When the coil is changed on the F75 (or any detector) do you need to do a factory reset ? I see no place in the manual where this is brought up. I have always done this after every coil change but I am not quite sure where I picked up this habit. Does anyone have a technical explanation as to why this should be done or not ? My reasoning is that it can't hurt, and a factory reset every once in a while has always been suggested as a way to "debug" any settings that were inadvertently programmed into the menu. Some may say that a reset then requires you to redo your settings, but on the F75 this takes less than a minute.