At 08:33 PM 2007-08-11, Joe Barnes N4JBK wrote:
>I am currently running a 1/2 wave dipole on 75 meters and am looking for
>a bit more gain there if possible. I have tried a bazooka and a double
>extended zepp with marginal results. What is wrong with using a 1 1/2
>wavelength long inverted vee? or some other length? Hopefully this isn't
>a stupid question that has been done to death and I missed it. Thank
>you, Joe N4JBK
A 1.5 wl dipole or inverted vee at modest heights probably won't
provide any more usable gain than a half-wave dipole or inverted vee
under many circumstances, but it really depends on a lot of variables.
In general you can only get more gain by focusing the signal in some
directions at the expense of another. However, it might be possible
to increase the efficiency by raising the antenna or placing a ground
screen. Raising the antenna also can significantly lower the angle
of radiation and increase signals on longer paths.
It's no surprise that the bazooka didn't help, since it is just a
dipole with a fancy matching scheme (which can add some loss).
A double-extended zepp can have more gain (up to 3 dB, which can
often be hard to perceive in practice), but only broadside to the
wire (including straight up), while signals off to the side are
somewhat attenuated.
I'd be happy to model your existing antenna and any alternatives, but
it's important to consider what distance and directions you want to
cover and your limitations for mounting the antenna.
73, Terry N6RY
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