In the trip across the south pacific from ZL to VP6DX, we were about in the
middle when
the CQWW160 CW contest started. ( I was the only expedition member aboard at
that point-
we were bound for Mangareva to collect the rest of the crew). I had a 125 ft
horizontal
wire running the length of the Braveheart. When the contest started I hadn't
finished
getting things set up for operating topband effectively, but I could listen
(and /MM isn't
a multiplier, or even a 10 pointer)
I started listening about 4 PM local - 2 hours before sunset. I had 100
callsigns written
down on a yellow tablet in the first hour, ALL easy copy (but then, there isn't
much man
made noise 1000 miles from the nearest land). All of the callsigns were 5000
miles plus
away - 99% North America.
During the VP6DX expedition, we made many contacts before sunset and after
sunrise, some
quite notable distances. There is a recording of the SSB contact during the
SSB contest
with EA6 when it was almost 2 hours after sunrise at EA6.
I also note a comment about the signals coming in from the SW to eastern USA.
During our
XZ0A trip, if you had a directional RX antenna and wanted to hear us, that is
the
direction you had to listen from. There is significant repeatability to the
data on skew
paths and odd arrival angles near the terminator hours, We had to listen (at
XZ0A) on a
low horizontal dipole during the 2 hours at Sunset or we heard nothing. There
appears to
be some correlation with how well developed the northern oval is and the
magnitude of the
skew paths and high arrival angles. We were on the air with 1500W and a full
size quarter
wave (elevated) vertical for close to a month with daily repeatable results
that required
us to listen on a very high angle receive antenna at sunset, and eastern
stateside to
listen for us from the SW.
With all of this, the bottom line is:
1: If you aren't on the air, you cant work them
2: do not assume that traditional propagation modes and times are the only ones
that are
useful.
3: encourage the expedition folks to note both 1 and 2
Robin Critchell
WA6CDR, VP6DX, XZ0A
----- Original Message -----
From: "Tom W8JI" <w8ji@w8ji.com>
To: <topband@contesting.com>
Sent: Sunday, September 30, 2012 15:21
Subject: Re: Topband: Propagation to Conway Reef
schedule. The problem with many DX-peditions today rather than in the past is
they rely
on SR/SS charts for the East Coast before they even check the band for a few
test CQ's
prior to what the charts or the computer tells them what to do.
It is a HUGE mistake for anyone to assume propagation only peaks at sunrise or
sunset,
or that the sunrise or sunset peak is always the optimum or best time. It
really is
terrible planning.
There are many days working ZL/VK, and working Europe from here, when there was
no
propagation at sunrise or sunset and great propagation well away from the two.
Sometimes
sunset at one end is the peak, sometimes sunrise at one end is the peak, and
very often
the only opening or best peak is not near either.
During noise season operating at sunrise/sunset can produce a great reduction
in noise
at the end near daylight, and the lower noise makes things better, and many
times there
is a signal strength peak, but there are many times the best or only peak is not
remotely close to dawn/dusk at either end of the path.
People familiar with 160 listen at all times there is darkness in the path, and
people
unfamiliar listen only at sunrise/sunset.
73 Tom
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|