it glows at full brightness you have a short somewhere.
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themaritimegirl
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Indeed, the poor man's variac. I do exactly the same thing when testing fluorescent lamp ballasts for the first time.
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TheUniversalDave1
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I used a real variac when I fired up my 1941 Zenith Console, and I'm glad that I did. When I got up to about 50 volts, the current skyrocketed. I shut it down immediately.
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ace100w120v
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Interesting. Did you get any more work done to it since then? Anyone know if a VARIAC will work on a modifed sine wave inverter? (TRIAC wall dimmers get fried by those)
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themaritimegirl
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I would think it would be the same as any other transformer - just fine. I can't say for certain, though.
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