Hallicrafters T-54 Restoration

[Jon F]

Duplicate post

[Jon F]

Originally Posted by pearsonk

Jon, I'm doing a T54 now and was wondering if your replacement .047@6000
was used to replace the .03@6000, [shown on Sam's, Vert. sweep to crt pins # 10 & 11].
Sam's is for the 6au6 IF and I think Riders schematic is for the octal IF layout. My T54, with 6au6's in IF strip, uses .03@6000.
Your pics appear to show 6au6's in the IF.
My question is: Does it matter if I use .047@6000 instead of .03@6000?

Mine is actually the 505 [T54 in the wood cabinet], 9-48 date.

Sorry I never replied, my set originally had .047 mfd @ 6000V caps so that's what I used for replacement. My set uses 6au6 but the rest of the chassis matches closer to the octal set per the sams. (I have both SAMs sets for comparison )

[pearsonk]

Thanks for the reply Jon. Seems there was a change of values, even with
the 6au6 IF. Still wondering if the change was to: .03 -or- to: .047.
My date stamp was 9-49 [on bottom of cabinet]. If you have a date stamp, that would give us a clue. Probably does not matter, but sometimes values
were changed to improve performance, sometimes just because.
Mine did have .03, and that is what I have on order.

[Jon F]

Originally Posted by pearsonk

Thanks for the reply Jon. Seems there was a change of values, even with
the 6au6 IF. Still wondering if the change was to: .03 -or- to: .047.
My date stamp was 9-49 [on bottom of cabinet]. If you have a date stamp, that would give us a clue. Probably does not matter, but sometimes values
were changed to improve performance, sometimes just because.
Mine did have .03, and that is what I have on order.

The date on the QC tag looks like Sept 16th, 1948. Serial # is 152525

[pearsonk]

Ok, I was wrong on my date stamp, it was 9-48, not 9-49.
Otherwise, my QC tag is dated Oct 15, '48, serial # 166326.
It seems my QC inspection was approx. one month after yours.
So, it appears that if they changed HV cap values to .03, it was between
9-16-48 and 10-15-48. Evidently both values work.
Interesting, but probably not important.