Lesson 5

Contesting and DX Operating

International communications are an encouraged part of the FCC rules. That means operating DX, which is an abbreviation for distant signals. DX defined for continental US hams is any signal that originates outside that area. 

DX stations typically are in higher demand. Sometimes a DX station will transmit on one frequency and say they are listening for contacts on another frequency. This is called working “split” for split frequency. Some reasons a station works “split” include:   

  • Because the DX station may be transmitting on a frequency that is prohibited to some responding stations.
  • To separate the calling stations from the DX station and
  • To improve operating efficiency by reducing interference.

 All of these are correct is the answer to working split on the exam. 

To contact a DX station, send your full call sign once or twice when you are attempting to contact a DX station. That could be during a contest or just in a pileup. Generally, you’ll want to send that call sign phonetically, so AA1RC would send “Alpha Alpha One Romeo Charlie.” 

Please send your full call, not just “Romeo Charlie.” It is poor practice to send just the suffix, AND you’re not actually legally identifying yourself. A pileup is when many stations are competing with you to try and reach the DX station. During a pileup only the strongest signal, a quirk of propagation or luck of the draw will get your signal through. Therefore, a longer transmission of your call sign might be better to break through the pileup. 

Operating your shack by remote control? No additional indicator is required when a U.S.-licensed operator is operating an amateur station by remote control. As long as the remote transmitter is within the United States.

Outside of a contest, once the DX station calls you back, you’ll exchange information. Typically it’s your first name and your location, along with a signal report: “This is Elmer in Wyoming; you are 59.”    

During a contest, you may be asked to give a specific response. Let’s use the “Rookie Roundup,” as an example. In that contest you exchange your call sign, name, the last two digits of the year you were first licensed and state. So our friend Elmer might say “Alpha Alpha One Romeo Charlie, Elmer, 22, Wyoming.” Every contest does it a little differently, but there are plenty of places online to search for rules.   

When it comes to rules around contesting there are not too many. Amateur radio contesting generally is excluded on 30 meters. It’s also very rarely done on the 12, 17 or 60 meter HF bands. That makes them good bands to use if you feel overwhelmed by contesters on a busy weekend.   

Operating SSB or CW during a VHF/UHF contest? The segment of the band where you’ll find most operators is in the weak signal segment of the band, with most of the activity near the calling frequency.

At the end of a contest, logs are exchanged to validate contacts and name the winners. A standard for submission of electronic contest logs is called the Cabrillo format. Why is Cabrillo is used by contest operators? It allows automatic electronic cross-checking of submitted logs. The standard makes all log data consistent which aids in checking. In days past, paper logs were manually reviewed by contest operators, which was a tedious task!

Another format for exchanging log data called ADIF. The Amateur Data Interchange Format is supported by many logging tools. That includes our own World Radio League logbook.

When you have made a contact over the air, you may want to confirm it with a QSL card. They are postcard-sized and printed by hams to confirm on-air contacts via the mail. A station operating from a rare location will use a DX QSL manager to handle the receiving and sending of confirmation cards for a DX station.

Another online tool for confirming contacts is the ARRL’s Logbook of the World (LoTW). You can confirm contacts including:

  • special event contacts between stations in the US
  • contacts between a US station and a non-US station and
  • Contacts for Worked All States credit

 All these choices are correct when asked about LoTW on the exam. 

Let’s transition now into a couple of digital modes that are represented in the bands above HF. That would be Mesh networks and APRS. 

Mesh Networks

A wireless mesh network is a way of connecting devices together to share data between each other and other more distant networks. Amateur radio mesh networks send data using a similar protocol to your wireless home internet network.  

Mesh networks sometimes use frequencies shared with various unlicensed wireless data services.  Why share frequencies? Because amateur radio shares spectrum near generally used wifi frequencies. That’s why the answer to this question is worded this way. 

For an amateur radio mesh network a wireless router running custom firmware can be used. These are the same devices that might be used on your home network. They just have different programming. 


APRS stands for the Automatic Packet Reporting System, which was created in the 1980s. It is used to communicate digital data. That includes GPS coordinates, weather station telemetry, search-and-rescue data and direction-finding data. 

The digital protocol used by APRS is called AX.25.  AX.25 is used extensively on amateur packet networks. APRS beacon data transmission uses a packet frame type called unnumbered Information. 

APRS stations relay data by packet digipeaters.  These can be repeater-like units you are familiar with. They can also be small home brew units using an older radio interfaced with a Raspberry Pi.  

How far can a packet be relayed? It depends on how the sender has configured their request. In an APRS header you set a value called a path. The word WIDE is used with a number to indicate how wide you want your packet to be relayed.  If you saw a packet path that said “WIDE3-1” it means three digipeater hops are requested with one remaining.

Why would you vary your path settings? During a marathon, several support vehicles can be equipped with APRS. This allows race control to monitor the end of the race. They can also see where runner assistance vans are located. You don’t need a wide path here.

You might want a wide path when APRS is used to track balloons carrying amateur radio transmitters. 

Ham Radio Prep Logo
Download the FREE study app!