No detector, regardless of how powerful it is, can provide optimum depth if it is improperly tuned. In fact, the more powerful a detector is, the more critical the tuning becomes. Less powerful units are more tolerant of operator misadjustment, but are not capable of the depth of a properly tuned high power detector such as the Mayan.
If you will remember just one thing, and adjust your detector accordingly, you all achieve satisfying results. The thing to remember is, always operate the detector at "Threshold" (with a very slight amount of sound). Any time you operate a detector completely silent, you are losing depth. If the sound is too loud, you will also lose depth, because the weak signals from deep targets will not be as noticeable.
Following the tuning procedures outlined below will help you properly tune your Mayan to allow you to operate it at threshold, and will allow you to fully utilize its performance capabilities.
A. NORMAL MODE TUNING.
FIELD USE
The detector should be held in a position that is comfortable for you. Swing the detector from side to side in about a three foot arc. The Mayan does not need to be hurried, so go at a pace that doesn't wear you out.
Keep the detector tuned so that it is just beginning to buzz. In Normal Mode the detector ignores the ground, if properly adjusted, so this is easy to do. In Discriminate, the ground will affect the detector, so you should sweep the detector at a constant height above the ground (about 1 inch). Irregularities in the ground, as well as in your sweep height will cause variations in the tuning. These changes will usually be much slower than the abrupt signal caused by the coil passing over a good target. A little practice with a coin buried about 1 inch will enable you to pick out the target sound readily, as compared to the background variations. Turning the Sensitivity down will make it easier to maintain threshold. Always operate in Discriminate with the Sensitivity control set only as high as will allow you to operate in the unit at threshold.
In areas with well kept lawns, the easiest way to maintain a constant searchcoil height is to allow the coil to rest on the grass as you sweep from side to side. In rough and rocky areas it is best not to “scrub” the coil on the ground, as the rocks will act like abrasives, and wear away the coil bottom.
Since the combined MODE CHANGE/TUNING SWITCH allows the detector to be operated with just one hand, it is very easy to search in Normal mode until a target is found, and then switch to Discriminate to check whether it is a good target or junk.
Remember that when holding in the push button to change modes, the detector will always be in the automatic tuned mode. It may help to adjust the threshold slightly higher than the point where sound is just barely audible, as lightening for the null on trash items is just as important as listening for the increase of sound for good items, when you are trying to classify a deep target. If you can't get a definite response of either type, dig it. Also, the slightly higher threshold setting will help emphasize the difference between the "bonks" and "beeps". It also helps when classifying shallow targets, to listen to the audio response only as the coil approaches the target center. This requires that you pinpoint fairly accurately in NORMAL before switching modes with the push button. With little practice, you will find getting a definite response on deep targets is really quite easy in the automatic Discriminate mode.
Once a target is located in Normal mode, it is much easier to "find" in Discriminate, because you already know that it is there. Therefore, you can use a higher setting on the sensitivity control for checking known target locations than you could for checking known target locations than you could for hunting in the Discriminate mode. This is possible because you will be limiting your sweep to just a few inches, giving you much better control over your coil height variations.
Pinpointing can be easily accomplished by using either the audio response or by way of the meter. To use the audio response to pinpoint, simply move the coil around to find the spot where the loudest audio signal is heard. The target will be directly beneath the coil center. If the sound saturates over a larger area, simply push the tuning switch in the handle momentarily, close to the center of the loud response area. This will tune out most of the response to the target and the detector will go totally quiet if it is moved away from the target. This will cause an apparent reduction in target size. It may be necessary to retune a couple of times to almost totally tune out the target. This apparent target size reduction occurs automatically in the auto tuned modes, as the auto circuitry tries to tune out the target. Moving the coil slightly back and forth over the target will keep the target from being tuned out completely, and the response will diminish to a slight beep directly over the target.
The meter is also an excellent pinpointing aid, as it can also give you the approximate depth of the target, assuming that the target is a coin. Momentarily depress the tuning button with the coil not centered over the target. Release the button, and then move the coil over the target. Move the coil until you get the most forward deflection of the meter needle, And the target will be directly below the coil center. The meter will also read the approximate depth if the target is a coin. Since a dime and silver dollar obviously will give different signal strength at the same depth, the actual depth can very somewhat from the meter reading. Also, the depth meter readings can be obtained only in NORMAL or DISCRIM modes, and not in any of the AUTO TUNE modes. When operating in the AUTO TUNE modes, including any time the pushbutton is depressed, the auto tune circuitry will also attempt to zero the depth meter. The meter reading then will be indicative of the relative strength of the signal or its Intensity. This Intensity reading can also be used for pinpointing, but will not indicate coin depth.
In the Discriminate Mode, the tuning will not be affected by changing the DISC LEVEL control setting, so it is fairly easy to identify the target by increasing the DISC LEVEL control as the coil is passed repeatedly over the target, until the target response goes away. Being familiar with your detector and where typical junk items are rejected can save you much needless digging.
