[gvel]

Hello...I'm Greg...and some of you already know that. I've been tinkering with old radios for about 7 yrs but have been a "user" since the late 60's. I'm finishing up a Crosley Super 11 now, and a Zenith 6D311 is next. After that, my "Big Dog", a 37-675! 8)

I've done nothing to it so far, other than pull the chassis and clean the tubes. Yes, it's barn fresh. The finish on the cabinet, a real piece of furniture, may be savable, if not, it will be hired out. It deserves better than my refinishing abilities!

Anyway, thanks to forums like this, I know where to begin, but I still have a couple of questions. After the power supply and tuning mechanism, where would you go, the "main" chassis or RF chassis? Also, why didn't Philco put a speaker plug on this? This radio is quality throughout, yet they omit a plug?

Thanks for your help!

Greg

[TA Forbes]

Hello, Greg: wow, a 37-675 is a swell set and well worth doing right. Color me envious!

Since you have been doing this awhile I will refrain from the basics, which I am sure that you already know. What I will say is to be VERY CAREFUL when getting into the RF deck. The components there are difficult if not impossible to get to without some major de-soldering of other components that are in the way. As you know, the old wiring in these sets is not good about being disturbed, so you may end up with a major re-wiring project here. I have discovered that the electrolytic capacitor mounted on the RF deck can be tough, the one on my 37-670 had 3 values contained in it, so that is 3 modern caps that you must find room for. IF you do decide to do some "major surgery" here, I would consider replacing the RF deck's rubber bushings, as they are often pretty worn.

The rest of the 37-__ radios are pretty much straightforward.

[TA Forbes]

Oh yes, the speaker plug..... that is frustrating especially since many, but not all, Philco sets made previously had the plug.

[Radioroslyn]

I've got one of those bad boys.

[Image: http://farm5.staticflickr.com/4148/49650...1221_z.jpg]
Philco 37-675 by TBS-50, on Flickr

http://www.flickr.com/photos/42774321@N0...otostream/

Like Tom said the rf deck on these large 1937 Philco set are a pain to work on. Mine has a problem that's going to require it's disassemble and I've been putting it off. Also have a 37-116 which has the same deck that could use an overhaul. Anyway it's a great sounding set and very pleasing to the eye!
Terry

[TA Forbes]

FINE looking radio, Terry. Color me doubly envious....

[Sean]

The 37-675 is a really nice set. I restored one that does not have the telephone dial tuner a few years ago. In regards to the speaker plug I think that there are pins and jacks for each individual wire on the speaker that allows the speaker to be detached from the chassis. I could be wrong on that since it has been so long since I restored it and have since sold the radio but I did have the speaker sent off to be re-coned so had to get it disconnected somehow.

[Radioroslyn]

Sean you are right. It has four pins that slide into their mating connector. The pins are loose so you have to mind your Ps and Qs when plugging them in.
Terry

[planigan]

Gregg. hi. One thing to remember take a lot of photos ot the dial assembly when you remove it. I didn't and its going to be H**l putting it back together correctly. A lot of parts and levers. PL

[Ron Ramirez]

Planigan

Chuck's site has Service Bulletin 273 on his website, in four separate PDF pages, at the bottom of this page:

http://www.philcorepairbench.com/autodial/index.htm

Bulletin 273 goes into great detail on the automatic tuning mechanism, including an exploded view of the parts used. Perhaps this will help you reassemble yours.

[planigan]

Thanks Ron, actually I have the 37-650 which is strictly mechinical and is complicated enough when you forgot to take pictures or make scetches. PL

[gvel]

Thanks for your thoughts! Thank goodness the speaker leads can be removed easily.
I just realized - this has a candohm too!

Where would you start, RF or "main" chassis? I'm thinkin' the RF, since it's the most difficult.
It's too bad it can't remain connected while swapping things out.

[planigan]

gvel, hi. I would start by checking out the coils (transformers) in the RF section, if any of those are bad you may have a real problem. If they check ok then its up to you whether you want to tackle the tough part first or the easier part first. The RF on these are rough. No space to work, rubber mounts usually hard as a rock (they are available but cant' remembe the vender). Some mica caps inaccesssible without disassembly. It will be woth it when your done. PL

[gvel]

I would start by checking out the coils (transformers) in the RF section

Yes...that's protocol before I even replace filters. Every coil and transformer is continuity checked.

With that said, when I get around to this radio, it'll be the RF deck first. I hope to get it done quickly, so I don't forget how to put it back together. Disassembly is easy, putting it back together is another story!

[gvel]

I'm back, after some mindless 37-675 tasks.

I tested the tubes, and all but 3 are Philco, 2 of those are RCA M-R tubes: (6H6 and 6AD7G). The other is a Raytheon 6K8G, a sub for the 6A8G. There are 3 duds: 6N7, 6F6 and a 6Q7. This is the first radio, that I've had, with M-R tubes. I found that pretty cool, maybe it was repaired sometime during the War?

One M-R is a 6AD7G, in place of the 6F6G driver. Pins 1 and 6 are snipped, and I got confused? A well versed tech didn't have a 6F6 but knew what to do!

Mindless task number two was a quick vacuum of the top of the chassis and speaker. Hooked up a straw to the vacuum! 8) That got the loose stuff, but this chassis will need a good cleaning.

Time to bring out the DMM, and check for power transformer continuity. The 5X4 tested nearly new, so that's a good sign!
Edit: Power transformer checks out OK!

Still need to figure out a way to support this chassis, top side down. It'll be easier once the the tuner is removed.

I wonder if the original owners "decommissioned" this radio - when the tubes went south?

[gvel]

Well...I did some exploring...last night.

The chassis safely rests on it's back edge, but the speaker is soldered to it's termination points! It will not be disconnected it, but this shouldn't be too much of an annoyance, other than moving the chassis. This will be a rare occurrence.

The bottom side is very clean, and the wires still show their colors! I only saw one short "hunk" of rubber.

One of the electrolytics has been correctly replaced, leaving the original installed, yet disconnected. I wonder if it was the same tech that rolled his own 6F6?

I see 9 Bakelite blocks and one peculiar metal can pn:30-4470 or 72 on the drawing. This is essentially across each cathode of the 6H6. Only our Savior knows it's function, well, at least I don't!

Not one but two candohms! These could end up left alone, but I'll see.

The FC, choke, and both audio transformers show good dc resistances!

Lastly, the RF deck is a piece of art and reminds me of the RF deck on my HQ-140X, with all of the tuned circuits! Yes, it'll be a royal pain to restore, but Philco did not skimp here. Hopefully, all of the coils are good. Checking these will be my next task, but don't hold your breath!