[R-390] R-390A gear train help/advice needed (long)

[Phil Mills]

Hello,

I've been working on my R-390A with an apparent 1st mixer
problem for almost 2 months now.  I finally concluded that
the first mixer isn't working because the output tuned circuit
(aka first variable IF) is way off and therefore the mechanical
alignment was highly suspect.  So, I removed the Utah plate
from a workng R-390A that I'm keeping for a friend and compared
the two units.  My radio's slug rack levels are way different from band
to band as compared to the working unit.  The comparisons were
made with the KC dial set to +000 and I also watched the
1st variable IF rack not move much at all as I tuned from 7.000
to 7.500 which is not correct.

As an aside, when I first started work on the radio, I discovered that
the clamp on the shaft to the crystal oscillator was loose and I had
to set the oscillator switch to the correct position and tighten the
clamp.  Therefore, I suspect that someone has "overhauled" the
gear train and perhaps did not get it back together correctly or
left another clamp loose.

I have verified that the slug rack cam lobes are lined up as 
shown in the manual.  I have also verified that the bandswitch
itself is correctly positioned in reference to the MC dial.
It just appears that something in the gear train has got the
"starting point" for the slug racks way off as you go from
band to band.  It seems like the MC indicator says "7"
and the bandswitch is in the 7 MC position but the gear
train and slug racks are positioned for some other band.

Can anyone off advice as to where to look in either the manul or
geartrain itself to resolve the problem?

thanks, Phil   W5BVB