[Ron Ramirez]

Restuffing does make sense, yes.

I took the easy way out this time, again, to save some space underneath. As you can see by the under-chassis photos I have posted, this chassis needs all of the free space underneath that it can get.

After finding a few (more) wiring errors and discovering that I forgot to install a new resistor which (naturally) goes underneath the large two-section tubular resistor, which I had (naturally) reinstalled in place, I removed the large resistor (again) and quit for the evening. Long way to go yet on this one...

[morzh]

Man's got to know when to quit for the evening.
A night cap (the cap taken off a beer bottle, preferably a full one) makes that decision not too challenging ;)

[Ron Ramirez]

yup...

[Video: https://youtu.be/_VrFV5r8cs0]

I worked on the chassis a little bit this evening. Added the resistor I had missed previously, and bolted down the large bias resistor (again).

I decided it was time to turn my attention to the electrolytic capacitors.

It had two aluminum cans in place, but both were replacements. As space is at a premium in this chassis, I decided to try and find something closer to original to take up a bit less space underneath.

One of the cans I will be installing is a dual section electrolytic.

[Image: http://www.philcoradio.com/images/phorum/37640_037.jpg]

When I opened this can, I expected to find the usual two electrolytic sections encased in tar and paper. But I found a surprise instead:

[Image: http://www.philcoradio.com/images/phorum/37640_038.jpg]

When this can was manufactured, a 1 inch twist-lock electrolytic was sealed in a bit of tar at the top of the can, and leads extended to the capacitor terminals.

I'll heat up the can and remove the twist-lock can later, then proceed with the restuffing of the larger can.

[Ron Ramirez]

The weekend is here again, so now I can work some more on this chassis.

Tonight, I hit the aluminum can electrolytic with heat from the heat gun until I was able to pull out the twist-lock electrolytic inside:

[Image: http://www.philcoradio.com/images/phorum/37640_039.jpg]

Next, I installed two new electrolytics (both 10 uF, one @ 450 VDC and the other @ 50 VDC).

[Image: http://www.philcoradio.com/images/phorum/37640_040.jpg]

The can had a tapered portion near the bottom. I cut just above the taper so that I would be able to add a little glue and then push the cut pieces together:

[Image: http://www.philcoradio.com/images/phorum/37640_041.jpg]

To be continued tomorrow after the glue dries.

[Ron Ramirez]

I haven't been around the workbench for most of the day today, but I did manage to accomplish one thing to this 37-640 chassis.

Yes, Sam, I did it...

[Image: http://www.philcoradio.com/images/phorum/37640_042.jpg]

...I painted the power transformer.

I wasn't going to, but it looked pretty rough and it needed a fresh coat of paint.

Now I'm waiting for the paint to dry before I proceed with electrolytic replacement.

[Ron Ramirez]

Another day, another electrolytic capacitor can to restuff.

[Image: http://www.philcoradio.com/images/phorum/37640_043.jpg]

[Image: http://www.philcoradio.com/images/phorum/37640_044.jpg]

The original was 12 uF, 475 VDC. 22 uF is overkill but not too bad, considering the very wide tolerances of the original electrolytics.

After the can was restuffed, back into the chassis it went.

[Image: http://www.philcoradio.com/images/phorum/37640_045.jpg]

[Image: http://www.philcoradio.com/images/phorum/37640_046.jpg]

[Ron Ramirez]

After installing and connecting the freshly restuffed electrolytic cans, I cleaned, then reinstalled the off-on-tone switch.

The bakelite block containing the line-to-ground caps also went back into place.

I replaced the remaining capacitor on the right side of the chassis, a 0.22 uF which is connected between the cathode of the IF amp tube (6K7G) and ground.

A 700 ohm resistor in parallel with this cap turned out to be a problem. I did not have any 700 ohm resistors. So I improvised...I used a 200 ohm and 510 ohm resistor in series to end up with 710 ohms, close enough.

I also spliced new wires to the shadowmeter, rebuilt the shadowmeter lamp socket, and connected new wires to the shadowmeter lamp.

