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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.
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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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
(This post was last modified: 07-11-2016, 12:00 PM by
Radioroslyn.)
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Ahhhh...my error I meant the 14A7 tube...not 7A8.
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City: Buffalo NY
(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?
(This post was last modified: 07-11-2016, 01:45 PM by
Tgace459.)
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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.
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You need 0.00002uF (22pF) .
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.
(This post was last modified: 07-21-2016, 01:06 PM by
morzh.)