[mikethedruid]

In good news, the big wirewound bias resistor is right on, seems as good as the day it was made.

[mikethedruid]

I'm continuing to work on the audio amp-power section. I have finally removed all the condensers and resistors from the carrier strip, as well as removed and rebuilt the condenser block. I found that at some point somebody replaced the tone control / on-off switch with a pot with switch. I will have to rebuild the radio in this manner, no big deal, it just means it will have a better tone control. With a shot of cleaner into the crack at the terminal end, and working the pot back and forth a lot, it now works well and smoothly. Time to remove and rebuild the two electrolytics next.

[mikethedruid]

Well, another task rears its ugly head, Several of the wires going into the power transformer are frayed near where they go into the casing. I pulled the transformer, opened the case, and rang out the various windings. FORTUNATELY they are all OK. I am going to have to clip each lead, splice it close to the transformer itself, put on new wire of similar color, insulate the splice with heat shrink, and then close up and remount the transformer. What joy! This is the first one I have encountered where I have had to do this. Usually, just being careful prevents the wires from fraying. In this case, however, this radio is such a jam packed blivit that I have had to manipulate some wires, and this has caused the insulation to disintegrate, cloth and all. Oh well, something else to tackle and learn from.

[mikethedruid]

Well, the transformer is done. It wasn't as daunting a task as I thought. Thank God for heat shrink. It made insulating down near the stubs where I soldered a WHOLE lot easier. Tomorrow it goes back in, and then on to the filter condensers.

[Jake Blake]

" . . . wires going into the power transformer are frayed . . . "

I hope all windings are still good. This is probably the best reason why a radio shouldn't be powered, until this wiring is checked and repaired / replaced if necessary , . . . never mind the filter caps.
A hard lesson learned with the 39-6.  I'll keep a positive thought.

[mikethedruid]

I rang out all the windings, and they appear to be good. I reinstalled the transformer, rebuilt the filter condensers, and have begun to reassemble the power - AF amp end.

[Image: https://66.media.tumblr.com/7f73b6615ead...0fcbd3.jpg]

[morzh]

Mike

I hope you use more than one heatshrink layer in the transformer wires, considering they go through that metal hole with some signs of corrosion which makes them a bit abrasive.
I wonder if you could've used some small grommet to protect the hole edges.

[mikethedruid]

I THINK I am finally almost done with the power supply, final amp end. I still have to re-install the big wirewound power resistor, and the tone control / on-off switch. Philco's documentation on this radio leaves MUCH to be desired. Their parts location diagram does not show all the parts clearly, nor does it give a clear indication what all the connections for those parts are. Whoever is responsible for this should have been horsewhipped. It took me HOURS of going back and forth between the schematic, parts diagram, parts list for values, and my own diagrams to finally make any sense of it all. I had a lot of false starts, had to disconnect and remove and reconnect things a number of times. Before I go much further I am going to make some drawings which show these connections more clearly to try to help the next poor soul who ventures upon rebuilding one of these monstrosities.

[Image: https://66.media.tumblr.com/1acfa88df956...55f4ac.jpg]

[mikethedruid]

I have been a busy boy today. I finished the power / final amp end of the chassis. I ended up modifying it slightly to accommodate the switched potentiometer type tone control. Other than that it is as the schematic and diagram show. I also drew out a much clearer (I think) diagram showing the connections on that end than the diagram in the original Philco notes, or the Rider manual. Here it is:

[Image: https://66.media.tumblr.com/59f9cfd0e902...00c9a5.jpg]

If you ever need to convert a radio from the switched type of tone control to one which uses a switched pot, I based it on the information found in Everybody's Radio Manual, pages 114 & 115. This book can be found in the library on this site, here is the link:  https://philcoradio.com/library/index.ph...receivers/

[mikethedruid]

I have re-installed the IF and 2nd detector section to the chassis...
[Image: https://66.media.tumblr.com/dd32a8ec19d0...41ced1.jpg]

[Jake Blake]

"Whoever is responsible for this should have been horsewhipped." 

