[R-390] RF subchassis separation

[Mark Richards]

Tom,

Thank you for the generous offer.

May I hold it in reserve?

Let me see if my repair works.  So far with gears installed and front 
plate attached, things seem fine.

I noticed some awful mechanical rubbing noise when bandswitch is 
rotated.  Looking at the differential gear assembly, and specifically at 
the outer steel ring, it seems to have been ground down quite a lot with 
some of the steel material actually separating in small threads (or 
strings).  My guess is that the megacycle change detent plate was 
improperly adjusted with way too much tension and over time the damage 
was done.  I filed off the excess disk material and adjusted the detent 
to be effective but not overly so, and the grinding noise is lessened, 
although I see that the disk, apparently because the bandswitch was 
operated repeatedly within a certain range, is slightly out of round!

It would be sweet if this R-390 spins like a swiss watch.. instead of a 
cheap timex.  Further assembly, lubrication, and adjusting will tell.

/K1MGY