I'm gonna try once more with the antique radios
 

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 42-372 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.

That'll be a pretty schnazzy Philco when you get it done, don't get discouraged if you don't get it working right away its just a hobby it doesn't matter if it takes all year.

The model number is really 42-327, listed on Philco Radio.com.
Another fun Philco, to restore. Patience is really a virtue here. More rubber wire here. I hope the speaker is good on this one.

Oops. I mixed the numbers up.

I got this radio working today. My favorite AM music station has sadly dried up, so I have nothing to listen to until midnight. I've been told that there are small AM transmitters that can be plugged into an MP3 player or smartfone. Does anyone know anything about that?

I've been listening to Coast to Coast for the past hour, and I've noticed a strange phenomenon with this radio. For the first five or six minutes of operation, George Knapp comes in crystal clear. After six minutes have past, the audio slowly starts to degrade. Until after eight or nine minutes, the volume is turned halfway up, and the sound is extremely scratchy. I'm fairly certain that this is a tube. If I turn it off and let it cool down, then turn it back on, it sounds good again and the cycle repeats.

The audio coupling capacitor is leaky, driving the output tube grid positive.
The output tube is probably bad too.
That cap has to be replaced, first. :sigh:

Is there an easy way to indentify this capacitor? I plan to go back to the AHRS this Saturday and clean all the tube holders, check all the tubes on the military tube tester, and replace a few capacitors. Not to mention fix the dial cord.

The audio output tube is a 50L6... one end of the cap will be connected to pin 5 of this tube, the other end to pin 2 of the 7C6 detector/audio amp.

jr

Thank you.

Looks like I found the problem.

That's the cap, #40 on the schematic.
Replace it before you go to the meet! Then try it. Even if the tube is questionable, there should be an improvement. You still might have to replace the tube, for best results.

I have neither the materials nor the space to properly replace a capacitor at this time. I always wait until Saturday before I start any work on my radios.

I replaced the 50L6 tube with a known working genuine Philco tube, and that solved the problem. The doofus who owned this radio didn't insist on genuine Philco tubes. The tube at fault is an RCA Radiotron Electron tube.

First I want to say that it must be absolutely wonderful to have a place that you can go with all this equipment, parts and knowledgeable people. Weekly meetings and all. My mom is from Shelby, Alabama. Makes me wish I was there because in most places it seems like most people are just worried about the latest 'smart' phone!:no: I always feel like the only backwards a** person in existence anywhere around here that gives a darn or knows about old radios and TVs. TV collecting really can get you the hairy eyeball! LOL!

Finally, that previous owner just bought whatever tube he could find at the local dime store or repair shop. RCA made great tubes; so did Philco. The tube just went bad....