Choosing the Right Antenna

Step 2: Gain (dB)

Gain is the transmission pattern of your antenna, measured in decibels (dB). The higher the dB, the farther the range.

• As gain increases, beamwidth is narrowed.
• Small, lightweight boats, which tend to roll excessively in heavy seas, normally do not use an antenna with a gain rating higher than 6dB.
• Larger or more stable vessels can use higher gain antennas effectively.

3 dB Gain

Usually a 4-foot antenna.
Best suited for powerboats under 24 feet or sailboats.

6 dB Gain

Usually an 8-foot antenna.
Best suited for boats over 23 feet.

9 dB Gain

Usually any antenna 12-feet or taller.
Best suited for boats over 32 feet.

Step 3: Performance, durability, & other features.

Drown out the noise from other radios and the environment by having an efficient transmission system. An efficient transmitter improves the strength of signal and the amount of noise that another listener would hear from you. Would you pair a low quality speaker to a high quality stereo system? The same applies to your antenna.

The factors (within your control) that can improve the efficiency of your transmission are:

• Quality of your antenna elements
• Quality of your coax
• Quality of your connectors

Element Type

Better elements, better efficiency, better range.

Fittings

Stainless Steel > Chrome Brass > Nylon
To prevent wear, it is recommended to match the material on the antenna fitting to the material of the mount.

Construction

Ethafoam spacers protect the elements from vibration for greater durability. The outside shell is called the radome. A thicker radome also increases durability.

Removable

An antenna with a removable connection is easier to stow and replace.