"'Doc" wrote in message ...


Uwe,
'Bigger/longer' isn't necessarily 'better'! A longer
dipole -may- resonante on the desired frequency, but the
65 feet (approximate) is really all you need. Twice that
length would probably work for you, but feeding it in the
center would also be a very bad impedance match for 50 ohm
coax.

The impedance will still be 50-to-70 ohms if you add the extra
half-wavelength to just one end of the antenna.
i.e. The wire on one side of the antenna feed point (coax connection) is
still 32.5 feet, and the wire on the other side would be 65' + 32.5' plus
another 3.3', since there is no end-effect on the extra half-wavelength of
wire you are adding. So actually, one side is 32.5 feet and the other side
is 100.8 feet. You should get almost 2 db of gain in four directions (a
"cloverleaf") by doing that. You will also get a significant reduction in
signal strength (a "null") broadside to the antenna and off the ends. I used
a dipole like that for years in Florida where one of the gain lobes was NE
and the nulls cut out a lot of the stateside QRM for me during European
contests. The full-wave dipole was up about a half-wavelength (65 feet), so
I used RG59 (75 ohm) coax instead of RG58 (50 ohm) coax, and had a good
match. No balun was needed.

Andy