VK9WWI Operations on Top Band
Between Sep 22 and Oct 03 HA7RY (Tomi) and I operated
VK9WWI with a low band focus. This was intended to be a
simple âpersonalâ DXpedition. Equipment was chosen as the
minimum required for meaningful low band operation.
We had an Icom IC-746 PRO, an SG-500 solid state 500W
amplifier, and an SG-235 auto tuner, connected to four 12V
car batteries which were charged by two 30 A chargers
powered by a 1.5 kW Honda generator.
We set up an inverted L cut for 1.825 MHz on a 20 meter
Spiderpole fiberglass rod. The âhorizontalâ wire was
lowered for 80 m operation. The antenna was erected on a
narrow sand spit, which was surrounded by water almost
completely. (The station was up on dry sand about 1 m
higher up.) We added 12 elevated radials of between 10 and
30 meters long and about 0.7 meters above the sand, with
some extending into the water even at low tide. We have
also added a 2 meter long ground rod; the sand appeared to
be wet here at all times, so it may have done some good.
At high tide the entire sand spit, including the base of
the antenna, was under water.
During the short planning phase I sought advice on this
forum regarding receiving antennas for the low bands. As
reported before the operation, the advice fell into two
distinct categories, almost evenly divided. One group
stated that on a remote location like Willis there would
be no need for separate receiving antennas because of the
absence of man made noise. The other group stated that
receiving antennas are a must because of likely noise from
tropical thunderstorms and the Chinese âDragonâ. As it
turned out, both groups were right. On some nights the TX
antenna worked fine, on other nights the lightning crashes
made listening on the TX antenna painful.
During the course of our ten day operation, we have
erected two receiving antennas. A pair of Pennant antennas
was loaned by W8UVZ. One of these, aimed at North America,
was installed on the third day. For supports it used a 12
meter Spiderpole and a driftwood bamboo pole. The center
of the antenna was about 5 meters above ground. It worked
fine for the NA direction, drastically cutting noise of
lightning crashes. Still, the antenna produced very weak
signals, even with a K9AY pre-amplifier (which was loaned
by Gary, K9AY). Later we built a 140 m long Beverage
antenna, in an 80 degree direction (EENE); not perfect for
North America, but that was the best we could do, given
the shape of the island and the desire to stay far from
the salt-water. The Beverage worked so well that a couple
of days later we extended it to 220 meters. A strange
thing occurred at that time. The antenna, which in its
shorter form did not pick up noise from our generator that
was about 60 meters to its side, now was picking up
generator noise. The generator was located about 100
meters from the operating position and about 200 meters
from the main antenna. Its power cord was curled into
chokes at several points and it's chassis was grounded.
This configuration eliminated some early noise pickup. The
extended Beverage, however, produced much better signals,
especially on 160 m, and the noise was easily removed by
the receiverâs noise blanker, so we decided to stay with
this new configuration.
The Beverage worked very well for us for the rest of the
operation. It was very good on 160 meters and it was
superb on 80 meters. Its directivity was so sharp that on
160 meters we could switch between working Japanese and
North American stations just by switching antennas and
doing away with the need to listen up 5 kHz to get away
from the large number of Japanese stations calling! The
Beverage just simply cut them off, except for a few loud
ones. (Iâve missed KL7FG calling several times, until I
switched to the vertical, on which he was S9!) For Europe,
which started coming in the early morning hours, we
removed the loading resistor, turning the Beverage into a
bi-directional Beverage, which, despite its poor
orientation, was still much better than the Pennant or the
main antenna. The Beverage seems to have worked well
despite being near salt water. It was running parallel to
the shore about 30 meters from the high tide water line
and over sand that was about 3 meters above the high tide
sea level (5 m at low tide). The sand was dry in that area
and very likely a poor conductor.
We started on top band at on Sep 23 in the early evening.
Conditions turned out to be exceptional that night.
Our first CQ was answered by JA7FUJ at 0838. A long string
of JA and North American stations followed. At one point
we had to listen 5 and 6 kHz up to hear the North American
stations. The first European station was UA4DX, two hours
ahead of any other European. (I have repeatedly copied him
as VA4DX â not wanting to believe that the band would
already be open to Europe.) The North American stations
started to fade out after their sunrise and European
stations started to come in long strings. Altogether we
made 430 QSO-s on our first night on top band.
Signals from both North America and Europe were strong and
clear, with little QRN. We did not have a receiving
antenna up yet; we were using the inverted L for
receiving. The Dragon was also quiet. Indeed, 160 meters
had the feel of 80 meters on a very good night. At that
point I was convinced that we did not need a receiving
antenna. The next night proved me wrong and the need for
separate receiving antennas: in the early evening hours
lightning crashes were so strong that they were painful
through the headphones. Eventually we gave up on top band
for a while and QSY-ed onto 40 meters for a couple of
hours, after which the band quieted down (the
thunderstorms must have dissipated) and we had a decent
night of operation. Next day, we installed the Pennant,
which then proved its value during the next two nights,
after which the Beverage took over and we rarely used the
Pennant any more.
Altogether we made 1200 QSO-s on top band.
A couple points to make. When calling a DX on 160 meters,
unless you are very confident of your full size array,
kilowatts, timing and frequency, you should send your
call-sign two or three times. Due to noise, weak signals
and QRM it is common that the operator picks up only part
of a call-sign each time it is sent. A lot of time was
wasted by repeatedly asking stations to resend their
call-signs. Sending speed should be between 12 and 25 WPM,
neither faster, nor slower! The problem with slow speed
is, in this part of the Pacific anyway, that there are a
number of beacons that can be heard across the 160 m band
and these beacons transmit at about 5 WPM. I believe them
to be long-line fishing beacons, as they constantly
change, drifting with the currents and are removed at
intervals. They are easy to separate from calls provided
the calls are at higher speeds. Speeds faster then 25 WPM
are difficult to copy due to lighting noise or the Chinese
â Dragonâ triggering the noise blanker, which in turn can
obliterate high speed dots.
A constant problem was station who did not hear us. The DX
operator can quickly tell when a station does not hear
him. The chance of him being fooled into a valid QSO is
very slim.
Another important point to make is that you do need a
decent TX set up, not only the ability to hear. One
stationâs TX signal is the other stationâs RX signal and
when you start out with a weak TX signal, you will simply
not be heard. It is simply a matter of signal-to-noise
ratio and the noise is a given. We could constantly hear
the low rumble of weak stations calling, whose individual
call-signs were indiscernible.
On most nights the âDragonâ was not too bothersome and the
Beverage easily got rid of it. On 40 meters, however, it
is murderous. Is it possible that its frequencies have
been deliberately picked to fall into Amateur bands;
perhaps seen by the Chinese as less important and not
likely to arouse a reaction?
I believe that our 160 m results show that when receiving
conditions are good, and the interest is there, a
relatively modest station can do a lot on Top Band. Thanks
to those who have called, and especially those who have
assisted with advice or with equipment.
George
AA7JV
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