08-23-2014, 11:52 PM
I'm happy to report my old nemesis, the Philco 66, started playing radio signals at 10:30 PM CST. I had pulled the o/c. coil again to check resistance at the lugs and out of circuit, the long coil ohmed at 3.4, the small one in the middle ohmed at .8 ohms, and the larger wire short one at the bottom ohmed at 0 ohms. That sounded sort of reasonable to me and I can't see any of the dreaded green patches everyone talks about. I started cleaning it up so I could see the connections of the coils to the lugs better, and I decided to see what would happen if I removed the 70 ohm resistor across two of the lugs the service notes say should be in series with C14. I replaced it with a short piece of 22 gauge hookup wire. Just to see what would happen, I put the coil back in, replaced all the connections taking care to make good physical contact and strong soldering. Took a breath, plugged it in, turned it on, and got a buzzing noise at the high end of the scale. I turned the tuning cap to the middle and got static, turned it to the low end, and got a preacher telling me to read the Bible. I wound out the 10' antenna I had on it, put on a ground, and the dial cleared up significantly.
I still get buzzing between stations that disappears when tuned to a station and the volume at full is not that loud--but loud enough to fill the small room where my bench is, but the radio tunes across the dial, now. The buzzing is worse at the high end of the scale. I will take more complete voltage readings tomorrow, but the 6A7 grid cap puzzles me: it read at about .6 v positive voltage.
Thank you, Mike. Enjoy what's left of your vacation. Thanks to Mondial and Ron and Warren as well. My to do list is 1) Align this set as soon as possible, 2) find what voltage gremlins I have left, 3) clean up some more, 4) experiment with tube options for the best sound.
I still don't trust my signal generator, but I was able to get channel B to produce zero beat at 1200 and at 580 to day and repeat the operation, so I guess at least channel B is usable.
Advice on how to proceed, anyone.
I still get buzzing between stations that disappears when tuned to a station and the volume at full is not that loud--but loud enough to fill the small room where my bench is, but the radio tunes across the dial, now. The buzzing is worse at the high end of the scale. I will take more complete voltage readings tomorrow, but the 6A7 grid cap puzzles me: it read at about .6 v positive voltage.
Thank you, Mike. Enjoy what's left of your vacation. Thanks to Mondial and Ron and Warren as well. My to do list is 1) Align this set as soon as possible, 2) find what voltage gremlins I have left, 3) clean up some more, 4) experiment with tube options for the best sound.
I still don't trust my signal generator, but I was able to get channel B to produce zero beat at 1200 and at 580 to day and repeat the operation, so I guess at least channel B is usable.
Advice on how to proceed, anyone.
Charlie in San Antonio