I guess 90 degree phase shift might result in a cardioid pattern?
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tom W8JI
Sent: Wednesday, June 12, 2013 2:58 PM
To: topband
Subject: Re: Topband: My Turn For a Brain Pick - Sanity Check
> Christman phasing is at 71 degrees? I was thinking 90 degree phasing.
> Whats the reasoning for this?
Optimum phasing of two verticals 1/4 wave apart is never 90 degrees, unless
the user for some reason wants a single-point zero-angle null and less than
maximum gain. Optimum element current delay for Ham use is always more than
90 degrees, and generally around 110-120 degrees, with 1/4 wave spacing.
Making things more complex, phase shift in a delay line is never the line
length unless the line is either 1/4 wave long or a multiple of 1/4 wave, or
the line has a reasonably well-matched termination.
With that in mind, a 71 degree long line might produce considerably
different phase shift than the electrical line length, and the user probably
wants phase to be some other value than 90 degrees (if the user understands
arrays and patterns).
73 Tom
All good topband ops know how to put up a beverage at night.
_________________
Topband Reflector
All good topband ops know how to put up a beverage at night.
_________________
Topband Reflector
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