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

Philco 91 code 225
#1

I have been unable to find a schematic for this chassis. Anyone know if one even exists and where I might get a copy?

I've been working off of a schematic for chassis 126 & 226 and it seems to be accurate but I have a capacitor in my radio that doesn't show up on this schematic. It is in a small metal enclosure but not like the rectangular ones elsewhere in this radio. It is wired to the BC resistor which consists of an 85 ohm and 205 ohm section. One lead of the capacitor in question wired to the junction of the two resistors and the other lead is connected to the chassis. Stamped into the metal case is 50835, searching for this part number yields no results.

The metal case is soldered to the chassis whereas all other parts use screws or nuts and bolts. Makes me wonder if this was a factory installed part.

The cap measured .246 mfd, but I don't know if that number is reliable.

Does anyone know the real value of this cap? Should I leave it in place or replace it with a 
.25 mfd cap?

Any leads or advice would be appreciated.

Sometimes I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it.
#2

It would appear that it's used to decouple the audio signal out of the bias voltage going to the control grids of the 42's. That this point there is little voltage there like -20v. You could use a small electrolytic cap a few mfds @35 or 50v but be sure to connect the + side to the chassis and the - to the BC resistor.

OBTW Welcome!

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#3

Thanks for the information. I'm still getting used to the fact that the chassis can be a conductor for several circuits units at the same time.

Sometimes I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
trying to identify this wire type
...and modern wire of the appropriate gauges and insulation V-rating (300V minimum, usually shown right on the wire) is ...morzh — 05:47 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
I have a question about this radio, is there anyone that has access to this radio that has an intact unmolested speaker ...captainclock1988 — 04:28 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
Well what makes me confuse all of those companies is that all three of those companies (Setchell-Carlson, Stromberg-Carl...captainclock1988 — 04:21 PM
trying to identify this wire type
The red wire is rubber covered wire. The others are cotton braid over rubber often in colors or a tracer, also strand...Chas — 02:43 PM
trying to identify this wire type
Greetings Phorum members, Hope you can help me identify this type of wire in the photo I have attached.  I am not sure ...georgetownjohn — 01:53 PM
Philco 60 Squealing
All correct shields must be in place, all tubes correct no subs of any kind. Check any soldered, riveted ground conne...Chas — 01:24 PM
Philco 60 Squealing
I have recapped and replaced out of tolerance resistors and so on. Radio plays nicely on fairly strong stations. The pro...dconant — 10:55 AM
Philco 46-420 Code 121 Reception issues
Welcome Eric, I agree with Bob and far as the two main electrolytic filter capacitors did you change them yourself or w...radiorich — 11:43 PM
Philco 46-420 Code 121 Reception issues
You mentioned the Philco manual and going through the check points...just to be sure we're on the same page here's the m...klondike98 — 08:13 PM
Philco 42-1008 conversion kit
Interesting. I haven't seen that before.klondike98 — 07:02 PM

[-]
Who's Online
There are currently no members online.

>