This statement relates to ops wanting to work SE Asia:
The problem presented to operators in S.E. Asia and parts of the
Philippines and India is a nearly consistent reduced receive sig strength
while, at the same time, reports of higher sig strengths at receive
locations in NA and EU. An HS station is heard 10 over in EU but the EU
received sigs are all S-7 to S-9 or less in HS.
This problem has many reporters in the region and over all of a year and
for about twenty years--a long testing period, especially done by a weekly
20 meter sked between HS and Maryland USA. The reports are consistent
although the differences vary from time to time.
There appears some kind of one-way absorption of the signals coming into HS
but not affecting outgoing signals.
Internet research indicates that there is a possible relationship of this
situation to the MAGNETIC EQUATOR.
One reference is here http://www.wikiwand.com/en/Equatorial_electrojet
This and other reports indicate that there is an affected odd ionosphere
energy band about 10-20 degrees wide centered on the magnetic equator that
lasts about 12 hours and drifts East to West along the magnetic equator and
passes over Northern Philippines, then the area between Singapore and
Bangkok, and then on over the Indian Ocean. The link has a good animation
of this repetitive situation.
Notably, the magnetic equator does not nearly touch EU and bends Southward
to avoid NA and CA totally.
I hope some enterprising smart ham or a Ph.D. candidate will get interested
in this phenomena and fully explain the radio propagation factors in it.
Meanwhile, pardon me in HS if I report you S-5 when you hear me over S-9.
73, Charly HS0ZCW
CQ-Contest mailing list