Gain Explained

Gain measures how much of the energy sent from the radio to the antenna is concentrated in a specific direction, and in which direction the antenna has the greatest “reach” when receiving a signal.

The gain of the antenna is stated in decibels (dB) and measures the increase in field strength of the antenna when compared to a reference antenna, which can be either an isotropic antenna (dBi) or a dipole antenna (dBd). Comparisons can be made between dBd and dBi as follows: dBd=dBi-2.15

Some manufacturers use their own “Marine Gain”, stated as plain “dB”, which is not a true measurement, and simply allows them to put higher gain figures alongside their antennas. This can mislead customers into thinking that they are getting more gain for their money.

To allow comparisons of our antennas with antennas which state performance in “Marine Gain” we list both true gain in dBi and “Marine Gain” in dB.

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