This is possibly a more complicated subject than just performance. I gave a
lecture on this topic, comparing a Hi-Z circle 8, SAL-20, SAL-30, beverage
(unidirectional and bidirectional and BOG) and the K9AY array.
In this talk, I considered performance as a factor, but also considered
maintenance, size, mechanical stability, cost and ease of construction and
installation.
All things considered, the top 2 at my QTH were the Hi-Z circle 8 and the
SAL-30.
Here is a quick summary of my findings.
Circle 8: highest cost, most complex to install and construct, requires large
footprint of land, best of all antennas as it requires almost NO maintenance
and performance second overall to the SAL-30.
SAL-30: modest cost, modest install and construct, modest footprint, requires
minimal repairs (usually to the coupler wires) but overall performance best of
all for directionality and gain.
SAL-20: modest cost and somewhat simpler than SAL-30 to install and small
footprint. Performance almost identical to the K9AY array.
K9AY: modest cost but slightly more complex to construct as compared to SAL-20
and about the same size. Performance less than SAL-20 due to fewer directions.
Beverage unidirectional: mechanical stability good when constructed with copper
coated steel wire #14 or larger. Gain fine when desiring only 1 direction.
Depending on the location may be placed in half a day from start to finish.
Beverage bidirectional: mechanically unstable when constructed with commercial
products using either RG6 or twin lead. Requires frequent repairs due to
fatigue or failed connections. Performance overall is not on par with other
directional arrays.
BOG: simplest of all antennas to construct, install and maintain. Can be
installed in an hour or two. Should be unfolded at spring time each year to
keep wire from being incorporated into lawn. Convenient when only 200'
available. Can be band specific.
Just a quick summary. My location does not lend itself to beverage
construction. about 2/3 of my 25 acres are heavily and complexly treed with
brush so overgrown that it can be a chore to do almost anything for
installation or repair. This is why I prefer the SAL-30 overall. The circle 8
took me one summer (as my only project to install) by the time the land was
cleared, site measured, antennas constructed and all the coax installed. The
trade off is that this antenna has been the most mechanically stable of any
antenna that I have ever had.
---
David J Rodman MD
Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo
Office 716-857-8654
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