I recently purchased the small concentric coil for my Vaquero. Wow it's so little the machine seems weightless with it in place. Since the yards in the neighborhood are so trashy with iron chunks and nails I figured this would help. Sure enough it does. I found this coin in the middle of the yard behind us, slightly newer property dating from around 1890 or so. It was about 5 inches down in an area filled with iron nails and old metal stuff. The signal was loud and clear for a moment before crossing into more junky signals. I've been over this spot dozens of times. I have to wonder about it's history. A 1925 German coin in a yard in the deep south. Hmmm must be a story here.