The area covered by the transmitted sound waves is determined by the cone angle of the transducer and the water depth. The 50kHz frequency provides a 40° cone angle, with a coverage width that is approximately 2/3 of the water depth. As shown in the sidebar, the 40° cone angle (50kHz frequency) approximately covers the area of a 20 foot diameter circle at a 30 foot depth. The 200kHz frequency provides a 10° cone angle, with a coverage width that is approximately 2/10 of the water depth. As shown, the 10° cone angle (200kHz frequency) approximately covers the area of a 6 foot diameter circle at a 30 foot depth.
When using the Fishfinder 160 Blue in ‘Dual’ frequency mode, the unit transmits both 50kHz and 200kHz signals at the same time. The ‘Dual’ frequency capability of the Fishfinder 160 Blue allows the user to have
a large coverage area and still retain good bottom resolution. When in ‘Dual’ frequency mode the unit uses the 200kHz to display detailed bottom information, keeping “Dead Zones” to a minimum, and the 50kHz signal for the large coverage area.
Fish returns from the 50kHz and 200kHz beams will appear differently on the display. The 50kHz beam tends to show longer fish returns than the 200kHz beam. The examples below show simulated fish returns at 50 and 200 kHz.
On the Water
Transducer Coverage200kHz - 10˚ Cone Angle | 50kHz - 40˚ Cone Angle |
72" coverage at 30' | 20' coverage at 30' |
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