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39/44 tube
#1

I'm in the process of restoring a philco 71H, recapped it and changed out all resistors that were out of tolerance. after initial power up i notice considerable hum from frequency ranges 850 down to very bottom of dial, after testing the tubes i have 2 - 39/44 ... both test very good.....however 1 of these tubes glow at the top (made by raytheon) and the other (RCA) does not? i have a stark tester and checked for shorts on both tubes and there was not any. does anyone know if all 39/44 tubes should glow? just wondering if maybe my stark tester is not picking up a maybe dud tube here.....??
#2

Some tubes have the cathode pinched closed at the top so you cannot see the filament glowing where as others don't and you can see the filament, it makes no difference.

Gregb
#3

ok thanks fellow Albertan!
#4

No problem Dirk, anytime.

Gregb




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