Mobile Operations

My mobile rig is designed with emergency communications in mind.

The vehicle is a 2001 Blazer ZR2 4X4. A basic vehicle which should be able to handle any weather events which can occur in the area. It is also a comfortable vehicle with decent fuel mileage, which makes my life a lot more enjoyable.

Radio Power

The Blazer is wired for radio power with a dedicated 45 Amp line off of the Positive terminal in the under-hood service panel. I do not like connecting to the positive battery terminal, as this can lead to connection issues, and (with side-post type battery connections) introduces the possibility of debris getting into the connections. The ground is a direct run back to the engine block to minimize the chance of ground loops. This also has the added advantage of giving me the ability to add a second power source to prevent accidentally discharging the same battery which starts the car, if I decide it is necessary. Power runs to a three switch panel in the center console to make it easier to control power to each radio, and to add to the “nifty factor” of the vehicle. each switch is a SPST switch rated for 20A@120V. The whole run is fused at the source connection with a ATV bus-type fuse (currently 20A), and at the input of each radio. I DO NOT fuse the grounds, and recommend strongly against doing this.

Switch one controls the vehicle traffic radio (CB), switch two controls the main rig, and switch three leads to a 4 foot power pole cable (bundled in the passenger foot-well) for unforseen connection needs in an emergency.

Radio Antennae

The vehicle has two permanent antenna mounts added.

The 11-meter (CB) antenna is a Firestik FS4 series antenna (black, of course) mounted at the left rear of the vehicle. This is accomplished using an adjustable body mount secured inside the rear-hatch seam. This vehicle leaves enough room to run the cable right through the hatch opening without accidentally crimping or cutting it. I run the cable discreetly through the vehicle by placing the cable inside the armrest assembly.

The amateur-band radio is connected to a Comet SBB5-NMO 2-Meter/70-Centimeter dual-band antenna. It is secured to a Motorola Through-roof NMO base mount. These are the same mounts commonly used for commercial vehicles and for police and fire. This cable runs down through the passenger windshield support, through the dashboard, and into the center console to keep it safe from hands and feet. The selection of the antenna is based off of consumer review (), and the fact that it is based-loaded with a fold-down. The fold-down is important considering vehicle height, and a base loaded antenna has a significantly reduced wind load. Since I already had the vehicle apart, I also ran two lengths of CAT5e plenum cable from the center console to the upper center console for a possible remote head mount when I upgrade the radio. I didn’t see any reason to pull the vehicle apart twice, and the cost of the cable was minimal.

Radio Equipment

The vehicle traffic radio is a Cobra Model 19-DX-IV CB radio which I use to alert for traffic problems, and for occasions when I want to check in on the romper-rooms. It is mounted in-dash to keep it out of the way (a unused tape deck made this easy), and is supported by an accessory speaker mounted in the passenger foot-well.

The main radio is an Alinco DR-130 2-meter transceiver. It is currently rested against the passenger side of the center console. This an acceptable location for most users, and I don’t see any reason to make it more permanent (especially when I consider that an upgrade is planned for this radio).

I also carry a Yaesu FT-60 (2M-70CM) handy talky with a Diamond SRH77CA whip antenna. This comes in handy for local events (ham swaps…), and in case I need to move away from the vehicle.

Future upgrades include installation of a Kenwood V-71 dual-band transceiver to replace the Alinco radio, and a mobile mounted TNC for connection to a laptop in emergency situations (and for normal play).

Other Supplies

There are a few other things which I thought it was important to put in the vehicle…

I keep all of my basic radio maintenance parts in a single toolbox for easy transport, and (since I really didn’t have a place to keep it in the house anyway) I keep that in the Blazer at all times. This includes basic tools, a soldering iron, various lengths of wire and shrink-wrap, connectors and electronic parts, and any “tweenies” (adapters for connecting a radio or antenna to a dissimilar cable) that I happen to have.

I also keep my basic go-kit in the vehicle. There are many different opinions of what a go-kit should consist of, and I cover this in more detail on my go-kit page. The one in the Blazer contains the manuals for the radios, a mini-log, the ARES field reference guide, an emergency communications guidebook, notebooks (blank paper is good), pens and pencils (with sharpener), a few snacks, and various references for local repeaters and emergency contact numbers and call signs.

In the future, I will be adding a portable mast, and a matching antenna for increased range.

Posts

  • Making Your Go Kit
  • Mobile operations
  • The Shack


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