>I know during the peaks we had a 10m yagi at W3GM's for contests which was
at 20'. At mid day, it outperformed stacks to 100'.
Stacks of what? I am constructing 4 tribanders (C-3) on a 150 foot tower.
They will be positioned at 152, 119, 86 and 53 feet. The top two and lower
two will be hard-wire phased (SM-mini), then these two pairs will be switch
phased (SM-II). This design should allow selection of three take-off angles
to match propagation conditions.
Keith WD5DXL
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Jarvis
Sent: Wednesday, June 16, 2004 11:37 AM
To: Towertalk
Subject: [TowerTalk] ma550/ antenna height
Folks,
I had my 3 el SteppIR at various heights, in VT, on a military pushup mast.
30, 50, 65, 80, 100'. It wasn't dynamically adjustable, and it was now two
seasons ago, so there was more sun to play with.
However, in general, having the antenna a full wavelength above ground
improved performance on long distance contacts substantially.
Pretty much as you would expect, dx went up 10-20 dB and stateside went down
by the same.
Here in Suburbia, I'm condemned to stealth antennas, and an MA550 with 10'
of top mast (65')is the hoist of choice. It'll stow behind my roofline when
not in use, and I can motorize it to appropriate heights for each band.
I would assume that during times of high sunspot activity, as Bill (?) said,
higher angles would be supported by the ionosphere, and a lower antenna
would be better. I know during the peaks we had a 10m yagi at W3GM's for
contests which was at 20'. At mid day, it outperformed stacks to 100'.
N2EA
jimjarvis@ieee.org
_______________________________________________
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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_______________________________________________
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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