----- Original Message -----
From: "Pete Smith" <n4zr@contesting.com>
To: "Michael Tope" <W4EF@dellroy.com>; <towertalk@contesting.com>
Sent: Wednesday, April 18, 2007 4:08 AM
Subject: Re: [TowerTalk] 135deg cable
> But isn't current phase what phased arrays are all about?
>
> 73, Pete N4ZR
>
Yes, Pete, that's right. The 90 degrees lines are useful,
however, for converting two drive signal voltages with
a known amplitude and phase relationships into currents
with the same amplitude ratio and relative phase shift.
This is the so called "current forcing" property - that is
equal drive voltages force equal drive currents when each
drive signal is passed through a 90 degree line with the
phase relationship preserved).
So it is correct to say that a 90 degree line has 90 degree
phase shift regardless of VSWR as long as it is understood
that you are talking about current at the far end relative to
voltage at the source end. It's probably best to state that
explicitly so as to avoid the confusion between the properties
of 180 degree lines and 90 degree lines.
73, Mike W4EF............................
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