[Nathan Slingerland]

Looking great Ron - I have never seen IF cans so shiny. They're like new!

[Arran]

Ron;
  Bob Andersen made a restoration series for a 37-640 a while back. One interesting thing that I learned from his series is that you can actually dismantle the chassis by undoing those hex headed screws on the top and sides, and by undoing a bunch of wires connecting the sections too of course. So if lets say you wanted to strip the rust off the IF side you can remove the top section, dunk it in evaporust or whatever, and then put it back without disturbing the rear apron with the stickers all over it. In his case he had to derust everything, and replace almost all of the tube sockets too, but apparently evaporust doesn't harm brass or aluminum so you could leave them in place whilst derusting the chassis parts.
 I don't particularly like the design, I think that it added complexity with little to show for it, but I can understand why they thought it might aid production. I think that the idea was that they could make common sub chassis that would be shared across different models, the IF section would be shared across everything from a 37-610-640, the RF deck in everything from a 37-620 on up, and the power supply and power amp sections could be shared between the 37-620/630, and the sheet metal stampings were all the same of course. On paper it was a good idea, sort of like the modularity of a desktop computer, but of course it was all hardwired, and in the long run it may have saved some time but used more materials, like those hex head sheet metal screws for one, and they had more parts to manage and inventory.
Regards
Arran

[Bob Andersen]

Great progress so far and excellent photos
Here's the 37-640 thread Arran was referring too.  

http://philcoradio.com/phorum/archive/in...683-1.html

Evaporust uses a chemical process called "chelation" that does not harm anything except rust.  Of course you have to dry everything thoroughly after dunking.

[Ron Ramirez]

Thanks, Bob - and thanks to you, I finally worked up the courage to try using rottenstone to rub out the cabinet which this chassis is going into.

And thanks to all for the comments.

Arran, I don't know who came up with the idea of opening up those chassis first, Bob A. or John Goller. John described this method to me a few (or was it several?) years ago. I have simply chosen (so far) to not work on them in that manner. Nothing wrong with it; in fact it may be better than keeping it all together (save for the RF unit). It would certainly simplify replacement of capacitors and resistors.

And this chassis really does not have that much rust. Believe me, if it did, I would definitely do something about it.

[Ron Ramirez]

Tonight's progress:

[Image: http://www.philcoradio.com/images/phorum/37640_028.jpg]

No, I am not restuffing the caps.

Why?

Simple - look at the left side of the chassis. All of those caps in the audio section...replaced years ago...all blue sealed caps which cannot be restuffed. So why bother? Besides, in a cramped chassis like this one where space is at a premium, any extra space one can make is a good thing, I think.

The IF cans are also back in place:

[Image: http://www.philcoradio.com/images/phorum/37640_029.jpg]

Two more caps and two more resistors, and the right side of the chassis will be finished. Then on to the left side...

[Kenneth F. Besso Jr.]

COME on RON,,,get to the good stuff,,,like the deck you removed,,I can't want to see that,,,it's going to be Fun,,,lol

[Ron Ramirez]

Patience, Grasshopper...

I shall return to working on this set come Saturday.

[Arran]

No, I am not restuffing the caps...

Ron;
  Actually you can restuff those style of capacitor, SOMETIMES, like the Sangamo "Little Chiefs" or the bumblebee types, with a molded plastic shell. I'm not sure whether you can with those blue Cornell-Dubilier ones, but since they are replacements not original to the radio there isn't much point. The odd thing is that I have run across some of those plastic molded capacitors that still test good, so maybe the later ones used plastic film, or a combination of plastic film and paper, that holds up better then the pink and blue Sangamo ones. If anyone wants to find out how look up a You Tube channel by a guy named Dennis Carter, it's rather interesting, but it only makes sense to do with radios, and TVs, and in his case a Webcor wire recorder, that left the factory with such caps.
  One thing that I have been looking for are sources of smaller diameter cardboard tubing in order to make replica capacitor shells. So far the smallest that I have found are maybe 5/8'' inner diameter tubes from a Saran wrap or wap paper rolls. I have heard that one source of smaller tubes are those wire hangers that the dry cleaners use but I haven't found any of those yet. I was looking at tubing for fireworks but they seem to be thicker walled then capacitor shells.
Regards
Arran

[Radioroslyn]

One thing that I have been looking for are sources of smaller diameter cardboard tubing in order to make replica capacitor shells.

Back when I was working I was wearing company supplied uniforms. The pants hangers used a cardboard tube to support the weight of the pants. These tubes are just about perfect for making new shells for replacement caps. An old tube from a Sprague .1 600v is within a mm or so. New Mylars fit easily inside even though the wall thickness is bigger. Each tube is long enough to make about a dozen shells.

[Ron Ramirez]

[Video: https://youtu.be/XOILKHmZBwc]



P.S. Terry - Great idea

[Ron Ramirez]

Progress:

[Image: http://www.philcoradio.com/images/phorum/37640_032.jpg]

Almost finished with the right side. I only need to add one more capacitor and one more resistor here.

Plus, I will also have to attach new wires to the shadowmeter, rebuild the shadowmeter lamp assembly and add new wires to it, and reattach all four inside the right side of this chassis.

Meanwhile, I moved on to the left side:

[Image: http://www.philcoradio.com/images/phorum/37640_030.jpg]

[Image: http://www.philcoradio.com/images/phorum/37640_031.jpg]

Almost all of the tubular capacitors and almost all of the resistors have been removed. Only a few more to remove, plus removing and rebuilding the aluminum can electrolytics, then replacing all of the caps and resistors (save for the large two section wirewound resistor), replacing the speaker cable, and replacing the power cord.

Once that is done, I can move on to the most fun part of the project - the RF unit.

[Ron Ramirez]

After another hour or so of work:

[Image: http://www.philcoradio.com/images/phorum/37640_033.jpg]

Tomorrow I hope to finish replacing the paper caps and small resistors, then turn to the two large aluminum electrolytics.

I've also removed the single bakelite block which contains the two line-to-ground caps. Those will be replaced with safety caps.

 ...time for bed...

[Ron Ramirez]

The death caps having been replaced...

[Image: http://www.philcoradio.com/images/phorum/37640_034.jpg]

I then set the bakelite block aside and continued with the left side of the chassis.

I had to remove almost everything around the 6F6G output tube sockets in order to be able to replace parts and replace the speaker wiring harness:

[Image: http://www.philcoradio.com/images/phorum/37640_035.jpg]

I made a new wiring harness using four different colors of cloth-covered wire. Man, that is getting hard to do with my arthur-itis.

I unsodered the push pins from the original four wires and soldered them onto the ends of the new wires.

Here you go.

[Image: http://www.philcoradio.com/images/phorum/37640_036.jpg]

Man, this side is really difficult. More difficult, I think, than the RF unit is going to be. I keep getting mixed up on rewiring the two output tube sockets.

[Kenneth F. Besso Jr.]

WELL,,nice black sleeving job,,makes it really nice and neet,,,Nice job Ron

[morzh]

To me restuffing any old cap still makes sense simply because of the fact that those were a time-appropriate choice for repairs and though not original still don't look out of place.
This said, restuffing caps is a personal choice and is nonessential.
After all most of us who restuff caps use modern resistors, very few going the way of Russ and making molds/painted plastic sleeves etc.

After all its not like we are keeping the tube duds on top and hiding a solid state radio underneath the chassis it is still the same radio with the same circuitry working.