On Fri, 19 Aug 2005 20:21:38 +0000 (UTC), "Reg Edwards"
wrote:

There is a 3-phase transmitter feeding a 3-phase antenna via a 3-wire
transmission line.

The antenna consists of three 1/4-wave horizontal radiators spaced at
120 degee intervals.

Is the radiation pattern in the horizontal plane perfectly
omni-directional?
----
Reg.

No. Effectively you are feeding two legs with a -120 degree phase
and that will make it directional.

For Omnidirectional operation ALL legs will have to be fed in phase.
If the three sources are laggin in phase then the feed system will
have to correct the phase till all are in phase.

Many years ago, there was a CB (USA 27mhz 11m) that used three
vertical dipoles with phasing to get directionality or omnidirectional
gain.


Allison