Nice picture. I Have the same helix model as you for about 2 months.

I have just this weekend started to scan in 400 kHz. I was reluctant because of course I wanted the Mega (right!?). I am scanning 100 feet in each direction and getting good results. I turned up contrast and sensitivity a bit (not sure on exact settings).

Name: 20200426_111142.jpg Views: 636 Size: 86.4 KB