LF vs HF reading

 Hi Guys


wondering if anyone can help me with this. Generally fish in less that 50 meters, so run HF with no issues, but when I head out deeper to around 100 the HF begins to cut out. When I switch over to LF there is a huge amount of interference near the bottom. The photo below shows an example of the LF interference compared to the HF. If I reduce the gain down to about 1 the interference disappears, but so does the bottom.

im running an airmar p66 with the following settings.


Colour erase 15%
Clutter 10%
TVG - Med
Black - Hue background
Gain 5.0 HF

any thoughts or help would be appreciated.



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