ARRL

Chasing DX

  • What is DX?

     

    We tend to think of “DX” in the literal sense—a station operating from a distant location. While that may be true in some circumstances, the definition of DX is really in the eye of the beholder.

     

    For instance, what sort of distance defines DX? If you’re operating on the HF bands, that distance may be measured in thousands of miles. For a microwave operator, however, DX may mean a contact over a hundred miles or so.

     

    DX does indeed involve distance, but it also involves difficulty and scarcity. Take the little island of Desecho in the Caribbean. Desecho is near Puerto Rico, which makes it practically next door for signals on the HF bands. If distance is your only yardstick, Desecho doesn’t qualify as DX as far as HF operators in the United States are concerned.

     

    But Desecho is uninhabited. No hams live on Desecho and the island is difficult to reach because of a tangle of regulations that prohibit most visitors. Therefore, it is a rare day when a ham journeys to the island and puts a signal on the air. Such an event is big news in the DX community as thousands rush to their radios in the hope of making contact with Desecho before the hams pull down their antennas and leave the island.

     

    So is Desecho Island DX? You bet it is! It isn’t distance that makes Desecho such a big DX prize—it is because the island is rarely on the air thanks to the difficulty of getting there.

     

  • Breaking Through the Pileups

     

    When a station suddenly pops up in a rare DXCC entity, US state or grid square, the result is a chaotic swarm of signals as everyone tries to make contact. We call these on-the-air mob scenes pileups.

    The most difficult pileup occurs when everyone, including the DX station, is on the same frequency. The hunters have no choice but to transmit over and over in hope that the DX operator will hear (or decode) their call signs.

    A good DX operator will try to make order out of chaos by imposing some rules. The most common technique is to ask for calls in order of call sign district. It might sound something like this…

     

    “J77DR QRZ for sevens only!”

     

     

    This means that J77DR only wants to hear from hams in the 7th call district. If your call sign has a number other than seven, you must remain silent and wait your turn.   

    As pileups become massive, the only workable solution is to spread it out. DX operators do this by transmitting on one frequency while tuning and listening through a range of frequencies.

    For example, J77DR may transmit on 14190 kHz, but he will be listening for calls from 14195 through 14210 kHz. In this instance, the request for calls may sound like this…

     

    “J77DR QRZ, 195 to 210!”

     

     

     

    Or he may be somewhat less specific…

     

    “J77DR QRZ, Up 5 to 15!”

     

     

     

    This means that he is listening 5 to 15 kHz above his transmitting frequency.

     

    Spreading the pileup in this fashion is known as working split. To make this work, you need to understand how to place your transceiver into the split frequency mode. Most modern radios have to variable frequency oscillators (VFOs) that you use to set your frequency. These separate VFOs are usually labeled A and B. When you place your radio in the SPLIT mode, you transmit on one VFO frequency and listen on the other. The trick is making sure that you don’t have them reversed. Transmitting on the DX station’s transmit frequency is a major no-no when he is working split! Instead, you want your “receive” VFO tuned to his transmit frequency while you call somewhere in his listening range with your “transmit” VFO.

     

    Your best chance of making contact in a pileup is when the DX station is working split. You can analyze his operating patterns and pick a transmit frequency that gives you the greatest chance of being heard. Even though the DX operators says he is listening between 14190 and 14210 kHz, does he seem to favor a certain portion of that range? Listen carefully and you may detect a pattern that will give you the edge!

     

     

    Here are some more pileup tips…

     

    --Don’t call the DX unless you can hear his signal. This may sound like common sense, but you’d be surprised at how many hams will discover a pileup in progress and start throwing out their call signs when they can’t even hear the DX station! This causes misery for everyone.

     

    --When the DX station acknowledges someone’s call, stop calling until the contact is completed. The obnoxious practice of calling while the DX operator is trying to complete a contact is at the top of the list of DX annoyances. Wait until you hear “QRZ” or something similar before calling again. (In CW pileups, the end of the contact may only be signaled by the DX station sending his own call sign.)

     

    --When calling, send only your call sign, not the call of the DX station. And send your complete call sign, not just a few letters.

     

    --When a DX station is trying to sort out a call sign, he may send “W4? AGN,” meaning that he hears a W4, but can’t make out the rest of the call sign (AGN is a CW abbreviation for “again.”) If you aren’t the station he is looking for, don’t call! This will only make him angry and might get you blacklisted.

     

    --l If you’re trying to make an SSB contact, this is probably a good time to use speech compression (or speech processing) if your transceiver offers this feature. It may give you the extra punch to get through.

     

    --If you make contact, send only the information the DX operator needs, typically your location and signal report. Don’t try to engage in conversation; that’s not what he is there for! The DX operator just wants to get you into his log and move on to the next contact.