[TowerTalk] Log Periodics

[Pete Smith]

At 11:35 AM 12/8/00 -0000, Tim Makins,  EI8IC wrote:
...
I would thus
>be interested to hear comments on single-band log periodics versus single
>band yagis, with the same number of elements.  

This isn't directly apposite, in that it deals with so-called log-cell
driven yagis, where in addition to the log cell a parasitic reflector and
director are used.  However, after an exhaustive review of the literature
and his typical careful modeling, LB Cebik concluded:  

"As a gain enhancement, the log-cell driver technique has very limited
utility amid current yagi technology.  Its chief merits involve operating
bandwidth and front-to-back ratio.  However, even here, its utility may be
limited when the complexity and weight of the array are factored into
antenna design and construction decisions."
       --- NCJ, May/June 2000

Extrapolating only slightly, I think there is even less of a case to be
made for a single-band LPDA without parasitic elements, since such an
antenna offers the worst of both worlds -- less gain, less F/B, greater
weight and complexity, and no better useful SWR bandwidth than an
equivalent-boomlength OWA yagi or other modern design.

73, Pete N4ZR

Contesting is ... Extreme Radio

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