Philco 620 voltage readings - Printable Version
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Philco 620 voltage readings - Mississippi Joe - 10-13-2019
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
RE: Philco 620 voltage readings - klondike98 - 10-13-2019
Schematic info including voltages at: http://www.nostalgiaair.org/pagesbymodel/804/M0013804.pdf
and a clearer version of the schematic is here: https://philcoradio.com/library/download/service%20info/wiring%20diagrams/vol1/split/Part76-Philco%20Wiring%20Diagrams%20Vol.%201.pdf
RE: Philco 620 voltage readings - Mississippi Joe - 10-13-2019
Thanks, I will check it out. Joe
RE: Philco 620 voltage readings - Radioroslyn - 10-13-2019
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
RE: Philco 620 voltage readings - morzh - 10-13-2019
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.
RE: Philco 620 voltage readings - Mississippi Joe - 10-14-2019
Thanks for the help. I think I am going to enjoy visiting this site.
RE: Philco 620 voltage readings - morzh - 10-15-2019
Oh I am sure you will. It's addictive. And there is no Naloxone for it.
