He's operating split? What
does that mean?!?!
You're a new General
and have been operating HF for about two weeks. About 7:00UTC Sunday,
during the IARU World Championship, you are tuning down the 40m band
about half asleep. Without realizing what you're doing you have tuned
down to 7090 and hear a station calling, "CQ CONTEST, CQ CONTEST this
is zed-zed-zulu-zed listening 7155 and this frequency". You pull-up QRZ.com on your web browser and enter the call sign, 00Z0. Suddenly
you are wide-awake. This guy is the rarest of all DXCC entities; he's
located on Zero-Zero Island; 0-degrees Latitude, 0-degrees Longitude
just off the coast of equatorial Africa! His DXCC entity number is
00. You're a bright girl (or guy) and you know 7090 is well outside
your General Class privileges in the USA. Even Extra Class operators
have a lower limit of 7125 on 40m. So how do you reply to this rare
treasure?
Actually, he just
told you how to reply. He is transmitting on 7090 and he is listening
on both 7090 and 7155. His radio has dual receivers, or
dual-band-watch, which is fairly common on today's mid-range and above
radios. So you need to transmit on 7155 and listen on 7090, but how
do you accomplish that feat of magic? You operate split.
Every modern HF
transceiver I know of, even the least expensive entry-level radio,
will allow you to operate split. The exact setup procedure will vary
from radio to radio, but generally the procedures are similar. I used
a Yaesu FT847 for a long time before buying an Icom radio. I had
used the split function on the FT847 often enough that it was second
nature. The controls and procedures to operate split on the Icom were
so similar to the Yaesu that I was able to set-up split mode on the
Icom without referring to the manual. The keys needed are shown
below.
Enable Split
|Swap VFO Contents
Transfer VFO-A Contents to VFO-B
You may have noticed that your radio has two VFO displays but you
never concerned yourself with why. When you rotate the tuning knob
only one of the two VFO displays changes frequency and that's all that
matters. An example for the Icom VFO display placement is shown
below. When the tuning dial is rotated the upper VFO display (VFO-A)
changes.
If you enable the split function by pressing the
"Split" key shown previously, the display changes. You will now
transmit on VFO-B.
The display above indicates that you will now
transmit on 14.255 MHz. If you rotate the tuning knob the upper VFO
display (VFO-A) is still the display which changes. But 7.090 MHz is
not the frequency we want to change. So set VFO-A back to 7.090 MHz.
If you press the "Swap VFO Contents" button the
display will appear as below.
The contents of VFO-A have been swapped with those
of VFO-B. The set-up shown above isn't what we want, but we are
getting closer. The upper VFO display is the display effected by the
radio's tuning functions. First we need to change VFO-A from 20m to
40m. On my Icom I need to press the[7 3] key to select the 7 MHz band
(40m).
The display would look like the following.
Closer, but not exactly what we want. Rotate the
tuning dial to set VFO-A to 7.155 MHz. Remember, the main VFO display
is always the display effected by tuning functions of the radio. In
this case, the upper VFO display is the main display.
After tuning to 7.155 MHz the display should appear as below.
The display above is exactly opposite of what you
wanted to accomplish; you want to transmit on 7.155 and receive on
7.090.
Press the "Swap VFO Contents" button again, the display will appear as
below.
You've done it!! You are now set to listen on 7.090 MHz and transmit
on 7.155 MHz. You respond to 00Z0 and he comes back to you on the
first call. He is in your log and the QSL card should be on its way
to you shortly. But be patient, mail from Zero-Zero Island is slow in
arriving.
Please, do not be intimidated by
the instructions above. Attempting to explain anything in writing is
far more complex and time consuming than actually doing it. I tried
this hypothetical case on my radio and it actually took less than 10
seconds to accomplish. Think about what we did, it really wasn't
complicated: 1) press the split button to enable the radio's split
function, 2) swap the VFO contents so the TX VFO was in the main VFO
display, 3) set the required transmit frequency in the main VFO
display, and finally, 4) swap the VFO contents for a second time.
Read the section of your manual which describes setting up split
operation; it shouldn't differ much from the example above and it
really will not be difficult.
So why do many DX stations operate split
frequencies? In the case of zed-zed-zulu-zed on 40m, he wanted to
increase his exposure during the contest. In his part of the world he
is not permitted to transmit above 7.100 MHz. In our area, we are not
permitted to transmit phone below 7.125 MHz (Extra Class). The only
way we can communicate via phone is by operating split. By
transmitting on 7.090 MHz and listening on both 7.090 and 7.155
station 00Z0 can legally work stations anywhere in the world. And,
stations anywhere in the world may legally work him.
On other bands, 20m for example, the reason a DX
station would operate split is different. If the DX station is really
rare, he is going to create a huge pile-up (thousands of stations
calling him). On 20m you may hear a rare DX station on 14.210 MHz
calling, "CQ, CQ this ZD8Z up 5". ZD8Z is
transmitting on 14.210MHz, he is listening up 5KHz on 14.215. His
reason for operating split is different from the 40m example. In this
case he wants to be heard above the thousands of stations returning
his call. If he were transmitting and listening on the same
frequency, the roar of a thousand stations calling him would likely
continue for several minutes and each QSO would take a very long time
to complete. By operating split he has a clear frequency on which to
be heard (14.210 MHz) and he only needs to pick one call sign from the
chaos occurring up on 14.215. Things will move along much more
quickly and everyone is going to be happier, or at least less
frustrated.
73 and good DX
Terry KD5RA