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Tesoro Electronics
has done it again! Since their inception nearly 20 years ago,
Tesoro has built a reputation of quality machines at affordable
prices with topnotch workmanship and a lifetime guarantee. Their
name has been synonymous with tough, easy to use, quiet machines
that out perform competitor units costing twice as much. The
Tesoro name is also a very dominant player at competition hunts,
easily the preferred choice of the majority of regular entrants
at hunts held all around this great country. That in itself
is a huge indication of Tesoro’s ability to make great
machines. They also have a service department that is second
to none. I am here to introduce the newest addition to the Tesoro
family, the next generation target ID machine, the Cortés.
I
find it somewhat daunting to believe some field test reports,
especially if I know nothing of the person performing the test.
That said, allow me to list my credentials. First of all I do
not work for Tesoro or any detecting magazine. This field report
is a freelance effort. I have been detecting since 1977, and
I consider myself a very avid detectorist. Some label my detecting
desire as "fanatic," but I prefer to call it "my passion." My
experience with Tesoro machines started back in 1984 and I have
owned and used many different models since then, as well as
a few "other" brands from time to time. I have been a very active
member of the Four Lakes Metal Detector Club (Madison, WI),
serving as Vice President and President repeatedly since I first
joined the club back in 1983. I have been the editor of our
club newsletter now for nearly three years and have won our
club’s "Treasure Hunter of the Year" award 8 out of the
last 9 years. I divide my detecting time between water hunting
and relic/ghost town hunting, and I would be hard pressed to
say which of those I like more. My first Tesoro field test report
was published last year in the 17th Edition of the
MDI magazine, on the Tiger Shark, and now I find myself blessed
yet again testing the new Cortés.
Gene Scullion with the new Cortés
The
anticipated introduction of the Cortés held my keen interest
because my primary land machine for the past 7 years has been
the Toltec II, Tesoro’s previous production model target
ID machine. I was ready for a new target ID machine and I wanted
it to be a Tesoro. The Toltec II has now been out of production
for nearly 2 ½ years, and needless to say, dedicated Tesoro
users (myself included) have been anxiously awaiting its replacement.
In the following report, I will only make minor comparisons
between the Cortés and the Toltec II because they truly are
entirely different machines all together.
My
first involvement with the Cortés actually occurred way
back in April of this year. Tesoro sent me the very first prototype
for three days, not to actually write a report on, but to view,
play with, try, test, and otherwise offer some general feedback
on. In the limited time I had to play with it, I only made a
few recoveries but one was outstanding (more on that later).
FIRST IMPRESSION
My first impression as I opened the box was that the control housing
is obviously bigger than the existing line of MicroMAX machines,
but only slightly. I then noticed that the battery compartment
had been moved externally to the upper end of the arm assembly
just below the arm bracket.
I
had initially thought that the actual display size seemed too
small to be effective and that surely the characters would be
too small to seen effectively, but I have since totally reversed
my stance. There is an amazing amount of information constantly
within easy view of the user. I also noticed that the lower
pole extension (the part of the pole assembly that attaches
to the coil) was entirely made from plastic. The previous standard
had been part plastic and part metal. I surmised that the entire
piece now needed to be plastic so as not to interfere with the
increased depth capability of the new spoked coils.
The
feel was great and it seemed very well balanced. It is a pinch
heavier than the MicroMAX family machines (2.9 pounds vs. 2.2
pounds) but still lighter than most competitors’ target
ID machines. A glance at the control panel did not create any
immediate confusion or questions in my mind. Having had previous
experience with Tesoro machines, I recognized all the intended
uses of each control. In fact, I was able to use the machine
easily without reading any operating instructions. It is that
easy to use. The display is straightforward and easy to understand,
and you have a lot of target information always available to
see, including target depth and battery power.
SPECIFICATIONS
The unit comes equipped with the standard S-handle pole assembly
(3-piece, interlocking), the new 9 x 8 concentric "spoked" coil,
and a padded grip and arm bracket. It has a built-in 2¼" speaker
situated on the backside of the unit with a louvered opening
to prevent dirt and debris from entering the housing, and it
has a fixed audio output volume. Also on the backside is a ¼"
stereo headphone jack. Eight AA batteries are housed in two
different compartments, one on each side, below the armrest
bracket. Drop-in style holders are used, each holding 4 batteries
apiece, making changing them a snap. Tesoro rates the battery
life at 10 to 20 hours, but that is if no headphones are used
and the display light is not used. Using headphones should greatly
improve on this rating. It operates at 10kHz, has an optimum
operating range of from 30 to 100 degrees F and from 0 to 75%
relative humidity. It is compatible with all 5-pin µMax and
Series II coils (some ground balance calibration may be required
for optimum performance) and carries Tesoro’s famous Lifetime
Warranty.
