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37-602 Cap question
#1

http://www.nostalgiaair.org/Resources/207/M0013207.htm

Does #35 seem like a bad idea? To my way of thinking it would couple 60cy ac (hum) into the dc hv. Typically it would be from the plate of the 25Z6 to B-.

Tnx!

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
#2

I'm thinking #35 acts like a noise suppression cap that is placed across the line. It us a small enough value to be able to pass hash on the ac line but not much 60 hz component into the dc power supply!

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#3

The reason I mention it is that I had a set that was recapped by someone that miss wire a cap in this fashion. Should have been across the line not across the rectifier. It had a terrible hum. After checking the tubes for shorts and the filter caps I saw a cap across the 25Z5 socket wasn't shown on the diagram wired like that. Rewired it to B- and all was well.

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
#4

I know I've seen another set wired like this that I've worked on, can't remember brand or model. Maybe your cap is fairly leaky. No harm in rewiring it across the line with appropriate X safety cap.

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#5

I see no good reason for that cap. I would try the radio with and without the capacitor.

Steve

M R Radios   C M Tubes




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