[amsat-bb] 4 omni antennas plots (nulls)

Zach Leffke zleffke at vt.edu
Wed Mar 16 16:42:12 UTC 2016

the second plot and third plot with the patterns overlaid is for 7m 
above ground, doesn't specify what type of ground.

-Zach, KJ4QLP

On 3/16/2016 12:29 PM, Robert Bruninga wrote:
>> Comparing DCA, QFH, Lindenblad and turnstile (eggbeater) antennas :
>> http://www.qsl.net/py4zbz/4ant.htm
> All but the QFH show significant (10 dB) nulls all over the place.
> I'm sorry, I cannot read the language, but does he say anything about these
> nulls and the height of the antenna over ground?  And what kind of ground
> was used in the model?  Perfect or real... or free-space
> Since all of the antnnas are multi-element, those lobes could all simply
> come from the multi elements more or less independent of the ground
> reflection...
> Bob, WB4aPR
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