For
those of you that would like a nutshell listing of its features:
The Cortés has four operating modes: No Motion ALL METAL, Silent
Search DISCRIMINATION, SUM Discrimination, and NOTCH Discrimination
(narrow/wide). The All Metal Mode is a manually ground balance
mode with adjustable threshold level, and the Discrimination
Mode is factory preset ground balanced. The two Notch Modes
have factory preset widths. The Sum Discrimination Mode allows
improved target identification by averaging signal information
and utilizes a 9-tone audio ID. It also has a backlit display
(low/high) for hunting in minimal lighting conditions. The digital
display ID’s targets 3 different ways simultaneously (alpha
characters, numerical, bar graph), shows probable target depth,
and battery condition constantly, and in all modes.
DISPLAY
The Cortés is a combination of microprocessor technology and
traditional Tesoro analog technology. This combination makes
for a powerful detector that is very easy to adjust and operate.
Tesoro decided long ago to design this new machine without requiring
any complicated set-up routines or programming, and as a result
it is very easy to use and a joy to hunt with.
Faceplate
The
heart and soul of the machine is the 2x16 character display,
and it shows a lot of information in a very easy to understand
fashion. Nearly all of the information displayed is target specific,
that is it pertains to whatever you just scanned and after 6
seconds, this information will be erased from the screen. By
clearing the screen every 6 seconds, the user will be able to
tell if another discriminated target has been passed over. Seeing
this information allows the user to make better decisions on
when to dig and not dig. It also allows you to see how much
"trash" is in a given area without the constant beeping in your
ears (nice feature!). When no target information is displayed,
the Cortés displays alpha characters indicating what mode you
are presently in: ALL METAL, DISCRIMINATION, DISCRIMINATION
NN (for narrow notch mode), or DISCRIMINATION WWW (for wide
notch mode).
The
top line of the display I will call the "alpha character" display
line. It will indicate potential target information in abbreviated
terms, such as: "IRON OR FOIL," "NICKEL RING TAB," "ZN CENT
SCREW CAP," or "SIL COIN CU CENT." This line will also display
a special message if a target is overdriving the circuits, and
it will tell you to lift the coil for a more accurate reading.
This display works in all modes and regardless of the discrimination
settings. What that means is that you can visually see what
targets you have passed over, even when no audio is present
because of discrimination or notch settings.
The
bottom line of the display is the meat and potatoes of the machine.
On the left-hand side is a two-digit probable depth indicator,
calibrated in inches. When a target is scanned, it will display
its probable depth to the nearest inch. On the right side is
the battery power indicator, which is a solid rectangular block
when at full power, and it gradually shortens in height as your
battery power decreases. This icon is always displayed so you
have a constant indication of your battery life. Also, on the
right side is a two-digit numerical display called ID NUM (ID
Number), which is a numerical representation of target characteristics.
In the center is a nine-segment bar graph also representing
target information. The last two areas described (bar graph
and ID NUM) display the most important user information so I
will spend some time explaining each.
The
engineers at Tesoro applied a 0 to 95 numbering scheme to the
standard range of targets. "Zero" being the far left or bottom
end of the scale (iron) and "95" being the far right or top
end of the scale (dollar). Additionally, they decided to put
the most resolution in the middle of the scale, this being the
area where nickels, pull tabs, gold rings and virtually everything
else lies. Because of this approach, iron will always read "0"
and silver targets will always read "95". A benefit of this
"expanded recognition" is that pull tabs, for example, can vary
greatly in different areas around the country, making it difficult
for a machine to be calibrated and accurately identify them
equally. By widening the resolution in the middle range of targets,
each hunter can be assured of more accurate readings once the
pattern of targets (and their associated ID NUMBERS) have been
determined. For example, round pop-tops in my area generally
read between 36 and 40 on the ID NUMBER, but in another area
of the country they may read between 30-36. With repeated use,
you will learn the pattern of ID NUMBERS for the typical targets
in your area. The bottom line is that this gives you more information
on your targets, allowing you to make better decisions on whether
to dig a target or pass it by. This feature gives the Cortés
great versatility no mater where it is used.
In
the center of the bottom line is a nine-segment bar graph display.
Tesoro divided the full meter spectrum of targets into nine
segments, and each is represented by a solid bar on the screen.
From left to right the nine segments represent: IRON (1), FOIL
(2), NICKEL (3), ROUND TAB (4), SQUARE TAB (5), ZINC PENNY (6),
COPPER PENNY AND DIME (7), QUARTER (8), HALF AND DOLLAR (9).
