Behind the Screens Page 5
By Ben Ellison
Airmar Broadband Transducers
It used to be true that a transducer’s sensitivity was closely tied to how narrow a frequency it could ping at, but the innovators at Airmar have developed a recipe of acoustic materials and a build process that flips that truism on its ear, so to speak. Already available in several high-end transducers, like the 2-kW R199 in-hull model shown, is a 200-kHz element that actually broadcasts from 150 to 280 kHz. The immediate result, according to Airmar, is that existing fishfinders get more information to better discriminate individual fish in a school, as well as fish close to the bottom and shallow bottom itself. The assertion is backed up by the fact that manufacturers like Furuno and Raymarine like what they see so much that they plan switching to the broadband-added models despite the $100-plus increase in cost. But this is just the beginning. Airmar hopes to bring broadband down to the low-frequency, deep-water level (especially tricky as there are 15 50kHz elements in that R199), and expects that future fishfinders will allow users to “tune” to the best frequency, and therefore beam angle and detail, for various species and environmental situations. The company expects that broadband transducers will eventually lead to “chirp” frequency-modulated sonar, and “a quantum leap forward in fishfinder performance.” Oh boy!
Airmar ( (843) 394-3565. www.airmar.com.
This article originally appeared in the November 2005 issue of Power & Motoryacht magazine.