Field Testing the Tesoro Lobo
in the heart of some of America’s finest gold country, Tesoro Electronics of
Prescott, Arizona has been manufacturing quality metal detectors for nearly
thirty years. Founded in the family garage back in 1980 by Jack and Myrna
Gifford, the family owned company set out to supply a good product at an
affordable price while backing it with an unbelievable warranty. The idea
worked, and since then, the company has prospered, becoming one of the most
respected manufacturers in the industry. The reputation of their products and
excellent support has continued to win over customers, and now Tesoro has
dealers in virtually every US state and several countries throughout the world.
Ownership of the company has now passed to their sons James and Vince, but the
original business philosophy set in place by Jack and Myrna has not.
In August of 2009, I had the pleasure of testing
Tesoro’s finest gold machine, the Lobo SuperTRAQ. Since the Lobo is equipped
with discrimination circuitry it can double as a coin and relic hunter, but its
primary purpose is for sniffing out nuggets. The Lobo weighs in at approximately
3.5 pounds and operates at 17.5 kHz. It is supplied with a 10” elliptical
widescan coil and features a built-in external speaker as well as a ¼” headphone
jack. The Lobo is powered by eight AA batteries which typically offer 20-30
hours of run time.
As far as controls go, there are very few; making
the Lobo an incredibly easy detector to use. All the knobs and switches are
located on the front panel and readily accessible for quick adjustment in the
field. The first of the five controls is the THRESHOLD, which is used to turn on
the detector and set the constant audio level or ‘hum’ heard while detecting.
The second is the Ground Selection Switch which offers three possible settings:
ALKALI, NORMAL and BLK SAND. This switch alters the way in which the Lobo
performs in different types of ground and will be discussed further.
The third is the Mode Selection Switch. This
3-position switch allows the user to toggle between PINPOINT (no motion needed),
ALL METAL, and DISC (or discrimination). The normal setting for this control
while prospecting is the All Metal position. The Pinpoint mode is helpful for
determining the location of a potential target, while the Disc mode can be used
to eliminate certain types of metallic trash targets. The fourth is the
SENSITIVITY knob which is used to either increase or decrease the detector’s
level of sensitivity. Like the Ground Selection Switch, this control is also
important because it affects the size of targets that will be found, overall
depth penetration, and how the Lobo performs in highly mineralized soil. This
control will also be discussed further. The fifth and final control is the DISC
LEVEL. This knob adjusts the discrimination level enabling the detector to
accept or reject different types of metal targets. A low setting will allow most
all metallic objects to produce an audible response, while higher settings will
‘blank’ out typical trash items such as rusty nails, tin foil, bottle caps, etc.
The area I selected for my field test was first
discovered in 1863 by a group of prospectors led by Captain Joe Walker. This
famous gold deposit located in the northern Bradshaw Mountains is commonly
referred to as the Lynx Placers, and is coincidentally, only a short drive away
from the Tesoro factory. Official records indicate production somewhere around
80,000-ounces, but since many prospectors did not report their finds in the
early days, I would put the figure considerably higher. Many small nuggets have
been found here, including larger pieces weighing as much as four-ounces.
Unfortunately, the use of motorized equipment is now prohibited anywhere on Lynx
Creek, however, metal detectors and gold pans are still an acceptable form of
Detecting along the creek bed itself would seem a
logical choice, but after a century of heavy placer mining, it has become loaded
along its entire length with bits and pieces of man-made trash. Items such as
bullets, scrap iron, nails, bits of wire and pull-tabs are very common. Some of
these targets have worked themselves deeply into the gravels and retrieving them
can be quite a chore, and a disappointment. Rather than fighting my way through
an endless supply of junk, I decided to hunt the surrounding hillsides and
smaller tributaries that fed the main creek. These areas had produced gold for
me in the past, and while I had never found anything really large outside of
Lynx itself, at least I knew I wouldn’t be bending over to dig a piece of trash
every few swings.
The soil on the hillside I began sweeping contained
an above average amount of mineralization, and I was skeptical as to how the
Lobo would deal with it. After following the start-up procedure outlined in the
instruction manual I found myself rather pleased. For being a VLF machine, the
Lobo handled the iron-rich ground surprisingly well. One of the toughest
challenges new detectorists face is the act of ground balancing. Fortunately the
SuperTRAQ System found inside the Lobo automatically performs this troublesome
procedure. This self-adjusting ground balance technology is in my opinion, one
of the biggest selling points of this detector. SuperTRAQ senses changes in
mineral content and automatically updates the ground balance. This saves time
and frustration, but more importantly, it helps maintain a smooth and steady
threshold; something all seasoned nugget hunters know is crucial for success.
started off with the Ground Selection Switch in the Normal position, Mode
Selection in All Metal, Sensitivity at 10, and Disc level at minimum. I tried
this for a while but found it was necessary to reduce the Sensitivity to 7. I
was getting too much feedback from the ground and picking up lots of hot rocks.
