How to Choose the Right VHF Antenna
A long-held adage maintains that a marine fixed-mount VHF radio is only as good as the antenna with which you match it. Translation: Don’t spare the dollars. Major brands such as AirWave, Digital, Glomex and Shakespeare offer VHF antenna models in a range of prices to suit different budgets, but you want the highest-end model you can afford. The benefits of high-end models are more durable components, improved signal-to-strength ratio for more efficient broadcasting, and thicker fiberglass outer sheaths for a longer service life. Within each price-point category, there are also various types of VHF antennas to accommodate different boat styles and communication needs. Let’s look at some of the factors to consider when buying a VHF antenna.
Height
The higher or taller the antenna, the greater your range. That’s because VHF waves travel in what is known as line of sight, and the higher the antenna, the farther it can see over the horizon. With this mind, why do companies offer antennas ranging from 3 to 23 feet? Much depends on the boat and its communication needs. A sport-fishing yacht needs to communicate at greater distances when offshore than a family runabout cruising the Intracoastal Waterway. Bigger boats can also accommodate taller antennas. Mounting antennas as high as possible—such as on the hardtop—has the same effect in boosting VHF range.
Gain
Measured in decibels, antenna gain represents the VHF transmission pattern, and it can also affect range. Antennas vary from 3 dB for a 4-foot model to 9 dB for a 12- to 23-footer. Generally speaking, the higher the decibels, the greater the range, but with a caveat. Higher gains broadcast at a narrower pattern than lower gains. So, as a boat rolls and pitches, higher gains intermittently angle downward into the water or upward to the sky rather than toward the horizon. This reduces range. As a consequence, smaller craft prone to roll and pitch are better off with a medium gain. The most popular for boats ranging from 20 to 35 feet in length is an 8-foot, 6 dB antenna that provides less range than 9 dB, but it is also less susceptible to the effects of pitch and roll.
Cable Considerations
The standard PL-259 plug that connects the antenna’s coaxial cable to the back of a radio is relatively large in diameter. To make installation easier, these connectors are usually installed after the cable is routed through rigging tubes, pipes and bulkheads. Traditionally, the coaxial wires need to be soldered to the plug. Lower-priced antennas still have these, but higher-end models now feature screw-on plugs that dispense with soldering. Some antennas also feature a connector at or close to the base of the antenna that lets you easily remove or replace the antenna without the hassle of snaking a new cable through the rigging.
Read Next: Common Mistakes When Using a VHF Radio
Mounts
Ratchet-style antenna mounts are popular add-ons for boaters who need to clear low bridges—be it on the water or while trailering to and from the launch ramp. The female ferrule at the base of the antennas screws directly to the threaded mount. Want to get boujee? Consider Taco Marine’s electric mount that raises and lowers an antenna at the push of a button so you don’t have to climb on the hardtop to perform this task.
Colors
In the past, fiberglass VHF antennas were all white, but brands such as AirWave, Digital and Shakespeare now offer black antennas in case boaters want to complement a particular color scheme.
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