Posting from "The New Treasure Depot"
By Steve Herschbach
STEVES POSTING:-
I visited Gaens Creek, Alaska over the Labor Day weekend to do some
nugget hunting with some friends. I've visited the creek before, and used the Garrett
Infinium LS to find a 1.2 pennyweight nugget on an earlier visit. We scanned an area that
has been heavily hunted, for the same reasons that we were there. Three nuggets over 5
ounces were detected in the area
this year.
The Infinium ran smooth and clear, so much so that I found myself waving my ring over the
coil to make sure it was really
working. Absolutely no signals from rocks in the tailing piles. Very odd when you are used
to constant background sounds
back from a VLF detector. But every once in awhile I got a signal, and dug either a shell
casing, or an iron trash target.
The discrimination on PI (Pulse Induction) detectors is crude, and so iron targets that
might be rejected with a VLF (Very Low
Frequency) will often be signaled as "good" on a PI detector like the Infinium
LS. So although the discrimination system on the
Infinium was rejecting most of the iron trash, I was still digging some now and then. I
found the shell casings encouraging, as
that meant there was likely gold to be found. I figure if non-ferrous items like bullets
and shell casings are being missed, then
some gold has also been left behind.
Still, the area had been well searched, and the finds were few. I finally located a 13.8
dwt (dwt = pennyweight) nugget, and
then a 3.8 dwt nugget (20 pennyweight per ounce). The Infinium had done it's job.
In my use of the Infinium so far, I've been far more impressed with the dual-tone id than
the use of the disc knob itself.
The dual-tone does not always give a correct id, but digging hi-lo tones does result
primarily in turning up low conductive
targets like gold nuggets, gold jewelry, pull tabs, US nickels, and such while eliminating
most iron and steel. Not all, mind you,
but most. Pieces of wire and hairpins read hi-lo, and masses of flat, rusted flakes of
steel.
Supposedly a large enough gold nugget will read lo-hi, but I've tested up to 7 ounce
nuggets and so far all have read hi-lo.
The dual-tone id really does seem to work at depth. On this outing, a White's MXT located
a quart paint can at just over two
feet in a tailing pile. The MXT read it as a good, non-ferrous target all the way down.
The same can read lo-hi on the Infinium
all the way out to where it could barely be picked up at all. Frankly, I was a bit
surprised when this was observed.
I've also been digging nickels at about 12" that correctly id hi-lo. My feeling so
far is that the dual tone does work very well at
max depths, and does a very good job at separating low conductive and high conductive
targets.
The disc knob, basically increases the minimum level of conductivity a target must have to
give a signal. Unfortunately it also
seems to result in a direct loss of depth. So items at the edge of detection depth tend to
drop out as this control is increased,
regardless of their composition. This means that deep iron targets tend to drop out, and
therefore are incorrectly identified as
"low conductive".
Bottom line is simple. I've been using the dual-tone system a lot and have quite a bit of
faith in it at this point for certain
applications, especially nugget detecting. But I pretty much ignore the disc knob now, as
I have not seen that it really helps
much on the targets I most need help with... those deep ones! The disc knob seems somewhat
redundant on the Infinium.
All in all, I feel Garrett has done what they set out to do. Design a good general purpose
ground balancing pulse induction
detector for a reasonable price. The machine almost totally ignore hot rocks and
mineralized ground that give VLF units fits.
And the dual-tone id system is a real plus. The machine should see lots of use nugget
hunting, relic detecting, and of course
water detecting. Now if they would just release the accessory coils - 14" mono and
8" mono. They are slated to be in dealer
hands later this year.
Steve Herschbach