Dunno, I live in Houston where it's gumbo clay, and
mine seems to do just fine. If there is a decrease in
performance around clay soil, it must not be enough to
hurt things too much. I still wouldn't be afraid to buy
the 250. If by chance you find it really is a dud in your
area, they are a cinch to resell. Hot item in general..
But I don't think it would have much trouble at all.
As far as the sensitivity, this is my $2.81 worth..
In doing careful air testing, combined with ground tests,
I can say yes, increasing the sensitivity does increase
the depth. It shows up easily on the air tests, and I
found some deeper coins that would hit sporadic or not
at all if I reduced the level from a high setting.
But...What Willy and some of the others say is also correct.
It's quite possible to set it so high that the chatter
makes it hard to note the real targets. When starting out,
I wouldn't set it too high. I'd increase it until it starts
to chatter, and then back it off a notch or two until it
settles down.
But...Once you get used to machine, and the chatter, it
is possible to get a bit more depth if you can tolerate
the extra chatter at times.
Chatter is totally random and also ID's randomly.
Real targets, trash or good, will repeat, and also
repeat as far as ID. Sooo. The deal is you train your
ear to ignore the random chatter, and only lock on to
the repeat tones. Once you get the hang, you can tell
what is chatter, and what is real. Operating like that
can give you an extra inch or two, but it's not for everyone,
and even I don't do it all the time. In general, I adjust
as I go. If the ground is quiet, I'll crank that puppy up.
If the chatter gets to a point to where it's a nuisance,
I'll crank it down. Also the coil type effects the chatter
level also. My small sniper coil I can run flat out with
little chatter. But the big coil can get kinda noisy
if you crank it too high in a hot or busy area. So you
play it by ear.
I think the 250 would do ok for you, and the price is
hard to beat. But good luck with whatever you get.
Kellyco is ok I guess. Thats where I bought mine when I
started out. I didn't have any trouble, but other reports
vary.. But I've bought stuff from other places too.
Rons up in Tennessee "forum sponser, see ad at top" is a
good dealer if you can't get what you want elsewhere.
MK