----- Original Message -----
From: Gary Schafer <garyschafer@attbi.com>
Cc: <amps@contesting.com>
Sent: 05 October 2002 04:37
Subject: Re: [Amps] skin effect
> "There is a very good article in the Nov/Dec 2000 issue
> of QEX concerning skin effect and losses in
> antenna conductors. It has some interesting points
> such as the fact that stranded copperweld is not
> as low loss as solid copperweld below 10 Mhz; that
> copperweld can be better (lower loss) that
> solid copper under some conditions; and that skin
> effect can cause higher losses on the lower bands
> than it does on higher bands, especially at high
> current points and particularly when antennas are
> loaded causing higher currents. The reason is the fact
> that skin effect decreases more slowly as the
> square root of decreasing frequency while the
> conductor length increases more rapidly in inverse
> proportion to decreasing frequency. In other words,
> your adding wire at a faster rate than the
> conductor resistance is decreasing."
At longwave I think the actual skin depth comes into play as well - it's
around .15mm/.005" so if the individual strands in a bundle are too thin,
you lose out.
A useful place for UK readers - www.wires.co.uk - every size of copper wire
you can imagine, multistrand wires, silver plated copper and, for the
esoteric, gold plated pure silver.
Steve
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