[Antennaware] Multi- bobtailcurtain

[Joe Subich, W4TV]

> 1) If I put up an identical parasitic spaced say, 0.125
> lambda; can it be tuned from a reflector to a director by
> simply changing the resonant freq of the parallel tuned ckt
> attached to the center radiator of the parasitic element?

No, you will need to tune the lengths of each vertical.  The
parallel circuit does not tune the antenna - it only provides
matching.

> 2) Can two identical elements spaced 1/4 lambda be fed at 90
> deg and switched to change direction? I suspect a problem
> with the tuned ckt feed at the bottom of the center radiator
> of each of the two elements, though it seems that a match
> could be easily obtained, could the phase be preserved if
> both parallel tuned ckts were identical and tuned to try to
> keep the phase unchanged?(resonance?)

It's not likely to work very well as the feed impedances will
be grossly different due to the mutual impedance (coupling)
between the antennas.  I'm saying this without first modeling
the antenna.

73,

    ... Joe, W4TV




>
> I have EZNEC-4, but only recently obtained it and I am at the
> very bottom of the learning curve and time is running out
> before heat and hmidity here!
> I also have an HP vector voltmeter, dual chan osc, and MFJ
> 259B, sig gen, etc, all of which I do know how to use. Top
> feed at low impedence is mechanically out of the question
> here. I have read about phased bobtail curtains on the
> internet, but no one seems to describe how.
>
> Any help from a knowlegable person would be GREATLY appreciated.
>
> Thanks,
> Sam, W5LU
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