*EDITORIAL* Time to Split Up?

For a rare dx station, the decision on ‘if’ or ‘when’ to split-up is an important consideration — Split too early and you reduce your QSO rate — Split too late and and you frustrate your pile up.

For those radio comms hobbyists who don’t know, “working split” means the station is transmitting on one frequency and listening on another — an ability achieved by accessing certain functions in his transceiver.

On 11m for example, 321DA/0 might choose to RX on 27.580 MHz USB but TX on 27.590 MHz USB.



Why Work Split?

Split frequency ops is commonly done by rare DX stations when the stations calling are so plentiful that it’s tough, if not impossible, to log a contact on one frequency alone.

The primary goal of a split operation, then, is to get the frantic DX hunters far enough away from the rare DX station so that the pileup causes no interference on the frequency the DX station is transmitting on. 

In other words, to relocate the QRM!



For a rare or ‘most wanted’ DX station on 11m in times of good propagation, working split is often the most appropriate way to TX and RX signals without excessive repetitions to check on callsigns and radio reports.  

The goal of the rare DX station working the pileup, after all, is to log as many stations as possible, as smoothly and as quickly as possible.  

So if he works simplex and can’t disentangle the calls because too many ops are calling simultaneously on the same frequency, then changing to split mode and spreading out the callers will make it much easier for all parties involved!



One of the big problems with pileups is that many of the stations calling can’t hear the rare DX because of the QRM caused by other stations calling also.  

By all reports, this was a problem experienced by some ops in European countries during the 197DA/0 Vanuatu activity.

On this note, the simplest and most efficient system for resolving this predicament is the ‘split’ operation — where the DX station TX on one frequency and RX on a different frequency, or over a range of different frequencies.



When should a DXpedition Station go Split?

  1. When the DX Hunters being issued with reports are not confirming them
  2. When a report from the station worked is not able to be confirmed because of other stations who are continuously calling
  3. When the QRM starts slowing the rate of contacts down
  4. When rude operators call continuously on the simplex frequency despite not even hearing the rare DX station.


When is Split NOT the Best Option?

Despite the obvious advantages of working split to sort through pileups, there are times when split ops is not suitable and working in simplex mode instead is required. 

While the majority of 11m DXers these days are licensed hams using technologically advanced amateur radio transceivers with split function capability, one must remember that there are still some ops on 27 MHz who cannot or do not have this capability with their station.

Most island shacks in the remote Pacific Ocean area, for instance, house either old 10m rigs or modified citizens band radios which do not have the capacity for split function. 

It goes without saying then, that a DXpedition or rare DX station on 11m must employ a combination of both simplex and split modes if he is to access these stations.

While there are obviously some 11m ops (Just as there are on ham bands) who really don’t understand the whole concept of split, most comprehend how it works and can adjust their transceivers accordingly.

Here are some more tips for using split mode on 11m…



Tips

Before changing to split mode, the DX station should check if the frequencies he wishes to use for listening are free.

It’s very important to tell people where you are listening.  

As new stations arrive to join the pileup, they need to be instructed quickly as to what’s going on. 

Though it’s generally pretty obvious when a station is working split, a DX station working in split mode should inform others of his modus operandi during every CQ call.  

For example, “This is 321DA/0 listening 5 up”.

The split window should be at least 5-10 kHz as some signals of calling stations can be very wide and cause a lot of splatter on your transmit frequency.

Keep your listening window as narrow as possible to avoid interference to other band users and do not encompass any of the main calling frequencies (e.g. 27.555 MHz) within your window.

Occasionally check your transmit frequency because sometimes you will get operators who can’t figure out what’s going on and why you keep ignoring their calls. 

Don’t work them —just inform them of the listening frequency and then continue your split mode operation.

73 de Darren, 43DA001