[R-390] RF subchassis separation

[Mark Richards]

After all of the excellent suggestions, I took a gamble and decided to 
leave the RF chassis in place and as is.  I managed to pin the loose 
shaft in place, and this took some of the pressure off.  Perhaps not a 
good move.

My focus switched to restoring the gears to much better condition than 
when I began (accomplished!), re-cap the AF and IF subchassis, and have 
at an alignment.

Unfortunately, it appears that the RF deck will indeed need to be 
removed after all.

The crystal calibrator is not working properly at all (the calibrator 
signal drifts wildly and sounds like there's 60HZ FM modulation on it); 
the bandswitch needs cleaning.  Likely a re-cap here will also help, too.

The receiver functions, with some bands turning in a tremendous 
performance (as compared to my FT-900 on the same antenna.. not at a 
point where I can make S/N measurements).  So overall I've got a good 
unit here, with hope.

Questions:

1. Must I disassemble all the gearing to remove the RF chassis 
assembly?  Would be nice if it could be left as is, but looks to be 
non-possible.  Raises the question why the design of the RF deck is not 
as modular as the rest of the receiver.  Maybe compromises...

2. Why are one of the green headed philips screws that hold the RF 
chassis to the main chassis partially obscured?  Even with a proper size 
screwdriver I can't get a grip on the screw head.  Is this expected?  
Looks as if I have to remove the rear panel and dig a bit...

3. Is is possible to mix and match the slug racks?  Faint memory of 
someone mentioning the materials of these slugs may have specific 
qualities for each position.  Unfortunately these were removed from 
their original locations without reference to where they came from.  Not 
by me :)

/K1MGY