TO properly utilize this identification feature, you will need to be tuned to threshold at the same height as you are passing over the target so the ground minerals do not alias the readings. Automatic tuning is helpful here, as the auto tune circuitry will continuously keep your detector tuned to threshold. You will only need to sweep the coil a few inches across the target to get the proper response, unlike "motion" machines which may he to swing several feet for proper response.
One thing to remember, though, is that in Discriminate Mode, it is best not to use any higher Discriminate Level setting than necessary. Nickels and most small rings are rejected when the DISC LEVEL is set to reject pull tabs on all TR Discriminators. If you don't dig any junk at all, you are surely passing up a lot of other good finds too. Set the DISC LEVEL only high enough to suit the conditions where you are searching.
BATTERY REPLACEMENT
The Mayan has an automatic battery test circuit so you can always know you're getting top performance from your detector. The batteries should be tested after the detector has been operated for about ten minutes, and while the detector is making a loud noise, so the batteries are properly loaded. To check the batteries, simply turn the Mayan of for about five seconds, and then turn it back on and rotate the TUNING control completely clockwise. Depress the TUNING/MODE CHANGE button if it is not making lots of sound. The meter will indicate the battery strength for about four seconds. If the meter reads less than .6 during this period, replace the batteries.
To replace the batteries, pull the large knob on the battery door on the front of the unit. The entire door will pop out. Remove the battery pack from the detector, and then remove the batteries from the pack. Replace the new penlight batteries into the pack, observing the polarity indicators that are embossed into the insides of the pack. Slide the pack back into the detector, making sure that the battery clip lead is connected to the pack. Install the battery door flange into the top of the cutout in the chassis, and push the nylon fastener into the hole at the bottom of the chassis, making sure that the plungers are still pulled out. Then push the plunger back in to lock the door in place.
Should you desire to do so, rechargeable Nickel-Cadmium batteries can be substituted for standard penlight cells. Individual AA size cells are readily available at most electronic supply stores, as well as the chargers for them, and they can be inserted into the standard 8 holder used in your Mayan. The initial battery check reading will be slightly lower, but will not drop as much with use, until the batteries are completely discharged.
GENERAL CARE AND USE
If the detector is to be stored for a long period of time, it is best to remove the battery pack from the detector. This will prevent internal damage to the detector if the batteries should leak.
The searchcoil is waterproof and may be submerged in either fresh or salt water. Caution should be exercised to prevent water from entering the chassis, where it could damage the electronic circuitry, or from entering the upper stem, where it could leak into the chassis through the push button cable hole. After the coil is used in salt water, the coil and lower stem assembly should be rinsed well with fresh water to prevent corrosion of the metal parts.
There are several good books to help the beginner learn how to use the detector, where to search and how to recover a target without damaging the environment. A good coin shooter can recover a lot of finds and leave the area looking as though he had never been there. Above all, always fill your holes when you have recovered the target.
TESORO Metal Detectors are sold through independent dealers, who are almost always treasure hunters themselves. They can provide you with you much needed information about how to use your detector, how to probe, plug and dig in your locale, and answer most of your questions about treasure hunting in general.
The use of earphones will benefit you in two ways. Most earphones will very effectively block out most of the ambient noise, such as traffic noise and wind noise, which will enable you to better hear the fainter signals caused by the deeper targets. Obviously, the older, more valuable coins will probably be deeper than the ones which were lost last week, so you should take advantage of anything that will help you hear the weaker signals. Secondly, using earphones will greatly extend the battery life, since it takes much less power to operate them. The detector is not equipped with a volume control, but does have a limiting circuit in the earphone jack. If less volume is desired with earphones, you may want to use earphones with a built in volume control. Any good 8 or 16 ohm set with 1/4 inch stereo jack will do.
HAPPY HUNTING, and thank you for purchasing a TESORO.
WARRANTY SERVICE
Your Tesoro metal detector is covered by a Limited Lifetime Warranty, the terms of which are listed below. If your metal detector should require service, you may return it to the Tesoro factory, or tone of the factory authorized service centers. Contact the factory for the name and address of the nearest service center.
If you have any questions, don't hesitate to contact the factory.
LIMITED LIFETIME WARRANTY
This warranty gives you specific legal rights, and you may have other rights which vary from state to state.
This instrument is warranted to be free of defects in material and workmanship as long as it is owned by the original consumer purchaser. This warranty is not transferable, and is valid only if the warranty registration card has been completed and mailed within 10 days of purchase.
During the first two years, TESORO will, at its option, repair or replace any instrument covered by this warranty, without charge, except for transportation charges, at its factory in Prescott, Arizona, or at one of its authorized repair centers. After two years from date of purchase, TESORO will replace defective parts at no charge except a nominal labor change and transportation charges.
This warranty excludes batteries, damage caused by leaky batteries, cable breakage due to flexing on body mount units, and wear of the searchcoil housing. Also excluded are instruments which have been abused, altered, or repaired by an unauthorized party.
If warrant service should be necessary, contact the factory for nearest repair center.