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TopBand: Slinky Beverages

To: <topband@contesting.com>
Subject: TopBand: Slinky Beverages
From: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
Date: Fri, 1 Aug 1997 09:24:36 +0000
Hi Carl,

I won't repeat your tirade.

The surge impedance of a conductor is greatly affected by distributed 
inductance and capacitance. Impedance is governed by the surge 
impedance of the structure, not by the fact we "call it" a Beverage. 
Winding wire in a mutually coupled string of "coils" increases L much 
more than C. We use that effect for phase delay lines, as well as to 
wind inductors.

You seem to disagree, but directivity of a traveling wave antenna is 
GREATLY affected by PHYSICAL length. It is possible to get good 
directivity in short antennas, but phase delay and current 
distribution along the wire needs to be correct. (Any antenna, 
however, is always better than no antenna at all.)

If you send me a Slinky Beverage, and the typical dimensions you 
suggest, I'd be happy to measure the surge impedance and 
propagation delay along the wire.

If have personal comments, please reply by e-mail or in person.

73, Tom W8JI 

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