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Philco 620 voltage readings
#1

I am stalled on a 620. Does anyone have the voltage readings for pins on this model. I am new at this. I am not sure if I have proper voltages. Cathode voltages, plate etc.  Any help appreciated. Joe
#2

Schematic info including voltages at: http://www.nostalgiaair.org/pagesbymodel...013804.pdf

and a clearer version of the schematic is here: https://philcoradio.com/library/download...l.%201.pdf
#3

Thanks, I will check it out. Joe
#4

Hi Joe and welcome,
I'll add a few notes to the voltage readings. They may be somewhat higher (10-20%) as the higher line voltages and the meters used in those days had a low input resistance which would tend to cause a drop in the voltage being measured. Now days meters are 1Meg or much higher.
Should see abt -20dc on pin 5 of the 42 and a couple of -volts on the cap of the 75.
Don't think having the volume control full up is necessary. Shouldn't change the voltage reading just makes servicing more annoying.
I'm assuming that you've replaced the caps, if not do so unless you like chasing your tail!

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
#5

Changed caps, also check tubes and start the radio without any tubes in, only check power transformer.
And when tubes are in, make sure the speaker is good and plugged in before the power up.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#6

Thanks for the help. I think I am going to enjoy visiting this site.
#7

Oh I am sure you will. It's addictive. And there is no Naloxone for it. Icon_lol

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.




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