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Re: Topband: Zo of an individual CAT5 twisted pair

To: topband@contesting.com
Subject: Re: Topband: Zo of an individual CAT5 twisted pair
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Wed, 14 Aug 2013 01:04:55 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
On 8/14/2013 12:42 AM, Tom W8JI wrote:
The important point is voltage from each conductor to surroundings is what really determines the gender of balance, because ideally both coax and twinlead have equal and opposite currents in the two conductors.

Ideally = Alice In Wonderland. I've never met anyone who lived in the ideal world who wasn't smoking that funny smelling stuff.

This "ideal" makes the wildly optimistic assumption that the terminations on both ends are balanced, which is rarely true. The problem is that noise cancellation depends upon very DEEP cancellation, which required equal magnitude AND equal phase. That's a lot to ask of a real antenna, and of a real circuit, over a limited range of frequencies, let alone a wide range.

73, Jim K9YC
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