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Model 90 weak high end
#2

I would verify the osc output and that is level is fairly consistence across the band. It can be done a couple of ways. Use a scope to check the amplitude of the output across the band. Use a communication receiver w/an S meter to listen to the osc signal and watch the s meter to see if the signal falls off as you go higher in frequency.
Check the frequency of the osc as it tunes from 725kc at the low end up to 1675kc at the high end (1500kc). Once this is sorted we can move on the bigger things like a bad 24A mixer tube or bad 1st IF transformer.[Image: https://philcoradio.com/phorum/images/sm...wisted.gif]

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


Messages In This Thread
Model 90 weak high end - by skykng - 06-09-2020, 06:42 PM
RE: Model 90 weak high end - by Radioroslyn - 06-10-2020, 12:28 PM
RE: Model 90 weak high end - by Phlogiston - 06-10-2020, 12:38 PM
RE: Model 90 weak high end - by skykng - 06-10-2020, 05:06 PM
RE: Model 90 weak high end - by skykng - 06-10-2020, 06:16 PM
RE: Model 90 weak high end - by Radioroslyn - 06-10-2020, 07:42 PM
RE: Model 90 weak high end - by skykng - 06-10-2020, 09:27 PM
RE: Model 90 weak high end - by Tim Tress - 07-05-2020, 04:41 PM
RE: Model 90 weak high end - by skykng - 07-05-2020, 06:01 PM
RE: Model 90 weak high end - by tubejockey - 08-21-2020, 03:21 AM



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