musclecar
Full Member
Here is more info from my buddy gerrysdetectors.com. This information was provided by Steve Herschbach.
These settings and this info was provided by Steve Herschbach, a friend
and
detectorist from AK.
I myself have tried them on my last trip to Ganes Creek, AK in June
2005 and
ended up finding over 17 ounces of gold nuggets. I recommend these
settings
in areas with a lot of trash and larger gold nuggets. Photos of gold
are
on my web site in the PHOTOS section.
Steve's opinion
" I've used a lot of VLF gold nugget detectors over the years, but have
been
particularly happy with the White's MXT. One huge reason is that unlike
other dedicated nugget detectors it has a LCD based visual
discrimination
indicator (VDI) system. I'm sure White's included this mainly in line
with
the MXTs intended goal as a multi-use machine. But it turns out that
for
certain nugget detecting tasks the MXT has extra capabilities only now
being
realized.
Alaska has huge areas of old mining tailings that provide great
opportunities for nugget detecting. Virgin ground is covered by
overburden
thicker than detectors can penetrate in most cases, so in many areas
these
tailings are all there is to detect. And the nature of the old
operations
were such that many of the very largest nuggets were lost into the
tailing
piles.
But there is a huge catch. Some of these tailing piles contain
incredible
amounts of iron junk, and at any depth. Some creeks were mined many
times,
and so old campsites and dumps were churned up and mixed in with the
tailings. This junk can be anything from rusted flakes and slivers of
steel
on up to cans, bolts, washers and nuts, and finally even 55 gallon
drums,
and various large steel plates, pipes, boilers, or even larger items.
Ganes Creek, Alaska is possibly the best known of these locations. New
visitors from areas in the western US where the Minelab SD/GP detectors
have
reigned supreme have had a hard time adjusting to the concept that
there is
such a thing as too much power when coupled to a poor discrimination
system.
If you run a Minelab at Ganes Creek here is a likely scenario. You are
in a
field of fist-sized and larger cobbles. You get a nice little signal
and no
iron blanking. So you start to dig, as best you can in a pile of rocks.
It
is as much hand excavations at times as digging. After some effort you
are
at two feet, signal is louder, but no target. You pull out another
cobble
and half the hole falls in. You pull all those rocks out, and get
another
foot down. 45 minutes has passed. You pull out another rock and the
hole
caves in again. 15 minutes later you are at 3 feet again and really
tired.
Over an hour has passed since you started this hole. The signal is very
loud
now...too loud really. You dig down a bit more, then some more, and the
whole thing caves in again.
You walk away in disgust.
How deep can you hit a large can with a GP 3000? How about a 2'x 2'
steel
plate? How about a 55 gallon drum? They are all there waiting! Normally
you
would just figure it is junk past a certain depth, but the big question
always must be how deep could you hit the 35 oz or 80 oz pieces found
this
summer, or the 122 oz chunk that stands as the largest found at Ganes
so
far?
Because of this huge junk problem VLF detectors have generally been the
way
to go at Ganes. The low mineral conditions means they keep you from
wasting
huge amounts of time going after junk targets. Most any good VLF
machine
works well for this, but the MXT gives you some extra capability once
you
learn its tricks.
Four things to know. 1. VDI numbers increase as the nugget size
increases.
So a ¼ oz nugget will read around 25 whereas a 1 oz nugget will read
around
60 and a 2 oz nugget will read around 70. 2. The larger a nugget, the
deeper
you can detect it 3. Certain steel items can give positive VDI numbers
and
4. VDI numbers are "pulled down" the deeper the nugget is buried. So a
¼ oz
nugget near the surface will read 25, but at depth might read 10, and
at max
depth may finally read at 0 or lower and actually be called iron.
This last point is very important, as if you run a Fisher Gold Bug 2,
or
Tesoro Lobo, or Troy X5 is disc mode to tune out iron, as is normal for
many
people at Ganes Creek, deep nuggets may read as iron. If they are, the
machines will reject them, you will get no signal, and walk past the
nugget.
