6A7 tube substitutes?

[Electronic M]

Originally Posted by mr_rye89

Some restorers wouldn't like me at all. I never re-stuff capacitors, except Bakelite blocks. My CTC21 still has the original multisection electrolytics attached to the chassis, but the leads are cut off and the new discrete electrolytics are under the chassis

And I woulda just used a .22 or .27uf cap, it's probably just used for a tone control/bypass/coupling anyways. Only the silver mica picofarad capacitors in the tuning/IF circuit have to be exact.

How perfect the recap job needs to be for a restoration depends on how desirable/important the set. My best stuff I restuff with quality new parts, worthless trash I want to play with gets used caps pulled from junked BPC sets lazily tacked in...and there's plenty of shades in-between.

[dtvmcdonald]

Originally Posted by Boobtubeman

Yep, it broke flush with the glass, i had enough to test with and the tube is marginal, so i bit the bullet and bought a NOS one off the bay..

While im inside this radio, is there a good sub for a .25MFD cap?

SR

In just about any radio, any spot ... either a 0.22 or 0.27 uF cap.
In fact, they would be OK in just about any TV, even in a timing circuit.
Normally use a 0.27.

Only in real hi-fi audio filters would it matter.

[Boobtubeman]

Fortunately, i found a .25 in my odd cap batch. In fact, i found useful matches from previous builds where i ordered extras..

The radio in question is a Fairbanks Morse model 56.. Now all i need is a safety cap for the line to chassis. I was thinking of yanking a pair out of a DIRECTV DVR power supply board i have been scavenging parts from..

SR

[dtvmcdonald]

Originally Posted by Boobtubeman

Fortunately, i found a .25 in my odd cap batch. In fact, i found useful matches from previous builds where i ordered extras..

The radio in question is a Fairbanks Morse model 56.. Now all i need is a safety cap for the line to chassis. I was thinking of yanking a pair out of a DIRECTV DVR power supply board i have been scavenging parts from..

SR

The .25 is a filter and decoupling cap for the fixed grid bias. It really does need
to be that big, but whether its 0.22 or 0.25 or 0.27 is immaterial.

[Boobtubeman]

Never had a radio act negatively with a new 6A7 installed.. It receives better with the old one. (new tube makes it whistle around certain areas of the SW tuning spectrum....... And the new tube tests strong with no shorts..
That and the fact the volume is still pretty loud in the Minimum position.. An odd acting radio i must say, but its alive..

SR