SteppIR sells a 4th element for 6 on the 3 el yagi and TWO six meter
elements for the 4 el yagi.
Yes, someone has modeled this.
;^)
H.
NQ5H
"Ian White, G3SEK" wrote in message
...
buddy clark wrote:
the beam in my estimation meets or exceeds all advertised specs. the
beam does not work well on 6m in my opinion, but my frame of reference
for that band was a 5 element on a 30 foot boom.

If the element spacing is anything like adequate for 20m, it has to be
way too wide to be optimum on 6m.

I'd guess there is more performance to be had on 6m by adding a fixed
reflector and at least one director at an optimum spacing. Using only
the variable driven element and the variable-length director at the end
of the boom, that would turn it into a reasonable 4- or 5-element with
some dBs more forward gain. You'd lose the 180deg beam reversibility on
6m, but you could quickly remove the front/back ratio by lengthening the
director. On the lower bands, the 6m elements would have very little
effect.

Has anyone modeled this? Part of the trick would be to use a
close-spaced first director to keep the feedpoint impedance reasonably
close to 50 ohms (see www.cebik.com on Optimized Wideband Antennas).


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek