[Elecraft] Split DX

[Stephen W. Kercel]

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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