Hello.I'm new to computers and forums so please bear with me!Bought my grey box locator(now known asMK1)second hand well over20 years ago.Used it hard,one collar died,one believedpinched .Like a wally I bought a complete mk3 set in 2006. Soon realised that I only needed to buy a collar as my old grey box works great with the mk3 necklaces! Reckon the mk3 is distracting ,requiring too much user input.Count the features;on/off switch,search mode/locate mode switch,flashing depth indicators and ....the volume control knob.This brings me onto the subject of noise---think 1968 Star Trek,think Haw