F/B ratio is largely a matter of personal preference.
Contesters in the North East USA like high F/B to
reduce interference from the rest of the country
while they cream us into Europe.
Personally, from SE USA, I prefer a low F/B (10 dB)
so that I can hear/work multipliers off the back of the antenna.
This is especially useful for hunt and call type of operating.
When I changed from a 2L Quad on one of my towers to
a TH7 (which is normally parked on Africa), I found that I
could no longer hear / work stations in the Pacific as I
did with the Quad.
On the WARC bands I use only dipoles and Long Wire
antennas with ZERO F/B. This is only a problem when
there is simultaneous Short and Long Path propagation
causing a lot of echo that can make copy difficult. I have
worked over 310 countries on each of the WARC bands
with these simple antennas.
de Tom N4KG
On Mon, 15 Jan 2001 Arthur Unwin <aunwin@fgi.net> writes:
> A review of presently offered H.F. Yagis show
> in general >20 db for F/B or F/R ACROSS a band
> One antenna manuf points to a a 38 db MAX which
> one may assume means a steep fall off either side.
> The Antenna Handbook seems to strive for even HIGHER
> rejection ACROSS band which would appear that there
> is some desirability for a HIGHER level of rear rejection,
> but for whome and what level would satisfy those needs?
> Do DX's have different needs than the normal
> ham ? Is it a technical plateau preventing increases in
> this area, or is it that further increases in this area would
> be perceieved as a negative by some users?
> Art Unwin
> KB9MZ
> aunwin@fgi.net
>
>
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