Just about the time I start finding all the mistakes I've made with my Silver UMax.I buy Dave's(Jabbo's) Vaquero with some exceedingly interesting modifications on it..Also, got his 3 by 18 inch ground sweeper coil...So now I've got two sweeper coils....Dan Brown has a Golden UMax...When he recovers from eye surgery, we'll start comparing the Golden to the Vaquero, and especially what the ground sweeper coils will do....After the tests, I only intend to keep the Vaquero 3 by18. coil.for soccer fields...Other will be up for grabs.. Reading the manual ,Dave's instructions ,trying to do some simple air tests..The Silver is a serious little machine in it's own right.The Vaquero is down right serious.There should be no wondering if older coins were an inch out of reach..They will be pocketed..This machine has enough power to pull me through the learning curve. It only took me about five minutes to become very impressed with it. Totally dark in the back yard, getting signals in a "clean" area .I'll dig it in the morning...Next stop, a" hunted out "1928 athletic field. that produced over 80 dollars in silver and nine gold rings in the early seventies...cordially Nad..