THERE IS NOTHING WRONG WITH THE MK1 BOX AND COLLAR I USED IT FOR YEARS AND TO BE HONEST THERE NOT AS FAST TO LOCATE YOUR TERRIER, WITH ALL THE WALKING UP AND DOWN SEARCHING BUT ONCE YOUR OVER THE DOG THERE MORE ACCURATE THAN THE B.F. THERE NOT WATER PROOF SO PUT PLENTY ELECTRICIAL TAPE AROUND THE BARREL ON THE COLLAR, AND DONT GET THE BOX WET. I HAVE THE B.F BUT SOMETIMES STILL USE THE OLD KNOCKER BOX AND COLLAR. I STILL GET THAT BIT OF A BUZZ WHEN I HEAR THAT CLICK CLICK CLICK. PS, ALWAYS CHECK THE BATTERIES. HAPPY DIGGING
Thanks for the advice on the insulation tape i will do that a