I had the Philco 645 chassis complete and performing very well. For advice on some electronic details I went to Philco Phorum and got exactly what I needed to know about a mysterious stray wire and the shadowmeter.
Then, two nights ago the radio suddenly, for no apparent reason, went silent. All that I could hear was a couple of stations on top of each other if I hooked up the long antenna and turned the volume to the max.
I checked socket voltages and found a discrepancy in the 6A7--Zero volts at the oscillator grid and 90 volts at the oscillator plate. When the set was working, it had -22 volts and 138 volts. All the other voltages are the same as when the set was working, including the power transformer. All transformer coils show appropriate resistance and continuity. I've checked the continuity of practically every circuit. Also retested and swapped some tubes.
Does the sudden failure and loss of the oscillator voltages point to something I should look into? Any likely, or even possible, causes?
I did query the pholks at the Philco Phorum but haven't seen a reply yet. Maybe I phrustrated them with my questions.
If anyone can help, here's a link to a legible schematic.
https://picasaweb.google.com/lh/phot...eat=directlink
Merci Beaucoup,
Winky