You 'detune' with a CZ using the pin point button. What you do is contiune to press/depress the button as you sweep over the target, sizing it up. As you sweep and detune, the target gets 'smaller' and the VCO sound 'sharper/quicker' unitl you can almost tell the size of the target. It has NOTHING to do with lowering/raising the sensitivity level.
Rounder targets end up sizing pretty small and in a tight spot while longer targets such as nails, rectangluar pieces of metal, etc. size larger and longer and possibly null out in the middle and actually have 2 points to them and will possibly sound off at those two points. When that happens, you can tell that the target is elongated. The secret is to sweep at multiple angles.
When sweeping at multiple angles, a round target will continue to be in the same spot and not have 2 points to it. At some point while sweeping at multiple angles over an elongated target, you will sweep over the 2 end points of the target, getting a hit on each point and a possible null in the middle. Clear sign the target is not a coin IF the target sizes big.
A small, double hit signal MAY be a coin on edge.
As they say...ya never know for sure unless you dig it up !!!
