04-13-2014, 04:14 AM
Tried a different 85;
Substituted new components for C50, C51, R48, R49;
Disassembled tone control to inspect and test C62;
Inspected all wiring for poor solder joints, shorts, and miswiring;
Replaced the tire on the wheelbarrow;
But 85 plate voltage remains 44V.
Thanks for all the advice on possible causes of the low voltage. With the radio performing well, I'm not going to pursue the issue any further at this time (unless, of course, someone has another idea to try).
The hum is under control! After much experimenting, I found putting both C58 and C59 at 12mfd leaves a barely perceptible hum. Incidentally, when I received this set those condensers had been replaced with a pair of 12mfd cardboard-tube electrolytics.
[Image: https://lh6.googleusercontent.com/-em4HB...520645.jpg]
Also, the power transformer seems OK--doesn't get hot.
So, I only have to add 4mfd to the C58 can. Thanks for helping me keep those in a safe range.
Substituted new components for C50, C51, R48, R49;
Disassembled tone control to inspect and test C62;
Inspected all wiring for poor solder joints, shorts, and miswiring;
Replaced the tire on the wheelbarrow;
But 85 plate voltage remains 44V.
Thanks for all the advice on possible causes of the low voltage. With the radio performing well, I'm not going to pursue the issue any further at this time (unless, of course, someone has another idea to try).
The hum is under control! After much experimenting, I found putting both C58 and C59 at 12mfd leaves a barely perceptible hum. Incidentally, when I received this set those condensers had been replaced with a pair of 12mfd cardboard-tube electrolytics.
[Image: https://lh6.googleusercontent.com/-em4HB...520645.jpg]
Also, the power transformer seems OK--doesn't get hot.
So, I only have to add 4mfd to the C58 can. Thanks for helping me keep those in a safe range.
