Topband: 3B9C propagation experiments

[3B9C]

Bill --
    Would you be so kind as to post the following to the Topband reflector?
Thanks.
-- Eric K3NA

==================
    The 3B9C Topband Team have been examining the past 9 days' experience
with our sunrise opening to North America.  The opening has started as early
as 2340z (first NA stations logged) and closed as late as 0201z (about 10
minutes after sunrise).  We have two hypotheses that we want to test during
the next several days, and ask the Topband community in North America to
help.

    Hypothesis 1:  Our experience here is that the band opens to North
America like someone flipped a switch in the ionosphere.  This is very
consistent.  Many consecutive CQs with absolutely no detectable response.
(When not actually working stations, we are calling CQ every 5 seconds from
1330z [half-hour before sunset] until 0230z [half-hour after sunrise]
through the entire night.  We've seen some emails from people who think we
are not on the band sometimes.  We are always on and transmitting -- if you
don't hear us, you don't have propagation.)  Then one more CQ, and the
listening frequency is immediately filled with many stations from all over
North America!

    We hypothesize that a small patch of the ionosphere between Somalia and
the Seychelles undergoes a structural change that allows us to exploit the
tilt on the dawn edge of the ionosphere.  This spot change, possibly in
conjuction with a F-E layer duct, allows us to illuminate all of North
America at once.  Everyone in North America who is waiting for us on 1822.37
hears nothing... and then, simultaneously, many stations scattered around
the continent will hear that last CQ and its QSX instruction, and they dial
up the frequency and call us all together.

    To test this hypothesis, we would like North America stations to note the
exact time (hour, minute, second) that they hear the first detectable peep
from 3B9C during the 2300-0200z period.  If many people over a wide
geographic region are hearing exactly the same transmission as the first
heard transmission, this will confirm that there is an ionospheric gate at
our end of the path that opens.

    Hypothesis 2:  We believe it is feasible to hook a signal by skew path
into the daylight sector of western North America during 0130-0150z.
Because of the great distances being covered, a small scatter or skew at the
Somalia-Seychelles gate (just a few degrees of azimuth change) would allow
signals to exit across the terminator, possibly below the fading D-layer,
and land into the afternoon daylight sector.  This means we could,
potentially, work southern or central California, Nevada, Oregon and
Washington states, and VE6/7 even though these regions are in daylight.
Signals from these areas may be very weak, compared to the rest of the
continent which is already in darkness.

    To test this hypothesis, we will be listening on TWO frequencies during
the next several days.  The announced frequency will be the usual UP 5 KHZ
(1827).  The un-announced frequency will be DOWN 5 KHZ (1817).  We are
asking Topband readers who are in California, Nevada, Oregon, Washington, or
VE6-7/KL7 ONLY to call us on 1817 kHz... but call us ONLY if you HEAR us.  A
second operator will be listening here.  If we hear any stations in these
areas, we will attempt to hail them on our transmit frequency of 1827.37.

    Naturally, this test will ONLY work if Topbanders are Gentlemen and
Ladies respectful of the traditions of the band.  If you are not in these
daylight regions, please... please... don't call us on 1817.  Leave 1817 for
those who have no chance to work us otherwise, and allow us to test our
theories.

    Thanks, and hope to see all of you in the log!

-- TopBand Team (G3SED, G3XTT, K3NA)