Dig-a-holic said:GB is over rated in my area. Only 5 silver coins I found last year were with factory preset machines. Never could find one with my Vaquero.
Pre-set GB units can work well in many areas...a lot depends on the degree of mineralization for a given area. Pre-set units come from the factory with GB internally calibrated with the supplied coil for best results over a broad range of ground conditions. A manual GB detector will allow the user to interchange any size coil regardless of configuration (wide-scan or concentric) and have the ability to set your GB precisely for that coil of your choice.