[attachment 66614 GTI1.JPG]Hi, again! I used the Ace 250 for almost two years, and was doing well. I learned its quirks and its way of interpreting what was under the coil. Then, I thought, in the spring of 2007, I needed more depth. The prospect of accurate ID with depth and size made the GTI an attractive prospect. The added bonus was that the learning curve would not be as steep as if I'd gotten another brand machine.
One thing though, even with the stock 9" coil, this is a machine that after 6 hours will make you run to the car and get that lighter back-up machine (in my case, the 250).
The GTI has an auto-track feature, which means that it adjusts itself constantly to the ground mineralization, thus saving you the time and hassle of pushing buttons. My approach is simple: if the grass or brush is short (4" approx.) I hunt in Relics or Coins mode, and Zero Discrimination. If the grass is taller, or if the loam is 10" plus, I go All Metal. In All Metal, if I happen upon a target other than iron, I switch to Coins to confirm ID. I'll often pinpoint over a "deep" target in All-Metal to try and further ID. I often switch to Zero just to have something to listen to, or to confirm whether or not there are iron relics: Where there are old ox shoes, there were people working... Where there were people working, there might be coins and other things. It's what I call "following the iron trail"; I have found a couple of good coins amidst soil littered with old nails and other iron items, which also means that if you work slowly enough, and know the machine, you can actually seperate good targets from bad in close proximity. The Ace 250 also works amazingly well this way, even with the 12" eliptical.
I've never tinkered with sensitivity or frequency. Never had to. Factory pre-sets seem to put the machine on its best behaviour. Bi-Level and Tone, is my personal preference, and I simply switch off the Treasure Talk feature, as I'm sure all GTI users do.
In all-metal, the GTI 2500 goes quite deep, even with the comparatively small stock coil, which is what I use 98% of the time. The 14" DD coil is a behemoth which I can see working well in fairly clean beaches or fields. The DD is the ultimate mineralization antidote, but it loves pulltabs and screw-tops. In New England, according to my experienceand that of others, you don't really need depth, but good target identification and discrimination - the GTI fits the bill perfectly for me.
In the end, it's a compromise... I cover less ground with the 9" coil, but do so with the promise of accuracy and decent depth. I know that with this machine, all I have to do is be at the right place, and go nice and slow.
I hope this info was useful, Jason. Good luck, and maybe I'll see you in the fall!?
HH