[dseverson]

Haven't done anything with the antenna coil (loop?) yet. I am going to rewind it with 38g magnet wire. Looks like it's 19 to 20 turns.

[Radioroslyn]

That will make it not work.
Terry

[codefox1]

Here's schematic.  Looks like someone subbed a PM speaker and used old output transformer.  Unplug set, scratch a 9 v battery arainst primary of output transformer and you should hear a click.  Next, replace the filter capacitors at very least before powering up again.

[dseverson]

The first thing I did was replace the caps and resistors and I got the click from the speaker and 9v battery.

[Radioroslyn]

Hi Codefox
I think we are getting to the bottom of this set. Seem like everything is working but it has no antenna coil (missing I think) All of the other stuff has been looked at and checked.
Terry

[dseverson]

Should I try replacing the 47uf filter caps with a higher rating? I rewind the antenna loop and got some static but nothing else. I think I will go back and replace all the caps again to see what happens.

[Radioroslyn]

Nah the 47uf are fine. Did you try adjusting the trimmer that the ant loop is connected to?? Do you have a signal generator?
Terry

[dseverson]

No, I don't have a signal generator and I haven't adjusted the trimmer.

[dseverson]

Well, it looks like I have a short somewhere. The dial light went out but I wiggled 35Z3 and it came back on. I then wiggled 50L6 and got static. Poking the mica cap on 50L6 gave static, too. I've been looking hard at all the wires but I cannot see any breaks or loose wires or anything else obvious. Something must be loose or shorted, right?

[Radioroslyn]

Prime suspect is dirty tube sockets/bad connection where pins meet socket.
If you think the 250pf cap on pin 5/50L6 is bad you disconnect it Set will work without it.
Terry

[dseverson]

I noticed I have one end of the antenna loop connected to Pin 2 instead of Pin 3. Have to fix that later this evening.

I don't think the 240pf is bad. It seems like the pins it is connected to on 50L6 are loose or dirty. I get static from the speaker when I gently push on the cap. I'll clean and check the connections again after I fix the loop antenna connection.

[dseverson]

Well, I cleaned all the tube sockets and it looks like there is some progress. Now I get a loud hum from the speaker but it isn't affected by the volume control. In other words, the hum stays the same whether at high or low volume.

I checked the resistors and found that the candohm resistor is now measuring 82ohms and .7ohms instead of 80ohms and 40ohms. When I first checked it, it was fine. I'll change that out for new 10w resistors I have.

[dseverson]

This is weird. I fixed the cadohm resistor and the loud hum went away. Put the antenna loop on the right tabs. Cleaned and tightened the tube sockets. Changed out the tubes. Adjusted the antenna trimmer. Still nothing but some light static. Even now when I touch the center tab of the volume control, the radio picks up one station, faintly, no matter where the dial is set. Is it possible the tuning condenser is bad?

[Nick3092]

If you only get one faint station and it's there over the entire dial, I believe that is an oscillator issue. Recheck your 7A8 voltages. And with the radio off, check the resistance from the proper tab to tab on the oscillator coil.

[dseverson]

Here are the readings I got:

7A8 - pin 2 = 160v, pin 3 = 161v, pin 5 = 84v

Oscillator measures between pin 2 and 3 = 6.8ohms and between 4 and 5 = 3.7ohms.