[R-390] Z-201-2 RF coil

[Craig C. Heaton]

To All,

Got an issue with a R-390/A. Seems RF coil, Z-201-2 has something that has
gone south. In peaking this coil the adjustment for the slug is within 2
turns of falling out of the holder. Too far down in it's adjustment range
compared to the rest of the coils. When looking for a peak at 550KC and
getting the sig-gen & receiver at the same frequency, there are two peaks.
One is below and one above 550KC.

Moving to 950KC the trimmer capacitor has two peaks, but not sharp and very
little drop off in the voltage at the diode load connection, while rotating
through 360 degrees. I've had this trimmer apart, cleaned, inspected, etc. I
don't think the problem is with the trimmer.

Can't remember reading anything in the archives or Pearls of Wisdom with
this challenge, so here we are looking for a guru who has been down this
road. My thoughts are one or more of the silver mica caps have changed
value. Before drill'en & blasting, using the wire cutters, and large
hammers, what's wrong with this R-390/A??

Thanks,
wd8kdg
Craig