What I was thinking about for my small suburban lot was a
big IR driven element attached to a mast pipe in concert
with a single regular IR parasitic element cantilevered on a
short boom off the mast. This would give 2 element yagi
performance on 13.8 to 54 MHz and rotary dipole performance
on 6.9 to 13.8 MHz, and still be reasonably "neighbor friendly".
The big IR driven element could be grounded to the mast with
a relay and used as tuneable top loading for a 160 meter
shunt-fed tower. For eighty meters I would probably just use
an inverted-vee.
As far as 80 meter yagi's go, I think the hot ticket would be
a center loaded element with small_IR element halves installed
beyond the center loading to serve as a continuously adjustable
elements tip. The IR element tips could then be adjusted from
the ground for optimized yagi performance from 3.5 to 4.0 MHz.
Getting the control wiring past the inductor might be a
challenge (you might be able to put it inside the coil tubing).
73 de Mike, W4EF......................................
----- Original Message -----
From: "Al Williams" <alwilliams@olywa.net>
To: "towertalk" <towertalk@contesting.com>
Sent: Thursday, October 07, 2004 9:51 AM
Subject: [TowerTalk] 2 element 40m steppir yagi
> I thank those that responded to my suggestion of a possible 80 meter
> steppir. The difficulties that loaded (linear or coil) elements would
> result never occurred to me. Perhaps that was because Force12 used to
> have a shortened element 80/40 meter yagi using linear loaded
> wires in there catalog.
>
> I wish I could thank those that responded to my other suggestion of a
> possible 2 element steppir as a modification of the already existing 4
> element 40 thru 6 meter steppir yagi. Not one response, yet there were
> 8 postings concerning the price (~$15/20) of a 500 foot roll of wire.
> Unbelievable! Maybe my suggestion was inadequately expressed?
>
> I assume that all Towertalkians are familiar with the Steppir yagi
> design, but maybe not their Monster model. It is a huge Yagi. Huge in
> price, weight, windload, and difficult( ?) erecting on the tower. But
> it is also huge in directivity gain, 40 thru 10 meter coverage with low
> SWR.
> Although some might argue that a 2 element yagi is better for some
> contesting because of the wider azimuth angle gain, I suspect that most
> would rather have the 4 element if their tower and pocketbook could
> accommodate it?
>
> For the rest of us, my proposed 2 element would have the weight and
> windload specs that would allow it to be installed on the heavier
> duty crankup towers and maybe even on a steel Martin tower and Hazer.
> Although the directivity gain would be less, it would still be
> worthwhile considering the inclusion of the 40, 30 meter bands along
> with shortwave broadcasting for those interested. The price would also
> make it more affordable. Perhaps most important the 2 element yagi
> could be easily installed on the tower by tilting the tower down and
> rotating the boom 180 degrees to install the elements while standing on
> the ground--or lowering the Hazer. No climbing towers, stepladders,
> cranes, etc.
>
> Have I totally misjudged Towertalkians interest?
>
> k7puc
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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