Hi Yuri,
I don't have the exact answer to your problem, however the way I usually
test all yagis is to put their reflectors on the dry ground, or small
non-conductive box or wooden sawhorse and aim them nearly straight up in the
air. If it's not windy, then you can just tie them off with a rope(s) to
something solid and it should stay there as you measure and make
adjustments. It can be a bit of a balancing act, but not Cirque-du-Soleil
difficult.
My AA-230PRO ;-) is great for taking these types of measurements. ;-)
I just did this with my A3S...and to verify, I put it on a pipe some 8'
above ground (flat/horizontal) and then afterwards with the REF on the
ground , aimed almost straight up and when I finally installed it (only @
24' I am afraid) the final SWR more closely matched when it was aimed
straight up.
It won't be perfect, but it will be closer due to less ground interactions
with DE and D1..I am sure there must be some kind of calculation you could
do, but I don;'t know it. Like, it will be resonant 100kHz higher or lower
when mounted @ 40' or something << just a wild guess used as an example only
!
73 Mike VE9AA
Mike, Coreen & Corey
Keswick Ridge, NB
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