I have added the numbers in parenthesis only to aid in my descriptions
during this report. I may refer to the NICKEL segment, for an
example, as "graph segment 3." Additionally, signal strength
of a target will be displayed by varying the height of the bar
graph section. A strong signal will fully light a graph segment
(about 3/16" actual height), but a weak signal may only display
the block at half height, and a very weak signal as only a solid
line across the bottom of that segment.
A
number of factors such as a target’s metal composition
or its orientation in the ground can cause what is called "smearing,"
where signal information will be displayed in multiple graph
segments simultaneously. This is where the ID NUMBER display
can be very helpful. You may encounter targets that smear multiple
graph segments but always ring up in a repeatable range of ID
NUMBERS allowing you to better identify them as a potentially
good target.
Immediately below each segment of the display (printed right on the
face of the unit) is a label identifier so that you don’t
have to memorize what each segment represents. In time you will
not even refer to these labels, but they are handy references
when learning the specifics of the display.
CONTROLS and OPERATION
The controls include MODE (All Metal, Discriminate, and Sum), ON/OFF/SENSITIVITY,
DISCRIMINATION, GROUND BALANCE and THRESHOLD (for All Metal
only), NOTCH FILTER, and LIGHT.
The
MODE control switch is a three-way toggle. The right position
is the ALL METAL Mode, the center position is the DISC (Discrimination)
Mode, and the left position is the SUM Discrimination Mode.
The
ALL METAL Mode has an adjustable THRESHOLD level and will accept
signals from the full range of metal targets. Target depth and
ID information is active in this mode and continually displayed
as targets are encountered. The machine specification claims
a "no motion" all metal mode, and that is technically true,
but because of a fast auto-retune built into the Cortés, the
machine will quiet itself rather quickly when held motionless
over a target. A very slight movement is needed, which is actually
a great feature because you can pinpoint very easily using only
a small amount of coil movement.
When
in the DISC Mode, the user is in a motion-based mode, meaning
the coil must be moving in order to detect a target, and it
is a Silent Search mode meaning no threshold will be heard.
In this mode, you may reject various types of metals by varying
the setting of the DISCRIMINATION LEVEL control, and you can
also enable preset notch filters (see the NOTCH description
below).
The
SUM Mode is the left switch position and you must press and
hold the switch in that position to engage it (it will spring
back to the center position when released). I should add here
that it is very easily done with your right-hand thumb while
still sweeping the coil. The SUM Mode is a totally new feature
from Tesoro. It is basically a "fine-tune" feature that improves
on the normal target identification capability of the Cortés.
The SUM Mode is an extension of the DISC Mode and works in conjunction
with the Notch feature and the Discrimination Level settings
and will not produce any audio on targets that have been blanked
out by either of those two settings.
The
SUM Mode allows the machine to analyze the target through a
series of multiple passes and then average that information
and display it on the screen. By averaging the coil passes over
the target, the processor can filter out most of the signal
noise that makes accurate target identification sometimes difficult.
In addition, when in the SUM Mode, the machine switches to a
multi-tone audio output. This audio ID has 9 different tones
(matching the nine different bar graph segments) and ranges
from a low tone at the "zero" end of the scale (iron) to a high
tone at the upper end of the scale (dollar).
The
SUM Mode comes into play on targets that are hard to pinpoint
and/or identify because of smearing (multiple graph segments
and inconsistent ID Numbers). When you wish to SUM the signals
on a target, you must push and hold the MODE toggle to the SUM
position and shorten your signal sweeps from 2 to 4 inches in
length. By repeating this short sweep pattern directly over
the target 3 to 7 times, the Cortés will average the information
together, which usually allows for a more accurate reading.
During this sweep process you will hear the audio ID progressively
getting higher and when it plateaus, the machine has reached
its most accurate ID possible. You may then decide if you wish
to dig the target or pass. This process does not always narrow
the bar graph ID to one segment. You may still get some smearing,
but it does narrow down the meter’s response. It is a
very nice tool to complement your "dig vs. don’t dig"
decision-making process. I found it sometimes helpful to vary
my stance while "summing", turning 45 degrees to one side or
the other, in an effort to find the optimum stance. Occasionally,
I would get a much better reading this way.
The
SENSITIVITY control is also the ON/OFF switch. It is adjustable
from 1 through 10, which is the normal range of adjustment.
Turning the knob into the orange area beyond 10 puts you into
the MAXBoost range. You should normally run the sensitivity
as high as you can to maintain maximum depth capability but
having it set too high may sometimes cause unwanted noises such
as "pops" and "ticks." This "interference" can be caused by
any number of external factors such as ground mineralization,
RF transmissions, proximity to high power lines, just to name
a few things. When this happens you should turn the SENSITIVITY
control down until the unit runs quietly.
