Andy,
The "half square" is of a family of "self contained verticals" that
Cebik (www.cebik.com) described as such, and includes the bobtail
curtain (like two half-squares together). It does not need a radial
system - that is what the "self-contained" means - the ground system is
contained in the antenna (i.e. the horizontal phasing wire).
A bobtail curtain, or a half square, can be made out of almost any wire
and just hung between two trees, with the coax at right angles to the
vertical wires. The bottom of the vertical wires should be about 12" or
more from the ground and protected from being touched by either being
higher than a person or insulated. I used pvc pipes to protect the ends
from being touched.
If there is room, the bobtail curtain provides about 2 dB more gain than
the half square. Both antennas are essentially verticals in phase, with
the accompanying gain increase and no need for any other ground system.
You can even create a beam out of two SCV antennas, but it is no longer
bi-directional.
A bobtail curtain beam is the antenna I used in Hawaii and covered all
of North America and Canada without any need for a rotator, but I was
5000 miles away, so the pattern was very wide at that distance.
73, Skip KH6TY
Andy obrien wrote:
See http://www.obriensweb.com/halfsquare.html for a brief article on
this antenna that I have found easy to build and has improved my
signals
Andy K3UK
