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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