Steve, AA4V, asked about the Pennant and Flag receiving antennas. I've
posted much about these antennas on this list before, but here it is
again. Anyone desiring more info should be able to find it in the
Topband Reflector archives at http://www.contesting.com/_topband/
Briefly, the Pennant and Flags are in the Ewe family, however, unlike the
Ewe, they are independent of any connection to ground.
Both the Pennant and the Flag are 14 feet by 29 feet in size. The
triangular Pennant was given its name by me because of its shape. The
other configuration, being rectangular, I decided to call the "Flag".
All modeling for these antennas was done with the tops of the antennas at
20 feet high and the bottoms at 6 feet high, with all wire #14 gauge.
The correct termination resistor for the Pennant is approximately 900
ohms, which can go either at the point of the Pennant or in the center of
the vertical section. The feedpoint is at the opposite end.
The correct termination value for the Flag is about 950 ohms, which goes
in the center of either vertical section, with the feedpoint in the
center of the other vertical section.
Both antennas are directional with a cardioid azimuth pattern with a deep
null to the rear, just like the Ewe. They are useful on 160m, 80m and
40m as a receiving antenna.
Like the Ewe or the K9AY loop, the usefulness of these antennas is badly
degraded when in the presence of a vertical transmitting antenna. K6UR
has solved this problem for his Flag by grounding out his tower's shunt
feed with a relay while receiving.
The reason for the Pennant and Flag designs was to come up with an Ewe
type of receiving antenna which was as independent of earth ground as
possible.
In an effort to overcome the Ewe's major problem of being so susceptible
to underlying soil conductivity, about a year ago Jose, EA3VY, designed
an antenna he called a "terra-proof Ewe". He sent me an EZNEC file of
the antenna. It was pennant-shaped and was about 13' by 23'. I noticed
that Jose's antenna had a low amount of reactance on 160m and I started
tweaking the antenna size and termination value in an attempt to improve
it. The result is what I've posted here, but EA3VY certainly deserves
credit for being the first to come up with the basic design.
And indeed the Pennant and Flag are "terra-proof", as Jose calls it.
73, de Earl, K6SE
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