Sensitivity can be used to optimize another form of searching and
that is when you might be looking for a target directly on the
surface. If someone asks you to search for a freshly lost article
of jewelry, for example, you would then know that it must be
right on or very near the surface. In this case, you are not
concerned with any deep targets, so you could turn your sensitivity
down until you are only registering surface targets (by watching
your depth meter). Many hunters fail to recognize and utilize
this ability of metal detectors when searching for surface or
very shallow objects.
The
DISCRIMINATION LEVEL control has "named" settings as opposed
to numerical levels, which I think makes it easier for beginners
and occasional users to relate to and remember. Instead of 1
through 10 reading left to right, it reads MIN, followed by
IRON, then FOIL, 5¢, TAB, 1¢/ZN, ending with MAX. You will effectively
discriminate out the item you have the adjustment set on and
everything below it (to the left), meaning if you set it to
TAB, everything below that (IRON, FOIL, and 5¢) will be discriminated
out and create no audible indication. The display will visually
register any of those targets, but you will hear no "beep."
GROUND
BALANCE and THRESHOLD are two controls used to manually ground
balance the Cortés. The GROUND BALANCE control is a 3 3/4-turn
pot allowing users ample adjustment range and is simply labeled
with a "–" on the left-hand side and a "+"
on the right. The THRESHOLD knob acts like a volume control
(low to left, higher to the right). Ground balancing
is a simple but very important task that you must perform in
order to operate the machine at its peak performance. Tuning
your machine to the exact ground matrix that you are hunting
in will give you the best possible depth and performance. I
will only summarize the procedure here because it is well explained
in the operator manual. You must first find an area free of
any metal targets, set the MODE to ALL METAL, and raise the
coil straight up from the ground (but always keep it level).
You then adjust the THRESHOLD until you hear a very slight "hum."
Next, lower the coil straight down to the ground stopping just
above it. If the machine goes quiet, you must adjust the GROUND
BALANCE up (positive) by turning the GB knob clockwise. If it
gets louder, you must adjust it down (negative) by turning the
GB knob counterclockwise. You make these adjustments in small
increments and repeat the process until you hear no change in
the threshold volume as you lower the coil to the ground. At
this point you have balanced the ground level of the machine
with the actual ground level of your search area. Keep in mind,
this ground balance is active only in the ALL METAL Mode (the
DISC Mode has a factory preset ground balance level).
The
NOTCH FILTER control is a three-way toggle switch. In the normal
center position, the notch feature is OFF. Switched to the left,
it is in the narrow position (NAR.) and to the right in the
wide position (WIDE). Notch is a term for effectively blanking
out certain targets from registering a response from your metal
detector. The two notch positions on the Cortés are factory
preset. The narrow notch effectively blocks round and square
pull tabs (graph segments 4 and 5), and the wide setting additionally
blocks zinc pennies (graph segment 6) or any other targets falling
within those ID ranges. The Cortés display will still register
bar segments as you pass over these types of targets, but you
will not hear any audio indication.
The
last control on the front panel is the LIGHT control. This is
also a three-way switch with the center position being the normally
"off" position. The left switch position produces a small amount
of backlight (marked LOW), and the right switch position creates
a brighter amount of backlight to the display (marked HIGH).
This feature comes in handy in when hunting at dusk or dawn
or inside shelters such as barns, caves, or root cellars.
Now
that I have explained the controls, let me explain the operation.
Turn the machine on, set the SENSITIVITY on 10 (for additional
sensitivity, turn it the entire way clockwise past "10" into
the MAXBoost range), set the DISCRIMINATION LEVEL just below
nickels, and go! That’s it! That is all you have to do
to begin finding coins right away.
TRASH vs. GOOD
Tesoro machines have a history of being rather good at eliminating
iron, and the Cortés is no exception.
Another
long running theme with Tesoro machines is that you should dig
any target that has a strong, REPEATABLE signal. This holds
true with the Cortés as well. When I encountered targets that
defied a repeatable pattern, either in the ID NUMBER or on the
bar graph, it was always trash. This is true in the All Metal
Mode as well when the variable audio tones would also jump all
over the scale. These types of targets also defied repeatability
in the SUM Mode. In my experience these always turned out to
be iron or some type of twisted and/or torn pieces.
In
contrast, you may get some targets that may not lock on to a
specific single graph segment or ID Number but may bounce between
a specific range of ID numbers and smear two or three graph
segments in varying degrees of signal strength. I don’t
mean the kind of signal that jumps all around the meter but
one that consistently stays localized between a couple of graph
segment positions and a small range of ID Numbers. You should
treat these as questionable but repeatable (to a certain degree)
and dig them just to be sure of what they are. Trash items near
good targets can mask and alter what the processor sees as well
as two dissimilar items like a copper cent next to a nickel.
