On 3/1/2014 10:09 AM, Jim Thomson wrote:
Date: Fri, 28 Feb 2014 17:37:48 +0100
From: peter chadwick <g8on@fsmail.net>
To: MU 4CX250B <4cx250b@miamioh.edu>, Fuqua Bill L <wlfuqu00@uky.edu>
Cc: "amps@contesting.com" <amps@contesting.com>
Subject: Re: [Amps] Cool Amp Silver Plating
## The stuff works superb. I use vinal gloves or latex gloves.....like the
throw away types.
I started using those when building the airplane. By the box, they are
10 cents or less each
I prefer the tight fitting latex, but those are difficult to get on the
one hand. The left had has improved to the point where I can put on a
vinal or medium glove if I haven't used the hand enough for the "tone"
to cause the fingers to curl. Once that happens straightening the
fingers causes the thumb to curl in tightly. Pulling, or forcing the
thumb out, causes the fingers to curl and it's a very strong reaction.
At that point, putting on a glove is a lost cause. <:-))
You would be amazed at how the stuff works on relay contacts etc.
I have had several brand NEW 30-50 A
DPDT relays..like deltrol, P+B etc, that have int contacts on one or
both poles. Also same issue with
DPST and also SPST relays. If these types are relays are used
for RF switching... what usually happens
is you lose all RX. After the usual careful cleaning... I applied
cool-amp to the contacts..all of em....and
no more int RX. b4... with a fluke dvm, I would see typ 3-80
ohms. And 0.0 ohms after the cool-amp
glop applied. They also make another product, called conducto
lube..which is pure silver powder
in grease. Its used on sliding contacts and also relay contacts. I
have not tried it...yet.
I've found the flash coat of silver is soft enough that it works well on
the rubbing contacts, at least for quite a while even if it is very
thin.. I have not tried the silver lube either. I wonder if it's the
same as the "Arctic Silver" thermal compound? I use quite a bit of that
working with high speed computers (4 to 5 GHz). It'd be pretty pricey
to use as a conductive lube and it's meant to "cure" with heat and
pressure, so probably not a good lube.
## I also use it on all cu tubing tank coils on my hb amps. I also use it
on all cu straps...
like used on vac caps...and tank coil taps to bandswitch, etc, etc.
I hate the look of plane
jane copper. The finish on this cool amp stuff is superb...much better
than real silver plating.
last forever....and doesn’t turn black.
## Trick is to clean the cu 1st. I use JETS or SOS cleaning pads...... like
the wife uses
for cleaning pots and pans. Sorta looks like steel wool embedded
with blue powder cleaning glop. AFTER you cut the cu strap to length
and punch holes in it, etc, then form it to say the tank coil to
bandswitch etc.... then remove it...and apply the cool-amp goop.
Forget rubbing it on with a cloth. Use all 10 fingers and use latex
or vinal gloves to apply the goop. When every square inch is
covered... then rinse the piece in warm water..then let sit on some
paper toweling.... and use more toweling to gently daub it to remove
any excess water. DON’T SCRUB IT to get water off.
Likewise, pure silver plating results depend a lot on the base metal
prep and usually requires polishing when done. Not sure why the coolamp
plating doesn't turn black.
73
Roger (K8RI)
## The usual deal is to silver plate a whole mess of coils and straps
etc.....all in one shot.
## Plane CU looks awful imo. It will discolour and even look worse down the
road.
The cool-amp powder has an indefinite shelf life. When u make a
paste with it..... make the
paste in a little tiny container. You don’t want it too thin..u want
it thick.
Jim VE7RF
Whether it's worthwhile electrically depends on the frequency. At 144MHz, the
skin depth is 0.2 mil (0.0002 inch) and you need about 5 skin depths to keep
99% of the current in the silver, or about 1 mil i.e. 0.001 inch. At 1.8 MHz,
you need about 0.009 inches for 5 skin depths....
But it looks a lot nicer than oxidized copper.
73
Peter G3RZP
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