>-----Original Message-----
>From: Jim Lux [mailto:jimlux@earthlink.net]
>Sent: Tuesday, October 04, 2005 23:26
>To: Tom Rauch; K8RI on Tower talk; towertalk@contesting.com
>Subject: Re: [TowerTalk] Elevated vertical
>
>
>I would venture to guess that a small number of radials could
>be made to
>work as well as a conventional ground system, for one
>frequency, at one
>time, etc., etc.
>
>As you note, the fewer the elements, the touchier the system gets.
>
>
Speaking of creating a touchy elevated vertical antenna system with a
small number of radials...
I am currently experimenting with an elevated vertical made with a
Steppir vertical antenna with a modified Steppir dipole serving as a
pair of tuned radials for it so that as the vertical changes length the
radials will dynamically change length to match.
A single Steppir controller is used to store the settings for both
antennas with an MFJ-269 being used to come up with the custom lengths
to be stored for use at each frequency. Preliminary fiddling indicates
low SWR and very low reactance will be possible in the HF ham bands.
Pictures of test rig using an 18-foot Glen Martin roof tower mounted on
my deck at http://www.w2qo.com/pics/steppir_testrig.jpg and
http://www.w2qo.com/pics/steppir_closeup.jpg
Decoupling not added yet and no objective empirical results to report
yet.
Purpose of experiment was to come up with a simple unobtrusive but
hopefully relatively effective antenna to put on the very steep, very
high roof of my Victorian house ( http://www.w2qo.com ) without having
to clamber about way up there on that roof and without arousing the ire
of the neighbors.
Plan is to lay the Steppir "radials" right on the roof and fasten the
vertical Steppir antenna to a chimney mount. (Roof is green and Steppir
elements are fortuitously green as well.)
Jamie Punderson, W2QO
_______________________________________________
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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