Generally speaking, the more Sensitivity the better. In quiet ground, a high
Sensitivity setting will greatly improve signal response on both small and
deeply buried nuggets. On the other hand, in bad ground, a high Sensitivity
setting will cause the detector to become noisy, unstable, and overall
performance will suffer. This is not a good scenario as valuable targets will be
masked by the background noise. The key is finding a good compromise. I
recommend that a person always start out high, and if the ground will allow it,
keep it there. If the ground is severe, it will actually be beneficial to run it
If reducing the Sensitivity doesn’t alleviate the
problem, try switching into Alkali. According to Tesoro, this mode is similar to
Normal except that the SuperTRAQ circuitry is allowed to operate over a much
wider range of mineral conditions. In the area I visited, I felt the Lobo
handled the soil better in Alkali and allowed a higher Sensitivity setting.
Another bonus was its ability to greatly reduce the response I was getting from
the hot rocks. After a few repeated sweeps of the coil, many of them virtually
disappeared. If the areas you prospect are littered with hot rocks, the Alkali
setting will certainly be worth a try. The BLK SAND (Black Sand) setting
actually handles extreme ground and hot rocks even better than Alkali or Normal.
It keeps the Lobo running smoothly in highly conductive environments by reducing
the detector’s overall sensitivity. A handy option to have, but one that should
be used sparingly, as it greatly diminishes the signal response on all targets.
If the nuggets in your area are small or deeply buried, you will probably miss
them in Blk Sand, so always try Normal or Alkali first.
Here are a few other observations I felt worth
sharing. While out detecting I did notice that when I lifted the coil a few feet
above the ground, or hit a very large metal target, the ground balance would
occasionally drift. This problem was easily fixed by stopping and pumping the
coil repeatedly over the ground. Typically after five ‘pumps’ the ground balance
returned to normal. Also, the Lobo is a motion detector. Unless the Mode
Selection Switch is set to Pinpoint, a target will disappear if the coil is held
stationary over it. For best performance, use a side-to-side sweeping motion
rather than a front-to-back. Regarding the Disc mode, I did find that it would
eliminate a bulk of the ferrous trash which plagues the goldfields. Being able
to reject iron is nice, but this ability comes at a price. From my
experimentation I noticed that small nuggets would generally not respond at all
if Disc levels were higher than 2. Larger nuggets would respond, but the signal
generated was broken and if a person were sweeping too fast, they could easily
be missed. Also, if a piece of trash was lying in close proximity to a nugget,
the trash usually overpowered the gold and the detector would blank both
signals. If you plan on chasing coins and relics, the Disc mode definitely has
its place. However, if gold is your primary focus, I strongly suggest putting
the Mode Selection Switch in All Metal and leaving it there.
field test produced an assortment of items, including numerous lead bullets, an
old buckle, several jacket buttons, small BB’s, and a collection of rusty iron
scraps. Luckily, mixed in amongst these goodies were also three small gold
nuggets. My search of the hillsides proved unsuccessful, but as I wandered down
a narrow bedrock filled gully my fortune changed. The first decent signal seemed
to be coming from atop the bedrock itself. As I bent down and blew away the sand
I actually saw it wedged in a tiny crack. If a good flash flood had come through
and stripped away the sand, I may have spotted it on the surface. It weighed
0.4-gram; not a bad start. The second and third nuggets came from further down
the gully. As I swept over a series of deep cracks I received a mellow, but
distinct ‘ZIP’. I removed close to three inches of debris and instead of the
dull color of lead I was expecting to see, I was rewarded with something butter
yellow! After coaxing the nugget from its hiding place I was excited, yet at the
same time disappointed. Based on the strength of the signal response I was
expecting it to be a little bigger. Before walking away I decided to recheck the
hole; something I was very glad I did. Lo and behold there was another signal. I
pried the crack open a bit more with my pick and spotted the source of the
noise. It was indeed another nugget that had become wedged beneath the first.
The two of them together weighed 1-gram, which is why the signal had sounded
sweeter. Finding multiple nuggets in a single hole always puts a smile on my
face. My treasures won during the field test weighed in at 1.4-grams. Not a
bonanza, but it proved a point. The Tesoro Lobo SuperTRAQ is indeed fully
capable of finding gold!
My overall impression of the Lobo was positive. It
offers great sensitivity and an automatic ground tracking system that really
works. The detector is also light weight, well balanced and a pleasure to swing.
The ease of operation makes this model an excellent choice for first time
detector buyers. To use, simply turn on the detector, select the All Metal mode,
adjust Sensitivity and Threshold, and begin hunting - it’s that easy! More
experimentation with the settings will yield better results, but even the most
inexperienced detectorist should be able to get up-and-running with little
If I had to find a fault it would be the fact that
the coil is not supplied with a skid plate. A skid plate is the first line of
defense against coil damage, so it seems only logical that one should be
supplied. I also didn’t care for the battery system. The battery packs tended to
rattle around in the compartment and I wasn’t a fan of the removable plate on
the rear panel. I would suggest a hinged door and possibly exploring the option
of developing a rechargeable pack that could be topped off in the field using a
vehicle’s 12V outlet.
Aside from this, I was impressed. Tesoro has built
a product they can be proud of, especially when you factor in their unbeatable
Lifetime Warranty. With a suggested retail price of only $799.00 and the
company’s outstanding reputation, this detector provides solid performance at a
reasonable price. Not to mention it is made right here in the USA!