06-20-2011, 04:00 PM
Kinda sounds like an AVC problem. When tuned to the shortwave bands, tthe average audio signal levels are much lower than standard AM powerhouse stations that will normally generate a sufficientAVC voltage to crank the front end gain back.
On SW, the AVC can be low to non-existant, causing the RF/IF strip gain to be "wide open" and can cause distortion in the mixer/local osc section or IF stage(s).
You don't mention fully re-aligning the set according to the service info. This can be critial to best AVC action. If you replaced ALL the caps in the set, then including the bakelite block caps, you could have a mis-adjusted IF or off-value or open resistors on the AVC buss that have not been checked and/or replaced when you restored. An open or way off value resistor in the AVC line could be suspect.
Chuck
On SW, the AVC can be low to non-existant, causing the RF/IF strip gain to be "wide open" and can cause distortion in the mixer/local osc section or IF stage(s).
You don't mention fully re-aligning the set according to the service info. This can be critial to best AVC action. If you replaced ALL the caps in the set, then including the bakelite block caps, you could have a mis-adjusted IF or off-value or open resistors on the AVC buss that have not been checked and/or replaced when you restored. An open or way off value resistor in the AVC line could be suspect.
Chuck
Chuck Schwark,
The Philco Repair Bench
[Image: http://www.philcorepairbench.com/images/philog3tiny.gif]
http://www.philcorepairbench.com
