W6TR wrote:
>I was basing it on my 20M KLM Big Stick, which played better with 4
>directors on a 57'boom. 27.5 feet on 10 is equivalent to 57 on 20.
What do you mean by "played better"? Here
are the results of 4M iterations of YO7's model of a
6 element single driven element:
2-stack, 6 el on 27.5' boom, single DE (i.e. yours):
Frequency 28.0 28.4 28.8
Gain 13.65 13.88 14.00
F/R 28.40 28.47 27.20
SWR 1.52 1.25 1.76
2-stack, 6 el on 27.5' boom, dual-driven DEs (i.e. KLM):
Frequency 28.0 28.4 28.8
Gain 13.40 13.73 13.91
F/R 26.68 28.01 29.79
SWR 1.25 1.19 1.24
I could tweak the Gain/F-R/SWR weighting of the latter for more
gain instead of SWR but these antennas are effectively identical
in the real world. YO7 came up with a close-spaced first
director much like an OWA design for broad-banding.
Practically directors 2-4 are used for purposes of gain and
F/R with the first director being used for broad-banding.
73, Bill W4ZV
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