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F-1740 Alignment/Diagnostic Advice Needed.
#1

I have recapped and changed resistors as required, installed a solid state vibrator and added new buffer cap. I have 212v at the rectifier. The manual oscillator coil was open, fixed that and the tuning condenser came to life. My problem is that I can only receive at 1570 kc and 1120kc at the same time and nothing else anywhere on the dial. When the presets are selected, nothing on the first 2 (580 to 1050kc) 3 is a weaker version of 4 and 5 (900 to 1580) which are loud and clear with 2 stations which sounds exactly like manual dial. The 1570 is a very strong local station. I noticed that the 2 station I receive are 455 kc apart. Alignment? The Philco sheet says to send 455kc thru .1mf cap to the antenna receptacle. I did that and the maximum output is where I have it, but no change in reception. I really like to figure as much of this kind of stuff out myself, but this beyond my diagnostic ability. Thanks for your thoughts
#2

Double check to see that the oscillator is running. You should have a little bit of - voltage on the control grid of the mixer tube like a volt or 2.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry




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