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Old 09-17-2005, 02:24 PM
Don Lindsly Don Lindsly is offline
Ex-Philco
 
Join Date: Jul 2005
Location: Colorado
Posts: 450
A couple of quick checks. Measure the tuner AGC. It should be about 2 volts negative. If it's much more, it's an AGC problem. There is 12 meg resistor from B+ to tuner AGC to bleed down the tuner AGC voltage. If it is an IRC it probably should be changed.

Also remove the 6AV6 audio amp tube. It is also the AGC clamper. If the weak signal recovers, the tube has heater-cathode leakage and is rectifying the 6 volts AC.

Also I would make sure the 1K RF plate resistor is good. It goes from plate circuit to B+. The B+ is a high resistance to ground and a defective load resistor may not show up in a resistance check to ground.

Don

Last edited by Don Lindsly; 09-17-2005 at 02:41 PM.
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