Gold has low conductance, but gold plating is usually very thin. Since it
has low conductivity it has greater skin depth and since gold plating is
usually around a micron thick most of the current flows thru the material
under it. However, it does provide for a good deal of protection for that
underlying material from corrosion. I have junked a lot of military
microwave stuff in my younger days that was used in aircraft. The cavities
were gold plated inside and out.
73
Bill wa4lav
At 11:14 PM 6/16/2005 +0100, hermans wrote:
>hoy All,
>
>Silver plated wire, we only used it in applications where very high Q
>was necessary. It helped stability in oscillator coils, since silver
>oxide has the same resistance as silver. So it is also OK for contacts,
>when Current passing through is not very low. ( less then few tenths of
>micro Amps).
>Gold .....is used for the same raisons, its good looking, but
>expensive.....
>Silver plating can easily be done with silver cyanide, but be aware it
>is a very very dangerous procedure when done at home without good
>knowledge and precaution. SO DON?T DO IT AT HOME.
>
>Jos on4kj
>
>-----Message d'origine-----
>De : amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] De
>la part de Steve Thompson
>Envoyé : jeudi 16 juin 2005 17:23
>À : amps@contesting.com
>Objet : Re: [Amps] copper or silver in tank circuit?
>
>Larry Carman wrote:
> > I was told by a pro amp builder to leave out the silver and use copper
>only
> > in the tank circuit. Reason: because it helps prevent parasitic on the
> > higher frequencies. I'm speaking of HF amps working to 30 MHz. Any
>Merits to
> > this???
>
>Not to mince words, it sounds nonsense to me. If that's the
>difference between a amp that's stable and unstable, them
>there's something much more fundamental needs fixing.
>
>I recall an article in RF Design (but not in fine detail)
>where the writer argued that oxidised copper wasn't as much
>of a problem as people sometimes think, as the current will
>tend to head for lower resistance paths, driving it deeper
>into the wire/tube/stripline.
>
>Will mentioned tin plating - I've seen harmonic filters
>(VHF, 200Wish) burn up pcbs and unsolder chip capacitors
>from the heat when enamelled wire was replaced with tinned
>to save on preparation time. Where the loaded Q is low, it
>will probably matter less.
>
>Steve
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