Shep, the issue of operating frequency is somewhat misunderstood. Yes, it is true that 60 kHz operation is a TINY bit more sensitive to smaller gold than lower frequncies, but NOT by as much as some advertising claims you may have seen. For example, the MXT, which operates at 13.88 kHz (hereinafter "14 kHz") AND the GMT, which operates at 48 kHz, have exactly the same prospecting circuit. The difference is in the operating frequency. MY tests, in the actual goldfields, indicates that the MXT, with the 10x6 DD coil, finds nuggets to as small as .25 (1/4th) grain. The GMT, with the comparable 10x6 DD coil, finds them as small as .1 (1/10th) grain. Frankly, THAT is NOT a lot of difference. I found that on nuggets weighing less than 4 grains, that the GMT gets about 30% more depth than the MXT on those same nuggets. Not much difference there, either. On nuggets weighing more than 4 grains, but less than (about) a DWT (24 grains) they are the same as regards depth. NOW.... where there IS a LITTLE more difference, i.e. a DWT or larger, the 14 kHz MXT CAN get slightly better depth in HIGHLY MINERALIZED SOIL. The reason for this is that, all other factors being equal, 14 kHz operation handles "hot" ground a BIT better than 48 kHz. In fact, the MXT is rapidly becoming the VLF gold detector of choice in the Australian and Arizona goldfields. It handles "hot" ground well, and still finds the tiny nuggets. Frankly, if you get an MXT, you will likely sell both the EX I and 18000. And when you get your MXT, be sure to get one of the DD coils, the 10x6, or 1400. AND, high quality headphones. Hope this helps; HH jim
