[amsat-bb] Quadrifilar Antenna at Orlando Hamcation
john at papays.com
Fri Mar 4 21:26:54 UTC 2016
Salvatore Bologna of Helical Technologies in Rockledge
Florida had his new quadrifilar uhf antenna at Orlando
Hamcation. Sal wanted to test it on my satellite demo
station to see how it performed against the Arrow antenna
we were using.
We set up an A/B switch on the UHF port of the IC910H so
we could switch between their quadrifilar and the Arrow
on a tripod. We tried it on FO-29 and SO-50 during
two passes. The results were not surprising. The Arrow
always did better but the quad did hear stations. They were
just down a few db depending on the elevation.
Their quad is housed in a pvc tube and was on a 10' pvc
mast. It is very stealthy and that's a nice characteristic
of the antenna. If you live in antenna restricted area,
this antenna will pass for a vent pipe or as part of a flagpole.
But there is no way this antenna can perform as well as a 7 el
beam adjusted for proper polarity. But it does work and
you can hear stations on FO-29. SO-50 is a much weaker
bird and signals were weak on the quad. But you could
hear stations and you could make contacts.
There is a video of my demo station at Hamcation on youtube.com
You can see Sal sitting in back of the radio, flipping the
A/B antenna switch during the passes. The audio is not perfect
so it may be hard to hear the difference between the antennas.
They are working on a vhf version. Their website is
Antenna selection depends on many different factors. You
write down your objectives and then consider your
constraints when making your decision to purchase. Every
case may be a little different.
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