[bfrohwein]

Does this help? the pin numbers are looking at the bottom of the tube. (clockwise from the bottom)

[Image: http://i1303.photobucket.com/albums/ag14...f162fd.jpg]

[murf]

I know how to read the pin numbers,

[morzh]

Murf

We can theorise here 'till we are all blue in the face, but why don't you test the transformer?
The ultimate proof is always the functional test.
And it is simple enough.

[murf]

Looking like a B+ problem.
Mark Oppat suggested that I check the voltage on the 42 tubes.
Did that and found around 50 volts on pin 2(plate) instead of the required 245 volts needed. Either have a short somewhere in the B+ circuit, or could this be caused by a shorted paper cap?
E caps are new, but paper caps have not been changed yet.
Pulll that diffuser offf the band selector indicator.
It has turned so dark with age, that the light cannot penetrate it anymore.
Bet you guy's are getting tired of hearing from me.
murf

[morzh]

Murf

We are not tired hearing from anyone but when we keep saying "recap before you troubleshoot" we do it for a reason, and when you decide not to heed that you 1) give yourself extra work and 2) render us helpless to help you efficiently as we go on wild goose chase looking for a legitimate reasons for all kind of weird stuff, while you have not done replacing old paper caps.

[Arran]

Low B+ can be caused by bad paper capacitors as well as bad electrolytic capacitors. When a paper capacitor becomes leaky enough it behaves more like a resistor, and with the bypass ones, routed between a plate or screen grid and B- it can load it down quite a bit. If this set had a treble control capacitor across the primary of the output transformer I would also check and replace that capacitor. Philco typically connected those between one end of the output transformer primary and ground, with a resistor in series, even so it should still be replaced. Another fault that this set may have is that the big multi tapped resistor, in series with the B- side, may have a section that opened up, Philco liked using candohm style resistors that were riveted to the chassis, it's very common for those to become open.
Regards
Arran

[murf]

Caps are all in.
Everything unchanged.
Still need to get some juice down to those 42's.
Spot checked some resistors and did not find any open.
No cadohm resistor on this one.
Checked voltages on the 42's again and still have approx. 6o volts on pin 3 on both, and on pin 2, I found 50v on one and 4.5 on the other.
murf

[morzh]

Murf,

What does the output tranfosrmer centertap meaures at?
And as long as you are at it, what voltage do both ends of the field oil show?

[murf]

I am calling the centertap from output transformer, the center wire from the tranny to pin 3 of the 42 tube.
That checks 61.5 volts.
The other 2 wires from the output tranny check 50 volts on pin 2 on one of the 42 tubes, and 4.5 volts on pin 2 of the other 42 tube.
Thanks,
murf

[morzh]

Murf

I am not sure what you are talking about.
I need the centertap pin of the primary of the output transformer.
AND both ends of the speaker field coil.

And, when done, BOTH plates of the 80 tube.

Can you do it?

[morzh]

Murf

I think the 42 that has 4.5V on the pin 2 is bad.
Easy way to chek is swap the 42 places and see if the 4.5V migrated with the tube.

[murf]

Swapped them out and no change.

[Arran]

What is the B+ voltage at the center tap of the output transformer? Also what is the voltage on the screen grids of each #42 tube? (pin 3).
Regards
Arran

[Ron Ramirez]

Do not operate the set any more than necessary to make quick voltage measurements. Obviously you have a major B+ short to ground somewhere; now it is up to you to find it using professional troubleshooting techniques. The guys here can help...

[morzh]

I was hoping that was a bad 42 tube.

Now is the time to check the caps.

1) First start with caps attached to the ends of the output transformer primary (plates of the 42s).
2) Also the electrolytic cap at the output lead of the field coil (cannot make out number) - where it ges to the output transformer CT.

3) Also caps 8 and the 33.

Start from powered down unplugged state and check every cap with ohmmeter to GND.

4) Last thing: check the output transformer primary (any lead) to GND. Need to eliminate the insulation breakdown.

5) Is the speaker pluggable? if yes unplug and meaure the volage at the output of the field coil when powered up.
ONCE DONE PWER DOWN AND PLUG THE SPEAKER BACK TO DISCHARGE CAPS !!!