Now, other than attaching the power cord and taking care of two or three minor odds and ends, I believe the main chassis is finished!

[Image: http://www.philcoradio.com/images/phorum/37640_047.jpg]

Next up: The RF unit!

[Sinatra1982]

Ron, I have a Philco 37-624 and I am not sure how to replace the black bakelite cap box with another  one.  Can I do it without taking it out and just unsolder the wires to a new one?  And does it have ground?  I am in the process of replacing the caps.  It is powering up but not picking up any stations or static.  I can hear a click in the speaker when I change the band switch.  Thanks.

[klondike98]

The bakelite block caps are replaced by taking the old caps out of the block and putting new modern caps inside the old block. There is a nice thread at this LINK that shows how you can do it without desoldering everything, although I often take them out completely so they are easier to clean up and stuff.

There is lots of information on which blocks have grounds and on which terminal at this LINK.

[Ron Ramirez]

And so let us begin work on the RF unit.

I have said many times over the years the following: It is my opinion that David Grimes, the person responsible for the design of this...thing...should have been sentenced to servicing Philco radios with his lousy Unit Construction, 18 hours a day, 7 days a week, for the rest of his life.

But anyway...

The only way I have found to properly service these is to taken them apart. It is the best way to access the paper capacitors which are often hidden between band switch wafers.

Once the RF unit is out of the radio, you begin by removing the metal sides. Each side is held in place by three bolts. One side will have two copper braids soldered to it. Unsolder these where they are soldered onto the side, then remove both sides.

Then you must carefully unsolder two wires from the bottom side of the antenna and RF sections of the tuning condenser. Don't worry, you can get to them from the side. You will also have to unsolder one end of two of the paper capacitors from the frame of the tuning condenser.

Once that is done, remove one bolt and the antenna section comes right out:

[Image: http://www.philcoradio.com/images/phorum/37640_048.jpg]

Now I can (sort of) get to the hidden capacitor. While I'm in here, I also replace the connecting wires. Once finished, this is how it looks:

[Image: http://www.philcoradio.com/images/phorum/37640_049.jpg]

Next, I remove the RF section. This time, I not only have to remove one bolt, but I also have to unsolder the grounded end of another paper capacitor, the other end of which connects into the oscillator circuit. I also have to unsolder the wire from pin 3 of the 6K7G RF tube before I can finally pull the RF section out of the unit.

As with the antenna section, I replaced paper caps (two in this case) as well as the connecting wires.

And here is where things stand now:

[Image: http://www.philcoradio.com/images/phorum/37640_050.jpg]

I still have to do some work in the oscillator section. This is best done while the antenna and RF sections are out of the unit. There is also another aluminum can electrolytic that needs to be restuffed.

Interestingly enough, out of all the RF units I have rebuilt over the years, I cannot recall a single instance in which this electrolytic capacitor can was not still filled with its boric acid solution. I am sure this electrolytic was not put under as much of a strain as were the two main filters. Nevertheless, this can will still be rebuilt.

[GarySP]

Nice work, Ron.  What burns my buns is how easy you make it look!  Take care, Gary

[Ron Ramirez]

Thanks, Gary...

...and, no, it is not easy work at all.

[morzh]

None of this is easy. And sometimes the patience runs really thin.

[Kenneth F. Besso Jr.]

I presume that all them little coils check out ,,OK,,,do you still disconnect one end ,,like with resistors to check,,,And you Do GGreat work,,Nice Job,,,CHEERS

[Ron Ramirez]

The coils in the antenna section are OK. I will check the other coils before I reassemble the RF unit.

Resistors? In the RF unit, I usually don't bother them unless one end of a resistor is connected to a wire that I am replacing; in which case the resistor also gets replaced since it is being heated by the soldering iron.

Now -

I've rewired the oscillator section, and replaced the single paper cap in this section.

[Image: http://www.philcoradio.com/images/phorum/37640_051.jpg]

After I took this picture, I rebuilt the dial lamp socket.

Next up: Restuffing the single electrolytic capacitor can which mounts on top of the RF unit.