[TowerTalk] Antenna Grease--Deficiencies and Remedies

[Ken Hirschberg]

Gentlemen:  I've been following this thread for some time now.  Please consider
the following:  What is put into aluminum antenna element joints serves 2
purposes. First, lubrication for assembly and disassembly.  Second, and most
importantly, it protects the connection by excluding moisture and air at the
points of contact.

Contact between the pieces will occur between 2 or more points, depending on
how the pieces are fastened.  It is unnecessary to include metal particles in
the formulation to make a good connection.  Some of the commercial formulations
(e.g. NOALOX, Penetrox, etc.) that have been mentioned (and even used by
reputable manufacturers) are intended for electrical wiring.  The antenna
environment is a different, much tougher ball game.  If the carrier of these
metal-loaded formulations happens to be silicone-based and is thick enough,
there is little or no problem; if it is petroleum-based, it is quite likely to
be washed away, leaving a dissimilar metals problem.  (The copper-loaded
compounds, e.g. Penetrox B, can be really bad news)

What to do:
Simplify the problem; just use a thick silicone grease.  It has proven itself
in very harsh environments.  BTW, it is also the goop-of-choice to put inside
connectors such as PL-259's to exclude moisture.

Where to get it:
 Thick silicone grease is available as High-Vacuum grease, a Dow-Corning
product, from scientific supply houses.

GC (formerly General Cement) packs it in small tubes, which are available
through electronic supply houses; Newark, Allied, etc..

My company, CAL-AV Labs., supplies it in 1/4 oz. containers as part of the
assembly kits sold with our antennas; we would be happy to sell the grease
packs alone if you can not find them locally. (cal-av.com)

It is also available at SCUBA diving shops, typically in 1/4 and 1 1/2 oz.
packs or tubes.

Sincerely,  Ken K6HPX



wbh3@daimlerchrysler.com wrote:

> FWIW when I built my  kt34-xa about 7 years ago, KLM supplied a little can
> of  copper-colored paste to put on the joints.    After a move and whenn I
> was reassembling the end units I found this paste had turned very solid and
> seemed to be a good insulator as the resistance checks I made on each
> element end were very high.  Don't know what KLM used but I don't think it
> was very good stuff.
>
> Bill Haselmire  WX8S
>
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