Four simple tips on how to ensure a healthy VHF antenna

by Sail-World Cruising on 3 Aug 2010 A boat's VHF antenna is one of the vital links in the communication chain on-board. You depend on it for most ordinary communication, but in times of distress it can make the difference between surviving and not.

Regular inspection and testing are both vital and easy to ensure this important equipment performs properly when needed.

Here Shakespeare Marine offers tips for simple and quick testing:

1: Visual Inspection:
Antenna maintenance begins with a simple visual inspection. Signs of wear that could affect system performance include large cracks or fractures on a fiberglass antenna. A metal whip that is bent or badly nicked can also cause problems.

Beyond the antenna itself, loose connectors or those with excessive corrosion can interfere with communications. Equally important, the entire length of coax cable between the radio and antenna should be examined to ensure it is not kinked, crushed or cut. Damaged cable should be replaced.

2: Pre-voyage testing:
Before every trip on the water, the radio system should be tested. A simple method is to make a series of transmissions to a friend's boat, from a range of known distances on a non-emergency channel. Both owners can then assess the quality of each other's transmissions.

Performing a solo test starts with tuning in a distant VHF weather station. After disconnecting the antenna at the radio, the signal should weaken or disappear. Reinserting just the tip of the coax connector should produce a signal that will improve as it is fully reconnected. If instead the signal disappears again, there may be problems with the connector or antenna. Likewise, if wiggling the connector causes large changes in signal strength, its connection to the cable itself may be faulty.

3: Using a meter:
More accurate and sophisticated testing comes with the help of a meter that measures system performance. The ART-3 Antenna Radio Tester offers a cost-effective method of ensuring the radio and antenna are performing to their best efficiency. Simple to use, this unit tests radio output power, antenna VSWR (efficiency) and receiver functionality. Designed with boat owners in mind, the ART-3 displays RF output power up to 30 watts on an easy-to-read, built-in scale. It has an internal battery or can be connected to the onboard 12V DC power supply.

4: Back-up 1:
Having a good backup plan in place is also important in the event of an antenna failure or incident on board, such as the loss of the mast, if that is where the antenna is located. Carrying an emergency antenna provides the reassurance and security for such a situation. The 5911 and SL156 emergency antennas each offer the ideal solution; both are compact and easily stowed.

5: Back-up 2:
A hand-held VHF radio is an extremely useful item to keep on board a cruising boat. Not only is it there in times of emergency, it also typically acts as a shore or dinghy radio to keep crew in touch with the yacht at all times

For more information about any aspect of this article, consult the Shakespeare Marine www.shakespeare-marine.com!website.