Several of you are asking me this directly so I'm going
to post a simple procedure you can use to determine the answer
yourself. Assuming you have entered your correct coordinates into
your local DXcluster, type in the following:
"sh/su vk0/h" (this gives you Heard sunrise/sunset for today)
VK0/H Heard-Is-VK0/H Sunrise: 2302Z Sunset: 1527Z
"sh/su" (this gives your own sunrise/sunset for today)
W4ZV QTH - Sunrise: 1229Z Sunset: 2229Z
Now, subtract your sunset from Heard sunrise (2302-2229 = +27).
If this number is positive (true for most of the Eastern USA), you are
in luck since there is at least some common darkness on the path. I
would guess the probabilities are as follows:
" Common Darkness" Probability (my guess)
>60 minutes "Excellent"
>30 minutes "Good"
>zero "Marginal"
<zero (neg #) "Unlikely"
There is one "kicker" in this. There might actually be a sweet spot
for greyline enhancement, which I would estimate at around 30 minutes,
but no one knows for sure since there has not been much activity from
this area to base any estimates on. 30 minutes is what I've typically
seen on 80 meter longpath (like XZ1N) but I don't know if it will
apply to 160.
To check the sunrise path, do the same but this time subtract
Heard sunset from your sunrise (1229-1527 = -178 minutes). Since this
number is negative (true for most of Eastern USA) there is no chance of
propagation. But let's look at the case for VE7:
"sh/su ve7"
VE7 British-Columbia-VE Sunrise: 1603Z Sunset: 0038Z
Here, it looks fairly good (1603-1527 = +36). Remember that the common
darkness will increase for both our local sunset and sunrise openings
as we approach the end of their stay (~1 February). In my case, the
common darkness goes from 27 to 47 minutes during two weeks time due to
the changing position of the sun. VE7 changes only slightly from 36 to
38 minutes. Remember also that the opening window will gradually shift
later for the East Coast and earlier for the West Coast over the next
two weeks.
Yes, we have all worked stations well past their sunrise, but
don't count on doing this when both ends of the path are in daylight!
On the other hand, anything is possible on 160, so stay close to your
radio the next couple of weeks and you may be rewarded!
Good luck!
Bill W4ZV
P.S. My comments apply only to North America since Europe and Japan
will both have extended common darkness paths to VK0.
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