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From: jeffw@midas.TEK.COM (Jeff Winslow)
Newsgroups: rec.audio,sci.physics,sci.electronics
Subject: Re: Mercury Filled Speaker Wire
Message-ID: <1933@midas.TEK.COM>
Date: Tue, 22-Sep-87 18:37:10 EDT
Article-I.D.: midas.1933
Posted: Tue Sep 22 18:37:10 1987
Date-Received: Fri, 25-Sep-87 07:08:11 EDT
References: <1549@culdev1.UUCP>
Reply-To: jeffw@midas.UUCP (Jeff Winslow)
Organization: Tektronix, Inc., Beaverton, OR.
Lines: 29
Xref: mnetor rec.audio:3383 sci.physics:2247 sci.electronics:1399

Let's be careful, debunkers...

In article <1549@culdev1.UUCP> drw@culdev1.UUCP (Dale Worley) writes:

>As long as we're debunking things, note that the "skin effect" (if
>it's the skin effect I know and love) involves a "penetration depth"
>measured in fractions of a wavelength.  Since the wavelength at 20kHz
>is ... hmmm ... 5 kilometers, it doesn't seem too significant.

According to a paper I have in front of me, skin depth at 1Ghz in copper
is .0002 cm, which is a *lot* less than a wavelength. And it is a fact
that windings in power transformers for switching power supplies running
at 20kHz must be oversized due both to skin effect and proximity effect.
I've designed several such supplies, and have worked closely with the
magnetics experts who designed the transformers.

>Humor Dept.: I remember hearing about a great audiophile discovery
>(I'm not making this up!): The electricity isn't conducted *in* the
>wire itself, but in a cylindrical shell *around* the wire.  Of course,
>this showed that to get *really good sound* you had to buy very
>special (and very expensive) cables (from the company that made this
>discovery).

Find a fields and waves book and look up Poynting's vector. Not that it
justifies this particular company's silliness, but it's probably the
source of their "justification".

		Jeff Winslow
		"Hit him again!!!" - Elektra/Strauss