[R-390] RF deck, points of clarification

[Tom Frobase]

My procedure is as follows:

With a little effort the entire mechanical section can be removed.  From
memory, there are few screws holding it to the main chassis and a few 1/4"
hex screws and nuts under the chassis holding to the faceplate, I use a
small 1/4" box end wrench to remove these, you will also have to
disassemble the antenna trimmer assembly and unhook the band switch shaft.
 It sounds difficult but the results are much better this way.

Once this is complete separate the mechanical chassis from the electronics
section.  I also remove each of the ferrite slugs from the rack and sean
them as well, be sure not to mix up the RF deck and intermediate IF slugs,
they are different.

There have been a number of methods discussed on the list to clean the
mechanics, my current approach is to degrease the assembly in a large
ultrasonic cleaner first using a water based degreaser, alter that is
complete I use cheap sudsy ammonia cleaner to brighten up the brass and
aluminum, make sure this is done at room temperature.

Rinse thoroughly with clean water and dry, I use the hot Houston sun.  I
use a similar concoction as Trisha to re-lubricate.  I also revisit each of
the cam rider bearings to make sure they are free and lubed well.

When this is complete I remove each of the coil cans in the RF deck they
are held in place by a captive 4/40 screw.  I pull each of the cans apart
and clean the tops first with a tooth brush to remove the loose stuff and
then a rag with a small amount of denatured alcohol.

Once all the coils are off it is a simple task to clean the deck since
there to impede the cloth.  I use a cloth with denatured alcohol and a pair
of straight hemostats to clean inside the non removable cans and sockets as
well as using a deox cleaner on the plugs and sockets.

I have good success with this approach and have been using it since the
'70's.  When you button it back up only you will know what kind of effort
was spent doing the job and that is what counts! tom, N3LLL


For the cans the most I resort to is unplugging them and giving each a

> wipe-down with the aircraft grade of simple green. Then hand cleaning the
> baseplate underneath and maybe a dot of De-Ox-It into each electrical pin
> socket.
>
>
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> Ms. Tisha Hayes/ AA4HA
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