Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 20 voltages
#31

Thanks, Rob. I'll admit, I didn't pull the coils out of the cans to inspect them. I'll do that, and rewind in necessary.

Pat
#32

And now, the end of the story.

Voltages all close enough when measured from the right place. Bought a sheet of mica, split it to .001-.002 thickness and replaced all three variable cap trimmer insulators. Now I can adjust them all to between 300 and 700 picofarads (if I read my LCR meter correctly). But the biggest problem was the 71A tubes.

There was only low volume. When I pulled one of the 71A's, the volume doubled. I tried 5 different 71A's, and finally got the proper volume. All the tubes tested fairly high. But I guess they really make a difference in this radio.

All said and done, it was fun. And thanks for the help to all. Now I'm starting on another 20. This should be alot easier. At least re-stuffing the bakelite blocks takes less than 5 mintues each, now. Got one or two more 20's to follow.

Pat
#33

Pat

I do not remember this problem with 20. I did not have to pick and match 71A. Not sure what your case is, but I would recheck each RF stage alignment. Yes it might in theory be dependent on 71A . Though not much.

Or if you are satisfied, then call it done.

Your two other 20s will tell you if your assumtion is correct.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#34

Thanks. I'm sure I will get more info with the others. Just in case, I'm keeping the weak 71As. and I'll try them in the others.




Users browsing this thread: 5 Guest(s)
[-]
Recent Posts
Hickok AC51 tube tester
Note that no power cord, power switch, or power transformer switch are shown. That (along with my experience with full s...DaleHCook — 07:09 AM
IF can wire size and Rubber mounts?
A pair of wire strippers can give you an idea of what the existing gauge of the wire leads are in the IF can, I think it...Arran — 06:07 AM
My last cabinet for this year
Hello Dan, That is really beautiful what great looking radio you have ! I have friends who live in Calgary and the wea...radiorich — 01:51 AM
Philco Predicta Siesta picture over time getting dimmer
I found that the wire insulation was burnt.  The fly back needs corona dope! Why would someone put that there?Platinumblonde36 — 01:09 AM
Philco Predicta Siesta picture over time getting dimmer
This is what it looked like beforePlatinumblonde36 — 01:01 AM
Philco Predicta Siesta picture over time getting dimmer
Platinumblonde36 — 12:58 AM
Philco Predicta Siesta picture over time getting dimmer
Platinumblonde36 — 12:57 AM
Philco Predicta Siesta picture over time getting dimmer
I'm finding some strange things in my set and for the most part it's also original, so I need to start going over everyt...Platinumblonde36 — 12:55 AM
12' Philco
Not anymore Mike. Andre The Giant Born: May 19, 1946, Coulommiers, France Died: Jan 28, 1993 (46 years), Paris, Fran...RodB — 11:53 PM
IF can wire size and Rubber mounts?
Renovated Radios do carry what you need. As for the voltage, a wire should be at least 300V-rated.morzh — 11:13 PM

[-]
Who's Online
There are currently 3360 online users. [Complete List]
» 2 Member(s) | 3358 Guest(s)
AvatarAvatar

>