On Sun, 29 Nov 2009 19:33:56 -0600, Gary E. Jones wrote:
>I have several sets of drawings and taper schedules for 20, 15, and 10m OWA
>style yagis, however, I can't fine dimensions or NEC files for the 40M yagi.
There is a DOS program that comes free with the ARRL Antenna Book that allows
you to scale any Yagi design from one frequency to another. You enter as data
the design of the original Yagi, with element taper data, AND element diameters
for the new antenna you are designing. So it would be no trick to transpose any
one of those designs for 40M. I did it to build a 4-el Yagi for the FM
broadcast
band (which works fine).
BTW -- I just built a 4-el 15M yagi based on the design on the British ham's
website. Preliminary testing shows that it works fine. Haven't run a pattern or
measured gain, but rotated it while my neighbor watched a voltmeter cailbrated
in dB on his RX (actually, the dB voltage indicator in his K3). I will build
more of these puppies!
73,
Jim K9YC
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