[VHFcontesting] Science of antenna polarity and practical results on 6m

[Kenneth Silverman]

I've read the recent polarity thread with interest, as I've done a lot of
research into it.

While my team and I have had great success using verticals on the beach and
setting multiple CQWWCW world records, I never really understood the
science of polarity other than knowing the take off angle seemed to be the
most important factor.  If any of you use HFTA you know that many long
distance signals on HF come in at very low angles.  The only way to achieve
that is by a very high antenna, or verticals on the beach

This also applies to 6m, as I've used verticals on the beach on 6m with
great success from Jamaica.  When planning for the 2015 VHF C6ATA operation
www.qrz.com/db/c6ata, I started digging into the science polarization to
try and find the best location for the effort (I do a LARGE amount of
research to find the best villa to rent to achieve maximum results).

K9LA has a very interesting article on polarization of a *single hop
signal,* and I had a couple rounds of email with him based on my experience
with HF and 6m verticals on the beach.  http://k9la.us/Polarization.pdf,
While Karl's article deals with HF, he confirmed that any signal going
through the ionosphere has the same results (i.e. 6m).

Key point from article: At the entry point, the horizontal polarization
splits its power equally into the o-wave and x-wave (since they are
circularly polarized). Likewise, a vertical antenna would split its power
equally. Then both characteristic waves arrive at the exit point with the
same strength (since the split was equal and the absorption is equal).
Finally both characteristic waves, being circularly polarized, excite the
vertical equally. Likewise, they would excite a horizontal antenna equally.
In reality, horizontal polarization on both ends would be favored due to
other considerations where horizontal antennas respond less to man-made
noise (since man-made noise is generally vertically polarized) and they are
not as dependent on ground conditions for low angle radiation (the
exception would be if a vertical is over salt water).  What this all means
is that in theory is the polarization at the XMTR and at the RCVR is
essentially irrelevant for single hop (K2KW: and presumably multi-hop Es or
F2)

*Biggest Takeaway: having gain at the correct take off angles is far more
important than antenna polarization. *

Most 6m single-hop take off angles are 0-10 degrees. See the following
articles:
http://k9la.us/Elevation_Angles_Required_for_6m_Sporadic_E.pdf
http://www.qsl.net/ve3sma/VE3SMA_Antenna_Height_for_6m_Es.pdf

While Karl's article only deals with single hop, I've used 6m verticals on
the beach from 6Y and worked hundreds of EU via F2 on SSB, and even more
stations via single and double hop Es into the USA.  Here's one picture of
a 6m vertical array I used in May.  It looks lame, but looks can be
deceiving.  2001: http://k2kw.com/6y1a/6y1a_6m.html.

Regards, Kenny K2KW