[TowerTalk] 4 Square phase line length question

[Michael Tope]

From: "Tom Rauch" <w8ji at contesting.com>
To: "Jim Lux" <jimlux at earthlink.net>; "Dan Levin" <dan at andlev.com>;
<towertalk at contesting.com>
Sent: Saturday, May 08, 2004 7:23 PM
Subject: Re: [TowerTalk] 4 Square phase line length question


> > Here's the interesting thing..I assume you're using some
> scheme where you
> > use 1/4 wavelength lines for current forcing, right? so
> the element current
> > will be what it should be, regardless of the element
> impedance.  The
> > mismatch at the feed eventually winds up back at the
> hybrid/phasing network,
> > where you can take it out by changing the L or C of the
> phasing network (or,
> > just ignore it, and take it out at the array feed point).
>
> Forcing equal currents requires equal input voltages and
> correct input voltage phase. 1/4 wl away that becomes equal
> currents and with correct current phase.

I hadn't thought about it before, but since the 1/4 wave lines
force equal feed currents for equal input voltages, one could
use a dual-trace oscilloscope at the phasing network/power
splitter to set the relative amplitude and phase of the element
currents. Seems like that would make it really easy to get
the array currents dead nuts on.

73 de Mike, W4EF..................