[R-390] RF Deck, Module Washing (dishwasher)

[Tisha Hayes]

While reviewing the latest draft of the R-390A inspection process I found a
few references to cleaning the RF deck in a dishwasher (Page 9, Section 4,
activities 8,9). This brings up an interesting point for discussion and I
wanted to share with the reflector on my experience with cleaning a radio in
the dishwasher.

I have a bunch of ARC-5 stuff, one item that joined my collection was one of
the ARC-5 transmitters that was in pretty rough condition as far as being
loaded up with dirt. Worried about things like Haunta-Virus (from rodent
droppings) or the many other things that can go wrong I decided to give this
thing it's own cycle in the dishwasher. I pulled the tubes and the crystal
reference plug-in and set it all by itself in the dishwasher. Since it IS a
dishwasher you cannot use detergents that foam up so I dropped a Dawn
dishwashing packet into the machine and let it run through a cycle.

This was set to the most aggressive cleaning cycle on the dishwasher (heavy)
with heat drying at the end. What came out looked really nice, the aluminum
was even shiny. I had pulled off the bottom plate so the soap and water
could get up inside, below the tube sockets and removed the tube removal
plate on top and left open the front IF coil adjustment window and the
little flip-door at the back top of the radio. The antenna tuner worked
really nice and it even cleaned up most of the tarnish on the contact wheel
and the turns.

Not thinking much more about it, and wanting the thing to sit for quite a
while before I applied B+ to wiring that still had some moisture in the
cloth I left it to sit on top of a heating register in my office for a few
weeks.

When I got back to it the aluminum had taken on a terrible, tarnished look
(greyish-black in appearance). It seems that the aluminum did not like the
dishwashing method. Strange since my kitchen cookware is also aluminum and
it does not seem to mind.

The point I am trying to make is that a dishwasher is probably not the best
way to wash radio modules or the RF deck. Any kind of detergent that is
rated to run in a dishwasher (non foaming) is fairly aggressive. I do not
think you can run Simple Green in a dishwasher, at least not MY dishwasher.

Can other folks elaborate upon their attempts to clean modules in a
dishwasher? (if you have tried it) What were your experiences?

It is one thing to mess up an ARC-5 (that I have almost a dozen of),
something completely different to put an RF deck or R-390/A module in there.

Maybe it is best to stick with the Simple Green, parts brush, garden hose,
followed with distilled water routine. If the dishwasher is a bad idea we
may want to remove references to that technique from the R390A Inspection
Process guide.
-- 
Ms. Tisha Hayes/ AA4HA
-
Optimist: *The glass is half full.*
Pessimist: *The glass is half empty.*
Engineer: *The glass is not sized correctly AND we need a backup system.*