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Ham it up on the water

Equip your boat for amateur radio

It’s hardly surprising that many boaters are hams and many hams are boaters—both activities attract those interested in expanding their skills and overcoming challenges.

Starting gradually: the handheld station

Equipping a boat for ham radio need not involve major effort or expenditure. With your amateur VHF handheld transceiver, you can check in with the local repeater group or keep in touch with other ham boaters. Ham channels will likely be less crowded than marine ship-to-ship channels—a real plus.

Most of today’s VHF handhelds can monitor marine channels and NOAA weather alerts. With two marine receivers, you can monitor for calls on your usual ship channel while leaving your VHF marine transceiver set to Channel 16, the calling and distress channel.

Moving aboard

It’s no great leap to install a mobile-sized amateur VHF transceiver next to your VHF marine radio. Both mount and hook up the same way. Plus, it’s harder to lose over the side.

The marine frequencies (156–162 megahertz) are close enough to the 2-meter ham band (144–148 MHz) that I can use my sailboat’s mast-mounted marine antenna for both, toggling between the two bands with a small coaxial switch.

The mismatched antenna and transmission line cost me some power, but thanks to the added height and resulting long line-of-sight distance, I don’t notice the loss. Boaters with lower antenna mounts may do better with a wideband antenna designed to cover the range.

MF through UHF marine mobile stations

Arguably, a mobile transceiver that operates in MF through VHF or UHF ranges can be installed as easily as a VHF/UHF mobile radio and doesn’t cost much more. Figure 1 shows my all-band radio mounted beside the marine VHF set.

What kind of radio for your craft?

With Windfall, a 25-foot diesel auxiliary sloop, I wanted to use a single radio for both HF and 2-meter operation. In addition, I wanted to operate from the cabin below as well as from the cockpit while under way. That led me to a transceiver with a removable control panel that could be placed in either location.

Marine HF SSB systems

Vessels that travel outside the line-of-sight coverage of marine VHF FM radios often use marine HF single side band radios for ship-to-coast station and ship-to-ship service. Note that HF marine SSB radio users must have an FCC ship station license and a commercial operator’s license or restricted radio operator’s permit in addition to an FCC amateur license of the appropriate class. While there is no prohibition against using marine radio gear in the U.S. amateur bands, you should check with the appropriate agency if you’re outside the country.

Not all marine HF SSB radios can operate on the HF amateur bands. Before you make a purchase, check with manufacturers to see which models can be used on the amateur bands and how well they perform both roles.

Power source

While both a VHF-only transceiver and an all-band radio can operate from a (fully charged) vehicle battery, the all-bander will pull around 20 amps key down versus the typical 50-watt FM transceiver’s 10 amps. This translates into a need for heavier primary wire—typically 10 gauge or larger, depending on the distance the wire runs.

Note that the total current drain for a 100-watt SSB transmitter and a 40-watt FM transmitter is about the same over time, depending on speech patterns and compression settings, because of SSB’s lower duty cycle. Thus, they can discharge a battery in about the same time.

To provide maximum life, the radio battery should be deep cycle, not a starting battery. Starting batteries, which are designed to provide a short burst of high current and then be quickly recharged, won’t survive many of the deep discharge cycles that a radio battery undergoes.

On Windfall, I have two gelled electrolyte deep cycle batteries. Whenever I’m aboard without the engine running, I switch to the BATTERY 2 setting, saving BATTERY 1 for starting the engine. While the engine is running, I switch to BATTERY 1 & 2 to have the alternator recharge both batteries. So far I haven’t needed a jump start.

Another issue for hams is operating from a partly discharged battery. It doesn’t take long for a battery that isn’t being recharged to sag to 12 volts or less, even though it still has a lot of energy.

If you expect to operate for more than an hour or so, consider adding a battery boost regulator to your system. It will provide 13.8 volts to your radio equipment as long as the battery provides 10.5 volts, about the limit to maximize battery life.

Maritime HF antenna systems

High-frequency antenna systems for boats have been a stumbling block to some; after all, trees are not in abundance aboard a boat, although sailboats come equipped with at least one artificial “tree.”

On Windfall, I had my rigging shop install insulators at both ends of my backstay while the mast was down one winter. To avoid variable coupling to the stainless topping lift, I replaced it with a topping lift made from low-stretch synthetic material.

For boaters without an insulated stay or a mast for that matter, marine electronics dealers sell antennas and tuners suitable for both marine HF SSB and HF amateur services. Most of these antennas require a cabin bracket 3 or 4 feet up from the base in addition to a base support.

If you have a sailboat, you could also hoist a temporary wire up the mast. Keep the base to some uncluttered corner so the wire will be as far as feasible from the mast and wire rigging, which will distort the pattern.

Most marine HF antennas require a ground connection and an antenna tuner for reasonable operation on more than one frequency range.

Ground systems

The ground connections will depend on the craft and its electrical system. The optimum setup would be a short connection to a solid metal hull. Even if the craft were insulated by layers of paint, the capacitance to ground would work well.

Unsure what I would need, I added ground arrangements until I had something that worked. I placed my automatic antenna tuner aft, near the entrance arrangement for the backstay wire, on the same side of the craft as the battery system and the engine ground stud. I ran the ground braid from the tuner directly to the engine ground where it met up with the other ground wires. This gave me the capacitance of the engine block to the seawater, including a seawater path through the cooling system, the connection through the wet propeller shaft and propeller, and all the power wiring capacitance to the water surface.

The antenna tuner

I use an aftermarket automatic antenna tuner midway between the ground connection and the antenna feed. Marine SSB sets put out up to 150 watts, so you’ll want a tuner that can handle that much if you plan to use it for your marine SSB as well as your amateur transceiver.

Operating afloat

As with a home station, you’ll need a comfortable operating location. I can quickly set up to operate either from the radio location for quick casual contacts or from the cabin while at anchor (Figure 2). The removable control panel makes it easy to operate from the helm as well (Figure 3).

If you operate outside U.S. waters, you should familiarize yourself with the frequency allocations of the region and identify yourself as maritime mobile. Note that when operating in another country’s waters, you need an appropriate permit from that government and are subject to that country’s regulations.

The maritime mobile suffix is not appropriate within U.S. waters. No special identifying suffix is required for U.S. amateurs in portable or mobile operation within the U.S., but I use marine mobile as it is both descriptive and within the rules.

Enjoy both hobbies this summer, but make sure you don’t get distracted, especially in Long Island Sound where I set sail!

Joel R. Hallas, W1ZR, of Saugatuck River Sail & Power Squadron, is the technical editor of QST, the official journal of the American Radio Relay League. A longer version of this article appeared in the July 2009 issue of QST.