George
First, EZNEC is available from Roy Lewallen, W7EL
for $89 -- at PO Box 6658, Beaverton, OR 97007 -- Tel:
503-646-2885 -- email: w7el@teleport.com
This program uses the NEC-2 computation engine, a well-
proven program with some well-documented limitations
(read the manual and past articles by Roy and L.B. Cebik
W4RNL, who is a regular participant in this reflector).
Regarding your proposed setup --
Tribander to 6M beam -- Perhaps four feet is the absolute
minimum spacing you should accept, more is better. If you
need to have minimum spacing, modeling and/or signal
strength measurements at different spacings will prove to be
valuable.
2M Yagi -- This one should be modeled, as both polarizations
need to be accounted for, and the other antennas are
beginning to "look" like large surfaces. A good starting point is
1/2 wavelength (3-1/2 feet) between the ends of the vertical
elements and other antennas
8-band vertical -- Modeling says you shouldn't put verticals
too high. The pattern is degraded by high angle lobes that
contribute little for communication (This is a good example for
one of your first modeling experiments). Put the vertical on a
pole or a single-story rooftop that gets it above nearby
metallic materials (including house wiring, fences, gutters)
Have fun!
Gary Breed, K9AY
-----Original Message-----
From: GeorgeHumphrey <gah@koyote.com>
To: antennaware@contesting.com <antennaware@contesting.com>
To: <antennaware@contesting.com>
Date: Tuesday, December 22, 1998 11:40 PM
Subject: [antennaware] Antenna Stacking
>
>Antenna Folks,
>
>Easy on me here, I am a newbie working on my code and erecting a station
>tower. This is my first question of this group, so excuse any blunders.
>
>I would like to stack the following antennas on one mast on one 45' tower.
>I don't have the software to model it, nor would I know how to model it at
>this time. How much space should I leave between the following antennas, or
>is this just a dumb idea all around?
>
>lowest - Cushcraft Tri-Bander 10-15-20M (space up from tower?)
>moving up - 6M yagi
>next up - 2M Cushcraft Vert/Horz yagi
>on top - MFJ 8 Band vertical
>all rotated by a Ham-M rotor.
>
>One more question, if allowed, where would I pick up the software you guys
>use for modeling, PC (EZNEC) I think.
>
>73 and Happy Holidays and a great New Year,
>George KC5WBV
>gah@koyote.com
>
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/antennaware-faq.html
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>Problems: owner-antennaware@contesting.com
>
>
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