As i understand it, a metal detector works off the same basic principle as say the old navy radars i used to operate, that it sends out a signal and the signal bounces off a metallic object and gives a return signal to be interpreted by your equipment. Pretty simple in theory i suppose...Now my question is this. The strength of the outgoing signal can be lowered or raised by your adjustable Gain " that is what a radar electronic tech" told me", and the incoming "returning' signal can be fined tuned with your sensitivity settings, if a metal detector does not have an adjustable Gain like the Whites V-series detectors, does that mean your outgoing signal strength is set internally and you have no control over the strength of your outgoing signal, and you can only fine tune the returning signal with your sensitivity settings? OR does the sensitivity settings work in conjunction with gain to strengthen or lessen your outgoing signal, if your detector has no adjustable Gain? Whew, i think i just confused myself.