[Milsurplus] contact cleaners

[Brooke Clarke]

Hi George:

I have found that the number one problem with older equipment, after 
cockpit errors, is bad contacts.  This in my opinion is due to oxidation.
Many times just cycling the contact will break through the oxidized 
layer and restore function.  Note that contact includes any metal to 
metal joint, such as tube pins, any connector, including Gold plated 
ones, as well as moving contacts like switches.  I can see how a product 
called Deoxit would help with this problem.

For examples of this see my Hints & Tips web page at:
http://www.pacificsites.com/~brooke/HaT.shtml

I have been using Radio Shack "Lube Gel" on contacts once they are 
working.  It's a silicon grease, made under patent 5,037,566
<http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=5,037,566.WKU.&OS=PN/5,037,566&RS=PN/5,037,566>
Which I would paraphrase as saying that they go to a lot of trouble to 
keep oxygen out of this stuff.  So a thin coating of this insulator will 
prevent future oxidation.  It's rated for -45 to +450 F so normal 
electronics type temperatures are no problem.  Note that this is great 
stuff to put inside coax connections that are outside.  The dielectric 
constant is near the plastic used in coax and so is suitable for 
microwave systems.

Does anyone know what "D5" is or how it works?

73,

Brooke Clarke, N6GCE
http://www.PRC68.com

>To: hwhall@compuserve.com
>Cc: milsurplus@mailman.qth.net
>Date: Thu, 2 Oct 2003 08:19:59 -0500
>Subject: Re: [Milsurplus] contact cleaners
>From: aGEnuine Ham <gl4d21a@juno.com>
>
>Group:
>
>Follow-up on contact cleaners.  Wayne Hall asked a question which is a
>legitimate concern about cleaners and contact enhancers.  Are they
>conductive?  As far as I have been able to read, and my crude
>experiments, NO.  Apparently they displace whatever keeps contacts from
>making good contact, and permit good, metal to metal contact when the
>switch or whatever needs it, but on an insulator, they are
>non-conductive.  I have not run HIGH voltage (>300V) tests, nor have I
>tried to measure dielectric constant, but in applications ranging from
>some  low voltage, low power, battery operated microelectronics, to
>vacuum tube receivers (AR-88 and 51J-4 to name a couple of real switch
>eaters), I have experienced no problems which would lead me to believe
>the contact enhancer is conductive.
>
>Another note.  This is likely unnecessary, but after cleaning contacts 
>with Deoxit, I usually bathe them in lots of alcohol or Freon to wash all
>the corrosion and cleaner residue away before applying the enhancer.  I
>would be more concerned about residue from the contaminants being
>conductive than the enhancer.
>
>Has anyone ever seen a good treatise on this subject?  Someone needs to
>spend the time documenting the process and write it up.
>
>73,
>George
>W5VPQ
>
>
>
>  
>