Synonymous with quality and excellent customer service, Tesoro Electronics has earned the reputation as a manufacturer of reliable, easy to use metal detectors. Since their first machine rolled off the showroom floor nearly 20 years ago, Jack Gifford (president & founder) has been dedicated to providing treasure hunters across the globe with innovative technology at an affordable price. This family owned company learned long ago the true value of customer input. By listening to actual detectorists they were able to gain a better understanding of what features were needed out in the field and incorporate them into their new designs. It is this relationship that has helped them get to where they are, not to mention they stand behind their products 110%. Tesoro is so confident in their workmanship that they offer a lifetime warranty on every detector they sell! 

Recently I had the pleasure of field-testing their newest coin machine, the Conquistador mMax. If you enjoyed the original Conquistador, you’ll love the newly improved Conquistador mMax. Tesoro equipped it with their latest microprocessor, added a VCO all metal pinpointing feature, changed the Mode switch to include a switchable battery test, and did away with the cumbersome “trigger-switch” found on the previous model. It is also the first Tesoro detector to have a built-in frequency shifter, a handy device that will be greatly appreciated by competition hunters. This machine has a preset ground balance, so no adjustments are necessary. The machine is outfitted with an external speaker but still retains the ¼” jack to allow the use of headphones. The Conquistador comes standard with an open-face 9 x 8” concentric coil. Additional searchcoils are available. A single 9V battery supplies the detector’s power. Assembly is incredibly easy and requires no special tools. 

Features

 The Conquistador features five separate controls (knobs or switches) used for operation, these are: Threshold, Sensitivity, Discriminate Level, Frequency (FREQ), and Mode. The headphone jack and battery compartment are located on the back of the control box.

The Threshold level can be increased by turning the knob clockwise, and decreased by turning counterclockwise. The purpose of the threshold tone is to establish a “background” reference point for the location of metallic targets.

The Sensitivity knob is used not only for turning the Conquistador On & Off, but also used to raise or lower the gain. Gain can be thought of as a measurement of how much a signal is amplified. The higher the gain the more depth and sensitivity to small objects a detector has. Unfortunately an increase in gain will also amplify unwanted background noise and interference sometimes causing the detector to behave erratic. The Sensitivity control is used to find the best gain setting in any location without letting the detector become unstable. The Sensitivity knob is numbered 1-10. Beyond the 10 is an orange area called the Max Boost Zone. For normal hunting conditions, a setting anywhere in the numbered zone will work well. Placing the Sensitivity knob in the Max Boost Zone will enhance sensitivity and depth, but in some cases may increase the power to the operational amplifiers to the point of overload.

The Mode switch controls the way in which the detector reacts to metallic targets. It also doubles as a battery test. In the center position the detector is in its ALL METAL mode and will respond to all metallic targets regardless of composition. In other words, no targets will be discriminated against. In the right-hand position the detector is in its Discrimination or DISC mode and becomes selective in the types of targets it will sound off on. The discriminate circuit utilizes a silent search mode, meaning that no sound will be heard until the coil passes over a target. When the Mode switch is placed in the left-hand position it acts as a simple battery tester. The most common use of the detector is to hunt in the DISC Mode and switch to ALL METAL to pinpoint a target.

The Conquistador mMax is the first Tesoro to be equipped with a Frequency (FREQ1, FREQ2, FREQ3) shift switch, which allows the operator to quickly choose between 10.2, 10.4, or 10.6 kHz. The most practical application of this feature is for eliminating “cross talk” in large group hunts where many detectors are being used in close proximity. The ability to alter the frequency will also help when searching urban areas where electromagnetic interference from power lines, cell phones, and radio transmitters is streaming in from all directions. If interference proves to be a nuisance even after adjusting the frequency, decreasing the sensitivity may help alleviate the problem.

The Discriminate Level knob works in conjunction with the DISC mode and controls the Conquistador’s level of target selectivity; a very useful feature for weeding out unwanted trash from valuable targets. The knob is labeled with various settings corresponding to the level of discrimination. For instance, placing the knob in the TAB setting will be sufficient to reject pull-tabs and most ferrous targets while still allowing valuable items like coins and jewelry to be found.