In the last example (a copper cent next to a nickel), you will
not see the NICKEL segment and the COPPER CENT segment fully
lighting on the bar graph, but rather some varying segments
between those two positions. Or the display may favor one or
the other occasionally as you vary your sweep or your scanning
stance but still favor graph segments somewhere in between.
The ID Number will also be an odd number not normally representing
either one of those two items. The user needs to be aware that
conditions like this can occur, as my air testing points out
(see below).
On
the other hand, under ideal conditions with clean targets (not
masked by trash or other targets), the Cortés is brilliant in
target identification. Under these conditions, the ID numbers
are stable (or stabilize very quickly in the SUM Mode) and the
bar graph is solidly lit in one segment. Occasional targets
will have conductivity that may fall directly on the line between
two bar graph segments. When this happens, you may get varying
degrees of signal strength in the adjoining graph segments (or
it may jump from one to the other), but it will be consistent
in that it only lights those two segments and doesn’t
bounce around to adjoining segments. On targets like this, the
ID NUMBER usually remains very stable, even though the graph
segments may not, which is a good indication that the target
has a fixed form and conductivity, and you should probably dig
it.
AIR TESTING
One of the first things I do with any new machine is perform an air
test using a standard set of items. I record this information
and keep it for future comparisons. I don’t place a lot
of emphasis on air test depths because actual in-ground results
can be totally different, but it is a nice indicator when used
for comparison purposes.
All
of the air testing I do is done with the exact same targets.
I carefully maintain a group of items so that my statistics
always have a common basis. This kit includes one of each silver
coin type, clad coins, copper zinc and large cents, pop-tops
and tabs, a gold ring, a .55 cal musketball, an eagle button,
and various sizes of rusty iron nails.
The
Cortés air tested slightly better (deeper) than the Toltec II,
which was a good indication to me but not too surprising since
my Toltec II is 7 years old. I made my comparisons using the
9x8 and 12x10 spoked coils on both machines.
Another
air test I performed was to see how target masking would affect
the graphic display. I used a silver Mercury dime and a pop-top
taped one inch apart on a wooden ruler. Individually, the dime
would read "95" and light graph segment 7 (Dime) and the pop
top would read about "37" and light graph segment 4 (RND Tab).
I ran this set of targets under the coil center, first centering
the coil directly over their center, then centering the coil
over the dime, then centering the coil over the pop-top. In
each case the target ID numbers showed slight differences but
grouped very close (between 46 and 60) and the bar graph segment
was always segment 5 (SQ Tab). But when I switched to the SUM
Mode in the above three examples, there were notable differences.
When centered between the targets, the SUM settled on "50" and
segment 5. When centered over the dime, it settled on "60" and
segment 5. But when I centered on the pop-top, it settled on
"44", and the bar graph segment dropped to position 4 (RND Tab).
I did not expect the bar graph to change all that much and indeed
it did not, but the target ID NUMBER showed significant differences
between the three cases when the SUM Mode was used.
I
next tried the same sequence of tests using a smaller 7" concentric
coil. I assumed the numbers would be better and more stable
due to the better pinpointing ability of smaller coils, and
I was correct. The numbers showed slight improvement. But even
when centering over the dime, I did not get a clear indication
that this target could be a silver dime.
I
tried similar tests using a rusty iron nail and a silver dime,
but because of Tesoro’s great ability to mask iron, the
results were much better. When centering on the silver dime,
it was somewhat erratic but stable enough to always read "95"
and segment 7 (Dime), and SUMMING locked strongly on "Dime".
I
also experimented with a copper cent and a nickel, one on top
of the other, first with the cent closer to the coil, then the
nickel. As expected, the machine did not match the individual
characteristics of either, even when SUMMING. The numbers and
graph segments were always somewhere in-between the two expected.
Even when the nickel was on top of the cent, the machine saw
both coins in the same fashion and responded accordingly. I
could throw more numbers at you here, but I don’t think
that’s as important as recognizing what is happening and
using it to your advantage.
What
does all this mean? It tells me that masking can have significant
effects on what your display tells you. That’s not a bad
thing, but it means you need to be aware that it can happen.
It
also means that a target masked by a lower value target (good
or bad) will always read lower on the ID and graph scales than
expected. As seen above, a silver dime masked by a pop-top SUMMED
at "60" instead of the normal "95". The same would hold true
in an opposite case if a nickel was masked by a screw cap (which
is higher up the scale). The resulting ID and graph indication
would read somewhere between the two. The target would read
higher than a normal nickel would read. This is important information
to know if you hunt areas that have a lot of one particular
kind of trash. You should do some testing on your own to see
how it affects the meter values of the "better" targets you
hope to find, thereby arming yourself to recognize potentially
good targets that don’t read as "good" targets. Instead
of passing on a poor reading, you may recognize the ID pattern
as being that of a masked target, and then dig this particular
target. Even if it turns out to be a good target only half of
the time, you have still recovered a keeper that you would have
otherwise missed. Know your machine, it will put more goodies
in your pouch!
