Bill, W0ZV, made some good comments about the upcoming Heard Island
DXpedition and Top Band. Let me look at another aspect: Heard Island is
very close to the southern auroral oval. In this respect it will probably
experience propagation conditions similar to, say, Edmonton, Alberta (VE6).
Maybe one of the VE6's can relate their propagation on top band, but poor is
a pretty good adjective. That's the down side.
There is a good side, however. VKO is surrounded by water, VE6 isn't. More
important, beam headings from Heard to most of the populated areas are away
from the auroral zone. This is unlike VE6 where the paths to two heavily
populated areas, Europe and Japan, pass through the auroral zone. As though
who live next to the auroral oval well know, paths away from the aurora are
the best.
The guys on Heard are probably going to find their best paths are
perpendicular to the southern auroral belt. This means Europe will have a
good path. Not only that, they will have a path from basically Heard sunset
to Heard sunrise because of the season. Certainly, closer countries in
Africa and southern Asia will be louder, but there's just not a lot of Top
Banders in 5H or VU. This means the Hearders (pun intended) will have to
watch the sunset/sunrise times for North and South America and probably the
Pacific, too, if they are intent about spreading the wealth. A good trick
here might be to QSX for NA in a part of the band such as 1805 where most of
Europe can't transmit. Especially on days when the geomagnetic field is
quiet and previously absorbed paths begin to open. Another problem is that
the sun sets more slowly at higher latitudes. 8 hours between sunset and
sunrise is not 8 hours of true darkness. Especially for the ionosphere.
Maybe a VE6 could comment on how much "useable" 160 meter time they get
during a summer night.
How will this affect DXers on top band and even other bands? If the path
between you and Heard Island passes through that southern auroral oval,
you'd better be loud. Real loud. A long path might be a better choice.
Best days will be when the K index is 0 or 1. The closer your path gets to
that aurora, the worse your chances are. The best times are probably going
to be around your sunrise or sunset as long as Heard is well within
darkness. Skew paths seem more common around the auroral areas, so watch
for signals coming from unanticipated directions. For many of us, working
Heard on 160 is certainly possible, but with very limited openings and stiff
competition it's not going to be easy. Good luck.
Dan KL7Y
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