Hello,
I recently acquired a 37-690 and will be doing the electrical restoration on it. I'll be contacting Chuck Schwark to get all of the schematics for it.
I must admit it is a bit daunting thinking about the multiple chassis' and the 3 speakers. Has anyone ever documented their electrical restoration of this model? I'd love to have a guide to help me get this beauty restored and playing properly!
Thanks in advance
Chris
Just take you time and be very careful to make sure you replace all the caps and out of tolerance resistors carefull so they are right the first time.
If all the parts are there to start with, the radio should play like new wen you are done.
The lamp sockets are important too if like the 38 690 as the insulation rots. Ron has a fix for that o this site.
I used this procedure on my 38 690 four years ago and it is still playing strong every day. I had only fixed small radios up to that point. Taking eack chassis step by step.
Steve
Thanks Steve! I appreciate the input.
Chris
I just pulled the 2 chassis' out of my 37-690 to get a good look at them, and I find that I have what appears to be a 38-690 chassis in my 37. There are 6 tubes on the power chassis instead of 7, and 14 tubes on the receiver chassis instead of 13.
The tube layout on both chassis' match the 38-690.
My question to you is did Philco possibly run out of the 37-690 chassis and substitute the 38-690 chassis?
All of the caps and resistors are original with the exception of 2 lytics, so this hasn't seen much service.
I'm fine with this, just trying to understand.
Any help you can provide is appreciated!
Thanks
Chris
Ron should weigh in on this one but I do know that there are examples of left over cabinets from prior years having the next year's chassis installed in some models. I don't know about the 37/38-690s though. I merged you question with your earlier thread on the same radio.
What power output tubes are used in the power supply/amp chassis? The 37-690s used 6G4Gs I believe, whilst the 38-690s used 6L6Gs. I would not rely on that alone, however, if someone was unable to find the 6G4S they may have decided to update the chassis to use 6L6Gs since they are much more common and used in the 38 model anyhow.
From what I heard the tuner chassis used fewer tubes in the 38-690, though as everyone is well aware Philco was notorious for producing running changes under their various code versions, as well as during different production runs, I don't know if this was true with the 690s but it was with the 116 models and everything else down the line.
In terms of using power supply/amp chassis meant for a 38-690 in a later production 37-690 this was not typical of the way Philco operated, what would be more likely would be for an early production 38-690 to get the late production 37-690's chassis. If it is out of of 38-690 then perhaps the original power supply failed and someone either bought a replacement chassis from Philco or salvaged a replacement from a junker 38 model.
Regards
Arran
Thanks Arran! The output tubes are 6L6. I compared the differences between the 37 and 38 chassis and this has all the tubes that should be on the 38. In addition, there are definite differences between the chassis layouts.
Chris
There are many documented examples of Philco installing a chassis from one year into a cabinet of a previous or successive year. I have a 38-2650 in a 37 cabinet.
Does the tube diagram inside your cabinet have the 37-690 or 38-690 tube layout? This would be a key bit of evidence.
The tube layout in the cabinet shows the 37. That's what confused me so much!
Well, Bob said that I should comment, so I will...
While it is entirely possible that Philco did some cross-matching at the factory, the fact that the cabinet still has 37-690 stickers indicates to me that someone installed the 1938 chassis at some point after it left the factory.
Yes, Philco did make their own Phranken-Philco sets, more often than some folks may realize. Case in point: I own a 200X. Only it isn't a 200X. It has a 201 chassis inside. And the cabinet stickers indicate model 201. One of the stickers was placed over a 200X sticker, but in such a way that you can still read "MODEL 200X" under the 201 sticker.
That was a factory job. And it must have been done towards the end of production of the 201, and here's why:
My friend, Steve Geary came over here about a year ago. He had a 201 chassis with him. His set came with the stock 201 cabinet. The serial number on his is lower than the serial number on my 201 chassis, so mine was made later. Since it was mated up with a 200X cabinet, my guess is that Philco was closing out their 1935 model line in preparation to introduce the 1936 models, and started clearing the factory of all the leftovers. My Phranken-200/201 is the result.
On the other hand...
A few years ago when I was still restoring radios as a sideline, someone sent me a 37-690 upper chassis. My job was to mate it with a lower chassis.
I couldn't find one.
So the owner found - and bought - a 38-690 upper and lower chassis which I rebuilt for him, after which he installed it in his 37-690 cabinet.
This is what I think happened to your set, Chris.
I certainly wouldn't be upset about that. In my opinion...you have the best of both worlds. The better performing 38-690 chassis in what is (arguably) a classier piece of furniture.
In any event...great catch!
Thanks Ron! I appreciate your comments on this one. I'm very happy with the radio as it is. I love the cabinet, which is one of the main reasons I bought this radio. I had ordered the 37 schematics from Chuck, and now I'm ordering the 38 schematics. I just got all the caps and resistors for the 37, so I'll compare what I have with what I need.
Thanks again to everyone who replied.
Chris