I bought a second hand unused Whites 120 mm bullseye pinpointer and at best got a 1/2 inch depth on a dime..Took the four small screws out of the back( eyeglass screwdriver works well) and don't touch the larger black screw as it holds the rod securely.
Upper righthand corner was a trimpot which I adjusted clockwise as far as it would go and increased my depth but the unit sounded off when button was engaged..The trick is to turn it slowly counterclockwise until it doesn't sound off unless a target is present..Happy to say am now getting approx. 1 1/4 inch on a dime and 1 1/2 on a quarter which is as good or better than most handheld pinpointers..
I have no knowledge of the earlier Whites(White) unit or the new improved 11 version they now sell...
Upper righthand corner was a trimpot which I adjusted clockwise as far as it would go and increased my depth but the unit sounded off when button was engaged..The trick is to turn it slowly counterclockwise until it doesn't sound off unless a target is present..Happy to say am now getting approx. 1 1/4 inch on a dime and 1 1/2 on a quarter which is as good or better than most handheld pinpointers..
I have no knowledge of the earlier Whites(White) unit or the new improved 11 version they now sell...