[ccomer1955]

I have all three dials representing the same physical position for the gangs, now. And I did in fact already replace the resistors. One of the old wire wound ones was open (and cracked), and the other was only showing 460 ohms, so I replaced both. I also replaced the by-pass capacitor and both interstage transformers.

I experimented with tubes a bit. I even put a 200a in as the detector, but that didn't work at all. The rest of what I have is a mix of 201a and 301a tubes that test really well in my Triplett (in the 80s and 90s) and one ST 01a that tests in the 60s. I moved the 01a to the audio stage, and have my strongest tubes in the RF spots and the detector. What doing that gave me when I connect the antenna was nothing at the antenna post, and strong volume and clear signal that is tunable when I move the antenna to the grid of the 2nd RF tube, and a really strong signal and volume at the lead on the screw of the tuning gang beside the detector that has a lead going to the grid leak resistor.

I've noticed the fins of the tuning gangs are also just a bit off center relative to each other. I see a set screw that would require removing the RF coils to get to, but it might be worth it to do a good cleaning and get the gangs exactly true.

So, the audio phase and detector are working, the third gang and 2nd RF seem to be OK, too. My problem is between the grid of the 2nd RF and the antenna post, right?

Am I missing anything? I feel like I'm just about there.

[ccomer1955]

Correction: moving my strongest tubes to the RF spots and the detector has yielded a faint signal with the antenna on the antenna post. I have not looked into the antenna assembly as of yet except to measure continuity across the three points on the coil, but think it might be a good idea.

By the way, voltages are as follows:
F+=5v on all tubes.
Plate:
Audio 2=75
Audio 1=87
Detector=22.5
RF2=87
RF1=87

[Radioroslyn]

Well the voltage look good so I think you have something that is open. So let measure the resistance from the 1st tuning cap stator to the rotor. Then measure the resistance from the stator to the grid pin of the first rf tube. Measure the resistance from the ant post to the stator. Rotate the ant switch. All should show a low resistance.

Terry

[ccomer1955]

Well the voltage look good so I think you have something that is open. So let measure the resistance from the 1st tuning cap stator to the rotor. Then measure the resistance from the stator to the grid pin of the first rf tube. Measure the resistance from the ant post to the stator. Rotate the ant switch. All should show a low resistance.

Terry

You are on to something here! 1st tuning cap star to rotor=4.7 ohms, Stator to grid pin=689 Kohms!!!, antenna post to stator=16 ohms? But when I turned the antenna switch to the different contacts, the ohmage dropped to 2 ohms or so.

689K! I'm measuring the grid resistors, of course. In my defense, I am profoundly colorblind, so color coding is lost on me. I have to rely on position of the light at stop lights, and I simply misread 689K as 689 Ohms. Stupid.

I have to go to the local electronics store for the correct homage resistors, but I should have it soldered in by this evening. I guess your advice and a good night's rest is all I needed. I feel dumb, but excited. Thanks.

I have the new resistors in on both tuning caps, and the radio sounds clear and strong through my headphones. I'm wondering if the signal isn't strong enough to drive my AK model E speaker? At any rate, thanks for all the advice.

[Radioroslyn]

Don't feel bad I do it all the time!!! Resistance isn't critical it does need to be fairly low you could put a jumper across it and see if it works. That resistor is in there to limit the grid current so the tube doesn't oscillate. (that's how they accomplish neutralization)
Should drive the E spkr fine.
Terry

[ccomer1955]

It does, indeed. But I have one last annoyance with the set. A previous owner must have had the dials off at some point, and this person has put them back with no particular attention to placement. It turns out that most of my tunable stations are now found off the scale, so I will have to figure out where "1" should be and start from there. I'm guessing the lowest dial marking should represent the lowest amount of physical engagement of the stator and rotor plates.

[Radioroslyn]

It's been a long time since I've worked on one but I would guess that 1 should be with the cap closed and 100 at minamiun capacity. Doesn't matter much and when you tune in a station they wouldn't all be tuned to the same number.

Terry
ps After looking at a few pics I think it should be the other way around.