02-23-2007, 06:09 PM
UPDATE: Having finished the electrical restoration of the radio, I can definitely say one thing for sure: IT WON'T WORK WITHOUT THE SHIELD! The IF amplifier breaks into oscillation if peaked and the shield is not in place. This radio has no RF amp and gets all its gain in the 2 IF amp stages. The second stage runs wide open - no AVC is applied.
By the way, this is one hot radio. I think is works even better than the 16B (but of course, the audio is not as good).
So now I am leaning toward a field modification. Perhaps there was a later service note or a change that was not in the service pack I purchased. I don't think the original shield design worked that well. I cannot imagine why Philco did not simply use normal separate tube shields like were installed on the oscillator and 1st audio stages.
By the way, this is one hot radio. I think is works even better than the 16B (but of course, the audio is not as good).
So now I am leaning toward a field modification. Perhaps there was a later service note or a change that was not in the service pack I purchased. I don't think the original shield design worked that well. I cannot imagine why Philco did not simply use normal separate tube shields like were installed on the oscillator and 1st audio stages.
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