Richard Harrison wrote:

That`s usually right. The reflector is lengthened and directors are
shortened to conveniently produce phase relations which determine
reinforcement or repression in directions as desired.

However, this is not the only way. Commercial broadcast curtain antenna
arrays use parasitic elements which have the same length as the driven
elements in some instances. Short-circuit stubs repalace drive lines in
the parasitic elements, and these are adjusted for the desired phasing
instead of adjusting element lengths.


That's a nice trick. Of course that still means they aren't resonant
since you just displaced the "center" of the element. Seems a good way
for a broadcaster to be able to adjust the pattern if needed after
construction.

I seem to remember an HF wire antenna project that used that method to
go from driven plus reflector to driven plus director to get a
reversible beam. I also remember a set of 5 slopers that were in the
ARRL antenna book or handbook that could be steered.

Oh well, way off topic here now. cul

Tom
K0TAR