05-26-2017, 11:00 AM
The schematics are here: http://www.nostalgiaair.org/Resources/118/M0013118.htm
The mystery involves what capacitor values seem reasonable in specific circuit locations. Why? The schematics in Riders Volume two have two different number schemes for the capacitor block (can)!
If you look at the bottom diagram on Philco Page 2-36, you will see the top row, from left to right is 5, 3, 1 and the bottom row is 6, 4, 2. If you then go to Page Philco 2-38 you will see that the top row is 1, 2, 3 and the bottom row is unlabeled ground, 5, 6.
This leaves us with a need to study the circuit and decide which values seem most reasonable in the various locations. That is where I need your help. Specifically:
1) For the capacitor from the low end of the volume control to ground, is 0.5 or 0.15 more reasonable?
2) For the capacitor from after the field coil to ground, does it seem more reasonable that it would be 1.0 or 0.5?
3) For the capacitor from the second (screen) grid of the last '24A tube to ground (across a resistor), does it seem best if it is 0.5 or 1.0?
4) The capacitor from the B+ feed to the primary of the audio push-pull driver transformer is 0.5 either way.
5) For the capacitor connected from the high voltage winding center tap to ground, does it seem more reasonable that the value would be 0.015 or that it would be 0.5 for the 60 cycle radios and 1.5 for the 25 cycle radios?
The mystery involves what capacitor values seem reasonable in specific circuit locations. Why? The schematics in Riders Volume two have two different number schemes for the capacitor block (can)!
If you look at the bottom diagram on Philco Page 2-36, you will see the top row, from left to right is 5, 3, 1 and the bottom row is 6, 4, 2. If you then go to Page Philco 2-38 you will see that the top row is 1, 2, 3 and the bottom row is unlabeled ground, 5, 6.
This leaves us with a need to study the circuit and decide which values seem most reasonable in the various locations. That is where I need your help. Specifically:
1) For the capacitor from the low end of the volume control to ground, is 0.5 or 0.15 more reasonable?
2) For the capacitor from after the field coil to ground, does it seem more reasonable that it would be 1.0 or 0.5?
3) For the capacitor from the second (screen) grid of the last '24A tube to ground (across a resistor), does it seem best if it is 0.5 or 1.0?
4) The capacitor from the B+ feed to the primary of the audio push-pull driver transformer is 0.5 either way.
5) For the capacitor connected from the high voltage winding center tap to ground, does it seem more reasonable that the value would be 0.015 or that it would be 0.5 for the 60 cycle radios and 1.5 for the 25 cycle radios?
Web site: http://www.masekconsulting.net
Radio Photos: http://www.photobucket.com - album id FStephenMasek
