[TowerTalk] keyhole antenna pattern

Pascal J.A. Plovyt Pascal J.A. Plovyt" <pplovyt@imul.com
Fri, 22 Jan 1999 13:52:45 +0300

Dear OMís

Greetings from Uganda!

Who can help?
I want to put up a VHF repeater for the UARS, Uganda Amateur Radio Society
here in Kampala, with a 6dB omnidirectional collinear antenna, together with
a 6-el.-Yagi antenna for a ďKeyhole antenna patternĒ!
The Collinear antenna is mounted on the top of mast, and the Yagi, (at
present 1 lambda ) below.

Who knows the correct vertical spacing for that kind of setup!
I canít find anything in the ARRL antenna book.
Iím using a Procom  Harness / or combiner cable, and exact 3m coaxial cable
between the two antennas, for correct phasing.
But the system seems not to work properly.
Poor signal in 30-km distance, in the direction of the Yagi, as well in the
back, where the omnidirectional should do the job!

Any help is highly appreciated!

N.B. Iím working here for a communication company, as the Technical Manager,
and Iím looking as well for good quality, commercial mobile HF antennas
(fiberglass). Any ideas? Outbacker, or Comet, do they manufacture commercial

Vy 73ís 55

De 5X1C, Mario Berger

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