[R-390] Megacycle Change Detent Lube?

[Flowertime01 at wmconnect.com]

Mike,

The current century lube of choice is some Mobil 1 synthetic oil. Pick up 
an empty can from the trash of your local Mobil Station and have a large 
supply. Buy a whole quart and treat your lawn mower and receiver forever.

-----
The big ring of the megacycle shaft with the detent notches in it grinds 
into the detent stop spring plate. It will cut a notch through the stop bump 
on the spring plate. This is because the spring plate is adjusted to tight. 
It is adjusted to tight because the whole gear train is not clean and lubed. 
It takes to much friction to keep the MC setting still as the KC is changed.

Once you clean the whole gear train and lube it, much less friction is 
needed to keep the MC from falling out of the detent.

You install a couple of washers under the detent spring plate to move the 
grove off the detent ring. Adjust the spring plate to just hold the MC shaft 
in the detent.
Moveing the spring plate wear off the MC shaft detent plate will make the 
MC shaft operation much soother.

Hang your receiver off the front edge of the table.
Get your foot out of your combat boot. Tuck the aglet ( the little plastic 
end cap) of your combat boot shoe lace into the KC knob hole. Wrap the lace 
around the KC knob twice. If the weight of the boot will not unwind the lace 
off the knob, your gear train needs cleaning and lubing.

That test may not be exact or scientific but it should give you some idea 
of how easily the gear train should move. If your receiver is giving you a 
sore wrist your receiver may need maintenance.

Undo the RF slug rack springs from the rack tops.
Remove the springs from the RF deck.
Take the RF slug rack out of the RF and variable IF sections of the RF deck.
Clean the little roller wheels and lube with Mobil 1 synthetic oil (any 
grade).

Take the receiver out side on a sunny day to the picnic table.
Hang the RF gear train over the end of the table.

Take care not to get any stuff (any stuff = water, lube, cleaner, crud or 
any stuff) into the fiber bushing at the top of the antenna trim can on the 
RF deck.

You will need to turn the receiver up side down and clean top to bottom and 
bottom to top.

Compressed air helps a lot. Brush in some cleaner and blow it through. Turn 
the gears a ways and clean some more. Work top down and bottom up.

A wet vacuum works nice. You can use some duct tape to make a small dia 
pick up.

You can brush in some solvent and vacuum it out.

Oil heavy and blow out as much as you can. This will work it in every where 
and still get the excess out. You can do this without getting the antenna 
bushing messed up. You can just wipe it often and quickly if you do get it 
moist.

The two shafts MC and KC go through front panel bushings. It is worth the 
time to loosen the nuts and align these bushing for minimum friction.
You may want to move the VFO around a bit and gap the oldham coupler a bit 
to releave any gear train binding from the VFO. The VFO front bushing may 
need cleaning and lubeing.

Look into the dial lock and ensure the lock is not dragging on the KC dial 
lock plate. 
Check that the Zero adjust comes free from the Zero adjust clutch and is 
not dragging.

Hope this all helps you to get a nice smooth gear train.

Roger Ruszkowski