On Sat, 20 Aug 2005 11:28:52 -0700, John Smith
wrote:

nospam:

That cb antenna (with the 3 dipoles arranged so as to go omni/directional)
was called a "scanner", made by antenna specialists I believe (reed
switches in a relay box control the elements.)

Yep thats it, got stuck for a name.

I cut one down, along with the phasing harness to the center of the 10
meter band, works great! And you are correct, the three 120 degree spaced
vertical dipoles are fed in phase for omni-pattern.

Many years ago I help a ham friend (now SK) set up a foursquare. that
four vertical monopoles with goundplane with phasing feed for gain and
directionality. It was a very good antenna for 20M.

Early in my commercial career I worked part time for an AM BCB station
and would help with antenna tuning for directional pattern. Imagine
three big (300ft) towers in a field with about that much space between
them in a line. The feed and phasing coils were BIG, the usual
pattern was cartioid with the weak null facing the atlantic ocean to
the southeast. Just a bigger version of many phased arrays I'd see
in my commercial career.

Allison
KB1GMX