If the Jungle-Job is horizontally polarized, you're kidding yourself if
you think there is any significant difference in takeoff angle if both
antennas are at the same height above ground.
73,
Dave AB7E
On 8/7/2014 8:48 PM, Yan (XV4Y) wrote:
Hi,
I want to build a portable antenna for 20m. This antenna will be installed temporarily
at a low height, around 3m above ground (10’).
I’ve modeled two antennas in MMana-GAL and compared their gain : one Moxon, one
Jungle-Job (G4ZU).
The Jungle Job is a clear winner, showing almost no degradation in its gain diagram from
a « high location » (above 1/2 lambda).
On another hand, the Moxon shows a drop of 3dB in max gain, and the max gain is at
60° elevation, versus 22° for the Jungle-Job.
At 10°, the Jungle Job still has 7,4dBi gain, while the Moxon shows a -2,3dBi
loss…
The diagrams are on my blog.
Don’t worry about the article in french, it does not contain more details than
the diagrams.
http://xv4y.radioclub.asia/2014/08/08/antenne-directive-portable-proche-du-sol-comparaison-entre-jungle-job-et-moxon/
73,
Yan.
---
Yannick DEVOS - XV4Y
http://www.qscope.org/
http://xv4y.radioclub.asia/
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