On these pages in 2002 I wrote about the art and joys of mobile contesting (Road Warriors, March/April 2002 NCJ). Since then my fellow road warrior Jim Snell, W8DRZ, and I have been out regularly in the Ohio, Michigan and Pennsylvania QSO parties, and have also done one trip each in West Virginia and Indiana. In addition, when Jim was unable to make the trip for the 2005 PAQP, I teamed up with Hal Offutt, W1NN, who has been doing mobile contesting for about a sunspot cycle longer than anybody else.
In short, it's still a great way to contest, trading the ham shack walls for a window on the world, while being a new guy on the band with a fresh pileup every half hour or so. More people have discovered this in the past four years, and also that it can be a lot of fun chasing the mobiles and others while operating from outside the featured state.
Here's an update on what I've observed and learned in the past four years.
My biggest single improvement since 2002 was solving the computer power supply noise problem. Back then I was using a dc to ac inverter to power the laptop 120V power supply. The combination made a lot of noise, as inverters (or at least most of them) simply make a 60 Hz square wave that gives the same RMS power as a 120V sine wave. I had been forced into such techniques as turning the inverter on or off depending where the RF spurs happened to be.
I now use a Car Adapter, a dc to dc converter, to provide the 18 volts for the laptop. These are readily available on eBay for $30 or so. The computer noise is now entirely gone. One caveat: having had a supply of 12V, 26 A/h batteries that had been pulled from UPS service, I used one of these for the computer, mostly to avoid a tangle of wiring into the car's electrical system. When I suggested the car adapter idea to K8CC, Dave tried it but still had serious noise with it powered from his car's electrical system. He then tried it with a separate battery and his noise was gone. Apparently keeping the car adapter isolated from the vehicle ground is necessary to keep the noise down.
A 26 A/h battery will run the laptop for a 12 hour contest, but without much to spare. I was reminded of that the hard way in the 2005 Indiana QSO Party. I forgot that I had been running the laptop for 3 hours before the start of the contest while operating the MARAC county hunters contest on the drive out to Indiana. With an hour left in the IQP the laptop died in mid pileup! I soon diagnosed the problem, hooked up a spare (external) battery, and got back on, though minus the pileup.
I still believe that the HamStick line of antennas gives the best bang for the buck, but there are times during a contest when having three bands available at the same time (and maybe more when the sunspots return) is a significant advantage. Therefore I've acquired a Hustler antenna with a triple resonator mount. This is a larger, heavier system that requires extra mechanical support when used with a magnetic mount. I use Dacron rope guys tied to the front of the roof rack on each side of the car. With careful driving this will likely be good enough, but after a VHF rover effort with even heavier antennas (another story for another time), I've recently added some sideways bracing with PVC pipe. With this PVC mount the hinged fold over feature is not useable, so I take a six foot step ladder to climb onto the van roof to change resonators or do other antenna adjustments.
The Hustler antennas do not have as wide a bandwidth as the HamSticks. This is an issue only on 40 meters, where the IC-746 tuner will cover both SSB and CW on the HamStick, but not on the Hustler. Therefore I now use the 40 meter HamStick full time on the front of the van, and the Hustlers for 80-20-15 on the rear. For 80 meters I have used a 75 meter resonator with added top hat loading wires for CW, similar to what I described for the HamStick in my original article. However, after using W1NN's 80 meter (CW) resonator in the 2005 PA test, I've acquired my own for use in future trips.
For the complete version of this article as published in the NCJ, view the pdf version. W1NN's Some Thoughts on Mobile Contesting article is also available as a pdf version.