[R-390] R390 (non-A) broken tuning slug

[Roger Ruszkowski]

Kevin,

The real trick is not to drop the springs through the hole into the RF deck so that
you have to pull the deck to get the spring back.

Run the slug rack to the bottom of the travel.
Loop a small wire / good thread under the top of the spring.
Lift the spring off the slug rack.
Do not drop the spring into the RF deck.

Going back, hook the deck end first,
and lift the spring up onto the slug rack.

Once you have the springs off, the slug rack will just lift out.

Clean and lube your guide pins. The R390A has rollers
in the newer production runs. Early R390A had fixed pins
like the R390's The fixed pins look just like the rollers but do not 
have moving parts. Pins and rollers that have been neglected
get flat spots.

Putting the slug rack back in can be a bit tricky.
You have to get all three slugs started into the coils at
the same time.

Just try it once as a learning experience.
The next time you do it you will be a pro.

You may want to loosen up the two small bolts the
hold the slug adjust nut to the slug rack.
Run the slug rack all the way down and let the slug nut plate
float to a best alignment position to center the slug location 
under the slug rack. Tighten up the two small bolts for the
slug nut plate. Repeat for each slug. You would only do this 
after you repaired or changed a slug. You need not get the spring center
or exact after a repair. Do an alignment on the top end with the slug
up out of the coil. Then run the rack down, and float the nut plate
to a position of minimum friction. If there is some off set between the slug and the 
adjustment screw, just let the nut plate float free while you get the thing mostly
aligned. Then you can tighten the nut plate bolts. You will not be spinning the
slug several turns, so it will mostly hang with minimum friction. If you do need
to make a 1/2 turn adjustment, you may want to re adjust the nut plate center.

You can do the spring release and re install with a good pair of needle nose pliers.

You can super glue the broken slug.

You can re solder a broken spring between the 
adjuster and the slug.

You can re glue a spring that has separated at the slug with epoxy.

A break in the slug will change its properties but it can be re adjusted to fair 
performance.

If you need a replacement slug ask for one here and see if you get
for an offer direct. You may get offers on your original mail.

Some of the Fellows have parts for sale but in such limited
quantities it just is not worth the time to make a list.

Ask for what you need and see what you get offered.

Roger