The KØNR Radio Site
So You Want to Be A Rover
Step one in understanding rover operation is to read the contest rules carefully to understand the rules specific to rovers. (Information on the ARRL contests in June, September and January is at www.arrl.org/contests/). The CQ Worldwide VHF contest is sponsored by CQ Magazine and the rules are available at http://www.cq-amateur-radio.com I won't cover this here except to say that the basic concept is that rovers are allowed and encouraged to move from grid to grid, making contacts with stations multiple times. This type of operation is extremely valuable here in Colorado since many of the Colorado (and Nebraska, Kansas) grids are not occupied by fixed VHF stations.
The first question that comes up is "what equipment do I need?" Again, this will vary greatly depending on you how much time, money and energy you want to put into rover operation. I will focus on getting started and you can build from there.
The minimum capability for rover operation is 2M SSB capability with a horizontally polarized antenna. Obviously, this station needs to be portable so that you can move from grid to grid. While you may want FM capability along with you, the vast majority of operation will be on SSB. Don't rely on a vertical antenna to operate SSB, since all serious contest stations will be horizontally polarized. Using the wrong polarization will cost you 20 dB or more in signal loss. There are a number of omnidirectional, horizontally polarized antennas for mobile use such as the Halo, SQLOOP, HO, Big Wheel, etc. You can mount these antennas on your vehicle and operate while in motion. Another alternative is to use a small Yagi antenna (again, horizontally polarized). This will require a more advanced mounting scheme and may require you to "stop and point" to operate. Of course, a Yagi has a significant gain advantage over omnidirectional antennas. Even though the coax runs are short, use low loss line such as 9913 or (at least) RG-8. In recent years, various dealers are offering "Flex 9913", which has the low loss of 9913 but with a stranded center conductor for good mechanical flexibility, which is great for rover operation.
There are two basic approaches to rover operation, Run-and-Gun and Stop-and-Shoot. "Run-and-Gun" means that you make contacts while in motion. This requires some careful thought as to how to point antennas (if they are directional), perform logging and not get into a traffic accident. "Stop-and-Shoot" means that you stop at an appropriate location, set up antennas and operate there. Many stop-and-shoot operators also have the ability to at least listen on 2M while in motion, so they can stay in tune with contest activity. Stop-and-shoot stations need to be quick to set up and take down, so that minimum time is lost between locations. Most beginner rovers will choose stop-and-shoot, as it is inherently less difficult.
A basic VHF portable or rover operation that
is set up for "stop and shoot".
After you have the basic 2M SSB station covered, you can expand your station via additional frequency bands and increased station performance.
Additional Frequency Bands
There is no "single band" contest category for rovers, so adding additional bands is an important way to improve your score, your competitiveness and your operating fun. Six meters is probably the most important band to add to your rover operation, since this band is most likely to have propagation to distant grids. When 6M is open, you'll want to focus your operating on this band to quickly gain contacts and grids. Antennas for 6M are more of a challenge, since even a 3-element beam is quite large for mobile operation. Most operators tend to choose a small, omni antenna. Sometimes I've used a vertical on 6M, which will does well on long distance propagation but suffers for local communication due to polarization loss.
The next band to add is probably 70 cm (432 MHz), due to its popularity, then 1.2 GHz, 222 MHz, etc. Check out the contest rules to understand the increased points per contact for the higher bands. It is helpful (but not necessary) to monitor multiple bands simultaneously, so that you don't miss an opportunity on one band while making contacts on another.
Another VHF rover operation that is set up for "stop and shoot".
A VHF rover operation that is set up for "run and gun."
Improved antennas are probably the first place to look for increased station performance. Rovers tend to operate with marginal antennas (at least compared to the big gun fixed stations). Increased antenna gain or height benefits both your transmit and receive performance. Even a small Yagi has many dB of advantage over an omnidirectional antenna. Antenna height is important, so many rovers develop mast systems that allow their antennas to get high off the ground (20 to 30 feet), improving their station performance.
