[kstesney]

: I want to take a stab at restoring a Philco Transitone radio, but I need the schematic. The problem is I cannot seem to find the model number of this particular radio. I have searched the internet and found lots of pictures of Philco radios, but I have not been able to locate this one yet. Does anybody know the model number of this radio? If so, thanks a million. Link is below:

http://pg.photos.yahoo.com/ph/top_invest...pg&.src=ph :

[Chuck Schwark]

There is not brown and white paper sticker glued to the inside of the cabinet or on the bottom? Usually the sitcker has model number, code version, voltage, watts, etc. and a small pictorial showing tube types and tube placement on chassis.

It's a post-war model. Will get exact model later - am at work right now and cannot look in my archives.

[kstesney]

There are some labels inside (see picture link below), but it does not indicate a model number. Perhaps it is not all there.

http://pg.photos.yahoo.com/ph/top_invest...EBMaRtOtwo

[Chuck Schwark]

I see now why you have not been able to ID that set. That Philco chassis is not in a Philco cabinet. Just looking at the front and rear pictures, the dial face does not lineup with the case opening in front. The chassis is too small for the cabinet and the speaker is also offset from the cast circular rib on the inside. The chassis may be a Philco, but the cabinet is not. There would have been a 2-3" rectangular paper sticker on the wall inside or on the bottom center of that bakelite case.

Maybe a larger good photo of the top of that chassis (straight down) showing tube and major component placements AND listing the tube types may be of help to ID the Philco model.

Just by looking at that dial face, it could be a 1942 42-PT25 or 42-PT26, or a 1941 PT-42 or PT-44, or a 1940 PT-26 or PT-28.

[kstesney]

Wow! It's amazing that you figured that out. Here are a few pictures of the chassis. Maybe this will help. Thanks.

http://pg.photos.yahoo.com/ph/top_invest...EB8dR0Otwo

[Chuck Schwark]

Those chassis pics are not much help - please list the tube types. Also, what is written on that white paper tag on the IF transformer can?

Also remove that last bit of cardboard back and see if there are any ink-stamped numbers on the rear chassis apron.

We are closer . . .

[Tim Tress]

With only one can-type IF transformer, it could be a PT-42 or PT-44 chassis. As Chuck said, look for a rubber-stamped number on the back of the chassis. It may take a close examination to find it, as the ink sometimes fades.

[Chuck Schwark]

The PT-42 and 44 do have two IFT's Tim. ??

[kstesney]

Just back from work and can inspect the radio...I have the following information. Looking down from the top with the radio facing away, the tube in the upper (forward) right position is 35A5, then working counter clockwise...35Z3, 7A8 (?), 7B7, ...and the last tube in the upper left I cannot read.

There is a number of some sort in ink on the chassis that says 7720.

The part number for the dial face is 27-5572.

On the white paper on the IF transformer it just mentions a bunch of patent numbers. The IF transformer itself might be part no. 39-5955.

Hope this helps. Thanks.

[Chuck Schwark]

OK! We have a winner!

The dial part number was the key: You have a chassis from a 1940 Model PT-25 (or PT-25, PT-39). Same chassis in three different style cabinets. Your tube lineup matches as well. The tube you cannot read is a 7C6 (or should be).

BTW, that 39-5955 is the Philco Part Number for that white paper tag itself. Part numbers with a 39-xxxx are paper products, tags, stickers, pamphlets, etc.

[kstesney]

Most excellent, Chuck! Thanks for your help and expertise. Now I can see why they pay you the big bucks. Is there a schematic for this little beauty? Karl.

[kstesney]

While poking around in the chassis of my Philco Pt-25, it occurred to me that it might be wise to remove the speaker for fear of damaging it during the recap process. There are four wires exiting the speaker assembly (coils and speaker). I snipped two of the heavier wires about in the middle making it easy to relocate where they reconnect when I am ready to reassemble. One of those wires goes to one of the tubes and the other one connects to some strange-looking device that I don't know what it is. But the other two narrow wires exit from a wrapped wire coil closer to the speaker and they are thinner wires. I seem to have snipped those off at the ends, maybe thinking that it was so obvious where they go that I would need no clues. Well, lo and behold, as I fiddled with practicing the replacement of the speaker, I could not remember where those other two wires are supposed to connect. Any clues would be appreciated.

[Chuck Schwark]

Check the schematic - two are the voice coil (smaller gauge probably) and the other two (heavier gauge) are the field coil (electromagnet with also serves as the power supply filter choke, called out as part no. 27 in the schematic.

Next time tag both ends of any wire you cut or remove to facillitate re-connection.

[kstesney]

By golly, I'll be darned if I did not track down the cabinet for that Philco PT-25. It looks just like the Lafayette T-99 found at the radio Archives...

http://radioatticarchives.com/images/l/L...e_T-99.jpg

And here is my radio, the PT-25 chassis in the Lafayette cabinet...

http://pg.photos.yahoo.com/ph/top_invest...pg&.src=ph

The only strange thing is that Lafayette at the Radio Archives has a single knob and mine has two knobs. Otherwise they look identical!

You correctly surmised that the cabinet was not the right one for that Philco chassis. I just hope I can get that Philco chassis to fit snugly into that Lafayette cabinet.

[Tim Tress]

Hi, Chuck.... The second IF transformer is visible under the chassis, near the volume control; it's one of those "cartwheel" types.