John ...where you hunt makes a big difference in how well this mod works..From what I've seen so far ..if PP is deeper in your area then you will see a big difference in performance. I would like to get feed back from everyone that does this mode, and hopefully honest feedback. I can say sofar with using the excal with this mode there is a 4 to 5 inch depth increase in OC, Md. Atlantic city there was about a 3+ inch difference, on the few deep-es I found. Boca Roton Florida, there was about the same improvement, 3+ inch's. One thing I can say for sure, and I have seen a few post that if you hunt in Almetal/PP your coils foot print is only under the coil, {smaller}. {Wrong}.............. With the Amp you will see that there is a secondary field and it does reach out, so a faint target could be under your coil or a few inch's away from the edge. Just remember, this is good for winter Beach's where there are not alot of targets, Sanded in Beach's, NOT trashy area's and in PP only.......... And it's not water proof....
http://www.docsdetecting.com/docsplace/coiltek/coils3.html
This is the set up I have used for about 18 months, and it does take some fine tuning
............Amp off...........just adjust the threshold on the excal as low as you can hear it, then turn the amp on, like 3/4 strength, then adjust your threshold down again, turn amp almost full, then turn your threshold down again, to the point of a very faint hum..sometimes I even keep it up just a little..more