Field Test

After assembling the detector and reviewing the instruction manual I was ready to get out in the field for some serious detecting. I grabbed the new Tesoro, jumped in my truck and headed for the town of Salome, Arizona. In 1888 a rich gold mine was discovered in the mountains about eight miles to the south. A 20-stamp amalgamation mill, erected in 1891, made an estimated production of $1,600,000 in bullion within three years! The mine was indeed rich and continued to be worked until April 1934. There was no doubt in my mind that something of value would have been lost around the mine during its 46-year life span; finding it amongst the typical mining camp rubbish would be the real challenge. Upon arrival I found that my hunch had been right; there was definitely no shortage of trash here! My attempt to hunt in the All Metal mode lasted no more than an hour; there were simply too many targets to dig and not enough hours in the day.

With the DISC mode activated and the Discriminate Level knob set at IRON, I began working a patch of earth around the remains of an old arrastra. For those not familiar with this term, an arrastra is a circular stone device used by early prospectors to crush gold-bearing ore. This one was in excellent condition and appeared to have been modified to accept a steam driven motor. The area proved to be less lucrative than I had originally hoped. A thorough search yielded a handful of bullets with my best finds being two jacket buttons. Climbing to the top of a nearby rock dump I noticed a dilapidated building beyond the next ridge. The structure looked as if it had been a work in progress. Some parts looked rather modern being made of wood, while other sections were constructed entirely of mud and Saguaro cactus ribs! Whether it was a miner’s cabin or work of art, at that point I didn’t care, I was looking for something to take my mind off the 2-hour drive back home.

I fired on the detector and began scanning the ground near the entrance to the building. BEEP! BEEP! The Conquistador announced it had located a target. I increased the discrimination level but the target remained solid and clear. Three and a half inches later a tiny silver coin popped up out of the soil. I’m not exactly a coin expert, but I knew enough to identify this as a Mercury dime, 1943 to be exact. Things were looking up; perhaps more of these beauties were hiding close by. I spent the remainder of the afternoon working around the fringes with a limited amount of success. I managed to locate another old button, a few shell casings, more lead and two modern day coins dating to the 1970s, but alas no more prized treasures were to be found.

Before closing I would like to share two observations, the most important of which concerns discrimination. Metal detectors that make use of discrimination will experience some loss of sensitivity and depth; the Conquistador is no exception. When hunting in the All Metal mode the operator can maintain a normal hunting speed with little chance of missing a target. However, moving the coil too fast with the DISC feature activated will allow deep targets to escape detection. For best results the operator should decrease his/her coil sweep speed to about half of that used during normal hunting. Although less ground will be covered, it will enhance the possibility of locating targets that other detectorists unknowingly whizzed by.

I also discovered that in order to “knock out” the abundant ferrous garbage encountered at the mine site, the Discrimination Level knob needed to be set slightly higher than the IRON mark. My preferred setting was closer to the FOIL mark. If trash is not extremely plentiful it will be advantageous to operate with as little discrimination as possible.   

Summary

It’s hard to believe that Tesoro was able to pack so much “detector” into such a tiny box. Weighing in at only 2.2 pounds, this machine can be swung for hours on end with very little user fatigue. The supplied 9 x 8” coil provides an ample amount of ground coverage, but is still small enough to work amongst trash and tight brush. The Conquistador is truly a “turn-on-and-go” detector. Although this was an unfamiliar machine I found myself comfortable with its operation after only a few hours in the field.

My only dislike was the silent discriminate search mode. It has been my experience that deeply buried targets will not always produce a true or distinct signal, but rather only cause a slight variation in the threshold. Without a constant reference point many of these subtle changes could go unnoticed. It is for this reason that I would have preferred some background noise while operating in the DISC mode.

Another wish would have been a pair of headphones. As mentioned earlier, the Conquistador is equipped with an external speaker, which for general detecting works well. However operators wishing to increase their odds of hitting those “barely audible” targets on windy or noisy days would find a decent pair of headphones a worthwhile investment.

My overall impression of the Conquistador was good. It’s a topnotch detector possessing two of my favorite qualities, simplicity and performance. The Conquistador mMAX is covered by Tesoro’s famous limited lifetime warranty, one of the best in the industry. The company will repair or replace any instrument covered by this warranty without charge, except for transportation charges, from its factory in Arizona. With a suggested retail price of only $399.00 and Tesoro’s upstanding reputation, this detector provides solid performance at an affordable price. For more information on Tesoro’s line of metal detectors contact the factory at: Tesoro Electronics, Inc. 715 White Spar Road-Prescott, AZ 86303 - (928) 771-2646 - 1-800-528-3352, or visit them on the web at www.tesoro.com. Don’t forget to mention you read about it in Lost Treasure!