No subject

All the rotor plates except the slotted one had been removed from each 
section, but all the stator plates were still in place. 

There was some damage to two adjacent stator plates (and probably to the 
missing rotor plate that had been between them at one time) from what 
looked like an electrical arc, possibly a nearby lightning strike.

Suspecting that the remaining, unused stator plates might be the cause of 
the ringing, I very carefully removed all of them, leaving only one in each 
section.

During this process, I happened to drop one on the concrete floor and it rang 
at the same pitch as the ringing I had experienced.

I also carefully cleaned and lubricated the rest of the cap, removing, cleaning 
and reinstalling the wipers where I could.

Reinstalling the capacitor, the dial, the tuning knob, all the IF transformers, 
the tuning cap's shield can, and the tubes, I then fired it up.

Of course, the calibration was off from where it was before the latest 
"operation", but was easily brought into calibration by the trimmers.

The result was most impressive when I peaked the tuning on L3/C4D/C4F 
for the mixer grid. 

The signal from my cheap Eico 324 signal generator, set at its lowest 
possible setting, literally blew me out of the room when I peaked the mixer 
grid, which was a vast improvement over that before the latest operation. I 
had to turn the audio gain (which I had added) down very low to get a 
"reasonable" level of sound.

Furthermore, drift was minimal: from dead cold to 30 minutes later, the 
receiver drifted possibly 5 KHz (I am only guessing, but will measure this 
later), which was vastly better than it was before.

The antenna trimmer peaked easily as it did before.

Tapping on the receiver (with the BFO off) results in barely audible noise. 
There is no apparent frequency jumping or change, even following some 
harder blows. 

Much of what remains of the noise, is,  I suspect, coming from the can-cap 
replacements around the mixer/HFO which I installed as I was not able to 
mount them as solidly as the can-caps originally were. I'll fix that by painting 
everything in that area with several "layers" of Mike's coil dope and letting it 
solidify.

I will also work on the BFO next, and will let everyone know the result.

It appears that I am finally making significant progress.

I repeat: what a gigantic PITA. Who ever had the original idea should be 
horse-whipped.

Kenneth G. Gordon W7EKB

"Courage is being scared to death but saddling up anyway."--- John   Wayne