  . . . Ooooookey Mike!  Great job!

[Nathan Slingerland]

Great work so far!

[mikethedruid]

Today I am sorting out the wiring from the tuning section. As I wrote before, I decided to use the tuning section from the 37-630 chassis since the coils on the original were in much worse shape, and the ones on the 37-630 look perfect. Now, I had marked all the wires from the original when I took it out, but I used paper labels cut from a sheet of return address label blanks, Sadly they did not seem to stick to the original wires very well, and I am having to sort through each wire from the tuning section, one by one, double checking each, looking carefully at its origin, and then tracing it on the schematic. Some, like the filament supply are pretty easy, others are much less so, especially figuring out each one which comes off one of the switch plates, then tracing it from the schematic to see exactly where it connects to the rest of the circuit. I have finally finished, now to put the tuning section in, and keep my fingers crossed that everything is traced out properly.

[mikethedruid]

The chassis is basically done. I'll have to pull the speaker before I can connect it to the chassis and do testing and alignment. By the time I was all finished I had about 4 inches of solder left ! I have more on order. It should be here Friday. I also went through a LOT of solder wick in this project, about 4 rolls ! have just one roll of my former supply left. I just got in 10 more rolls. NOTE : If you use solder wick to remove the old solder, don't use it just as it comes from the roll. Squinch it up a little, so the copper fibers spread out a little, and brush on some rosin flux. I make this liquid rosin flux by dissolving powdered violin rosin in isopropyl alcohol. It works MUCH better this way.  You can use it right away, and it still works great after the flux dries on it too. Another thing to note, you MUST put the band switch shaft back into the tuning section BEFORE you put the section back into the chassis. If you don't, the band switch shaft mounting ears part won't clear the front of the chassis and go back in, which means you will have to remove the tuning section, put in the band switch shaft, and then re-install the tuning section.The trick of removing the shaft before you remove the tuning section, and replacing it once the tuning section is back in does NOT work on this model. I know from bitter experience. Here are some pictures of the chassis back together.

[Image: https://66.media.tumblr.com/95d261a18944...a0d1ac.jpg]

[Image: https://66.media.tumblr.com/c3551b1fc0de...10d3e8.jpg]

[Image: https://66.media.tumblr.com/3928dc71b1bf...e246fd.jpg]

[mikethedruid]

Ya ever have "one of those days"? Well today is one for me. I finally got around to pulling the speaker out of the cabinet preparatory to hooking it up to the radio so I could begin testing and alignment. I used a little spatula all around its edges so that if the cardboard ring of the speaker had stuck to the mounting board it wouldn't damage the speaker and it would come loose easily. I learned my lesson the hard way on that, if you've read my previous posts about repairs you know the story.It came out fine. I then traced a cardboard shield for the front to protect the cone, cut it out, and punched holes in it so that the sound could come out. I then taped the cardboard over the speaker. While I was putting on the final pieces of tape, I get a look at the underside of the cone. It is now clear to me that mice have been at the radio, which accounts for the condition of the chassis, and the dirt, which had a lot of tiny grey hairs in it. Inside the basket were sure signs of mouse droppings, and the wires that run from the voice coil to the transformer were gone from the little metal clip inside the basket to the transformer. The wires from the voice coil itself are intact up to the little metal clip, but one of the tabs from the transformer is broken off short, the one which should have that missing wire going to it. There is enough left to solder to, and enough of the voice coil wires so that I can reconnect everything so it should work OK. I have yet to ring out the transformer completely, or ring out the field coil. I have stopped for the night in disgust. I see little way of performing the repair I am going to have to do short of removing the cone, and doing the voice coil wire repairs, then putting in a new cone, which, fortunately I have. Oh well. I've gone this far, may as well keep going. It is disheartening though. This is, by far, the most annoying radio I have ever worked on. Had I realized its condition before I bought it, I would not have looked at it twice. It's a real shame though. The original cone is in great shape. If anyone has any idea how to go about this repair any other way than to pull and replace the cone, do let me know. I'll give it a rest for a day or two and see if any of you have any ideas.