On Jan 4, 2006, at 4:14 PM, Keith Dutson wrote:
> I am planning to install a 2 el 80M Yagi. Originally it was going
> on a 120
> foot Rohn 55G tower. I now have some flexibility and can put it on
> a taller
> tower, up to 190 feet. What are the recommended heights for this
> type of
> beam, and why? Thanks in advance for your comments.
120 ft / 280 ft = 0.43 wavelength high
190 ft / 280 ft = 0.68 wavelength high
It's generally considered that horizontal antennas don't have much of
a directional pattern until they are 1/4 wavelength high or higher.
But, even at 190 feet, you still aren't one wavelength high yet. Not
even 3/4 wavelength. The ground will have a heavy influence on the
I'd go with higher - you'll have a more distinct pattern from the yagi.
Bill Coleman, AA4LR, PP-ASEL Mail: firstname.lastname@example.org
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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