Please help the hammerhead

[bobi]

Please Contact one of my hammerhead why not work on low frequency
a very good work on high frequency

[Carl-NC]

It might be the voltage inverter won't run that slow. Try removing R37.

[bobi]

I tried by removing R37 but got no result. with what else to try

[Carl-NC]

So tell me what you mean by "not work." Poor depth? Or no detection at all?