[RMVHF] JA Opening on 6m

[LANCE COLLISTER]

Hello Bob,

On Friday afternoon July 11, I noticed that there was a rare Es opening across 
southern BC plotted on the map.  I turned the antennas up to the northwest and was 
amazed by all the strong JA signals!  For your archives regarding these JA contacts, 
I made the following contact:

2252 JF2WXS on 50.090

I heard a number of other JA stations, most of which were between S5 and S9.  I 
called about a half dozen of them, using both antennas and full power on my end.  I 
never got even a QRZ!  This is EXTREMELY bizarre, since all my domestic and Carib Es 
contacts have always seemed to be reciprocal in polarity.  This experience with the 
JA stations was sure.  I know other Pacific Northwest stations were working the JA's 
with no problem, but I just couldn't seem to get through!  Perhaps it was QRM from 
the USA, or QRM in Japan....but it seems very strange to me, and worth noting! 
Anyway, after a short amount of time, the Es cloud over BC moved to the west as they 
do, and I lost my link to the JA path.

Traditionally, the summer Es openings to japan have been late a night our local time, 
when the geomagnetic field lines on the REAL TIME MUF map more closely follow the 
Great Circle Path from here to Japan.  It is interesting to note that, during these 
particular JA openings which occur much earlier in the day here, the North American 
stations need an Es opening to the northwest of them to drive the 6m signals down out 
of the ionosphere.  Over the last month, it seems that we have quite frequently had 
Es clouds in the center of the country, providing many opportunities for most 
stations across the country to connect with the JA's during the 2000-2400Z time 
period.  On those occasions when there did not appear to be any Es clouds over the 
continental USA, there were no JA contacts reported.

I suspect that the signals stayed up in the ionosphere, and continued on their Great 
Circle path toward the Carib or South America.  And of course, that is how HI3TEJ got 
into the path one evening. I don't know what the situation is with the ionosphere at 
that time of day as the geomagnetic equator is crossed, but I wonder if stations in 
South America might also have some anomaly that would finally bring these signals 
down to the earth there...  There probably are not many stations in South America 
looking up toward the USA at that time of day right now!

The question remains how the JA stations launch the signals into the ionosphere on 
their end.  It would be very interesting to learn if the geomagnetic field lines tilt 
down toward the ground in Japan at that time of day (early morning local time I 
believe) or the Es layer is just so low then that stations with a high antenna and a 
low angle of radiation can more successfully launch a grazing signal toward the Es 
layer and have it propagate chordally around the auroral oval despite the low MUF 
(probably only possible due to the very low Kp now, since we are at the bottom of the 
sunspot cycle now).  Do you know of any 3-D ionospheric global graphic anywhere that 
would provide this type of view?

I wonder if some of this same mechanism might be responsible for some of the 
propagation that the East Coast USA enjoys along geomagnetic field lines to Europe as 
things line up at primarily two times during the day, as shown clearly at:

http://www.spacew.com/www/realtime.php

A better understanding of this is particularly interesting, since if we understood 
the mechanisms better, we could possibly look for other propagation paths between 
other parts of the world at different times of the day, utilizing the same phenomena. 
    The chat page at www.ON4KST.com has sure been a help (or very possibly the most 
important tool) in discovering this very reliable propagation path.  There sure will 
be lots to talk about at the 6m BBQ in Austin this September!

VY 73, Lance




-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728
URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11/6m DXCC #815

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