[AMRadio] Deoxit

[Donald Chester]

> I've noticed after years of using DeOxit that the? cleaning agent dissipates and all is left is the oil base.?

> Fix maybe to simply wash out the old and apply new...Hal/WB4AEG

My only experience with DeOxit was a (very expensive) tiny vial I purchased one year at Dayton.  I wasn't impressed. 

The best contact cleaner I have found is WD-40.  But use it with caution.  Do not let it get on phenolic switch wafers 
or other porous material, just the contacts.  I do this with a short piece of small gauge wire, bent an the end like a 
bobby pin.  Spray the WD-40 into a bottle  cap or other small container.  Dip the bent wire into it, and it will hold a
small drop at the bent end.  Then carefully transfer it to the contact without letting it get on anything else.  Another 
transfer method I have used for precision application is a small-gauge (#20) gauge hypodermic needle.

I have sprayed the interior of noisy pots, for example the AF gain pot on my 75A-4.  Contact and control cleaner
sold for the purpose would stop the noise for a few weeks and then it would re-appear.  In desperation I unloaded
a big swish of spray into the pot.  That  stopped the noise and years later it is still quiet.  I have also used it on the 
sliding or rolling contact of rotary inductors.

Sometimes before using a lubricating type of contact cleaner, a de-greasing cleaner used first will clean up the crud
and then the lubricating cleaner re-lubricates the cleaned contacts.

Don k4kyv