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Field
Testing Minelab’s Eureka Gold |
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CHRIS
GHOLSON
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I
rolled over in bed unable to sleep; the bright red numbers read
4:35 AM. “To early to get up yet, I’ll just lay here and think
for a while,” I told myself. My mind wandered. I thought of all
the things I had to do that day, and all the things I could be
doing instead; like prospecting. I adjusted the blanket and
glanced once more at the clock, it glowed 5:15 AM. “Forget this;
I’m going detecting!” I decided kicking back the covers with my
foot.
In
less than forty minutes I found myself bumping along the Black
Canyon Highway, Polaris 500 loaded and my trustee Eureka Gold
resting peacefully in the backseat. I was drawn to an area on
the eastern flank of Arizona’s Bradshaw Mountains, a spot where
I had managed a handful of nuggets a year or so back with the GP
Extreme. If I remembered correctly, the ground mineralization
was not incredibly severe and there was plenty of exposed
bedrock - just the sort of place for VLF workout.
The
Eureka is Minelab’s finest gold machine for under $1,000. It is
similar to the earlier version, the XT18000, which also featured
Automatic Ground Balancing and Adjustable Operating Frequency.
However, refinements have been made, which include: target
detection with pitch variation, better signal-to-noise ratio in
the electronics, and a 10” elliptical Double D coil supplied as
standard equipment. The control box can be mounted in a variety
of positions, including: forward shaft mounting, rear shaft
mounting, hip mounted, or chest mounted (carrying bag for the
latter two is sold separately). Personally, I tend to prefer the
rear shaft mount position, as it reduces fatigue on the forearm,
and eliminates annoying cable snags on brush and tree branches.
The unit is powered by a rechargeable 12V NiMH battery, which
also includes a 110V mains charger.
I
arrived at the gully quickly enough and began my usual ritual,
which usually (if I don’t have the quad) goes something like
this: double-check the battery, strap on snake-proof chaps, load
up backpack with 2 water bottles, grab pick, and finally lock
the truck doors…..walk away,…..then come back a few moments
later to make sure the truck doors are really locked (slight
case of OCD)!
The
sun was starting its’ slow rise in the east flooding the cactus
covered slopes with a brilliant orange light; the desert could
not have looked more beautiful. This was a great time of day to
be out detecting. It was still cool, and there was very little
air traffic so interference was at a minimum. The gully I was
walking towards had never given up monster nuggets, but the
fractured schist bedrock poking out along the sides was
extremely inviting.
I
rotated the Volume control to the maximum position; the Eureka
beeped back signaling all was working well. Next, I adjusted the
Threshold to a reasonable hum. Then I grabbed hold of the
Sensitivity Control and rotated it fully clockwise. This control
is an important feature because it affects the strength of all
signals including: metal targets, mineralzation and external
interference. Setting this control is simple – crank it up as
much as possible! If the detector behaves erratically and you
experience difficulty ground balancing, turn it down until
things stabilize.
Flipping the Balance switch into the Fast Track position, I
pumped the coil gently over the surface until the groaning
threshold smoothed out. In variable ground, Fast Track will
re-balance more rapidly and therefore maintain a better balance,
however, very weak signals could be eliminated if the coil is
repeatedly swept over it. In lesser-mineralized areas, Slow
Track will maintain a suitable balance without threat of
tracking out a target.
With
the detector set in the 60kHz position I set off. One of the
things I love most about the Eureka Gold is its’ ability to
shift operating frequencies. With a simple flick of the switch,
the user can select between 6.4kHz, 20kHz, or 60kHz. A nice
touch of flexibility - bravo Minelab! Generally speaking, lower
frequencies (6.4kHz) are best suited for seeking large nuggets
at depth, while higher frequencies (60kHz) are preferred for
chasing smaller bits near the surface.
The
first 45 minutes were rather boring; not a single target to be
found anywhere. Shortly thereafter I encountered a modest rocky
waterfall. I got zilch down below, but once above it I quickly
snatched a small bit of yellow metal lodged within the schist.
Okay, things were looking better! A few feet from the
waterfall’s edge I spotted a pile of dead branches lying in the
gully. I walked up to it and swung across the top. “Was that a
signal I just heard, or am I starting to hallucinate under the
Arizona sun?” With the help of my Diamond Tip pick, I quickly
cleared it away so that I was looking at nothing but gravel. If
this was a signal it was incredibly faint.