Granted,
this is only an air test and actual field results might be totally
different (given the same circumstances) because of soil and
"halo" conditions. But nonetheless, it does indicate that masking
can affect meter readings in significant ways. Further proof
that if you’re in doubt about the identity of a target,
the only sure way to know is to dig it, and all the more reason
to dig any target that is stable and repeatable.
FIELD TEST
Due to circumstances beyond my control, I only had a three-week time
frame in which to test the Cortés. This three-week time frame
happened to coincide with a rather dry spell here in Wisconsin,
so I knew the depth capability of the machine would suffer.
Additionally, I should tell you that the soil here in Wisconsin
is highly mineralized and pulling a coin at 10 inches, even
under the best circumstances is almost unheard of. A coin found
in the 6 to 9 inch depth range is considered a deep target (and
coins found at 9 inches are rare). I was also unable to test
it at my favorite ghost town and stage stop sites because most
of these areas were planted with soybeans and impossible to
hunt at this time of year. I did all my testing with the standard
9x8 coil, unless otherwise noted.
5.68 pounds of "float copper."
As
I mentioned earlier, my very first experience with the Cortés
was way back in April of this year, when I had a weekend to
try the very first working prototype. At a favorite ghost town
site, I detected a very strong, repeatable single reading at
the extreme high end of the scale (dollar). Even though I had
to cut through an inch of frost, I was bound and determined
to recover this target. At 6 inches no target and still a strong
reading. At 10 inches, no target but still a strong reading.
I nearly gave up. At 14 inches I finally hit a target but from
what I could initially see, I knew it was not a coin. At the
bottom of this 14-inch deep hole, I could clearly see the deep
green patina of a large piece of copper. Initially, I thought
it to be a large sleigh bell or a small piece of sheet copper,
but I soon realized it was neither. I carefully widened the
base of the hole where this piece rested and somehow I was able
to do this without nicking the target (which is amazing considering
I did not even know what I had at the time). Twenty minutes
later I finally pulled it from the ground and was shocked by
its weight. When I finally pulled it from the hole, I immediately
knew I had recovered a large chunk of natural copper ore! I
quickly ran the piece back to my truck where I rinsed the mud
and dirt from its surface, then stood in awe looking at this
gorgeous piece of copper! I have since had several experts tell
me it is known as "float copper." Float copper is copper that
is torn from host rocks and moved by glaciers, hence the term
"float copper." This specimen weighed in at 5.68 pounds and
is rounded and worn smooth from long-term glacial action.
My
first test with the present machine was during a workday lunchtime,
only hours after receiving the machine from the UPS driver.
At the time the manual had not yet been completed so James included
a one-sheet set of brief explanations and instructions. The
instructions were so straightforward that I could comprehend
everything without even looking at the faceplate of unit. I
want to stress here that this machine is very easy to use and
even easier to use if you have had previous "Tesoro" experience
(because you will recognize nearly all the controls). In a flash
I was half a block away at the site of a local farmers’
market. There is a large open-air tent covering an area maybe
30 feet by 60 feet, where once a week for 3 hours, the local
growers sell their goods to the public. I had cleaned this area
out early this spring finding close to $10 in change and a few
kids’ rings. I did not expect to find much but it was
close and I would be sheltered from the hot noonday sun, and
it would be easy to recover targets from the wood-chip "floor."
I was amazed to pull 73 coins (nearly $9 in change) in only
45 minutes! Some of the coins were dark and deep in the wood
chips indicating I had previously missed them. The display readings
were right on the money each and every time, clearly identifying
each coin type and several square tabs as well. I tested the
effectiveness of the notch each time the meter indicated a target
in that range, and in every instance the notch would blank out
the pop-tops and tabs. My first outing was a success. The machine
was accurate and very easy to use, and I found a lot of coins.
After one outing I was already "hooked" on this machine!
Treasure finds with the Cortés
I made several other outings purposely to trashy areas because I
wanted to test its abilities to work well in junk. I must say
it was admirable. Given the air testing results I did after
this search, I probably missed some good targets that were masked
by trash. Nonetheless I managed to pull a man’s silver
ring in an area loaded with pop-tops and bottle caps, along
with several wheaties in the 4 to 5 inch range and a silver
earring.
I
then lined up several private yards to hunt—one home built
in 1858, the other built in 1900. Both had historical significance
in the Madison area and I thought the great finds I would surely
make would make for great writing and pictures in this report.
I was disgusted to discover both had been previously hunted.
Nonetheless, I pulled three wheaties at six inches and managed
a silver Roosevelt dime and an interesting cuff link. I also
dug some deep chunks of lead, all in the 5-6 inch depth range.
