I personally rarely hunt in AM mode on the 250.
I find that the constant "bloops" of iron detection is more that I can handle.
In fact, the only time I really switch to that mode is when I'm getting a confusing signal and/or pinpoint, and I want to verify the presence of iron along with possibly a good target.
You can cherry pick any time you want. The tool is in your hands, to use as you see fit.
There are no set and fast rules as to what you can or cannot to, when or where or even why.
If your driven crazy by constant junk, go to custom mode and notch out everything excpet pennies, dimes and quarters. Maybe nickels, but then some foil and bottlecaps will still be in play.
This will cut down on a large portion of junk signals [and also all but eliminate the chances of finding gold/jewelry].
I wouldn't recommend doing this often ... Its just an option to consider.
I find that the preset coin/jewelry modes work fairly well, but I do go crazy on notching on custom mode on occasion in trashy areas, or when I'm in a hurry and just want a quich chance of silver without sorting through the myriad of signals.
Keep in mind that a majority of the sites most of us choose to hunt have very likely been hunted before, and the pickins may simply be slim. Thats why its important not to get frustrated when you hit a site your sure will yield goodies, yet turn up dry.
Good sites are out there, 1,000's of them, and its a matter of patience, research and luck finding them.
I have been lucky enough to stumble upon a few obvious virgin sites with high yields, and finding one of these makes up for dozens of previous fruitless searches.
As far as sensitivity, run it as high as you can without the machine going flaky.
If your more into hunting solitary coins than anything else, master the pinpoint.
That right there will 90% of the time tell you at least if you are dealing with a coin sized object, for if the pinpoint drags on half a foot or more, you know you are not dealing with a coin, at least a single coin.
Another way to tell if you are dealing with a coin sized object is, when getting a decent, repeatable signal, lift the coil off the ground a few inches.
If it still dings like mad, either the coin is right on the surface, or [more likely] it is a much larger and denser metal object than a coin.
Might it still be something good ? A cache ? A stack of coins ? Old watch ?
Maybe, but not a coin. Here, the old dilema " to dig or not to dig" rears its ugly but decidedly intriguing head.
Also, if you don't have a handheld pinpointer, get one.
