[Amps] Skin depth: silver plating of tank circuit coil

[Jim Thomson]

Date: Tue, 05 Oct 2010 08:18:37 +0100
From: Steve Thompson <g8gsq at f2s.com>
Subject: Re: [Amps] Skin depth: silver plating of tank circuit coil
feasible with

Yes and no appears to be the answer - rf current doesn't take the 
lowest possible resistance path, it crowds on the outside surface 
of a conductor. Once there it appears to look for the lowest 
resistance path.

Steve

##  apparently, on a tubing type tank coil, it's  supposed to bunch up on the outside edge,and
at the same token there is supposed to be little or no RF flowing on the inside walls of tubing
coils.    Strap, on the other hand, will conduct RF on both sides.  3/8"  wide strap will handle as
much RF as  1/4"  tubing....since both have the same circumference.   I always suspected that was
the case... then read it in the infamous VO stoke's  TX book,,,, in the appendix, 

## IMO... I detest the look of plane, clean copper  tubing,strap, in tank circuits, or else where. It looks like
you built a house, then forgot to paint it.   I use the cool-amp glop on all of it.   Some of the 3/8"  tubing coils,
and straps of various widths.... [ up to 1.5" wide in some cases].  I did 10 years ago still have a perfect finish. 
On the same subject,  I have used cool-amp silver plating compound  on relay contacts, contactor's, sliding
contacts, buss bars etc,  and in each case the DC resistance drops to nil.  The stuff works superb on open frame 
relay  contacts.    Ever had relay contacts go open on RX.... but ok on TX...like on a remote switch box ?  
This  stuff will cure it.   After the contacts are 1st cleaned,  I apply the cool-amp glop.   When done,  an ultra thin layer
of their other product..called 'conducto-lube'   is applied.    Conducto-lube is  just pure  ground up silver powder, 
suspended in grease. Conducto lube is made for things like relay contacts, sliding contacts, etc.  

##  You have to be careful with 'conducto lube'.    Unlike  Dow corning DC-4  grease,  conducto-lube will
conduct..and very well.   You don't want to be getting any on  ceramic insulators.    I  have seen  several instances
of where cool-amp is used, where buss bars are overlapped, then bolted.  Power co's  buy it by the case load. 
Cool-amp has an indefinite shelf life.   I use latex dentist gloves,  when applying the glop.  Then you can get in there
with all  your fingers, and really get it applied  good.  When done, rinse off with warm water, then place on
paper towel's to dry.   I usually try and do a whole bunch of straps and coils, all in one sitting.  The CU  has to
be ultra clean 1st.   Nothing looks better than a big tank coil, made from 1/4...3/8...1/2"  tubing..when it has been
silver plated.   Same deal with the wide/narrow  strap. 

Jim  VE7RF