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Model 81 woes....
#1

Greetings to all in Philco land!! I am brand new to this site, but have been rebuilding old radios since i was a teenager. Its a labor of love! I have run into one of "those" that is the oppositte of keep it simple stupid. I have an 81, that will not play for anything! I have completely recapped the unit, using chuck's method of rebuilding the blocks. I replaced all the dog bones, and filter caps. The tubes are very strong, and I have checked all my transformers and all windings are within 3% of dc resistance specs. Soo y does it not pick up stations??? I know my AF amp is fine, having injected a signal into the top cap of my detector/af amp. I checked, I have an oscillator running, and doin the math, it is right on the money frequency wise. I have noticed that the amplitude of my oscillator diminishes as I get towards the high end of the bc band. I have put my signal generator on it, and i have my if signal going into my if transformer (18). It is of adequate p-p amplitude. Coming out and going to my detector, I have almost nothing. With generator maxed out, i can get a barely disernable amt of audio out of the speaker. I replaced my 4 meg resistor (19) as well. What obvious in front of my face problem have i overlooked?? Has anyone else run into this problem? I would greatly appreciate any help on this one.
Rick Icon_smile


Messages In This Thread
Model 81 woes.... - by Guest - 03-12-2006, 06:29 PM
[No subject] - by Guest - 03-13-2006, 03:29 AM
[No subject] - by Chuck Schwark - 03-13-2006, 09:23 AM
[No subject] - by Ron Ramirez - 03-18-2006, 10:20 AM



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