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How to work 3B9C : Rigs &
Techniques |
Rigs and Operating
Techniques
by Don, G3XTT

What about your transceiver?
The
answer is that most transceivers these days are more than capable of doing
the job, and almost all elderly ones are too. The only feature you will need
that you may not be using in your day-to-day ragchewing is split-frequency
capability. 3B9C, like almost all DXpeditions, will operate split-frequency
at all times in the early parts of the expedition, though may revert to
co-channel working later, when the pile-ups diminish, for those without the
capability. What is split-frequency operation, and why is it used?
Quite simply, DXpeditions transmit on one frequency and listen on a
different frequency. For example they will transmit on 28.495MHz and listen
between 28.500 and 28.520MHz. There are two reasons:
1. If the DXpedition station listens on the frequency on which it is
transmitting, it will not be heard by those calling because of the pile-up
on that frequency.
2. The DXpedition operator will be faced with a huge barrage of calls and
will not be able to differentiate between them if they are all calling on
the same frequency.
Experienced DXpeditioners will tune slowly up and down their listening band.
Listen to the stations working the DXpedition and establish the operator’s
tuning pattern. Work out where he is likely to be listening next and then
call – bingo! Never, never transmit on the DXpedition’s transmitting
frequency unless the DXpedition says “Listening this frequency”.
On CW, generally all you will need to do is set your receiver to the 3B9C
frequency and then use XIT (transmitter-incremental tuning) to offset your
transmitter by the necessary split (see your transceiver manual if you
haven’t had occasion to do this before). Activating RIT (receiver
incremental tuning) will also allow you to hear the calling stations, while
leaving your main receive frequency on 3B9C.
RIT and XIT usually only work for splits of up to 10kHz, which may not be
sufficient for SSB operation. In this case you need to bring your second VFO
into operation. Set, say, the A VFO on the 3B9C frequency. Set the B VFO on
the frequency where 3B9C is listening, and activate “Transmit on B, receive
on A”. Again, your transceiver’s manual will explain how to do this.
When 3B9C responds to your call, the exchange will consist simply of an
exchange of signal reports. Make sure the 3B9C operator also has your
callsign correct. The reason for the short, contest-style exchange is simple
– the expedition operators want to maximise the number of people who get a
chance to work 3B9C, so contacts are kept as short as possible. Information
such as QSL route, etc. have been announced in this magazine and elsewhere,
and there will even be a log lookup facility on the 3B9C Web Page so you can
be sure that you are in the log OK. If not, then do feel free to have a
second attempt. If your contact is, indeed, OK, then please try to work 3B9C
on other bands and modes.
So where on the bands will you find 3B9C? The plan is to focus initially on
the frequencies listed below, subject to change for technical or operational
reasons. In any case, the team is well aware that band plans in some
countries, including the USA, restrict certain classes of operator to
sub-sections of the band. This will not only be reflected in the range of
listening frequencies used, but in transmitting frequencies as the
DXpedition progresses. With widespread use of PacketCluster (via VHF/UHF and
Internet) and the DX Summit Web pages, even if you don’t hear 3B9C
immediately, you should always be able to find out very easily where the
expedition is currently operating.
|
Mhz |
CW |
SSB |
RTTY |
FM |
SSTV |
PSK |
|
1.8 |
1822 |
1842 |
- |
- |
- |
- |
|
3.5 |
3502 |
3795 |
3570 |
- |
- |
3580 |
|
7 |
7002 |
7052 |
7035 |
- |
- |
7037 |
|
10.1 |
10102 |
- |
10137 |
- |
- |
10140 |
|
14 |
14022 |
14195 |
14085 |
- |
14230 |
14071 |
|
18 |
18072 |
18145 |
18100 |
- |
- |
18100 |
|
21 |
21022 |
21295 |
21085 |
- |
- |
21071 |
|
24.9 |
24892 |
24945 |
24920 |
- |
- |
24920 |
|
28 |
28022 |
28495 |
28075 |
29580 |
- |
28071 |
|
50 |
50102 |
50145 |
- |
- |
- |
- |
|
50
Beacon |
50090 |
- |
- |
- |
- |
- |
|
Satellite |
Look
for us on OSCAR-40 (if it's working by then :-) |
|
Moonbounce |
70cm
band and possibly 6m |
Regarding the above frequencies, note that the team is aware of at least one
other major DXpedition to be active while 3B9C is still on the air, so may
decide to change transmitting frequencies to avoid confusion. Typically, a
DXpedition SSB station transmitting on 14.195 MHz will listen up in the
range 14.200 to 14.220 MHz. If 3B9C finds itself operating on the same
transmit frequency as another DXpedition it will, for example, move down
around 5kHz typically to 14.190 MHz and will then listen down say between
14.165 and 14.185 MHz so as to split the pile ups and avoid confusion.
Listen to the operator carefully. Each has been briefed to give the 3B9C
callsign at least after every two QSOs and to announce the listening
frequencies every five QSOs. Incidentally, 3B9C will not work by numbers;
believing that with good ears and equipment this is quite unnecessary.
There really isn’t the space here to discuss how to get started with the
more specialist bands and modes, but the team does encourage readers to have
a go. There have been many articles written about getting started on RTTY
and PSK, which is straightforward using a personal computer and its built-in
sound card. There will be a section on the 3B9C Web site giving some hints
and tips, with links to useful references. The same is true of satellite and
EME. The latter requires a well-equipped station, but satellite operation
through AO-40 doesn’t require large investments in equipment, especially if
you already have a 70cm multimode radio (3B9C will be using the popular
FT-847) and 70cm Yagi. Again, follow the links on the Web page for suitable
advice on getting started.
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