Thread: 2 meter yagi
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Old October 18th 06, 02:01 AM posted to rec.radio.amateur.antenna
Tom Ring Tom Ring is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 230
Default 2 meter yagi

Scott wrote:

If you don't mind having a little less gain than is ultimately possible
by using an antenna modeling program, the NBS (Nation Bureau of
Standards) designs are pretty straight-forward. For a 6 element Yagi,
here is element lengths and spacings for building with insulated
elements (insulated from the boom, so I would use wood, 1" X 2" X 8.5')

Lengths:
Reflector = 3' 4"
Driven = 3' 2-3/16"
Dir 1 = 3' 7/8"
Dir 2 = 3' 7/16"
Dir 3 = 3' 7/16"
Dir 4 = 3' 7/8"

Spacing:
Ref to Driven = (187.2/Fc) X 12
Spacing between all other elements = (234/Fc) X 12
where Fc is the design center frequency in MHz, ie 146 for the center of
the FM portion). The spacing calculations give the answer in inches.

Then you need to feed it. I use delta matches. Are you good at
qrz.com? If so I can send you a drawing of the feed to get you started
(but you would need an SWR meter that works at 2M to get it adjusted).

Scott
N0EDV


Sorry, I didn't give an alternatives in my previous email. Please see
the K1FO series in the ARRL antenna books. They are among absolutely
the best possible, very replicable,, low build sensitivity, and fairly
short to very long boom plans are available.

If you do not have one of the ARRL Antenna books available, I, or others
here, have copies as needed.

tom
K0TAR