[morzh]

No. I mean the short bright green wire going from your repaired coil, the right of the two greens.
It goes up and looks like the copper then is wrapped around some lug but not soldered to it. Right near the point where it crosses that blue wire.
I do not question cut wires, if they are, there is a reason....usually.

[Ron Ramirez]

Good question. I would assume it had wax at some point. Why it doesn't now, I don't know...that is the band "B" oscillator coil, part (25).

[Ron Ramirez]

Mike (morzh), I edited my post before your last reply so you may not have seen my edit. I soldered it to the proper terminal on the band switch after I took the picture.

I know in the photo that it looks like that terminal is touching the grounded terminal of the terminal strip, the terminal that is cut off. It isn't touching it at all, really. The angle of the photo makes it appear that way, though.

[morzh]

No I was not worrying about touching the GND, it was about no solder, but now that you said you soldered it, I am worrying no more

[Ron Ramirez]

Acked, and understood. I just wanted to throw that in there about the lug appearing to touch the terminal strip, since the photo does make it appear that way.

[OZ4]

Look's great Ron. Hope nobody already asked, but How did you decide on what color wires to use where?

[Ron Ramirez]

For the most part, I used the same colors for the new wires to match the original colors of the old wires.

Philco didn't always follow the RMA color code in their wiring, although they claimed that they did so in the May 1934 issue of Philco Serviceman. Chuck wrote about it 10 years ago at the other forum.

So most if not all of the filament wires are red; B+ is white or yellow; black is ground for the most part.

[Chuck Schwark]

Ten years ago!?!   

Tempus fugit

Well, now that I see my Joined Date just to the left, it
makes sense, but sheesh!

<<<----------------

[Ron Ramirez]

Today was the day for opening and restuffing electrolytic capacitors.

[Image: http://www.philcoradio.com/images/phorum...770-45.jpg]

Here is cap (78 ), originally 40 uF. Next to the old can is a new Nichicon 39 uF capacitor which will be used inside the original can.

You can see that I've already cut the top of the can off, as it is also shown in the picture above.

[Image: http://www.philcoradio.com/images/phorum...770-46.jpg]

After cutting off the top of the can, I carefully remove the old capacitor's anode. I used a drill to slightly enlarge the insulated hole where the anode came through the bottom of the can. Using a smaller drill bit, I also drilled another hole just below the threads of the can; this is for the negative lead.

I then ran a scrap piece of 10 gauge, solid, insulated electric wire through the anode hole, and a length of 22 gauge wire for the negative lead through the smaller hole.

I soldered the positive wire of the new electroytic to the heavy electric wire, and the negative lead to the thin wire. It is very important that both joints be insulated from each other!

I also added some hot glue where the wires were insulated with heat shrink tubing. You want to be careful and not get the hot glue on the bottom of the electrolytic. Some of them can take the heat; some can't. I learned this the hard way. But it is good to get a glob of hot glue on the wires, well below the bottom of the electrolytic (and not touching it), for added insulation between the electrolytic and the old aluminum capacitor can.

[Image: http://www.philcoradio.com/images/phorum...770-47.jpg]

The next step is to carefully pull the wires back down so that the new electrolytic goes down into the can.

[Image: http://www.philcoradio.com/images/phorum...770-48.jpg]

Peek-a-boo...

The top of the 39 uF Nichicon can be seen inside the can.

[Image: http://www.philcoradio.com/images/phorum...770-49.jpg]

Now all that remains is to attach it to the radio chassis, and then glue the top of the can back on.

[Image: http://www.philcoradio.com/images/phorum...770-50.jpg]

I rebuilt capacitor (79) in a similar manner. It was originally 18 uF; it is now 22 uF. The only difference with this one is that it had disc insulators on both sides of the chassis, to isolate it from the chassis as its negative side (can) is at B- potential, more negative than chassis ground.

There is a third electrolytic in the 39-770 - part (47), 3 uF. It was in a smaller can that mounts to the chassis with two studs and nuts. It had (and has) wire leads. It was easier to restuff than the others, as it was simply a matter of pulling the original innards out and installing a new capacitor.

