Philco Radio Parts Identification

[KilgoreCemetery]

These parts are from a 40-180 console radio that I'm looking to restore. I'm hoping someone on here can tell me what kind of components these are and possibly their values as well.

This looks like a foil capacitor covered in wax, but there are absolutely no markings on it:


Are these two resistors? How do I determine their value? Are they high wattage?


All I can think of here is marshmallow covered in caramel. I'm guessing by the size and the direct connection to ground that it's a high-watt resistor. The only markings show "370 30 1157"

 

[davenn]

This looks like a foil capacitor covered in wax, but there are absolutely no markings on it:

maybe a cap … I first thought an inductor … wire wound on a ceramic former covered in wax
can you scrape off the wax without damaging what is below it ?

Are these two resistors? How do I determine their value? Are they high wattage?

yes they are ….. probably not overly high wattage, maybe a few watts

measure them as you would with any other resistor ( multi meter in Ohms …. you may have to disconnect one end to stop rest of circuitry causing false reading

All I can think of here is marshmallow covered in caramel. I'm guessing by the size and the direct connection to ground that it's a high-watt resistor. The only markings show "370 30 1157"

most likely a mica capacitor and 370pF

 

[kellys_eye]

Best method would be to source the schematic - which is very likely easily available (as below) - and essential for anyone doing restoration work.

The 'wax covered thing' looks to be an inductor - the schematic doesn't give a value but does show it to have a DC resistance of 9.5Ω.

You'll have to show more of the chassis and trace the valve pinouts to determine where the other parts are located.

 

[duke37]

The resistors could be body, tip dot. I cannot see the dot on the big one but the other could be 15Ω.

Measure the valve voltages and see how they compare with normal levels. If the schematic is the one you want, it should give voltages.

 

[(*steve*)]

I would be very careful applying power of you suspect the filter capacitors of being faulty.

You may damage the rectifiers, or even the mains transformer.

edit: clarified "filter" capacitors

 

[73's de Edd]

Sir Kilgore Cemetery man , . . . . .

Pic 1 is a widely resonant RF choke load in the plate circuitry of the 1st Rf amplifier . . .about 3.5 ohms resistance.
It is identified as Item 13

See if your two olde tyme carbon composition resistors are the ones shown being in series from the 84 rectifier tube to ground.
Marked as items 59 and 60.

There are two 370 pf silver mica associated with the pushburtton tuning assembly . . .Items 24 and 23.

You have a few potted black modules on the unit that will have bad paper caps within them.
1A-B . . . .40 A
To be digged out or heated / warmed up to permit removal of that tar surround potting compound and cap replacements.
They are listed as A-B-C supplements to the normal item numbering scheme.

Upon completion and celebration . . .this little puppy requires 78 candles on its birthday cake . . . .

Le OLDE TYME SCHEMATIQUE . . . . .

73's de Edd
.....

 

[duke37]

The parts are resistors 59 and 60.
The big one is body tip dot but the body and tip are the same so it is not obvious. 150Ω

 

[duke37]

The voltage drop across the speaker is about 85V so about 80mA.
Power is I*I*R so the 150Ω resistor (#60) will dissipate about 1W. Use a 2W resistor if you have to replace it

 

[KilgoreCemetery]

I would be very careful applying power of you suspect the filter capacitors of being faulty.

This thing needs a lot of work before I'll put power to it. Lots of cracked wiring! When the time comes, I have a current-limiting setup that I'll use

Thanks for all the info, guys! I'll be looking into this more and confirming everything as soon as I can!

 

[KilgoreCemetery]

The resistors could be body, tip dot. I cannot see the dot on the big one but the other could be 15Ω

The small one has drifted to about 17Ω, and I'm guessing the large one is supposed to be a 150Ω (now closer to 176Ω).

See if your two olde tyme carbon composition resistors are the ones shown being in series from the 84 rectifier tube to ground.

Yes sir! That looks to be correct!

You have a few potted black modules on the unit that will have bad paper caps within them.
1A-B . . . .40 A

Hmm... I've seen the letter designation used before to indicate different sections of a multi-can capacitor, but this model has two separate cans with only one value each, 16uF and 12uF. I'm not sure where the potted black modules are..

 

[KilgoreCemetery]

You have a few potted black modules on the unit that will have bad paper caps within them.
1A-B . . . .40 A

I bet it's this black box. I'll have to see if I can get it apart

 

[kellys_eye]

The resistors will have a tolerance of, at best 20% so your readings are within allowance.

The 'potted' capacitors referred to are these:

 

[73's de Edd]

Sir KilgoreCemetery . . . . .


I think that you lucked out on this one, as this is a '40 model and most of those blocks . . . the one of which you DID zero in on . . . . were more prolifically used in the '30' models.
After laboriously checking out all that your pic would let me see, that is item # 40, in which, there are two 0.01 capacitors being potted inside.
In present 21st Century time, you would want to replace them with X or Y rated safety capacitors, that are being rated to be safely wired across the AC line, such as these are .

With the old paper caps, they were being across the AC line and the AC line was working just fine. . . .until a storm brewed up and there was lightning, then the lightning bolt hits the AC line outside and enough of an instant excess of voltage runs inside the house, finds that cap and makes a pinhole arc thru the paper dielectric.
That instant of having an ionized path, then lets the full wrath of that 120VAC at up to potential decades of amps then RUSH in across the same conductive path, and explode the cap and blow out its end caps.

UNTIL there is an open circuit again, by no capacitor being there anymore. Ahhhhhhhhhhhhhh . . . . smell that distinctive aroma of OZONE ! Plus blackened adjunct chassis areas. . . .no extra charge !

Zenith got rid of all of that tom foolery, by just replacing most capacitors with 1KV rated disc ceramic types, where they didn't want to worry about cap leakage again .

Looks like someone in the past had done some shortcut servicing by just shunting one of the sets two wet electroltic capacitors with the YELLOW Aereovoz 16u at 450vdc dry electrolytic.

The rest of the A-B-C sufixed components are relating to components which are hidden within metallic cans, like the 2nd IF transformer, or in the oscollator section or the RF sections.

The 'potted' capacitors referred to are these:
No, those are being just conventional "postage stamp" silver micas . . .he has found the "potty"

73's de Edd
.....

 

[KilgoreCemetery]

Looks like someone in the past had done some shortcut servicing by just shunting one of the sets two wet electroltic capacitors with the YELLOW Aereovoz 16u at 450vdc dry electrolytic.

Yep. There are supposed to be two of the metallic cans, but when I got it, there was only one. Took me a while to realized that the Yellow Aereovoz is supposed to take the place of the second can. They changed how it was wired in, though, too. It's supposed to be underneath, between the button and coil arrays, but I don't think there was enough room for it.

I don't know if I'll replace it with a metal can, but I can certainly wire it like it's supposed to be and make it look like it belongs

 

[KilgoreCemetery]

So before I go on a shopping spree for parts, I just want to confirm one thing. Is uuf the same as pf? I've seen mmf before, but not uuf.

After laboriously checking out all that your pic would let me see, that is item # 40, in which, there are two 0.01 capacitors being potted inside.
In present 21st Century time, you would want to replace them with X or Y rated safety capacitors, that are being rated to be safely wired across the AC line, such as these are .

Something like this: https://www.digikey.com/product-detail/en/vishay-cera-mite/440LS10-R/BC2757-ND/2687072 ?

 

[kellys_eye]

Yes, μμF is picofarads.