The PHILCO Phorum

I have just aquired a Philco 37-9 and I am wodering if there is something odd about this thing? I have not seen much on the net about it, including this forum, although I did see it mentioned in the "changes" download.

It appears to be a 9 tube model, and the cabinet is pretty basic, although there is some nice contrasting inlay.

It would certainly be nice if I could get my hands on a schematic so that I can recap this thing and get it playing. I have not plugged it in yet. and I will go through the chassis before I do. New caps, resistors, check the transformer etc... then ramp it up with a variac.

The only modification that I can notice on it so far is an adapter for the rectifier tube on the transformer.

I am not a master woodworker, although I do know my way around, I also know my limits, and I need to figure out how to do a bit of sprucing up on the cabinet, as the top is pretty rough and there is a little bit of cracking on some of the inlay veneer.

Any assistance in pointing to reference materials would be appreciated.

Thanks for the great forum.
73,
Kurt

Note from site admin: Sorry, but the photos which were attached to this post are no longer available.

Hi Kurt

I suggest you go here for service information:

http://www.philcorepairbench.com/schematics.htm

The site is run by Chuck, who is also a moderator here. You will not be disappointed! The service data will be well worth the modest fee he charges.

Not sure, you'd have to check the schematic, but I think the original power rectifier should be a 5Y3. The Rectifier tube in the picture looks like a 5U4GB, and the adapter looks good from here. I've done the same subbing a 5Y4 for the 5Y3. It should be OK, but the 5U4 generates a lot more heat.

It should use a 5Y4 rectifier. Only draws 2 amps filament and 5U4 draws 3 amps. Get the service info and check socket voltages and pin outs from the top and see if it matches schematic. looks like a few tube shields are missng also.

How important are the tube shields?

What will a lack of shields affect?

I know I have some shields out in the garage, but I don't think that I have any of the square ones that I believe it is looking for.

Most of the tubes, if you look from straight above, they don't look like the glass will even allow a tube shield to fit over them and clip properly.

Thanks,
Kurt

Lack of shields can cause many ill effects; whistles/howls/oscillation/etc.

The glass G type (ST envelope, also known as "shouldered" or "taper-top") tubes originally used in these Philcos will fit snugly inside those square shields. Sometimes they are difficult to get out of the shields because of the snug fit...but that's the way they were when they left the factory.

The good news is that even though someone tossed the tube shields, why I don't know since the set is full of glass tubes, that the square ones should be easy to find. Philco used that style of tube shield for at least five years on millions of sets between 1933 and 1940 so the only issue is finding ones of the proper size. Until you find some you can always use some aluminum foil for testing purposes.While you are at it see if you can find a matched pair of output tubes, one looks like a compactron TV tube mounted to an octal base, the last one of that style that I saw was a 35Z5 in an early 1950s Admiral radio.
Best Regards
Arran