The sizing feature is a very handy one. I was very slow to warm to it, but now that I have, I really like it. as I hunt Aussie coins, they are going to be different to US coins with different challenges. The sizing feature needs more than 2 inches from the coil to work and more recently, I found that lifting it so that it was sizing at 5 inches gave the best results. Our $1 coins which are a common find, bounce around a lot between B and C sizes. It in in the screw cap range, where screw caps mostly register size C. Lifting the coil, locks the $1 coin into size B fairly solidly.
The only drawback on the GTI's is that with the imaging, it causes the detector's recovery speed to be slow. Although I wouldn't hunt in a real trashy site with it, I would and have with a high degree of success, hunted with the 10x5 Scorcher DD coil. It is deadly in high trash and because the imaging is not operating, the recovery speed is quite noticeably faster. Using this coil last year, had my best ever day with $118 recovered in a single day out of 2 parks. Both these parks have a total of 12000 party goers in it every year, who party for 12+ hours, to welcome in the new year. So you can imagine how many crown caps have been dropped there over all those years. These are very old parks! Yet despite the insane amount of crown caps, I was rarely fooled by them, even though they can register in the same area of our $1 and $2 coins, as they gave off a different signal to a coin. (they were less consistent.) With the DD coil on, by whipping it over the target, coin sized targets and smaller give a proportionally less than full tone while size C and bigger targets (screw caps and bigger) give a full tone when the coil is whipped over them.
I hope that that gives you something to think about. A word of warning. You need to be accurate with your pinpointing, if you want the imaging to work right. The smallest sizing occurs when you have the target centred.
Mick Evans.