The signals were strong and repeatable, even in the dry soil
conditions.
My
backup plan, if these two yards failed, was yet another historical
landmark in the area, a mansion built in 1888 situated on the
lake with a great view of downtown Madison. I had previously
hunted this site many years ago, and even then I was not the
first to swing a machine there. But the grounds are large and
spacious, and I surmised that I could not have possibly cleaned
it out on my earlier trips.
Targets
were few and far between and I dug quite a bit of trash items.
In many cases I knew these targets would be trash by the way
the meter jumped around, but I dug them to prove the readings.
I also dug some lead chunks at 5 to 6 inches deep and those
were all strong repeatable signals. I found several newer coins
at shallow depths, one wheatie at about 6 inches, and two silver
dimes.
Closeup view of the finds including the silver dimes
The silver dimes were both found in the area right behind the house
overlooking the lake. This is where I had found the largest
concentration of coins on earlier hunts, and where I thought
I would find nothing because I had previously hunted this area
using a bigger coil (10.5 inch). Nonetheless, at three inches
I dug a silver dime that registered loud and clear. Not expecting
anything very old I wiped the dirt from the face of the coin
and was pleased to see a Mercury dime. A glance at the date
stunned me: 1916! My heart started racing immediately, and I
paused briefly before turning the coin over to look for the
mintmark, knowing full well the next few seconds might be a
glorious explosion of delight, or deep disappointment. After
turning the coin over I could see a mintmark at the bass of
the coin, but I could tell what it was without my glasses! Dang!
It was then that I remembered I had a magnifier in my pocket,
AND that I was very close to making a "scene" in plain view
of the occupants of the house. I slowly stood and moved down
toward the lake, below a terrace and out of sight of the house.
It only took seconds to find my magnifier (but it seemed like
hours), and I was quickly viewing a mintmark of the letter "S".
All of my excitement came to a screeching halt. I was hoping
for the elusive 1916 "D", the most rare of all Mercury dimes
and one in the condition of this coin would have been worth
about $2,400.00! As it stands, with the "S" mintmark, it is
worth about $15.00. I soon realized that I had no reason to
be disappointed. I had made a great find, experienced the thrill
and excitement that so attracts me to this great hobby, and
now I had another interesting story to tell around the campfire,
reliving the excitement every time the story gets told.
The
other silver dime was also a Mercury, 1942. This coin was over
6" deep but gave a strong and accurate signal. I was impressed
with machine’s ability, especially in the dry soil conditions.
I
also took the Cortés to one of my favorite spots, a ghost town
I have been hunting since I got my first Tesoro detector (the
Silver Sabre) back in the mid 80’s. Having worked this
site for so many years, I decided to put the 12x10 coil on the
Cortés and give it a try. The areas where I have found the most
coins were all covered in soybeans so I could only hunt a fringe
area that is now a pasture. I have never pulled much from this
area, but it was the only area where I could swing a coil. Normally
cattle are at one end near a very old stone barn, but today
they were up in the corner where I had wanted to hunt. It turned
out to be lucky for me because I ended up making a nice find
down by the old barn. After two hours of fruitless searching,
I finally got a good signal. In the hard packed soil, down about
4 inches, I pulled a very nice 1854 large cent! The signal was
unquestionably strong and unwavering. I have almost come to
expect large cents from this site (although not many lately).
Over the years I have probably pulled a couple dozen from this
ghost town and many other coin types as well (bust dimes and
half dimes, seated dimes and quarters, Indians, and even an
1806 half cent!) But as you might guess, the finds are now few
and far between, especially since the land owner uses no-till
planting (the fields never get plowed anymore) which means fresh
"stuff" doesn’t keep getting turned up every year. At
this site I hunted with the SENSITIVITY at the maximum and I
was getting a lot of noise ("pops" and "ticks"), and I was a
little concerned. I was way out in the country, away from power
lines, houses, everything! Unless the noise is unrelenting,
I will always hunt with the highest sensitivity, especially
when hunting for relics.
On
the way home I drove by another favorite spot, an even smaller
ghost town site. This one was pretty much just a crossroads
community, but again I have pulled some nice coins here in the
past. I discovered that one small field had not been planted
with crops at all, and that the nearby owners had created a
makeshift ATV figure-8 track on it instead, and they had it
mowed! I could not let this opportunity go to waste so I pulled
into the driveway to get permission (the last time I had hunted
this field it had been standing corn, several years ago). Permission
was granted and I spent the next 2 hours working this small
field. Here too I had the SENSITIVITY all the way up and at
this site the machine quieted down. I reasoned the soil conditions
at the last spot must have been really bad (I found it interesting
to finally learn that after so long, is this machine that sensitive?)