I
suspiciously flipped the switch into the Boost position and
swung the coil over the spot again. What a difference! From that
moment on, the switch might as well have been super glued in
place! The Signal switch provides three levels of audio
response: Normal, Fine ands Boost. I have always favored strong
audio; I like to hear what is going on. The Boost setting offers
a greater deal of amplification and (from what I noticed)
substantial gains in depth penetration. Targets that were barely
audible in the Normal and Fine positions were crisp and defined
in Boost. As I learned later, the drawbacks of running in this
setting can be heard when venturing into heavily mineralized
ground. It amplifies the good stuff (i.e. gold nuggets), but it
also boosts the unwanted background noise, making it difficult
at times to differentiate between true metallic targets and
spurious ground noises – and it gets even worse in 60kHz! In
these situations, switch into Normal and reduce Sensitivity. You
might also try elevating the coil slightly.
I
didn’t want to take the chance of balancing it out, so I toggled
between Fast Track and the Fixed position. This locked the
machine in place guarantying that the target would not be
tracked out. Taking an inch or two off the top made a huge
impact, there was definitely a target lurking below. At five
inches I banged into the bedrock. This was it; nothing can get
deeper than this. A few scratches with my fingernails revealed
exactly what I was looking for. It stood out like a beacon
against the rusty clay – a shiny 1.5-gram nugget! Early
retirement wasn’t eminent, but it put a big smile on my face! A
thorough search of the 10-foot area, yielded another 2 nuggets,
both smooth as silk indicating they had made quite a journey
from the original source.
Visions of gold pulled me further up the wash and through the
desert brush when suddenly my ears where met with an all too
familiar sound, an eerie sort of hum. That hum was none other
than about 5,000 bees!!! They were gathering pollen from the
tiny yellow flowers blooming on the Palo Verde trees. Almost all
of the bees in central Arizona are now classified as
Africanized, or Killer Bees, and when they attack they mean
business! It is not uncommon for unlucky victims to receive
several thousand stings, sometimes proving fatal. Mountain
lions, spiders, crocodiles, I can deal with - but to hell with
those bees!
I
tucked my courage into my back pocket and did an immediate 180°!
I meandered down to a stretch of the gully that I had never
really hammered on account of the rubbish. I was never sure why
this spot had accumulated so many bullets while the rest of the
gully was rather clean. Only thoughts are that the flash floods
separated it out, or someone used this spot as a backdrop for
target practicing. The Eureka is outfitted with a Discriminator
which aids the operator in distinguishing between ferrous and
non-ferrous targets. When activated, a blanking of the audio
threshold alerts the operator that the coil has been passed over
a ferrous object. In this case the discriminator would be of
little help for wading through the lead. Even so, unless I am
coin or relic hunting, I do not use discriminators. Unlike
coins, nuggets vary greatly in both size and shape. They are
also found at a wide range of depths, usually in the nastiest
iron-saturated soils on earth. Rather than gamble, I opt for the
All Metal mode and try to dig as many targets as humanly
possible. If you do decide to run with discrimination know this,
it has difficulty processing large targets near the surface. I
would suggest investigating these signals, especially when
working known patches. In either case, the bottom end was a dry
run. I was more than satisfied with the 4 smooth nuggets in my
jar and happily hiked my way back to the quad, giving those Palo
Verde trees plenty of breathing room! I’d be back, but next time
in body armor!
Conclusion
I was
impressed with the overall performance of the Eureka. Actually I
would rank it among the top 2-3 VLF machines on the market
today. The low weight (2.2kg) and excellent design are a
definite bonus. The controls are user friendly and the
instruction manual is well written, so there is no guesswork
here. Adjustable operating frequencies, variable ground tracking
speeds, and the plethora of control box mounting positions were
all major selling points for this nugget hunter. My only
complaints in the performance department where stability over
black sands, certain varieties of clay and of course, the always
pleasant volcanic basalt. However, in all fairness, these are
problems inherent to all VLF machines, not just the Eureka. I
might as well go ahead and gripe about the lack of headphones
and the incredibly limited selection of search coils too. A 15”
Spider DD coil can be purchased separately, but come on fellas….
I’d like to see some mid-sized coils possibly round, and how
about a monoloop coil – wouldn’t that be a dandy!
As I
mentioned above, this machine scored well with me. I would place
the Eureka at the top of the mid-range class. It offers great
performance at a reasonable price. So, if you’re looking for a
maneuverable, lightweight, highly sensitive metal detector that
will do damage to nuggets wedged in the bedrock, but not your
wallet; the Eureka Gold is probably your baby! For more
information on this and other Minelab products, please visit
their website at
www.minelab.com, or by calling 1-888-517-2066. Additional
information on electronic prospecting can be found on the
author’s website at
www.arizonaoutback.com. See you on the goldfields! |