[R-390] Starting the tear down

[Bill Hawkins]

Friends,

Conversations like this are why I still read this list, after age has
made it
necessary to sell off the heavy stuff. Roger is a precious resource, and
I read
every word.

Remember that WD-40 is intended to displace water from naval equipment,
and
not to lubricate. You must re-lubricate, as Roger says.

My guide to washing electronics was Stan Griffiths of Tektronix. Your
main
concern is with ions left by the cleaner. Use plenty of compressed air
and rinses
with distilled (no ions) water. Use brushes to help remove dirt.
Compressed
air may not be enough.

Use compressed air from cans or whatever until water drops are not seen,
then
let it dry in hot sunlight or -20 dewpoints (only available in the
frozen north)
before you even think of applying power.

Completely ignore those who advocate using the dishwasher. The detergent
is ionic
and hard water will make it worse, not to mention the extreme
temperatures of
the drying cycle.

Yours for cleaner equipment,
Bill Hawkins


-----Original Message-----
From: Roger Ruszkowski
Sent: Sunday, November 25, 2012 4:46 PM
To: R-390 at mailman.qth.net
Subject: Re: [R-390] Starting the tear down


Robert,

The last two I done, I sun dried.

After pulling the slug racks and cans off the RF deck,

Hang the gears off the end of the table out in the yard.
 Buy two large cans of Wd 40 that you plan to spray 
both cans through the gears to clean them. The goal 
is not to see how fast you can get that done.

You may want to take some of the split gears apart to
wash between them. 

Work the WD40 in and blow it out with compressed air.
Spray it in and let it rest a few minutes and blow it all
out again.

Repeat until you have just used both cans.

Your trying to get 50 years of dust out and you will
not repeat this on that receiver again in your life time.

Then wash it all down to degrease and relube with 
Mobil One or other good synthetic oil.

No such thing as two much water into a receiver bath.

If you have a part that can not take water and dry out
without hurting it in an R390 or R390/A it needed replacing any way.

Do let the receiver dry out good.

Lots of compressed air to work out water and dust.

But that is no substitute for real air dry time.
It just get more dust out than a water wash.
You can not reach in and rub soap on every 
surface. The compressed air helps to reach in an rub
the surfaces you can not reach.

Roger AI4NI


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