The point is that director doesn't direct anything likewise reflectors
doesn't reflect, moreover a director doesn't live an own independent life
but is a part of the whole yagi array.
Directors and reflectors reradiate energy with certin phases and delay due
to their reactance and position in respect to the dipole.
A director opposite to a driven element instead of a reflector is not a good
idea because it's at the end a disturbing object not a director in the
strict sense..
In normal conditions the director reradiation reaches the dipole with the
proper phase and delay to positively add gain and/or directivity if behind
the dipole there is a reflector or even nothing.
The other directors in a classical yagi must be also strategically placed
and cut properly to enhance gain and directivity.
Another director/s behind a driven is not (only) producing a bidirectional
pattern (thus worsening S/N) but it's reradiation reaches te opposite
director/s with a wrong phase so producing a bad combination that damages
the whole array pattern and gain.
73,
Mauri I4JMY
----- Original Message -----
From: <N7DC@cs.com>
To: <antennaware@contesting.com>; <dx-qso@yahoogroups.com>
Sent: Saturday, May 25, 2002 8:53 PM
Subject: [Antennaware] weird question
> Any of you antenna gurus out there ever tried a simple dipole, with a
> director on each side of it? In other words , string a dipole, then place
a
> set of directors, parallel, and on both sides at once? I havent been able
to
> make head or tails of these antenna design software packages, guess I need
to
> set in a class to actually see one work. What I have is temporary loops
> installed for 17 and 12 meters, and have constructed "director" dipoles
which
> I have hung on verticle bamboo poles , just in front (facing East) of
them.
> Appears to be working better than just the plain loop - for that direction
of
> course. But, am wondering if I can get bidirectional antennas out of them
by
> hanging two such directors. Dont want to go thru the "phase switch"
method
> etc. Just experiementing to see what I can use on field days, scout
> camporees etc.
> Thanks
>
>
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