On one of my posts, GM_Amateur asked about the newer version Fisher Gold Bug and Gold Bug-Pro.  He wanted to know if they are Gold Detectors or Multi Purpose.  I classify the Gold Bug and Gold Bug-Pro as true Multi Purpose detectors.  I put the MXT series and F75 in the same category too.  To me, it's a detector with medium kHz operating in the teens and having an adjustable Discriminator capable of rejecting ferrous and nonferrous targets if desired. When I tested the 1st prototypes of the Gold