Thanks for the plug Dan. I did the tests you mentioned primarily at
28MHz a couple years ago. Increasing the wire size 1 gauge is better
than silver plating assuming you have adequate spacing between the turns
so that the Q is not impaired by the turns being too close together. I
still like painting the coil with high temp barbeque paint which had
absolutely no Q reduction and looks very cool.
73,
Larry, W0QE
Dan Zimmerman N3OX wrote:
>> Has anyone done any tests on the comparative Q between Silver plated,
>> enamelled and tinned wire coils? I've always felt that factory
>> enamelled wire stood a much better chance of retaining a good Q for a
>> long time as the surface of the copper should still be pristine under
>> the enamel. The other question is how long the enamel will last if used
>> at high temperatures. Carbonised enamel is probably worse than
>> tarnished tin!
>>
>
>
> W0QE found that there wasn't a substantial difference between shiny copper
> and terribly corroded copper:
>
> http://www.bnk.com/w0qe/inductor_Q_tests.html
>
> Metallic platings should be analyzed based on the skin depth of the plating
> at the frequency of operation... if the plating is thin and the conductivity
> is low, more current will just flow in the base metal.
>
> W8JI had this to say about Miniductor stock, which I think is all tinned,
> right?
>
> "Miniductor-type coils have a surprising amount of Q for the wire size, and
> maintain Q better as self-resonance is approached than larger coils. "
>
> I've heard others on this reflector suggest that silver or other fancy
> plating is good to make the coils look pretty, and I would tend to agree
> with that based on the evidence I've seen.
>
> 73
> Dan
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>
>
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