Topband: Verifying integrity of 75 ohm coax.

[Mike Waters]

Anything is possible, but I know what I used and saw, Tom. It was a small
squeeze tube labeled "silicone dielectric grease".

I was the only person that serviced electronic equipment in that company
where I worked full-time. I put that stuff on an expensive feed rate switch
on an Allen-Bradley CNC mill control, after replacing that switch a number
of times. Very soon afterwards (a few weeks instead of perhaps a year), the
operator called me over to show me the problem with that switch. I know
what I saw, and I am convinced that it is abrasive. That grease accelerated
the failure of that switch by a tremendous amount.

I should point out that that switch got manually rotated throughout its
full range many times per day by the machine operator.

"According to Permatex's own information Dielectric Tune-Up Grease contains
up to 10% (by wt) of silicon dioxide (silica). This is a very effective
abrasive, and although Permatex claim it is not microcrystalline silica,
larger particle sizes will only grind the silver plating off rather than
polish it off".
http://forums.qrz.com/showthread.php?301386-RF-Roller-inductor-maintenance&p=2271612#post2271612

73, Mike
www.w0btu.com

On Sun, Nov 24, 2013 at 12:40 AM, Tom W8JI <w8ji at w8ji.com> wrote:

> Silicone dielectric compound ("grease") should not be used as a lubricant.
>> It's actually somewhat abrasive.
>>
>>
> I think you had something else going on, Mike, or you did not use the
> stuff being sold as dielectric compounds.
>
> http://en.wikipedia.org/wiki/Silicone_grease
>