Does it bug you that the old way lost by that much, though? I get why you'd want to trust what your grandpa did, since it worked for him for years, and it's a real bummer to find out the wrap job let you down after all that time. Kind of stings to admit the $150 gadget earned its keep. I'd be curious if the same thing would happen on a shorter stretch, like 3 or 4 months, or if the gap only shows up on the long haul.

Learned that lesson the hard way too, my Garrett carrot crapped out on me last spring and now I never leave the truck without a cheap backup in the bag. Picked up a used TRX off a guy on FB for like 40 bucks and honestly it saved my whole weekend more than once since then. The trick that worked for me was slowing way down once the main unit dies, because you stop trusting the beeps and start really listening to the tones on the main coil instead. I also started carrying one of those little plastic scoop sifters so I can run dirt through it and spot a silver edge without waving handfuls forever. Took me an extra hour but I pulled a 1917 merc that way and it felt way more earned than a normal beep and dig. Keep a spare in your kit and you wont be stuck eyeballing piles in the cold again.