This discussion prompted me to reread the article entitled
"Quads vs. Yagis Revisited" in the May, 1979 issue of "Ham
Radio" magazine. The author of this article, N6NB, dragged
a TH-2 Tribander on a 70' portable tower around to numerous
quad and yagi installations in Southern California. The
TH-2 had been calibrated against a reference dipole, and
was placed beside, and at the same height as, the antenna under
test. Gain measurements were made by comparing received signal
strength from a source a few kilometers away. There's a lot of
data presented in the article, and it makes
very interesting reading. The conclusions, though, generally boil
down to these:
A two element quad is better than a 2 element yagi.
A three element quad almost equals a three element yagi.
Beyond three elements, the yagi outperforms the quad.
This same article, by the way, shows that the TH-2 Tribander
exhibited a gain of at least 4 dBd over pretty
much all of 10, 15, and 20 meters. It performed remarkably
well, considering some of the large antennas with which it was
compared.
Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com
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