>
> 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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