On 9/30/12 12:18 PM, K8RI wrote:
On 9/30/2012 8:28 AM, John Tait wrote:
I run a pair of 1/4 spaced verticals East/West, using the simple 84 deg
feed lines, and a 71 deg phasing line, from ON4UN's fourth edition, page
11-9. It works very well for me, and is easy to build. It cost almost
nothing, and is very effective. Unless you can get to a sufficient
height, dipoles are cloud warmers, but good for the close in stuff. A
four square would be great, but if you don't have the space, a pair are
much better than one. Well worth the effort.
I ran a pair for many years when I lived near Breckenridge MI and they
worked very well. They were right at the East edge of the yard, with
the road on the North side. After the crops were out, I'd move the
northern most vertical to the East a bit and put the radials down for
I'd like to try a 4 square, but I only have one acre and even a phased
pair is pretty much out. I might try putting up some out in the woods
as I don't think the owner would care. OTOH I'd sure like to buy an acre
adjoining me to the West and clean most of the trash trees out of there
and keep the few good ones.
In theory, the big benefit from a 4 square is the very good nulls you
can get on receive, and that doesn't require 1/4 wave spacing; it
requires good control of phasing and amplitude, which these days, is
fairly easy to get with a DSP approach (I'm thinking of Victor Kean,
K1LT kind of schemes).
The forward gain is a lesser concern, although not negligible, but
should also not require big spacings (just as you can get high gain in a
The challenge with small (or uneven) spacings is that the the feed
system isn't as simple as a Collins quad hybrid and 1/4 wave current
forcing. I'm not sure, though, that this is as big a deal these days.
A computer controlled LC network, for instance, can get you there.
Broadcast arrays have used lumped LC for decades.
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