How to Choose a Metal Detector to Hunt for Treasure

You can use a metal detector to find coins, jewelry, gold, and even pirate treasure.   In this and the next two posts we’ll talk about what detector to use, where to use it, and how to use it for fun and profit.

There is a variety of metal detectors on the market in a wide range of price ranges.  Some are designed strictly for water searching while others must never be submerged.  Many metal detectors will find items at a depth of 8-12 inches below the surface.  More expensive ones, with advanced technology, can detect items deeper in the ground.  But remember; that means you’ll have to DIG deeper too.

Many machines are calibrated to find U.S. coins but will read Canadian coins as trash!  Ask if the machine can be used for Canadian coins as well as U.S. coins. 

Find a metal detector that has a higher-impact plastic.  It will be more durable.

There are detectors that do much better at certain tasks.  So your first decision is what your goal is (finding gold? coins? jewelry?); what type of terrain you want to explore (beaches, rocky steep terrain, river beds); and what are you willing to spend on your first metal detector.  

If your only goal is to search out gold nuggets, there are specialty metal detectors for that purpose.  But they’re more expensive.

It is not necessarily bad to select a detector which cannot handle certain conditions, since you may have little or no need to hunt in these.  However, don’t  subject a detector to conditions for which it was not designed and then expect it to operate at peak performance.  Although many detectors will work well at most tasks, they simply cannot provide the performance of today’s specialty detectors.

Some Terms You Need To Know

You will usually hear the terms VLF (or VLF/TR), Pulse (or PI), or RF in reference to common, modern metal detector types. You will also hear the term TR, which stands for transmitter-receiver, used with different types of detectors.

TR, VLF, and VLF/TR

The terms TR, VLF and VLF/TR can be confusing at first. The fact is they are all transmitter-receiver detectors. The terms TR and VLF are merely used to provide an easy way to distinguish the difference between the two.

In electronics, VLF stands for Very Low Frequency (3-30 kHz), but with metal detectors the term is usually used to indicate a “mineral-free all-metal” mode of operation.  TR stands for Transmitter/Receiver, but usually indicates a “non-motion discriminate mode” of operation. VLF/TR usually indicates “mineral-free all-metal” and “mineral-free discriminate” operation.  

Although they have their place, the higher frequency TRs are generally not competitive with the latest VLF/TR’s with silent search motion discriminators, as they are unable to handle the problems imposed by mineralization in the ground. TR’s have long since given way to the superior ground- effect control provided by the very low frequency (VLF) instruments.

TR’s are normally restricted to use on non-mineralized saltwater beaches and for saltwater diving as they are capable of ignoring the effects caused by conductive salts, if properly tuned.  Since TR’s cannot ground compensate for mineralization, they are incapable of obtaining the depth achieved by the newer VLF type instruments thus limiting them to finding only shallow surface targets when used in mineralized areas. Whereas, the newer VLF/TR detectors do ground compensate, thus accomplishing much greater depths of detection when mineralization is present. 

RF Two-Box

RF two-box instruments are very specialized detectors that can respond to large metallic objects at great depths.  Cache hunters sometimes find the two-box a useful tool, although almost all caches rate well within the range of VLF/TR’s equipped with large-diameter search coils.  The two-box also sees action in prospecting when massive mineral deposits are being sought and in a variety of industrial applications. However, they cannot respond to coin-sized objects and are therefore entirely limited to deep-seeking tasks of large objects. 

Pulse Induction 

Great achievements have been made in PI (Pulse Induction) instruments.  Once limited to underwater diving, great technological strides have been achieved by some manufacturers making this type of detector popular among saltwater beachcombers as well.  Although the PI is an “all metals” only detector, its popularity has increased in areas where little trash is located and on black sand beaches where PI out-performs the VLF/TR since they are capable of ignoring both conductive salts and mineralization simultaneously. 

Recent developments in PI technology have brought about innovative advancements like eliminating the annoying pulsing threshold sound and new kinds of search coils.  These search coils make it possible for the first time for a PI detector to find previously-undetectable fine gold jewelry and to be used for hunting gold nuggets in alkali and extreme hot rock areas, which are too difficult for the VLF/TR instruments. These search coils are not only different on the inside, but they are interchangeable in- stead of hard-wired as in the past.

Though PI detectors get excellent depth on sandy and wet beaches, some loss of depth will be experienced when operated over hard, dry ground.  Because of this, PI detectors are normally used only as secondary, specialty instruments and not as the primary detector.  One word of caution: this new PI technology is not universal and, therefore, most manufacturers do not have it available yet. You may need to check with a local dealer for more information. 

Two other types are BFO (Beat Frequency Oscillator) and TR (Transmitter-Receiver).  Although once popular, these two are no longer being made by professional metal detector manufacturers.  BFOs may still be around but they are normally confined to cheap, toy-type detectors. 

Most Commonly-Used Detector 

With all of these facts in mind, most detectorists will probably choose a VLF/TR motion discriminator with silent search as their primary machine.  VLF/TRs with discriminators have the capability of controlling trash and mineralization simultaneously.  The word motion indicates that the search coil requires movement in order for both ground control and discrimination to be achieved.

No longer is it necessary to rapidly swing or “whip” the search coil back and forth as in the past. Today’s motion discriminators require very little movement of the search coil in order to identify a target. This advancement has taken much of the fatigue out of metal detecting. The better instruments also allow instant switching from the motion Discriminate mode to a non-motion all-metal, or Normal tune, mode for pinpointing, and for general purpose non-motion non-discriminate hunting.

Several innovations deserve special mention.  Surface mount technology has now opened the doors to miniaturization, permitting extremely compact designs.  A select number of detectors are now available which utilize these hybrid circuit boards, though only available through select manufacturers at this time. This great achievement permits complex circuitry to be designed into small control housings. This greatly reduces the weight and bulkiness of the unit without sacrificing performance of the instrument. In fact, when properly engineered, this innovation provides even greater results, including virtually trouble-free operation. 

To read about a metal detector that I highly recommend, visit my InvestorsShoppingMall.com and read Use a Metal Detector to Find Buried Treasure!

Related Articles:  Where to Find Buried Treasure with Your Metal Detector, Tips for Using Your Metal Detector

2 Comments on How to Choose a Metal Detector to Hunt for Treasure

Tips for Using Your Metal Detector | Gemologist Sam


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Where to Find Buried Treasure with Your Metal Detector | Gemologist Sam


[...] Articles:  How to Choose a Metal Detector to Hunt for Treasure, Tips for Using Your Metal [...]

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