Topband: Long Path

[wb6tza@socal.rr.com]

Hi Folks

Just a quick reminder- especially with the hi performance effort at A61AJ 
coming up -  "Long path" does NOT always mean the great circle reciprocal 
of short path -  especially on top band and in the solar maxima.  Don't 
forget to listen ( and transmit) on the southern non polar paths - 
especially during the critical sunrise-sunset periods.

Those of you able to hear us from XZ0A last year will remember that neither 
polar path worked - The north polar path went thru the big nasty polar 
oval, and the southern "long path" went through lots of daylight..  The 
path that worked - EVERY NIGHT for 26 nights - was a "skew" path, generally 
southwest from the states, and southeast from XZ0.   There have been 
several explanations put forward, none of which fully explain it to 
me...  Nevertheless,  it is an observed fact that a high performance 
station can have propagation occur on what appears to be non great circle 
paths.

I will be most interested in learning if A61AJ is heard or worked on any 
southern non great circle paths.  It seems to take a high performance 
installation at the DX end to take the greatest advantage of this unusual 
propagation path, and A61AJ certainly is that.

At XZ0A, the 45 minutes at sunset from dusk to hard dark were the most 
critical, and had the greatest observed variance from a "normal" 
path.  Signals arrived virtually straight down, and from approximately 
140-150 degrees azimuth, AND generally were strongest from stateside 
sunrise areas (no surprise).   The longer after sunset, the lower the 
arrival angle appeared to become.  Signals were heard from east to west 
somewhat following the terminator as it crossed the states... but- oddly 
enough, this mode did not appear to continue to the west coast.  Most west 
coast contacts were short path received at our end.

I would suspect that similar conditions may apply to the signals to and 
from A61AJ, with the appropriate offset for the terminator 
positions.   This would appear to indicate that A61AJ should listen closer 
to east than south and with a high angle capable receive antenna 
immediately at dusk.  We used a full size dipole 10 feet high.  Most 
significant to note is that during the critical dusk period we could NOT 
hear stations calling when we listened on the beverage antennas - 
regardless of their azimuth.  Switched to the SE facing dipole & 
BANG!  there everyone was!

I will be MOST interested in observations of this path & mode.

good luck all

73

Robin Critchell
WA6CDR
XZ0A


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