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[TowerTalk] HB9CV/TET Antennas

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Subject: [TowerTalk] HB9CV/TET Antennas
From: (L. B. Cebik)
Date: Tue, 23 Jun 1998 06:06:22 -0400 (EDT)
> Feri has requested this info several times.  I sent him to the W4RNL web
> page as he has a topic on HB9CV.  Very little has been done with using the
> HB9CV as a cell for a larger array with parasitic elements except for a JA
> company TET, now out of business.  Does anyone know either the JA or
> stateside ham that sold/distributed TET who can help Feri?
One of the reasons why so little has been done in expanding the HB9CV/ZL
Special phased dipole pair into multi-element arrays (with directors for
gain) is that so little is gained relative to a Yagi of the same number of
elements, and at the same time, the phasing requires revision with every
experimental move of the directors, especially the one closest to the
phased pair.  The HB9CV/ZL Special does not make radical improvements in
gain, but does increase the front-to-back ratio over a comparable
2-element Yagi--which is limited in its F-B capabilities.  However, by
the time one designs a good 3-element Yagi, the F-B exceeds 20 dB.  An
HB9CV/ZL Special might have a deeper null at a particular frequency, but
cannot sustain more than about 20 dB across the band, and added directors
will not change this.  Since 3 or more element Yagis are mechanically
simpler for the same performance as a 3 or more element HB9CV/ZL Special,
the phased design has largely been set aside except for 2-element
versions.  Some work at VHF has been done, but for HF use, the Yagi
prevails for 3-element and up work.



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