[TowerTalk] Lubricating air variable capacitors

[Pat Barthelow]

You might want to look up Molydenum grease, or possibly litnium grease to 
see if it is corrosive. (I cant rember which one I used, it came out of a 
metal squeeze tube, and was an opaque, tan color grease)
Some years back I lubed the precision gears in the VFO/bandswitches in  an 
old TCK 7 WWII vintage transmitter....  Check out this picture; behind the 
chassis panel VFO dials are a machinists work of art (or nightmare, 
depending...)  I'd really like to find out what the manufacturing cost of 
these beauties were, at the time....400 watts out AM or CW, Pair of 813's  
I'm betting some equivelant in todays dollars of  $50K or more....

http://www.home.earthlink.net/~navyradio/id14.html

(a machinists work of art, makes the R-390 mechanicals look simple) and was 
shocked to see crusty oxides, corrosion of the gear teeth after a number of 
months... Somewhere I looked up the chemical and found that it was 
corrosive, if perhaps only to aluminum...

73, de Pat aa6eg at hotmail.com

>From: "Barrie Smith" <barrie at centric.net>
>To: <keith at dutson.net>, "Towertalk" <towertalk at contesting.com>
>Subject: Re: [TowerTalk] Fw:  Lubricating air variable capacitors
>Date: Sun, 2 Oct 2005 20:20:55 -0600
>  DuPont also makes a Teflon white
> > lithium grease in a spray can that would work as well.
>
>I was trying to think of that earlier.  We use it on various machines at
>work.
>
>If this is an old variable cap, chances are that not only does it need
>lubrication, but it needs to be cleaned.
>
>If the cap is intended for HV use, the accumlated junk on the plates will
>lower the working voltage considerably.
>
>I have a bunch (bunch=too many) of old variable caps here.  Since I've
>recently aquired a hi-pot tester I've been hi-potting everything.
>
>I'm amazed at the amount of leakage a cap will have before cleaning, and 
>how
>little it will have after.
>
>Also, don't forget to put contact cleaner on the wiper.
>
>Moving right along to WD-40 and my garage door:  For years I had to lube 
>the
>hinges on my garage door every couple of months, especially in the winter
>(which last 17 months, here in Montana), since the motor was just barely
>capable of lifting it.
>
>A couple of years ago I used 3 in 1 oil on all the hinges and have not had
>to lube it since.
>
>WD-40, when I'm out working on a tower, works great as a wasp killer.
>
>A friend of mine, who is in the tower business here, uses disc-brake 
>cleaner
>as an effective, and less-costly alternative to commercial wasp-killer.
>
>Whatever and 73,
>Barrie, W7ALW
>
>
>_______________________________________________
>
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>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any 
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>
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