08-29-2023, 09:17 PM
If you get tired of waiting it's not hard to rewind the primary. It's about 24 turns of #32 or #34 magnet wire. Wind it in the same direction as as the winding you removed and it probably would hurt to make a new insulator to go between the pri and sec. Primary turns count is not particularly critical as it's used to couple the rf signal. The secondary is as it's the tuned circuit that is resonant. Would not rewind it (2dary) unless I had to and had a precise way to measure the turns count/wire size involved.
Too many turns on the primary gives you poor selectivity. Not enough will lower the sensitivity.
Have worked on a few of the 87's and those bypass caps at the bottom of the primaries are usually leaky like shorted. So you you might want to take the 3 screws out and check the voltages w/those caps out of the circuit.
https://philcoradio.com/library/images/schem/87.jpg
GL
Too many turns on the primary gives you poor selectivity. Not enough will lower the sensitivity.
Have worked on a few of the 87's and those bypass caps at the bottom of the primaries are usually leaky like shorted. So you you might want to take the 3 screws out and check the voltages w/those caps out of the circuit.
https://philcoradio.com/library/images/schem/87.jpg
GL
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!
Terry
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