Mounting of antennas is a great challenge for rover operation, especially for run-and-gun operation. I won't go into detail here, but antenna mounting schemes that I have used include:
Many rovers use linear amplifiers to provide for a boost in transmit power. Often VHF and UHF amplifiers have low noise preamps built-in, which help on receive. Increased output power means more attention must be paid to supplying DC power to the station, which means use large wire. A 150-watt 2M amplifier will draw about 20 amps of 12 volt DC, which is a lot of current. (Just 1/10th of an ohm wire resistance will drop the supply voltage by 2 volts!) A 300 Watt amplifier draws about 48 amps.
For simple stations, you can just power the rig off your vehicle's 12-volt battery. However, you will need to run some heavy gage wire directly to the battery and you'll need to start the engine periodically so that you don't run the battery down. Trust me, this is easy to forget about when 6M opens up and you are the target of a large pileup. Many rovers use a separate battery to power their stations.
Once you figure out what equipment you will use, you need to decide where you will go. The run-and-gun approach will result in choosing an operating route, while the stop-and-shoot approach focuses on a set of operating locations. Either way, thinking through the route you will take is very important, since it affects how much operating time you will ultimately have in each grid.
Choice of operating location depends on three main things: grid rarity, accessibility and propagation to other stations. Grid rarity means that you want to operate from rare grids, ones that are not likely to be activated by other operators during the contest. For example, DM78, DM79 and DN70 along the front range of Colorado have large populations of hams and will be activated during the contest. By being in a rare grid, you offer a larger incentive for serious contesters to work a little harder to make contact with you. In addition, less serious ops that are working towards VUCC will also make it a point to work you.
Accessibility means that you need to be able to get to the location quickly. This is a serious concern since many locations in the mountains look attractive until you consider the time to get to the location. Snow can block backcountry roads, including during the June contest since it is still early in the summer season.
Operating locations should have good propagation to other stations. Fundamentally, the point is to make contacts, so if you are on top of a mountain with awesome propagation paths to locations with no one to work, it doesn't contribute to your score. In Colorado, you'll want to consider your propagation path to the front range where most of the stations are located. Good locations are higher than the surrounding terrain with an unobstructed view in all directions. A careful review of topographical maps will help you choose the best spots.
Maps, GPS and other aids
You'll need a reliable means of knowing what grid you located in. This starts with a macro view of the state...where are the grid lines at a regional level? I have a Colorado map with grid lines on it here. It is also very useful to have a standard state road map (one with roads and some geographic info on it) with grid lines drawn on it. This will give you the big picture on where you want to operate as a rover, but you will generally need something more precise to determine your exact location. The obvious choice here is a GPS receiver that can be set to display the "Maidenhead" grid directly. Another alternative is a good set of topo maps. However, with the reasonable price of GPS gear, it seems like the way to go.
A laptop computer is very handy for logging purposes. One popular logging program that can handle rover operation is "vhf-dx". Some rovers still use paper logs, but you'll need to have a scheme for keeping track of who you've worked from each grid. Otherwise, after working 3 bands from 3 grids, you can't remember if you need a QSO with a particular station or not. Some rovers just tape record their entire effort and sort it out later.
As mentioned earlier, the vast majority of contest operation is on SSB (and CW). FM can be used in contests but note that use of 146.52 is not allowed. My rover vehicle already has a 2M/70cm rig, so I usually monitor the standard FM simplex frequencies during the contest. Usually, I'll make a number of contacts there and it is a chance to generate some interest in serious contesting with the folks that hang out on FM. It is also common to run into operators that have 2M SSB but can only run FM on 70 cm, so we'll QSY over to 446.0 MHz to make an additional contact. On the other hand, I have only FM gear on 222 MHz, so I ask SSB operators to go to an FM simplex frequency and work me via FM. I often bring along a horizontally-polarized Yagi (not common on FM) for making these contacts so that do don't suffer the signal loss associated with cross-polarization. For weak-signal work, FM is FAR inferior to SSB and CW, but it may be a way for you to add an additional band to your station.
Rover operation is FUN. It starts out with the fun challenge of equipping your station and figuring out how to make it work. The actual event is fun because it gets you out of the shack, out of the house and cruising down the highway. Instead of being just another station in Denver or Colorado Springs, now you are new grid. Once you give this a try, you'll find all kinds of ideas on how to approach your next rover operation. So give rover operation a try and have some fun.
I think that is is only fair to warn you that roving can be addictive and your family and friends may try to obtain professional help for you. Here are some web links where you can see pictures of rover vehicles and read about some of rover operations: