Technical Articles

Ham Radio to Go: Portable Hamming

Yes, you can take it with you. Today’s smaller transceivers and accessories allow you to operate from anywhere, whether it’s a cabin at the lake, a weekend at Uncle Joe’s, hiking, or a hotel room. 

If you own an RV or trailer, so much the better—install your radio gear to make a rolling ham shack. Many RVs have a backup battery which you can easily tap for power, and most have generators. If you stay at a wired campsite, you can use grid power.

Antenna Options

As with all portable operations, the antenna should be one of your first considerations. It can make the difference between establishing contacts—or not. The usual rules apply: higher is better, bigger is better, and outside beats inside. However, space limitations may limit your choices.

Vertical antennas, which usually have a small footprint, need a counterpoise or radials. Comet HFJ-350 series “Toy Box” and MFJ 2286  portable telescopic antennas are typical examples of compact, lightweight antennas that you can stow in your luggage or backpack. The Yaesu ATAS-120A autotune screwdriver antenna is a perfect match for their portable/mobile radios, including the FT-818, FT-857D, and the FT-891. Tuning is controlled from the radio with the push of a button. Mobile “sticks” such as MFJ’s Monoband Mobile HamTenna Whips can be paired with a mounting bracket to construct a compact vertical or horizontal dipole.

Wire dipoles and end-fed antennas are also widely used and don’t require a counterpoise. They’re backpack friendly and are a simple solution that plays well for portable operation. Par EndFedz are half-wave end-fed (EFHW) antennas that don’t require a counterpoise and are available in single or multiband versions. The lightweight SOTABeams Band Hopper dipole also covers multiple bands—band selection is done with alligator clip jumpers. Another alternative is the off-center fed dipole (OCF), such as the Buckmaster OCF 40. Of course, there’s the option of building your own single-band dipole, a simple project done with wire cut to resonance, a center, and two end insulators.

All of these antennas are either resonant, easily tuned manually, or adjusted by the radio. It’s likely that an external tuner won’t be necessary. One other choice that fits these specifications is a magnetic loop, such as the AlexLoop HamPack Portable Antenna System . They’re efficient for their size, good for QRP operation in limited spaces, and include a variable capacitor and tuning indicator.

Bring enough feedline to connect the antenna to your radio. Also, consider bringing a compact fiberglass pole to support a wire antenna. The SOTABeams Tactical Telescoping Fiberglass Mast  has a collapsed length of about 23 inches, perfect for fitting in a backpack or suitcase.

HF Transceivers    

Think lightweight and compact when considering a transceiver. QRP models like the Icom IC-705, MFJ 9400 series and FT-818D pack a lot of features into a small, light package. The Yaesu 100W models mentioned in the last section will add some extra punch to your signal, but will require a heavier-duty power supply. In the compact but not backpack/carry-on friendly category are the Kenwood TS-480, Icom 7300, Icom 7100 and Yaesu 991A. These would be a better fit for more permanent installations like an RV or trailer.

Pack your radio in a padded hard or soft case, one that has some room for accessories like microphones, lightweight headphones/earbuds, power cables, coaxial adapters, short coax jumpers, etc. Do a dry run of your portable station setup to be sure you pack everything you need and make sure your equipment works properly.

Power to the Portable

Transceivers generally use 12-13.8VDC for their operation. The power sources you use will depend on the portable location and the availability of AC power. If you have access to standard 120VAC power—an RV park or hotel, for example—a mini 13.8VDC power supply is a good choice. The Alinco DM-430 and MFJ 4230MV provide 30 amp ratings, plenty to run your radio and accessories.

If you’re off the grid, batteries and solar chargers can keep you active. Lithium Iron Phosphate batteries (LiFePO4) offer the best balance between capacity and weight, making them a favorite choice for portable radio applications. Inverter generators, such as the Generac GP2200i, are a good choice if you’ll be operating in a fixed location outdoors.

Carry an 8- or 10-foot extension cord/power strip. You can never have enough outlets.

VHF/UHF: Opportunities for All

HF portable is not the only choice. 6 meters and above include privileges for Tech, General, and Extra licensees in all modes, giving additional options for portable operation. 

The 2 meter band at 144-148 MHz is usually the first one that Techs use to get on the air. It’s also the most widely used VHF band no matter what license class. Basic equipment is relatively inexpensive and there’s a wide variety to choose from–you can get on the air for less than $100.

A standard “rubber duck” antenna is found on just about every handheld radio. They work, but the radiated signal may be mediocre. Purchase a larger aftermarket antenna for your radio. A longer antenna offers superior performance to the original one. Diamond Antenna Dual-Band HT Antennas are one of several brands of HT antennas that can help improve your signal.

Mobile antennas can boost signals for handhelds as well. Having a magnetic mount antenna outside your vehicle can make the difference between a weak and a solid signal with an HT.  They can also be used as temporary antennas in a variety of situations. They can sit atop metal railings, window air conditioners, or a large steel pizza pan.

Simple base station antennas are often small enough to be used for portable operation. The Diamond’s X-30A is just slightly taller than 4 feet and is extremely light. Ground plane antennas are an easy DIY build using 12 AWG wire, or you can buy them in kit form (MFJ 1754).

If you plan to do VHF/UHF SOTA activations or mountaintopping, a compact beam is very useful. You get the advantage of both height at your location and the additional gain provided by the beam; getting contacts over several hundred miles is possible. The Diamond A144S5 Yagi Beam Antenna is built for portable operation and is pre-tuned at the factory.

VHF/UHF Transceivers

Two meter equipment is readily available, though many come as a 2M/70cm dual band combination. For the best of both worlds, consider a handheld radio capable of 5 watts output for home and travel. You can use this with an outdoor antenna array, mobile with an external antenna, or portable with a rubber duck antenna.

Mobile rigs are shrinking to book-sized packages, with power levels ranging from 10 to 80 watts output. They’re suitable for vehicle installation and portable deployment, or you can use them as a base station with a 13.8VDC power supply. In recent years, mobile radios (as well as handhelds) have incorporated digital systems, such as D-Star and C4FM, that offer more than just voice communication, such as data applications and locating features like GPS and APRS.

As you travel, you’ll find numerous repeaters along the way. Besides helping to increase your VHF/UHF radio’s range, they serve as a virtual watering hole for local hams–a good place to meet other hams while traveling. To find the locations/frequencies/settings, check the latest  ARRL Repeater Directory or Rfinder on the Internet. There’s also the traditional calling frequency, 146.52 simplex, to find others on the air nearby.

Be Prepared

Plan ahead! Make a packing list–and double-check it before you leave. There’s nothing worse that realizing you left something behind that was critical to getting you on the air. On my last trip, I had everything I needed minus a coax adapter. They’re tough to find in rural North Carolina.

Bring materials to improvise–extra wire, spare connectors, and other items you may need. Think about what items you needed (and didn’t have) at your last Field Day. Really important–don’t forget a basic tool kit for repairs, including a soldering torch.

Thinking back, I realize that the challenge of getting on the air in portable mode is sometimes more interesting than many of the contacts that I made. It turns a trip into a radio adventure.

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