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How to choose Work Frequency of Fish Finder transducer ?

The most commonly used operating frequencies for fish finders are generally designed for 50kHz and 200kHz; the most commonly used operating frequencies for freshwater general fish finders are generally designed for 77kHz and 200kHz.

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In general, the higher the frequency, the shorter the wavelength, the clearer the signal, but the shorter the propagation distance; the lower the frequency, the longer the wavelength, the longer the propagation distance but the signal will be blurred. If it is a wide range of search, you can choose low frequency, if you want to see the target clearly, choose high frequency.

Generally, 200kHz is the clearest for detecting fish echo, but the usual depth range is not more than 600ft/200m, and the beam angle is usually designed to be within 20°, which is suitable for shallow waters and mainly used for displaying fine target images.

render 4 v2 50khz and 200khz

If you are searching a wide area, you can choose a low frequency, if you want to see the target clearly, choose a high frequency.

Generally speaking, 200kHz is the clearest for detecting fish echoes, but the usual depth range is not more than 600ft/200m, and the beam angle is usually designed to be within 20°, which is suitable for shallow waters and mainly used for displaying fine target images.

The 50kHz fish echoes can be seen deeper, and the beam angle is also designed to be larger, usually up to 40° or more, mainly used for displaying the contour of the topography of the deep water bottom.

Due to the long wavelength, it is easy to miss some small targets. 77kHz detects fish that can be seen relatively deeper, but generally focuses on the use of freshwater lakes, especially increasing the beam angle to 30° or more. Different fish species such as marine fish and freshwater fish respond differently to different frequencies, but generally have a more obvious response to the 200kHz frequency, which is why 200kHz is the main working frequency of the fish finder.

The figure below shows the difference between the images of the same underwater fish swimming at 200kHz and 50kHz respectively on the screen of the fish finder.

As you can see from the picture, 50kHz is deeper than 200kHz, but the clarity is relatively lower than 200kHz, while 200kHz is shallower, but very clear.

In short, the fish finder is through the ultrasonic to detect fish, and then according to different frequencies to work, different power can also be for different needs of their own choice of high frequency or low frequency to work.

frequency 620 split screen

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