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

NBS yagis were quite horrible actually. Not good gain, horrid
bandwidth, high sensitivity to build errors , crummy patterns compared
to anything since the early 90's. Don't bother.

tom
K0TAR