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Philco 71b Filter Condenser Bank Question
#6

Also am yet again puzzled, and still a novice at radio restoration and troubleshooting. I tested all the tubes, this model uses a 42 for audio output, the st type already in the chassis tested bad and quite weak. I only have several Globe type 42's in my stock. It tested good, and I will use it as a replacement for the initial power-up. I first put the set in series with a dim bulb tester just to see if the transformer has any shorts and it didn't as I expected. I did tune the dial to see if I would get anything but didn't, most likely because of the voltage limiter caused by the bulb. I then did a slow power-up with the power cord plugged into a variac. The end result was; all tubes had a glow, there was also a 60 cycle hum heard when I increased the volume pot, it went away when the volume was at zero.

The most concerning thing is that I did not get any other type of noise out the set for those 3 minutes. I am hoping that a full recap of the electrolytics and caps will fix the problem, this is my first encounter with no noise from the speaker on an initial power up.

I also noticed the mica trimmers that come off each section of the three gang available capacitor are still present, but the second one is chipped a bit and the third one is bent up on one side as in the picture. I know there could be quite a few factors contributing but, could this of caused the silence in the set?


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RE: Philco 71b Filter Condenser Bank Question - by Philco281989 - 05-02-2013, 09:09 PM
Help on checking the coils - by Philco281989 - 05-03-2013, 07:04 PM



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