Brett:
There are several sensible reasons why a DX station works spilt. When
he makes a call he is likely to receive several (often many)
simultaneous replies, commonly called a pileup.
By asking callers to call "UP" (you almost never hear "DOWN"), the
callers are spread out over a range of frequencies rather than all
calling on one frequency. This increases the likelihood that the DX
can quickly pull out a recognizable callsign from the cacophony.
Just as important, if the DX does not work split, everyone is making
repeated calls on his frequency and most callers will not hear when
he actually does reply to someone. Thus, many callers will
unintentionally interfere with a QSO that they do not realize is
already under way. Also, with many callers on the DX station's
frequency, it is hard (if not impossible) to hear any instructions
from the DX station (e.g, Wait 5 minutes while I refuel the generator.).
If you are working split and QSK, you can recognize immediately when
the DX is answering someone else, and then stop calling until that
QSO is finished.
It is critical that the DX station transmit on a clear frequency if
he/she wants to control the pileup. They cannot maintain control if
nobody can hear their instructions over the QRM. Thus, I have no
sympathy for DX stations that run simplex and are not able to control
the pileup.
It is also critical that nobody else call on the DX stations transmit
frequency. The "tuner uppers", the lids who ignore the "UP"
instruction and call simplex, and most especially the "UP police"
simply impede the orderly operation of the pileup. Of all these bad
actors, the "UP police" are by far the worst.
When you are on an "empty" frequency and you suddenly hear 10 (only
10?) stations all "light up" at once, you are undoubtedly hearing the
reply end of a pileup.
There is no advantage to the DX station to run full duplex. He has no
need to hear what is happening on his transmit frequency. The worst
thing he can do is to reply to someone calling on his frequency. This
rewards bad behavior on the part of the lids, attracts a bunch of
other callers to his transmit frequency, and consequently destroys
the advantage that the DX had achieved by getting the callers to work
split to begin with.
Split operation is one of those counter-intuitive things. It only
seems to waste bandwidth. A well run split pileup (such as any
operation run by G3TXF) will rapidly and efficiently provide a great
many contacts in a minimal amount of operating time. Think of the
product of occupied bandwidth multiplied by operating time required
to work a given number of contacts. Split operation will consistently
produce a much smaller bandwidth-time product than a simplex
operation. Considering that a major DXpedition makes between 30,000
and 100,000 contacts, that efficiency is critical.
There is no commonly accepted split frequency. Many DX stations will
suggest an approximate split (e.g. VP6DX most commonly says UP 25.)
There is a great advantage if you can switch VFOs rapidly and listen
as the DX works a number of stations. The good DX stations will use a
unique but recognizable pattern is selecting frequencies to listen
to. If you can figure out the pattern, you can easily land on a
frequency on which he is listening, but nobody else is transmitting.
In which case, you get an easy QSO with a rare station. If you're
having trouble figuring out where he is listening, call up the Telnet
spots on a computer (any logging program makes this easy to do.).
Many successful operators will post the spilts on which they
successfully worked the DX.
73,
Steve Kercel
AA4AK
At 01:28 PM 2/22/2008, Brett Howard wrote:
I've not ever really worked a split DX station and ever since getting the K1
I've been working on building up my CW skills. I've gotten to where I can
get the jist of the info at 14WPM w/ 20WPM char speeds.
I've heard frequencies where it seems like nothing is going on and then all
of the sudden 10 stations light up. I'm assuming that this is a split DX
and I'm only hearing half of it.
But anyway it doesn't make much sense to me. So granted a station can
listen to both frequencies at once and I'm sure transmitting station is
probably only listening when he's not transmitting (unless he has two
separate radios and two separate antennas). This just seems like a waste of
bandwidth especially if he's not doing full duplex.
Is there a common split distance so that one may easily find the other half
or do people usually just go digging till they find it?
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