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Philco 48-200 Clear but faint - Printable Version

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RE: Philco 48-200 Clear but faint - morzh - 07-11-2016

Well...I am looking at the Nostalgia website sch which I am not sure the one you have (do you have the link to the one you have)?

the 7A8 is the input tube.

RE: Philco 48-200 Clear but faint - Radioroslyn - 07-11-2016

So here's the problem, pin 6 is the control grid of the 50A5. If you connect the .22 to it and the chassis it passes most of the audio to ground. Remove that .22 from pin 6 and connect it from B- (- side of the filter) and the other end to the chassis as per the schematic. Leave the .01 and the 470k resistor.

Terry

RE: Philco 48-200 Clear but faint - Tgace459 - 07-11-2016

Ahhhh...my error I meant the 14A7 tube...not 7A8.

RE: Philco 48-200 Clear but faint - Tgace459 - 07-11-2016

The schematic with the 5OA5....

http://s000.tinyupload.com/index.php?file_id=09954866154261184648

RE: Philco 48-200 Clear but faint - Tgace459 - 07-11-2016

(07-11-2016, 11:58 AM)Radioroslyn Wrote:  So here's the problem, pin 6 is the control grid of the 50A5. If you connect the .22 to it and the chassis it passes most of the audio to ground. Remove that .22 from pin 6 and connect it from B- (- side of the filter) and the other end  to the chassis as per the schematic. Leave the .01 and the 470k resistor.

Terry

If I'm remembering correctly, I believe that all the filters are grounded to pin 4 of 14A7 (right next to where the .22 is/was attached now). There's a ton of wires and leads attached to pin 4. I'm impressed the manufacturers were able to do it. I do recall that it wasn't the pin the "troubleshooting" section of the schematic showed it to be.

This radio also had a three section cap with one (20 mfd) lead cut and a separate 20mfd installed. I assume it was a repair/replacement.

So attach .22 to pin 4 14A7 then to another convenient ground pin?

RE: Philco 48-200 Clear but faint - Tgace459 - 07-21-2016

Solution found. Someone had recapped this I the past. The .22 mfd cap I pulled and replaced was the problem. Checking the schematic, the cap was listed as a 22 MMFD cap. When I put a .0002 cap in there all was well.

RE: Philco 48-200 Clear but faint - morzh - 07-21-2016

You need 0.00002uF (22pF) .