Topband: Geomagnetic absorption of horizontally polarized antenna signals?

[Tom Rauch]

> I wonder if anyone can offer opinions on the advantages that
> vertically polarized antennas have over horizontals on 160M related to
> geomagnetic Earth absortion?

I think the biggest problem for an absolute answer is a lack of 
reliable verification data. Very few amateurs have enough room to 
install a textbook perfect vertical, let alone a horizontal at a few 
hundred feet. 

All that aside, everything I have read from propagation experts 
indicates the polarization effects of ionospheric absorption are 
small compared to potential changes in antenna field strength at 
different radiation angles. We have a human tendency, however, to 
assume that trends somehow indicate repeatable absolute results. 

To further complicate matters, we almost always compare one less-than-
perfect antenna to another less-than-perfect antenna. The antennas 
are almost always electrically and physically so close to each other 
and other structures, feedlines, and antennas we have no idea what is 
actually radiating. (In many circumstances antennas interact 
noticeably with even a wavelength of separation, so you can imagine 
the coupling at .1wl or less spacing.)

The saving grace is at propagation peaks virtually any antenna will 
work pretty well, even a low dipole. The "peaks" we often experience 
near sunrise or sunset tend to equal things out.73, Tom W8JI
W8JI@contesting.com