A Complete? Mobile Station

By

Geoff Haines, N1GY

            One of the continuing projects I have been working on is to assemble or create the tools I find a need for when I go out to the field. By that I mean anything from Field Day once a year to the occasional charity long distance run or bike-a-thon and even just to go to the shore with my XYL so that she can get some sun and I can do a little DX portable.

            My needs may well be different from yours, but there are enough common items in each of our field kits that you can see what you might find interesting enough to add to your kit. If you are just starting out in this wonderful world of amateur radio, let me assure you, my kit did not come into being all at once and neither should yours. Like the ARES Go-Kit, it gets built over time, as needs become apparent and as the situation changes.

            I should also point out that there is some degree of duplication in my Field Kit. What I pull out of the back of my SUV depends on what the task is. If I am working on communications for a charity bike-a-thon, I will not need any HF antennas, but I will almost surely need the range that a tall VHF/UHF antenna will provide. If the event, whatever it may be, is going to last more than an hour, sitting behind the wheel of my SUV will not be comfortable. I will need a table and chairs from which to operate. Unless I want to run the vehicle all day just to keep the battery charged, and with the price of gas being what it is, nobody wants to do that, I will need to have an alternate source of power.

            On the other hand, if I am going to the beach for a little sunny DX, I want a way of erecting an HF antenna to "reach out and touch someone" on the other side of the globe. Where I live, on the Gulf Coast of Florida, authorities sometimes take a dim view of someone throwing a wire antenna up into the trees. They also would prefer that one not take up over a hundred feet of beach access with a wire dipole no matter what it is mounted on. Field Day might be a different matter, where the group has priority on the site they are operating from, but a lone operator just out for a little DX will usually find it is best to have a fairly small footprint.

            With all that said, here is a description of the tools and accessories that I use to be ready for "deployment" in the situations I mentioned above.

            My personal car, a 2000 Chevy Blazer, is equipped with the following:

ü      Icom IC-706 MkIIG

ü      LDG RT-11 water-resistant automatic tuner

ü      GPS

ü      Microphone selector module (to switch between the stock hand mic and my homebrewed headset). The headset is a cellular universal type that I have written about in QST and on my web site. In the case of my SUV, the adaptive electronics to allow it to play with my 706 are built into the selector module.

ü      A battery charger which can be connected directly to the vehicle battery when a source of mains power is available. This allows me to run the radio in the Blazer all day without running the car battery down. Doing it this way may seem a little inefficient, but the spiky waveform of some generators is smoothed out and otherwise I would have to carry a power supply too.

            Carried in the SUV, ready to be used at any time, are the various antennas, coax and accessories I might need. Since I live in Florida, this quantity of gear is rather larger than it might be in other areas of the country. I do live in a severe weather prone part of the United States, not just for "Hurricane Season", but also the "Lightning Capitol of the World". Storms show up frequently that are severe enough to do major damage and often amateur radio is called in to aid in the aftermath and the recovery. Instead of keeping my ARES Go-Kit in the house, I keep it in the car. You get the idea.

            Some of the "purchased" items kept in the car are things like a 100 foot electrical extension cord (to connect the battery charger to an AC source). A rain suit, two piece, (the weather, you know). Two folding chairs, the modern type that stow away in their own bags, plus a similar folding table for setting up operations outside the vehicle. More about the table later. I also have two different inverters, a small 140 watt one for my laptop PC and a larger 330 watt one for things like a soldering iron or the like. In addition there are tool kits and supplies for the vehicle and warning triangles if I get a flat.

            Where my list gets to be fun (for me) is in the array of "homebrewed" or DIY gear that I have built for the job. Many of these are featured on my web site and some have even made it to the pages of QST over the years.

ü      Two different dual band (VHF/UHF) antennas, both of which can be mounted on masts.

ü      Two different telescopic masts, one about 17 feet tall, one about 22 feet tall. The shorter one mounts on the trailer hitch at the rear of the car and is used for VHF/UHF only. The longer one mounts to what I call a "Bigfoot" mount that sits under one of the tires of the SUV. If I put it up all the way, it requires guy ropes, but it will carry a 5 band HF antenna array called "The Octopus" because of its eight "Hamstick" style mobile antennas arranged around a central hub. This system gives me dipoles on 75, 40, 20, 15 and 10 meters and band selection is automatic since the hub is wired in "Fan Dipole" manner. It can also carry a VHF/UHF dual band antenna above the HF array if necessary.

