01-25-2026, 01:34 PM
The 660 2nd IF transformer is unique in that it's triple tuned where most are double tuned. This is used to sharpen the selectivity. As for using a replacement you can probably retune a 455kc can up to 460kc or grab a 460kc can. The only caveat is that it needs to be either an input or interstage transformer not the output. It's designed to match a low impedance diode load not a high impedance grid. Will it work as good as the original probably not.
https://philcoradio.com/library/download...%20223.pdf
ps Service note the local oscillator adjustment for the bc band and the pol band are reversed to the chassis pictorial. Drove me nutz for a long time as I couldn't get the top end of the bcb to align because I was adjusting the pol band trimmer.
https://philcoradio.com/library/download...%20223.pdf
ps Service note the local oscillator adjustment for the bc band and the pol band are reversed to the chassis pictorial. Drove me nutz for a long time as I couldn't get the top end of the bcb to align because I was adjusting the pol band trimmer.
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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