Perfect example occurred today, when spots for VU7MS (Lakshadweep) in Zone
22 started popping up on the DX cluster from stations in NA at 19:00z -
that's 2PM EST, folks! I didn't hear him in the Midwest until closer to 4PM
local time, but it was well before the sun went down. Problem was, he was
strong here but Europe had stronger signals to him than NA. He attempted to
call for NA/SA a few times and a lucky few got through, but EU wouldn't shut
up and kept calling. He wasted a lot of valuable time continuing to remind
everyone "NA SA NA SA". Then the cops came out and things went to
h-e-double-hockey sticks. But I digress.
The VU7 wasn't a fluke, either. Similar conditions existed for an 8Q7 on 40
and 80 - openings to NA from their dark to our light in the middle of the
afternoon.
I must admit that after 40 years of hamming, I never would have thought to
look for good conditions to the Indian Ocean in the afternoon (broad
daylight) on 40M.
I never stop learning. Cool stuff, indeed.
73, Tom
K8BKM
-----Original Message-----
From: CQ-Contest [mailto:cq-contest-bounces@contesting.com] On Behalf Of
W8FJ via CQ-Contest
Sent: Tuesday, November 29, 2016 6:13 PM
To: donovanf@starpower.net; cq-contest@contesting.com; pvrc@mailman.qth.com
Cc: ve9aa@nbnet.nb.ca; tshoppa@wmata.com
Subject: Re: [CQ-Contest] 40M open early for DX in CQWWCW
Nice explanation Frank. You hit the nail right on the head. Thanks!
John, W8FJ...
-----Original Message-----
From: donovanf <donovanf@starpower.net>
To: cq-contest <cq-contest@contesting.com>; pvrc <pvrc@mailman.qth.com>
Cc: ve9aa <ve9aa@nbnet.nb.ca>; Tim Shoppa <tshoppa@wmata.com>
Sent: Tue, Nov 29, 2016 1:51 pm
Subject: Re: [CQ-Contest] 40M open early for DX in CQWWCW
Hi Tim,
Congratulations, you've discovered some of the affects of low sunspot
activity on DX contesting strategy. During the CQWW CW Contest those affects
were compounded by the Earth directed affects of an unusually large and
energetic solar coronal hole.
One of the most pronounced phenomena of the night time ionosphere during
fall and winter is the "mid-latitude trough"
(Google that term for more detail). Its a region of significantly depleted
total electron content (much reduced MUF) just southward of the northern
hemisphere auroral zone. The trough occurs during about half of the fall and
winter nights, and it strongly affects propagation on high latitude paths
such as the short path from eastern north America to Europe and Japan.
During about half of those fall and winter nights (those nights when the
trough is active), the trough typically develops near sunset at its westward
end and rapidly disappears at sunrise at its eastern end.
http://www.qsl.net/kl7j/images/latitude%20variations.jpg
Last weekend the night time auroral zone was pushed significantly southward
by the affects of an unusually large and energetic earth-directed coronal
hole that also pushed the mid-latitude trough directly over our north-
Atlantic propagation paths to Europe and our high latitude short path to
Japan. As a result, our best 40 meter propagation to Europe occurred during
north American daylight hours and after European sunrise. The mid-latitude
trough significantly shortens the duration of 40 meter propagation to Europe
and Japan for stations located at more northerly latitudes and somewhat less
for stations at more southerly latitudes during those nights when the trough
is active.
Our very brief short path propagation from the mid-Atlantic states to Japan
occurred near JA sunset (0730-0830Z). Soon after JA sunset our propagation
to Japan was mostly via the skew path that propagates via the tilted
ionosphere about 20 degrees south of the equator, Our east coast short path
to Japan usually strongly redevelops near east coast sunrise, but the
affects of the coronal hole significantly degraded our short path to JA.
While the most pronounced affects of the trough are on 40 meter propagation,
it also significantly shortens the duration of our openings to Europe and
Japan on the higher bands, essentially terminating the openings near sunset
at the eastern end of the paths during about half of the November through
February nights when the trough is active.
I ts a big mistake to consider 40 meters to be mostly a night time DX band
near the bottom of the sunspot cycle. Daytime 40 meter DX is significantly
enhanced near the bottom of the sunspot cycle by the reduced daytime E-layer
MUF which otherwise blankets the F layer during most daylight hours nearer
the top of the sunspot cycle. As a result, DX propagation is possible on 40
meters during most daylight hours , especially for stations located at
higher latitudes from November through early February. During those months
daytime propagation is common from the northern east coast USA to northern
Europe even at high noon.
Close to the bottom of the sunspot cycle, both the short and long paths are
strongly open from the East coast to Japan on 40 meters during many December
and early January late afternoons from 2130Z to about 2215Z. If you have a
directive antenna, some JA stations can be worked on only one of those paths
if they're also using a directive antenna. Without a directive antenna, some
JA signals can be an unreadable blur of overlapping echos.
True long paths from the USA to Japan (not skew paths) rarely exhibit
scintillation affects that are usually observed on the short path because
the long path propagates well away from the southern auroral zone during the
southern latitude summer.
73
Frank
W3LPL
----- Original Message -----
From: "Tim Shoppa" <tshoppa@wmata.com>
To: ve9aa@nbnet.nb.ca, cq-contest@contesting.com
Sent: Tuesday, November 29, 2016 2:12:10 PM
Subject: [CQ-Contest] 40M open early for DX in CQWWCW
Mike VE9AA -
You asked several good questions in CQ-Contest.
Below are some of my thoughts on the ebb and flow of band choices in CQWW:
>From the EU point of view, they can work most of the other EU's on 40M and
80M and 160M for points and mults. Here in NA, VE's only work W's and W's
only work VE's for points. And even that is lopsided because the VE's have a
lot more W's to work than W's have VE's to work.
So the EU's are on 40M even before THEIR sunset. And it is that it is often
advantageous (point wise) for a VE station to stay on 20M much later than a
W, because the VE can run W's on 20M for points.
The disturbed conditions on 40M after my sundown, caused a lot of us W1-W4's
to figure out that it was much easier to go to 40M to work EU's way before
our sundown rather than after. Also, because there was no chance of folks
like me running JA on 15M like in solar max, we were not spending a lot of
time running on 15M in the afternoon.
The usual thought that 40M is a "darkness band" is not true, even in
undisturbed conditions. It's very often for me to CQ on 40M in CWOps at
1300Z and get replies from VK's, even though both ends are in sunlight :).
Occasionally I will be CQ'ing at 1300Z in the deepest of winter, and be
picked up by skimmers in EU (especially GW8IZR who has the most incredible
skimmer ears, maybe only met by that VK4 skimmer) even though it is local
noon in EU.
I had a handful of long-path JA callers on 40M in my afternoon while I
thought I was CQ'ing for EU. The long path JA's sounded especially clear and
unwobbly to me. Both ends were in sunlight. Usually I don't get long path JA
callers until we are closer to winter solstice.
I had a VERY HARD TIME running EU on either 40M or 80M, but no problem at
all on 20M. This poor conditions on 40M/80M were very unusual for me. I'm
guessing that 80% of my 20M QSO's were running, and that 80% of my 40M QSO's
were S&P., and that's just unusual for me.
Mike, you also asked why the EU's weren't chasing us on the skimmer spots. A
very knowledgeable local shared with me, that in poor conditions the
pipsqueak EU's who might chase skimmer spots rather than CQ, they don't stay
up late working 40M, they're in bed, so there are many fewer to reply to my
CQ's even if we could hear other.
Tim N3QE
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