Tony N (Michigan) said:
I usually hunt in 8kHz. Maybe I should up the kHz for on edge coins. I wonder if I'd lose much depth going 12 as opposed to 8. Probably not much.
Depth on what?
12kHz is deeper on most coins then 8,4 or 18 kHz.
Perhaps 8kHz is deeper on 1 ounce copper but for the "regular" size coins 12kHz is the deeper freq by a considerable amount, assuming average "regular" mild dirt.
There might be certain situations where 8kHz hits lower due to bad mineralization or whatever, but that is the exception to the rule and a special situation.
18kHz is good for on edge coins, (But is shallower),I usually use 12 first then come back in 18 to eek out some extra coins and whatnot.
It appears that size factors into the frequency used as much as conductivity ultimately.