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[TowerTalk] Loading Coils

To: towertalk@contesting.com
Subject: [TowerTalk] Loading Coils
From: "jim.thom jim.thom@telus.net" <jim.thom@telus.net>
Date: Sat, 2 Aug 2025 12:52:32 -0700
List-post: <mailto:towertalk@contesting.com>
Date: Fri, 1 Aug 2025 15:19:10 -0700
From: David Gilbert <ab7echo@gmail.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Loading Coils



Nickel has about 4 times worse electrical conductivity compared to
copper, and the skin depth at 30 MHz is about 20 times thinner (about 12
microns for copper versus about 0.65 for nickel).? ChatGPT tells me that
standard nickel plating is roughly 5 to 10 microns thick , and that even
low cost nickel plating is typically 1 to 2 microns thick.

The math agrees with you.

I wonder if anyone has made measured comparison of his coils versus a
similar copper one.

Dave? ?AB7E

##  nickel plated,  He's joking right ?  Years ago, I replaced the silver
plated copper tubing coil in a hb amp with an IDENTICAL  aluminum tubing
tank coil.  Talk about HOT.

Nickel ?    You may as well douse it with lighter fluid, and toss in the
zippo.
Measure the Q of the nickel plated coil vs the copper coil, or silver
plated copper coil......and you will be in for a rude awakening.

Nickel is worse than phosphor bronze.  I just ran a typ 160m  coil through
K6STI's ' coil'  software....and using copper the Q was 1222.   With
phosphor bronze, it dropped to 464.....and nickel plated is even worse !  (
aluminum was a  Q of 857  using 3003-0 alloy).

No doubt he wanted nickel so it was weather resistant.

I wind my own copper tubing coils....then silver plate em.

Jim  VE7RF
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