What defines a ham radio mobile station? I once checked into a local radio net as “KE4WMF-mobile.” The net control station asked, “Are you actually driving or just sitting in your car?” I answered that I was parked, but also said that “mobile” is more of a descriptor of a station’s configuration or capability than its current use. Over the years, I’ve seen or heard of many different ways to define a “mobile” station. The most tortured way I’ve ever heard a ham declare themselves to be “mobile” was when he said that his permanently disabled vehicle (translation: a yard ornament that’ll never run or roll again) with a wire antenna still counted as him being a “mobile station.” I have no idea what he was using to power the transceiver! I think he was pursuing some sort of award for mobile operations and was stretching the rules, or lack of clarity within them, to achieve something. As a result, various contest organizers have closed a few loopholes to better define a mobile station.
Whether directly or by word of mouth, I think most contest organizers borrow heavily from what might be the only published definition of a mobile station ever presented by a commonly recognized authority within amateur radio. The American Radio Relay League (ARRL) “Mobile DXCC Award“ criteria defines a mobile station as follows:
A mobile QSO appropriate for this award is defined as a QSO made from a mobile station which is contained in a legally licensed, self-propelled, land-based vehicle capable of movement before, after, or during the QSO and which provides all power to the radio equipment (no commercial or external electrical power can be used), and using only antennas mounted fully on the same mobile vehicle or a directly connected attachment and which moves together any time the vehicle is moved. The vehicle station must make the QSO with the DX entity exclusively and directly using only the mobile station. Use of any remote station, radio repeater, and internet interfaced station or system to assist in making the QSO is not permitted. Any contact made with antennas set-up or usable only when stopped to make the QSO (for example, a dipole or yagi) is classified as “portable” and not “mobile.”
ARRL does not offer the award to maritime or aeronautical stations, but they clearly ARE mobile stations if you strip away their exclusions in the award criteria above. With that done, a “mobile station” is one that is contained in a legally licensed, self-propelled vehicle that is capable of movement before, after, or during the QSO. Some rules add “immediately,” as in “immediately before, after or during the QSO.” The station must carry or generate all power to the radio equipment (capable of doing so while in motion?) and use only antennas mounted fully on the same vehicle or a directly connected attachment that moves together any time the vehicle is moved (such as a trailer with antennas already erected as shown in this photo).
Photo by Andy, NY7N
In short, if the station is capable of operating while in self-propelled motion, even if it’s parked, then it’s a “mobile” station. As soon as a feed line is run outside to an external antenna, the station becomes a “portable” station (or a “rover” in some contests, such as the very cool VHF contest “micro-rover” shown here). If the vehicle is not capable of self-propelled legal motion as configured (for example, the antennas are too tall to be road-legal, or the antennas cannot withstand highway travel), then its not a mobile station. If the vehicle is not capable of motion at all, then it’s a fixed station.
Photo by Russell, W8UZZ
I added the “highway travel” bit due to a rule that the 3905 Century Club’s “Mobile Antenna Shootout” competition used at some point. I don’t know if the rule is still in use today. Apparently, they had at least one entrant years ago who arrived with a huge antenna that wasn’t roadworthy. The owner wanted to set up at the contest site. This Jeep by W8UZZ was NOT the entrant, but is shown as an example of how large some mobile antennas can get (height is 13’6″). I think 3905CC began gathering the vehicles at a location that required Shootout entrants to drive their configuration to the contest site, a practice that forced each contestant to prove that their setup was capable of travel, not just motion, as configured instead of a ringer that never saw real road use. I like the idea even though I’ve never entered a Shootout! What’s the point of entering a contest with a station that’s not used anywhere else? I say, “Let the Shootout take place between true mobile stations!” 🙂
Building an effective mobile station takes time, patience, research, and testing to pull-off. Doing it right can be a source of pride, especially since even the best mobile stations are a compromise when compared to a decent fixed station. So, if you hear a mobile station calling or making a great QSO, send your congratulations for a job well done!
Always Mobile!
Scott, KE4WMF