In the photo above, all three are now mounted to the chassis and wired into their respective circuits.

[Image: http://www.philcoradio.com/images/phorum...770-51.jpg]

A back view of the chassis showing the newly restuffed electrolytics in place.

[Image: http://www.philcoradio.com/images/phorum...770-52.jpg]

A closer look at the three restuffed electrolytics.

I will glue the caps back on the larger two electrolytic capacitors once I've tried the radio out and know that all is OK with them.

[Ron Ramirez]

[Image: http://www.philcoradio.com/images/phorum...770-53.jpg]

Everything seems to be finished underneath. The next step is to test all of the tubes, and then try it out.

[Ron Ramirez]

Not so good news...

[Image: http://www.philcoradio.com/images/phorum...770-54.jpg]

It doesn't work right.

At first it would not pick up anything.Then I noticed that the filament of the first audio amp, a 6J5G, was not lit. And I had just tested it! Well, I had a metal 6J5 on hand and stuck it in the socket instead.

Now, it made a little noise. It receives nothing on AM, or on SW bands C or B. It works on SW band A, as I was able to tune in a few stations including WWV.

Oh, and I found out that I wired the tone control backwards. That will not be difficult to fix, though - I only need to switch two wires around.

Time for further testing...

I aligned the IFs and that was no problem. With the radio set to the AM band, I tried injecting a 640 kc signal at the grid of the 6J8G det-osc tube. The radio received the signal. I then moved the generator to the grid of the RF amp. The radio still received the signal. But with the generator on the antenna terminal...nothing.

Like I said...time for further testing...

[sam]

Ron
Great job on cans
Stupid j5' s 
Come on just wire fix you can do it 

[OZ4]

Ron
After all the nice work I can't believe you are not going to give that power transformer a shot of paint.

[Ron Ramirez]

After all the nice work I can't believe you are not going to give that power transformer a shot of paint.

I'm not finished yet.

I did a little troubleshooting tonight. The RF and det-osc tubes are both receiving the correct voltages. The antenna coils have good continuity.

There is one thing that puzzles me. Capacitor (12), 250 pF. On the top side of this cap, where the signal generator is basically connected direct to the grid of the RF tube, I am able to pass a signal. But on the other side of this cap (the end which connects to terminal C4 on the band switch and to the first stator of the tuning condenser), it does not pass a signal.

The same is not true of capacitor (17), also 250 pF, in series with the grid of the 6J8G. I can pass a signal from either side of (17).

Maybe (12) is bad?

I'll find out tomorrow...

[Ron Ramirez]

Okay!

As I began troubleshooting this morning, I noticed something that, if it were not causing trouble, would do so in the future:

[Image: http://www.philcoradio.com/images/phorum...770-55.jpg]

Pardon the less than optimal quality photo, but if you look closely, you will see that part of the mica insulator is missing under the adjustment screw and plate of this compensator. This is the antenna trimmer for the AM band at 1500 kc, on top of the left gang of the tuning condenser (as viewed from the back).

For comparison, look at the RF trimmerr for 1500 kc, on top of the center section of the tuning condenser gang:

[Image: http://www.philcoradio.com/images/phorum...770-56.jpg]

You can see the mica sheet is still there under that trimmer.

I disassembled the antenna trimmer and removed what was left of the mica sheet (not much, actually).

Next, I cut a piece of clear plastic from a discarded blister pack:

[Image: http://www.philcoradio.com/images/phorum...770-57.jpg]

A better replacement for mica sheets in trimmers is clear plastic report covers as they have more flexibility. But I didn't have a report cover around, so I settled for second best. At least this will keep the two halves of the trimmer insulated from each other.

[Image: http://www.philcoradio.com/images/phorum...770-58.jpg]

I replaced mica cap (12) also. The left terminal broke as I was removing the wires, so I made another terminal from a couple loops of wire wrapped around and through the hole in the terminal. After reassembly, this is how it looks now.