[tbone]

Greetings, I hope you are all well!

I am restoring a 37-116 for Phorum Member Rich.

So far the Chassis work has gone well. I replaced all caps, re-stuffing the filter cans and bakelite blocks, and have completely dismantled, cleaned and repaired the sub chassis. There was a bad solder connection on one of the hidden oscillator section switch lugs. Must have been bad from the factory. I guess this is one reason we take them apart.

Besides a couple of self induced issues  I have the chassis playing on the bench. All is working well except the magnetic tuning, which I believe is a bad 80PF mica cap in transformer 81. With the 81S trimmer tight, I am close, but need more capacitance to get it right. I plan on tackling this next.

The rest of the set alignment went as expected. At first I was nervous since someone in the past connected a cap from the BC RF trimmer to antenna terminal 4. I was expecting an open coil, but that was not the case. It was just simply out of alignment. Now you start to hear a signal coming in between .5 and 1 uv at the antenna connection.

The set needs tube shields and other misc items. Rich was able to find another 37-116 in state for a reasonable price, and this is what I have questions about.

Both radios had a fused plug on the AC line. Was this a Philco supplied item?
The parts set had a bottom cover and the one I'm working on had no indication of one.
The speakers are different. One uses pins that push in, while the other one uses a socket and plug.
The wiring harness for the lighting is also built better on the parts set. It has a nice loomed harness with a plug so it can be removed.
The Magnetic Tuning transformer #81 is a square can which has a different 81S tuning cap. Could this be used in the set I'm repairing if needed?

I'm interested in what you can tell me about these clearly different versions of the 37-116. Also, if you have any tips on the Magnetic tuning that I may be missing other than the standard service information, I would appreciate the info.

Additionally, I will be installing an audio input jack. I have some questions on the best way to tackle this. How would you mute the radio audio while connecting an external source? What is the best location to connect to, volume control high? I was thinking of a simple switch along with a 3.5MM jack. All suggestions are welcome.

Attached is the schematic link from Riders which I am using, and a picture of the plug.

Thank you for looking.

37-116 Schematic