Be aware that there is an error in Figure 1 of the article referenced below.
In Figure 1B, the curve of current versus position along the flattop is
correct only for the center half; current polarity *reverses* at each
current null, however, so the currents on the left and right extremities of
the flattop should have been drawn *below* the wire. This makes the
currents in the lefthand and righthand vertical elements opposite in phase.
Since the currents in the two end verticals are 180 degrees out of phase,
there are nulls in the low-angle pattern broadside to the array (i.e., into
and out of the page). However, since the elements are a full wavelength
apart, they are also out of phase off the ends of the array. The maximum
low-angle radiation of this array occurs approximately midway between
broadside and end-fire. Figure 3 shows it modeling somewhere around 40
degrees from broadside. The modeled broadside null shown is not a deep null
-- probably due, at least in part, to imperfect cancellation by the
out-of-phase components of the flattop current pattern. (The current maxima
at the two ends are probably not the same amplitude as the maximum at the
center.)
Thus, for a given DXing objective (max signal in Eu from the USA east coast,
for instance), the N4GG Array will need to be oriented differently than the
bobtail curtain, depending on what you wish to maximize.
Bud, W2RU
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Steve London
Sent: Thursday, September 25, 2008 12:29 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Building a Contesting/DXing station with deed
restrictions,
Hal, N4GG, has done exactly what you want to do - built a successful,
single-op
contest station in a deed-restricted neighborhood.
Check out these articles:
- NCJ, January/February 2008, page 14 "Wires in the Woods"
- The N4GG Array, www.reelfootarc.com/Assets/N4GG%20Array.pdf
73,
Steve, N2IC
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