With the MXT I like to run the detector in relic mode, with the disc
set
precisely at 2. Non-ferrous items will give a hi tone, and ferrous junk
a
low tone. If you get a faint lo tone, the first thing you do is kick
and
inch or two off the surface. If the VDI number rises, keep digging!
Targets
that read iron initially and rise will often turn into non-ferrous
readings... hopefully gold. If the VDI number stays the same or goes
even
lower, you have an iron target. With one of these other machines you
would
need to run in all-metal, then switch to discriminate mode to check the
target. If the target was faint, and now disappears, kick off the
surface,
and check again. If it now beeps, keep digging. The end result here is
the
same, but the MXT makes it easier as there is no switching between
modes
needed to do this kind of checking.
Where the MXT really shines are on ¼ oz to ½ oz nuggets. Let's say
you get a
reading of 24. OK, that is about a ¼ oz nugget. Now, we know that you
can
hit a nugget this size at 10-12 inches. So you dig a foot, and no
nugget. A
large, deep iron item of a certain type can also give a 24 reading, but
these large items can be detected much deeper than a ¼ oz nugget. Dig
them
up if you wish, but once you go past that depth at which it is
reasonable to
find a nugget corresponding to a certain VDI number you are wasting
your
time. This method eliminates digging those false positive signals from
deep
items like steel plates. With the other VLF units the lack of VDI
number
means you have no way to judge the potential nugget size and so you end
up
digging deep for what may be a very large nugget when with a MXT you
would
know the VDI number corresponds to a smaller nugget. For the many
smaller
nuggets that are found at Ganes this method is pretty foolproof once
you get
the hang of it.
Finally, certain non-ferrous items can be found in quantity,
particularly
things like .22 shell casings. If you get into a bunch of these, they
are
usually very shallow. You can easily determine the VDI number of these
multiple identical targets and then simply ignore them. You would miss
a
nugget with an identical VDI reading, but chances are a nugget will
vary
enough to make it stand out. No way to do this with a non-VDI unit.
Many thanks to Dave Rankin for pointing out the correlation between
nugget
size, VDI number, and possible recovery depth. It was a real eye-opener
once
I put it into practice at Ganes Creek."
.
Steve Herschbach
These settings and this info was provided by Steve Herschbach, a friend
and
detectorist from AK.
I myself have tried them on my last trip to Ganes Creek, AK in June
2005 and
ended up finding over 17 ounces of gold nuggets. I recommend these
settings
in areas with a lot of trash and larger gold nuggets. Photos of gold
are
on my web site in the PHOTOS section.
Steve's opinion
" I've used a lot of VLF gold nugget detectors over the years, but have
been
particularly happy with the White's MXT. One huge reason is that unlike
other dedicated nugget detectors it has a LCD based visual
discrimination
indicator (VDI) system. I'm sure White's included this mainly in line
with
the MXTs intended goal as a multi-use machine. But it turns out that
for
certain nugget detecting tasks the MXT has extra capabilities only now
being
realized.
Alaska has huge areas of old mining tailings that provide great
opportunities for nugget detecting. Virgin ground is covered by
overburden
thicker than detectors can penetrate in most cases, so in many areas
these
tailings are all there is to detect. And the nature of the old
operations
were such that many of the very largest nuggets were lost into the
tailing
piles.
But there is a huge catch. Some of these tailing piles contain
incredible
amounts of iron junk, and at any depth. Some creeks were mined many
times,
and so old campsites and dumps were churned up and mixed in with the
tailings. This junk can be anything from rusted flakes and slivers of
steel
on up to cans, bolts, washers and nuts, and finally even 55 gallon
drums,
and various large steel plates, pipes, boilers, or even larger items.
Ganes Creek, Alaska is possibly the best known of these locations. New
visitors from areas in the western US where the Minelab SD/GP detectors
have
reigned supreme have had a hard time adjusting to the concept that
there is
such a thing as too much power when coupled to a poor discrimination
system.
If you run a Minelab at Ganes Creek here is a likely scenario. You are
in a
field of fist-sized and larger cobbles. You get a nice little signal
and no
iron blanking. So you start to dig, as best you can in a pile of rocks.