ü      In order to operate the radio outside of the vehicle, there are two different setups: The first is simply to dismount the control head from the car and use a spare remote mounting cable to allow the control head to be placed on the table. The second is used when changing frequency will not be done, such as a charity event. I built an "extension cord" and speaker module for the mic itself. This module also allows me to switch from hand mic to headset if I need to.

ü      In order to get the coax runs from the external antennas to the 706 used to be a matter of unscrewing the connectors and replacing the coax runs that go to the vehicle mounted mobile antennas. Now, I need only throw two coax switches and toss the coax extensions attached to them, out the back window of the Blazer. The box that the extensions terminate in clamps to the rear bumper of the Blazer and lets me hook up the coax runs from the external mast mounted antennas outside the car. Once I close the tailgate window the car is secure but the coax runs are outside. I could simply have installed pass-through connectors through the bodywork of the car, but I really didn't want to drill any more holes in the car.

ü      Now, the "more about that table" I mentioned a while ago. The table is pretty simple, a folding system of legs and screw tensioner to hold a fabric table surface relatively taut. It has 4 cup holders (one in each corner) and they are available at most sporting goods stores. My problem was that it didn't work very well for a radio and a laptop as well as the other stuff that I might need. The solution was a piece of scrap 1/2" plywood about 43" x 24". It stores on top of the various "milk crates" that I use to store the gear in the back of the Blazer and just lays on top of the fabric table when in use. The rigid surface allows me to use my laptop, the radio, a lamp and one or more of the inverters to power the laptop or my tools.

ü      The lamp I mentioned in the paragraph above is worthy of some mention as well. Wanting to keep the power drain down to a dull roar, I decided to use LED lighting for night operations. An inexpensive LED map light was purchased and by combining an old cigarette lighter socket with an old lamp base I was able to kludge up an LED "desk lamp" that runs off the 12 volt DC available from the car.

ü      In order to bring the 12 volt DC out from the car and make it available on the table, I built a 12 volt extension cord about 15 feet long. Made with Anderson Powerpole connectors and 10 gauge red/black zip cord, it has Powerpole connectors at both ends, one set on the end that plugs into the car and 6 pairs in a small project box at the other. I also installed a Powerpole outlet in the back of the center console of the Blazer, wired directly to the car battery. It is protected by fuses of course, but it allows me to connect any of my 12 volt gear without having wires running all over the driver's compartment.

ü      Another of the "milk crates" in the cargo compartment carries all of the guy ropes and stakes necessary to erect the larger mast. The "Bigfoot mount is also stored back there in two sections, the horizontal plate and the vertical 1 1/2" pipe nipple that the mast sockets into.

ü      The masts themselves, along with the "Hamstick" antennas and the dual band antennas are stored in a heavy ballistic nylon duffle-like bag that my wife created out of two shorter bags that were donated by a fellow ham, and good friend. The larger mast is almost five feet long when stored, so the new bag was made to fit.

ü      Also stored in the bag is an MFJ telescopic "stinger" which when added to the top of the larger mast makes it a pretty good 33 foot vertical antenna when a set of 8 wire radials are laid out on the ground around it.

ü      I should point out that the Blazer has "limo tint" on all of the windows back of the "B" pillar and that most of the gear is covered by a roll-out cargo cover when not in use.

            All of this stuff may have some readers saying "what the heck are you trying to do?" My answer is simple. The Blazer has the cargo capacity, and I would much rather carry it with me, ready to use, than to have to take the time to load it all up out of my shed when the call comes it. That applies not only to an ARES callout, but also to just heading off to the beach for a few hours. Our kids are all grown and have families of their own now, so having only three seats left in the Blazer (the rear seat has a split fold-down feature) is not a problem. If we need space for more people, we take my wife's car. Other than the usual ham radio mobile antennas, the Blazer looks completely normal on the outside which is great for just roving around town.

            However, when the need arises, it can be transformed into a complete communications facility in a few minutes. That is what this is all about. If I need to, I can put a second VHF/UHF radio into play and make available a two operator, multi-frequency station, all in the middle of nowhere. Believe me, once you have gone through one of Florida's multi-Hurricane season, even downtown in a big city can become "the middle of nowhere" in a hurry.