..... ACE250 is giving us false signals all the time!! (we dig them, signal disappears...ughhh...)
morbiusandneo, a bunch of answers:
a) me thinks you are using the 250 wrong. Yes it's true that that's an entry level detector. And yes it's true there's ones that handle minerals better, go deeper, etc... HOWEVER, since you're 1) looking for a very large object, and 2) estimate just a foot or so deep, then 3) a 250 still ought to be able to find a jar or toaster sized object at 1 ft. Even in bad ground. I don't know where you are at, but unless it's jet black nasty soil, or something strange at the continental divide mineralized-ground states, the 250 can cut most ground (albeit having to turn down the sens, etc...). Hence when someone complains of "disappearing signals", it's almost ALWAYS user error, not machine error. So ....
b) I would hook up with a proficient md'r in your area, and flag and compare suspected "disappearing signals". Perhaps your chasing 1 way flutter ? Perhaps your hearing the end of your steel toed boots ? Perhaps you're not understanding the subtle motion required while in disc. mode ? Etc... etc...
c) But assuming you're using it right, and assuming it is indeed a need for a better machine. I don't think at ATX will do you any better, but yes, it is a better machine. If you're finding lots of household/commercial type homestead junk, just be prepared that a better machine will simply find 2x that amount of junk.
..... screens out EVERYTHING and "sniffs" ONLY for gold very well from all my research.....
d) No. There is no machine that can sniff out "only gold", and reject all other metals. The only thing detectors can do, at best, is tell conductivity. And unfortunately lots of metals share conductivity. And size starts to play havoc on the conductivity. Ie.: while foil is said to be a low conductor, yet if you get a soda can size ball of densely packed foil wad, it will read up at quarter or whatever. Hence size plays into the TID. Thus no machine can tell gold vs silver, vs brass, vs aluminun, etc.... in a true sense.
e) Not to be a kill-joy, but be aware that treasure stories are a dime a dozen. Oh sure, when you hear them, they all seem to be bullet-proof and iron-clad. But when you're talking about 1808 to the present, then legends take hold, telephone game enters in, and all explanations to the contrary are long forgotten. Treasure lore is so fun and exciting to believe, that it just all-the-more-entrenched after 2 centuries, embellished and emboldened into absolute fact after enough tellings. Even original sources (faded newspaper clippings from the era, etc...) can have alternative explanations. Not saying that every campfire story urban legend is false. Just saying: be skeptical when hearing these wonderful stories.
f) I notice you say 12 to 15": That's a wise conclusion. Because there is a common misconception that all caches are, of necessity, super deep. And humorously: The more valuable the cache, then all-the-deeper it must be ! (6 to 9 ft. blah blah). But you're right: If someone way-back-when went to hide their stuff, then what the heck difference did 1 ft. versus 6 ft. make ? NOTHING. As long as the surface was invisible, then added depth did nothing more to hide it better. And go figure: the person was going to have to come back for it at some point they'd have figured. So why make it harder to retrieve ? If you've ever dug foxholes or bottle digging to 6 ft. deep, then you KNOW how much of a chore 1 ft. vs 6 ft. is. It's not merely "6x harder". The task grows exponentially, because to get a single foot of bottom space at 6 ft. deep, the the top of your hole is not merely "1 ft. wide", The hole has to be shaped like an ice cream cone, so that the sides don't cave in as you dig. So to get down 6 ft, your hole opening has to be like 6 ft. across ! Thus 30x as hard to reach 6x ft. versus 1 ft.
g) If you're truly looking for "big game" (a jar or toaster sized item), and hence don't want to fiddle with individual coins, tabs, nails, hinges, etc... : Then consider a 2 box machine. They will, by definition, simply not even hear object smaller than a fist-sized or can-sized object. Hence the perfect discriminator for pesky coin-sized items. And yes: They get a can sized object with ease to 1 to 2 ft. And yes can handle minerals if you're using them correctly. A TM-808 can be picked up on the used market for within your budget. And if you practice with it, by burying a soda can, mason jar filled with clad, etc... on the property, I'm betting that you will get your object to be quite distinct from false signals, flutters, etc....