Do It Yourself: How To Install A Vhf Radio In Your Sailboat

All sailors and boaters need to have a VHF radio transceiver. A fixed-mount unit is more powerful and capable of longer-range communications. Here's how to properly install the radio and antennae on your sailboat.

A VHF (very high frequency) radio transceiver is a must-have for all boaters. These radios allow you to listen and talk on the frequencies used by the U.S. Coast Guard, commercial ships, fishing vessels and all other recreational vessels. The VHF radio can be used to call for help in an emergency or to confer with captains of other vessels in passing situations where right-of-way issues might arise, or simply to chat with fellow boaters about the weather or the amenities of a nearby harbor.

While you can get by legally with a small hand-held VHF radio, these smaller transceivers are much lower-powered, transmitting with only 5 watts, max and therefore lacking the range of fixed-mount units. Fixed mount units also benefit from external antennae, which can be placed in a much higher position, and this also increases receiving and transmitting range. The third benefit of a fixed mount radio is that it operates off of your vessel's house battery bank, rather than the expensive disposable batteries hand-held units eat up in a hurry when transmitting.

Installing a fixed-mount VHF is not too difficult, and should be within the capabilities of most boat owners, even those without a grasp of electronic principles. The radio basically has only two connections: a 12-volt DC power source and the coax cable for connecting the separately mounted antennae. The location of the radio unit is the most critical decision to be made. It is ideal if the radio can be positioned in a way that you can listen and talk on it both down below in the cabin and up on deck in the cockpit where you will be navigating. In my boat I mounted the radio on the overhead cabin surface just inside the companionway. This way it is protected from rain and spray, but with the hatch open I can use the radio while steering the boat. In bad weather, I can go below and close the hatch and use the radio. Another option available on more expensive units is a wireless microphone for use on deck and separate speakers mounted in the cockpit.



Most radios will come with mounting brackets allowing a variety of mounting positions. Wherever you mount this hardware, make sure it is securely fastened so the radio is not flung loose when you find yourself in rough seas. A microphone hanger bracket is also included and should be fixed in a way to securely hold the microphone.

The 12-volt power connection to a VHF radio, like all other electronic devices on board, should be routed through a 12-volt breaker panel. Never wire a radio directly to the house battery. At the very least, if you do not have a breaker panel, make sure there is a properly-sized fuse in the hot side of the circuit that will blow in case of an overload.

Mounting and connecting the external antennae is the most difficult part of a VHF radio installation. Ideally, the antennae should be mounted at the top of the mast, the very highest point on your sailboat. This kind of installation will greatly increase your transmitting and receiving range, as VHF radio waves are propagated by line of sight, just like FM radio. Range is limited by the curvature of the earth and therefore the higher the antennae, the better. You will have to either climb your mast or lower it down for this installation, depending on which is easier for your particular boat.

Use the bracket supplied with the antennae and make sure the ground connection is good. The other connection for the antennae is the coax cable that connects to the back of the radio unit. This cable should ideally follow the shortest route possible between the antennae and the radio, usually down the mast, and inside it if it is a hollow aluminum extrusion. If you don't know how to cut and make up the connectors for coax cable, take your cable and connectors to a TV repair shop or other electronic specialist and have it done right. Coax connections are critical to the operation of your radio and must be done correctly. Try to eliminate any extra length in this coax cable, as extra length results in lost signal strength and performance of your radio.

This done, you are ready to start talking and listening to what is going on in the marine community around you. Take the time to learn proper radio protocol, as VHF radio use is regulated by the Federal Communications Commission and certain activities are prohibited and certain channels have designated uses.

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