[R-390] Latest update on the EAC R-390A

[Tisha Hayes]

Since you have the RF deck out I would give the gears a nice bath in a
solvent to remove grease/crud and re-lubricate with a high quality
synthetic (I use Mobil1 that is mixed with tungsten disulphide and
dispensed with a syringe, one drop per gear shaft)

If you are not afraid of pulling off the slug racks (held in place with
springs so be careful) maybe use a Q-tip wetted with alcohol to swab out
the slug bores. Gently wipe down the slugs with a piece of tissue paper
wetted with alcohol. Using a different Q-tip, and after everything is dry,
swab in a very slight amount of talc (baby powder) into the bores. Clean
off the cams, using your fingertip on every cam to look for a rough spot
(if a cam cuts your finger, you found a rough spot). Make sure the slug
rack end bearings are clean and spin freely, give them a drop of synthetic
lubricant and carefully re-install the slug racks. (the springs are very
sensitive to any sort of sideways abuse, even being banged about by their
own weight so be careful and do only one rack at a time so you do not mix
them up (different core materials are in use, you cannot just use any core
on a particular slug).
Maybe take the clutch mechanism off the front (complex set of gears in a
pack, right at the front) and let it soak overnight in penetrating fluid,
give it a few blasts with an cleaner (like brake cleaner) to drive out the
penetrating fluid and then use synthetic lube and re-install [that gear
pack has been a continual source of headaches for me, on three restores
each one of them would not engage the dial lock so I could re-zero to
odometer and they all needed "good luvin"]

Try to clean up the aluminum base plate that is under the RF deck.
Carefully clean up the long ceramic rotary switch decks with De-Ox-It (more
cotton swabs). Do not bend or break anything. Make sure that the rotary
switch mechanism lines up exactly when you do the MHz dial turns and that
the little MHz indicator telltale, odometer dial and rotary switch decks
are all happy through all 30 positions.

I did a few additional (and some will say unnecessary) additions before I
dropped the RF deck back in place. I added conductive elastomer (U shaped
rubber gaskets) to the bottom of each aluminum compartment under the RF and
IF decks (held in place with a dot of super glue every few inches) to give
better isolation between sections. (there is a little known mod out there
for adding finger-stock under the IF deck). The conductive elastomer is
about 20 years newer  technology than the finger stock alternative and I
had a big spool of it (use it on all sorts of test equipment and radios for
gasketing).

Hopefully you will never need to pull the RF/IF/crystal deck assembly out
again as it is a Pain in the A.. to do. Since you have gone this far, spend
the extra evening taking these minor steps.

-- 
Ms. Tisha Hayes/ AA4HA
-
"Life isn't about how to survive the storm, but how to dance in the rain"