At this site, I became convinced of the depth capability of
the Cortés. I began digging some very deep targets here. Nothing
of any major importance, but copper and brass items, pieces
of old oil lanterns, an old copper coat hook, a big heavy brass
washer (the size and thickness of a silver dollar), part of
a brass lock, things like that. I did not dig any coins, but
the items I was getting were locking on to one graph segment
and were very stable and repeatable. Some of these items were
between 8 and 10 inches deep, and I was delighted to be digging
targets at that depth.
One
last site I stopped at was an old tavern site. This field was
standing corn but I decided to brave it out. I only spent about
two hours here because the mosquitoes were lifting me off the
ground. Here too, the machine was quiet even with SENSITIVITY
at max. I dug a few more junk targets, but again they were deep.
As before, a few defied repeatability and they were always big
pieces of iron. I also dug two shot shell casings between 6
and 8 inches deep, and I got a one-piece flat button at about
6 inches. I also eyeballed a white porcelain button. More proof
of the depth capability of the Cortés. All of these relic fields
were very dry and pulling deep targets from them was a pleasant
surprise for me.
SUMMARY
The single biggest impression I have of the Cortés is of how easy
it was to learn and use (the word "JOY" keeps springing to mind).
There are no menus to scroll through and no need to learn programming
skills just to change your settings. Every adjustment is achieved
manually with controls right on the faceplate. You turn it on,
set your discrimination level, and go. If you have previous
experience with any metal detector (not just Tesoro’s),
you should have no problem at all operating this machine right
out of the box. Really!
The
display information was well thought out and it is easy to view
and comprehend. I found the target identification and depth
readings to be very accurate. Even though the conditions here
were very dry, I was able to pull a good number of coins in
the 6-inch depth range. This impressed me. Using my older machine
with a bigger coil, I would have had difficulty reading a wheatie
at 6 inches in this dry, heavily mineralized soil. I am sure
I will be even more delighted when I am able to hunt under better
(wetter) soil conditions, as well as trying it with the 12x10
coil. By the way, changing to a larger or smaller coil on the
Cortés will not affect the Target ID accuracy, but your depth
readings will be slightly off. In the All Metal Mode, ground
balancing will account for any impedance difference, but if
you plan on hunting in the DISC Mode, you should have your coil
and machine balanced at the factory. This is a simple procedure
that is performed at not cost, and it will ensure that you are
getting the optimum depth capability from your equipment.
With
most new machines of this caliber, there is usually a significant
period of time when you are just not sure if you’re adjusting
everything correctly and you’re just not sure what your
machine is really telling you. It usually takes awhile to build
that confidence level and to learn and differentiate between
all the different sounds. I did not experience that with the
Cortés. There was no period of time when I was not sure that
I was operating it correctly because it very easy to use. And
within a very short period of time, I felt comfortable with
the Target ID information because each time I dug a target,
it confirmed and validated what the meter had indicated, both
in depth and target type. In time I am sure I will begin to
notice slight variations in the audio, which will only add to
my skill level with this machine.
There
is also a lot more target information available, allowing me
to make better decisions on whether to dig or not dig a target.
Even though masking can skew the Target ID information, it appears
to do it in a consistent fashion, which means in time I will
better recognize these patterns and be able to make even better
decisions.
In
writing this summary, I found it difficult to identify any negative
features of this machine, and I don’t want to minimize
the terrific job that Tesoro has done because I really like
this machine. So let me say that I would have been even more
delighted if Tesoro had found a way to make the control housing
hip or chest mountable. I realize that this would be a difficult
task with the battery pack being mounted separate from the control
housing, but arm fatigue is a concern of mine because I typically
hunt long hours. The unit is very lightweight and acceptable
as it stands, but changing to the bigger 12x10 coil pushes the
total weight to over 3.6 pounds, and that will certainly cause
my arm some stress after 6 or 7 hours of detecting.
Another
thing that would have really delighted me was if there were
some target separation between a copper cent and a silver dime.
Copper cents and dimes register on the same graph section of
the display and both will read "95" on the ID NUMBER, so you
cannot tell the difference between them. I would have liked
it better if Tesoro had been able to open up the resolution
at bit, right in that area, only because I would much rather
dig a silver dime than a copper penny. When I asked James Gifford
about this, he assured me that doing so would have taken away
from other areas of target ID, sort of like robbing Peter to
pay Paul, so they opted to group those two together. I was glad
I asked.
That
said I still have to give the new Cortés "two thumbs up"! Tesoro
did a great job of making a powerful, lightweight, easy to use
machine that has great depth and accuracy yet is very "display-friendly."
Oh yes, and it is actually fun to use.
Thank
you, Tesoro, for affording me yet another wonderful opportunity
to test one of your great products!
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