06-29-2015, 05:26 PM
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.
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.
Charlie in San Antonio
