Topband: Morning EU

[Bill Tippett]

W7IUV:
 >So again what is the "normal" path for west coast
USA to Europe "long path" on topband??


 From http://force12inc.com/PCSDAT-002.htm :

"Each 2 element parasitic array is aimed exactly at 210 degrees (true,
not magnetic). Thanks to perhaps the most knowledgeable person on
this path, Bob, W6RJ for verifying this exact direction for the majority
of long path openings."

         Although written for 75/80 meters, I believe SW is
the "normal" long path from the West Coast for 160 also.  It was
true on 80m from Colorado, and for my grand total of two contacts
made from there on 160m (UA9UCO and JJ1VKL/4S7).  The person
who probably has made the most 160 LP contacts from the West
Coast is Bob N7UA, who I believe will verify the SW direction.

         If SW is "normal" LP, the West headings some reported
today may have been a combination of 2 effects:

1.  What I call "normal" morning long path appears related to times of
common twilight.  The peak often comes midway between DX sunset
and our sunrise (the DX end will typically see this path via the SE
after their sunset).  A recent example of this from the East Coast
was 9N7JO on 80m around 1200z.

2.  Auroral skew will typically skew signals away from whichever
magnetic pole is closest to the normal path at any time of day.  If
SW is "normal" LP, today's path may have been skewed northward
(to the West) due to auroral skew in addition to the "normal" long path
mode.

         With all due respect to my friend Bob W6RJ, I would say
the "Dean of 80m long path" is actually Dale K6UA who has been
doing this consistently for >40 years.  Dale has used rotary 80m
antennas for many years and will verify the SW direction for 80m.
I believe 160m follows the same characteristics as 80m, but signal
strengths are ~20 dB weaker making 160 LP much more rare.

         I'm not certain about the apparent Northern path you
saw today but remember we are near Winter Solstice, so signals
actually can come direct.  With auroral skew, that path would
shift southwards away from the North Pole making it more NW
from your direction rather than direct at 6 degrees.  Sounds like
that may have happened for most of your opening and then it
went into "normal" long path mode before your sunrise.  On 80m,
I've seen this happen many times.  Well before sunrise signals
will be short path, then shift to long path shortly before sunrise,
and then shift back to short path again at and after sunrise.

         Bottom line to all this is that there are at least 2 skewing
mechanisms at work (twilight LP mode and auroral skew), and
we sometimes may see a combination of both.

                                         73,  Bill  W4ZV

Aurora was Kp 2 (mildly disturbed during this opening).
To really analyze the direction shifts, you need to know
relative daylight at each end of the path for each station
and time.

W2VJN-@    1838.6 RA4LW       Now from SW                   1537 29 Dec
W6RJ       1838.5 UA4LW       still there                   1537 29 Dec
RA4LW      1829.3 N7UA        559 hr                        1533 29 Dec
N7UA       1838.5 RA4LW                                     1533 29 Dec
W6RJ       1834.0 OH3XR                                     1529 29 Dec
N7UA       1834.6 OH3XR                                     1511 29 Dec
N7UA       1831.0 UN5J        good sig                      1506 29 Dec
W2VJN-@    1831.1 UN5J        559                           1506 29 Dec
W6RJ       1831.0 UN5J        west                          1505 29 Dec
N7UA       1800.0 RA4LW       skewed NW here with echo      1459 29 Dec
RA4LW      1800.0 W6RJ        Bob tnx for new State         1454 29 Dec
W6RJ       1839.3 RA4LW       weak but building             1435 29 Dec
N7UA       1839.3 RA4LW                                     1430 29 Dec