Minelab Electronics Xt 18000
By Reg Sniff
From Page 15
August, 1997 issue of Lost Treasure
The Minelab XT 18000 detector is a perfect example of the improvements that have occurred in metal detectors over the last few years. This new "turn on and go" detector is both sophisticated, easy to operate, and most importantly very sensitive to the elusive gold nuggets while doing an excellent job of compensating for the wide variations in ground conditions that normally occur in gold hunting areas.
What I found that really makes the XT 18000 stand out is its excellent automatic ground balance capabilities. This feature has been significantly improved over previous models to the point that tackling extremely tough ground ladened with a wide variety of hotrocks is a relatively simple task.
Before going into the field test portion, I need to mention the features of this instrument. The Minelab XT 18000 has nine different controls that may look complex to a new user. Fortunately, this is not the case. Also Minelab has included a "Quick Start Instructions" page in the owner's manual that makes setup a snap for the most novice of users. More importantly, once set most controls can be forgotten about in most cases.
Some of the controls are easily recognizable to a casual detector operator, such as the TONE control (sets the initial tone of the threshold signal), the THRESHOLD control (low level audio level heard with no target present), and the SENSITIVITY control (how deep it will go). A control called SIGNAL VOLUME is a little different than a typical volume control. Instead of reducing the volume of all signals heard, this control only limits the maximum volume allowed, a feature that allows a wide range of earphones to be used without worry of too loud of a signal.
The remaining controls are toggle switches that allow the user to refine the settings of the detector by simply making a choice between two or three options. A recognizable toggle is the discriminating control marked SELECT. This control allows the owner to select between All Metals and Iron Reject. When in iron reject, large or easily identifiable iron targets still respond, but give a staccato (stuttering) sound.
One toggle labeled SOIL allows the operator to select between normal and difficult ground conditions, while another toggle labeled SIGNAL affects a target's response. This latter mentioned switch is one of two toggles that will likely be changed on a more frequent basis between three settings - Normal, Fine and Boost. The difference between normal and boost is the target signal is further amplified in the boost mode. The Fine setting does something a little differently. In this mode, a target responds with a "double beep" making it easier to distinguish a target from a ground change.
The second most likely toggle to be adjusted is labeled FREQ. This toggle allows the operator to select between three distinct operating frequencies - 6.4KHZ, 20KHZ, and 60KHZ. The three settings allow an operator to select a lower frequency for larger, deeper metal targets, or to select one of the higher frequencies for nuggets.
Finally, the last selector switch to be discussed is the GROUND ADJUST toggle. This toggle has two settings - Auto and Fix. In almost all cases this toggle will be left in the Auto mode.
When you purchase a Minelab XT18000, it comes with extras not normally included. For example, Minelab provides a Nicad battery pack, a corresponding charger, a coil cover for the standard 10-inch elliptical coil, and a blue hipmount bag that allows an operator to either hip or chest mount the control housing. Minelab also provided a set of basic earphones, as well as a belt mountable pouch to place retrieved trash items. Finally, included is an excellent instruction booklet which takes a new user through a systematic explanation of the XT 18000, its assembly, setup, and discussion of each control, plus some brief, but valuable prospecting tips.
The detector itself is equipped with a 3-piece breakdown shaft assembly for compact portability. The control housing is high-impact plastic equipped with Minelab's quick wedge fit shaft mount design, which makes attaching the control unit to the shaft a breeze.
IN THE FIELD
I received the XT 18000 while vacationing in Arizona on one of my nugget hunting ventures. Unfortunately, the detector arrived midway through my week's vacation and, because of the late arrival, plus the battery required a 12-hour charge, I was severely limited in time.
Although I had enough time to evaluate the detector and its many features in some really tough ground conditions, as any serious nugget hunter knows, you don't just run out the door and find gold nuggets. Such was the case with me. I was able to get a good feel for all the controls and how the detector responded to the typical conditions that plague a gold hunting site, but I didn't find any gold with it.
Fortunately, because my brother-in-law was staying in the area for a while, I left the detector with him and, wouldn't you know it, he found two small nuggets the first day he used it. Such is the luck of nugget hunters. His success also indicated how easy the XT 18000 was to use, since I didn't give him any specific instructions.
Because of my personal time limits, I started out at daybreak with the detector assembled as recommended with the control housing mounted on the shaft. Because I had been accustomed to body mounting detectors, the detector seemed somewhat heavy in the uneven terrain. After about an hour of hunting, I returned to my vehicle and converted to a chest mount using the provided hipmount bag. To make it more comfortable, I installed a second strap to the bag that went around my back. This second strap kept the control unit from falling forward when bending over. With this combination, the XT 18000 was extremely comfortable over a full day of hunting. I also abandoned the basic earphone set provided and began using one of my favorite pairs.
In the field, the XT 18000 was a pleasure to use. The automatic ground tracking worked excellent, tackling the worst of conditions including hotrocks. The normally highly reactive pieces of magnetite that would knock your earphones off responded with little signal. In fact, with the exception of one small type of reddish rock, which has fooled every detector I have used, I could easily distinguish a rock from a very weak target.
Although I tried all of the different settings, I settled on the following as the best for the area: Sensitivity at maximum, Signal on Boost, Freq on 60KHZ, Soil on Normal, Ground tracking on, and Iron Reject on. In essence, I had the detector set at maximum sensitivity and was able to hunt comfortably.
At the first location I picked, I hoped I would at least find a small nugget, but that was not to be. Instead, I managed to pick up several pieces of small lead shot (about a #6 to 7Y, size), among other things that had been left behind by other hunters. Because I was finding targets that small, I knew I could easily find a very small nugget if I passed over it.
One feature not mentioned earlier that I liked is the pitch variation that occurs when a target is encountered. In other words, as the signal volume goes up, so does the pitch of the audio. I felt this feature made distinguishing some small targets an easier task, such as pieces of tinfoil or little pieces of iron. When I encountered a very small target that caused the detector to squeal, I was relatively sure it was foil or a small piece of wire.
The iron reject feature worked about as expected. In most cases, small iron objects responded as good targets and only larger iron objects produced the staccato sound. I know how easily it is to reject a small gold nugget with typical discrimination and I realize Minelab doesn't want to reject a piece of gold.
All in all, I really enjoyed using the XT 18000 and look forward to more outings with this detector. I had extreme confidence in the automatic ground tracking and its ability to positively distinguish between the ground, a rock and a deep target, which are the most common problems. Except for the above mentioned type of hotrock, which I could readily see in most cases, everything that indicated a metal target was just that, some type of metal.
The detector also displayed exceptional stability, even when in use for long hours. Depth capabilities were also excellent. Although I didn't personally find gold during my brief field test, retrieving non-ferrous items such as lead bullets indicated the depth abilities matched or exceeded any other comparable detector I had used before. One controlled test of burying a 38 slug about 8 inches deep indicated all frequencies could easily detect a similar size gold target well beyond that depth. Also, controlled testing indicated an exceptional response to gold nuggets, including to extremely small ones.
It is easy to recommend the XT 18000 to both recreational hunters and professionals for all types of gold hunting, whether it be for extremely small nuggets or large, deep ones. This detector seems to do it all and do it extremely well in all types of ground conditions.
For more information about Minelab's XT 18000 or any other Minelab instrument, contact Minelab Electronics Pty Limited, toll free at 1-888-959-9599 for the nearest dealer, or 1-800-327-9697 for Catalog Sales.