It
is as much hand excavations at times as digging. After some effort you
are
at two feet, signal is louder, but no target. You pull out another
cobble
and half the hole falls in. You pull all those rocks out, and get
another
foot down. 45 minutes has passed. You pull out another rock and the
hole
caves in again. 15 minutes later you are at 3 feet again and really
tired.
Over an hour has passed since you started this hole. The signal is very
loud
now...too loud really. You dig down a bit more, then some more, and the
whole thing caves in again.
You walk away in disgust.
How deep can you hit a large can with a GP 3000? How about a 2'x 2'
steel
plate? How about a 55 gallon drum? They are all there waiting! Normally
you
would just figure it is junk past a certain depth, but the big question
always must be how deep could you hit the 35 oz or 80 oz pieces found
this
summer, or the 122 oz chunk that stands as the largest found at Ganes
so
far?
Because of this huge junk problem VLF detectors have generally been the
way
to go at Ganes. The low mineral conditions means they keep you from
wasting
huge amounts of time going after junk targets. Most any good VLF
machine
works well for this, but the MXT gives you some extra capability once
you
learn its tricks.
Four things to know. 1. VDI numbers increase as the nugget size
increases.
So a ¼ oz nugget will read around 25 whereas a 1 oz nugget will read
around
60 and a 2 oz nugget will read around 70. 2. The larger a nugget, the
deeper
you can detect it 3. Certain steel items can give positive VDI numbers
and
4. VDI numbers are "pulled down" the deeper the nugget is buried. So a
¼ oz
nugget near the surface will read 25, but at depth might read 10, and
at max
depth may finally read at 0 or lower and actually be called iron.
This last point is very important, as if you run a Fisher Gold Bug 2,
or
Tesoro Lobo, or Troy X5 is disc mode to tune out iron, as is normal for
many
people at Ganes Creek, deep nuggets may read as iron. If they are, the
machines will reject them, you will get no signal, and walk past the
nugget.
With the MXT I like to run the detector in relic mode, with the disc
set
precisely at 2. Non-ferrous items will give a hi tone, and ferrous junk
a
low tone. If you get a faint lo tone, the first thing you do is kick
and
inch or two off the surface. If the VDI number rises, keep digging!
Targets
that read iron initially and rise will often turn into non-ferrous
readings... hopefully gold. If the VDI number stays the same or goes
even
lower, you have an iron target. With one of these other machines you
would
need to run in all-metal, then switch to discriminate mode to check the
target. If the target was faint, and now disappears, kick off the
surface,
and check again. If it now beeps, keep digging. The end result here is
the
same, but the MXT makes it easier as there is no switching between
modes
needed to do this kind of checking.
Where the MXT really shines are on ¼ oz to ½ oz nuggets. Let's say
you get a
reading of 24. OK, that is about a ¼ oz nugget. Now, we know that you
can
hit a nugget this size at 10-12 inches. So you dig a foot, and no
nugget. A
large, deep iron item of a certain type can also give a 24 reading, but
these large items can be detected much deeper than a ¼ oz nugget. Dig
them
up if you wish, but once you go past that depth at which it is
reasonable to
find a nugget corresponding to a certain VDI number you are wasting
your
time. This method eliminates digging those false positive signals from
deep
items like steel plates. With the other VLF units the lack of VDI
number
means you have no way to judge the potential nugget size and so you end
up
digging deep for what may be a very large nugget when with a MXT you
would
know the VDI number corresponds to a smaller nugget. For the many
smaller
nuggets that are found at Ganes this method is pretty foolproof once
you get
the hang of it.
Finally, certain non-ferrous items can be found in quantity,
particularly
things like .22 shell casings. If you get into a bunch of these, they
are
usually very shallow. You can easily determine the VDI number of these
multiple identical targets and then simply ignore them. You would miss
a
nugget with an identical VDI reading, but chances are a nugget will
vary
enough to make it stand out. No way to do this with a non-VDI unit.
Many thanks to Dave Rankin for pointing out the correlation between
nugget
size, VDI number, and possible recovery depth. It was a real eye-opener
once
I put it into practice at Ganes Creek."
.
Steve Herschbach
