Hi Andy,
I have been having great success with my Infinium. I took it to Hawaii ecently and did well... see the link below. The last thing I did to prepare for my trip was buy and read your book "Advanced Water Working Techniques" Great info. Thanks!
I've read the online Infinium report you did and I am not seeing the tip you mention. I would very much like to hear what it is.
I've had reasonable success with the dual-tone id system. I've found that items zinc penny and below are hi-lo tone, and copper penny and above are lo-hi tone. Since we are talking PI nails fall into the top lo-hi range.
What this means is that in relatively iron free locales one can dig lo-hi tones and get all silver coins and copper coins. You lose nickels and zinc pennies (no loss there!). If there is a lot of iron trash you are in trouble, however.
For gold range items you dig hi-lo and get gold nuggets, gold jewelry, nickels, zincs, plus wire, pull tabs, small wire-like nails, foil, and other low conductive trash.
This may seem like a rudimentary system for people used to VLF detectors but for a PI unit it is as good as it gets so far. I've found the dual-tone so useful that I do not employ the reverse disc myself, but if the reverse disc is used even more info can be gleaned about some trash targets.
One tip I got about the reverse disc is that as it is varied it causes the dualtone separation point to vary slightly. This can possibly be used to identify items that fall right in the zinc penny/copper penny range. Some items will go hi-lo tone with the disc control at one extreme and lo-hi with it at the other extreme. In other words, the item is borderline zinc/copper. But I have not explored this property in actual use yet to see how much variation there is.
So far I've found gold nuggets with the Infinium, gold and platinum surf detecting, and some old coins at extreme depths coin detecting. The Infinium is killer on nickels! So for me at least the Infinium has truly lived up to it's billing as a multi-use PI detector.
On the flip side I would caution VLF users that it is not the machine for everyone. I'd say it's more a unit for serious detectorists looking to fill in niches their that a VLF unit might lack in.
Steve Herschbach
P.S. Those optional coils are very close to being reality!