Hey there. I had a GTAx-550...up until 2 months or so ago. It was my first machine actually. I don't think it's a bad machine for the price. I think it's a pretty decent little machine. Pretty hot on coins. I too had some difficulty at times pinpointing. Did you purchase this machine brand new
Recently? I ask because if you did, it should have the 7 x 10 eliptical coil.
In order to pinpoint with this coil...find the strongest signal point on the display (or shallowest depth reading) from left to right (the center)...then drag the coil back towards you until the signal just drops off. When that happens...your target SHOULD be under the front center of the INNER coil.
Note: when you first hit a target...move the coil off the target and place it so it is resting on the ground....then press pinpoint and drag the coil over the target without lifting the coil off the ground. (then proceed with the above instructions).
It can be tricky at first, but you get the hang of it.
As for the machines performance...I found I didn't get much depth out of it. I didn't pick-up any targets over 8" deep.
It certainly does not compare to my new machine (whites XL Pro), or any of the higher end models...but it will score you some good finds nonetheless
Wess
