Antenna - Rotation Matters

hi all,

found something that maybe you were not really aware (me too - up to 60 minutes before) of and might help you with your site.
while doing my antenna testing i found that - at least my jetvision - omnidirectional antenna is not really omnidirectional.
turning the antenna around her axis in steps of about 90 degree i can clearly see big differences.

tom

If it is a PCB antenna, tuning fork shaped, it cannot be truly omnidirectional.

The dipole, monopole whip with ground plane, Cantenna, and wire collier with coils are most close to a perfect omni directional.

As far as I know Flightaware antenna is a wire collinear with coils, and should be nearly perfect omni directional.

By the way, have you seen this:
Antenne active PCB 1090 MHz / 1090 MHz Active PCB antenna

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