By: Andy Sabisch
Minelab Electronics has earned the reputation of a company that designs radically new detector circuitry rather than simply taking an existing circuit, tweaking it a little and giving it a new model name. Since Minelab's formation in the late 1980's, circuits such as Broad Band Spectrum (BBS), Full Band Spectrum (FBS), Multi-Period Sensing (MPS) and Dual Voltage Technology (DVT) have provided detectorists worldwide with equipment that has been able to find targets deeper, with more accuracy and with fewer adjustments under virtually any ground conditions. Not resting on their laurels, Minelab's engineering and product development teams collected comments from users, along with a number of ideas developed in-house, and started work on a new series of detectors targeting users looking for high performance without a high price tag. After more than a year of development, the X-Terra series was unveiled.
Features The most important thing to remember when looking at the X-Terra's is that they are not intended to replace the other treasure detectors in the Minelab line such as the Sovereign, Quattro or Explorer. There are a large number of detectorists that wanted either a simpler or a less expensive detector without sacrificing performance and that's the market Minelab focused on while developing the X-Terra.
The first thing that strikes one when opening the X-Terra's shipping box is its size and weight--it is not a typical Minelab. The box measures just 10.5 x 25 x 3 and the longest section of the three-piece shaft assembly is only 19 long. It weighs 2.9 lbs. with the standard 9 coil making it effortless to swing for extended periods of time.
The X-50 is a single-frequency detector but Minelab's engineers have come up with another unique approach to eliminate one of the drawbacks single frequency detectors exhibit. When selecting a typical VLF detector, the operating frequency dictates what it will excel in; i.e., a lower frequency will detect deeper but is less sensitive to smaller targets and those of medium conductivity such as brass or gold. Higher frequencies are more sensitive to these targets but do not detect as deeply. Hence, one needs to select a model that excels in the locating the type of targets they typically search for and compromise on others. The X-50 solves that dilemma by changing frequencies based on the coil that is attached to the detector. The standard 9 concentric coil results in 7.5 kHz operation. For increased sensitivity to small targets and those in the mid-conductivity range, an optional coil will change the operating frequency to 18.75 kHz. The coils have an internal chip that automatically sets the operating frequency and ensures the depth and target ID readings remain accurate once the X-50 is turned on. This technology, combined with enhanced digital rather than analog signal processing, is called VFLEX. It not only makes the X-50 quite versatile but results in improved stability and performance under a wide range of ground conditions. The X-50 is controlled through a set of 9 touch-pads on the face of the housing. They are: POWER, PATTERNS, ALL METAL, MENU SELECT, PINPOINT / DETECT, ACCEPT/REJECT, GROUND BALANCE and [+] / [-]. Information about a detected target, current settings or possible adjustments is shown on the large LCD screen in the center of the housing. Adjustments available through the MENU function include Sensitivity, Volume and Noise Cancel. Sensitivity is self-explanatory but the other two options deserve an explanation. The Volume circuitry has a range of 0-20. Another unique feature on the X-50 is that a separate volume level can be selected (and then retained) for headphone and non-headphone use. A headphone icon will appear when headphones are plugged in letting the user know that the headphone volume setting is being used. This allows you to use a lower volume setting with headphones which can improve battery life. The X-50 will also automatically reduce the volume once the battery strength reaches the LOW level to conserve power and extend hunting time. Noise Cancel offers 3 settings (-1, 0, +1) which shifts the frequency slightly to reduce or eliminate any outside electrical interference. The discrimination circuitry is based on accepting or rejecting segments which correspond to target ID values displayed on the LCD screen. The X-50 has 18 segments in total; three negative numbers corresponding to ferrous targets and 15 positive numbers corresponding to non-ferrous targets. The segments were designed to afford maximum target separation and consistent target ID among commonly found items. In addition to the large target ID value displayed, there are four distinct tones which correspond to specific ranges of ID's which further help the user identify targets before recovering them. Patterns 1 and 2 can be easily customized to detect or reject specific targets and these adjustments are retained when the X-50 is turned off.
While the factory ground balance setting provides stable performance in most areas, manually adjusting it as needed to compensate for severe ground conditions is easily accomplished though the touch-pads. An operational tip that can give a bit more performance is to find the optimal GB setting; i.e., no audio change as the coil is raised and lowered and then increase the setting by 1 try it in "hot" ground and see the difference. The pinpoint circuit is another innovative addition developed by the Minelab team. When the pinpoint touchpad is depressed, the display changes to show a moving ring inside the one that appears when MENU is pressed that forms a complete circle when the coil is centered over the target. The audio response also aids in pinpointing by increasing in both volume and pitch as the coil approaches the target center. Combing the pinpoint circuitry with the depth indication provided through 5 arrows--each indicating approximately 2" in depth--the X-Terra allows for extremely accurate pinpointing and rapid target recovery which simply equals more "keepers" at the end of the day. The X-50 is powered by 4 AA batteries that fit into a compartment located in the housing itself. Alkaline cells will provide 20+ hours of operation. A headphone jack is located behind a protective rubber cover on the left side of the housing. Using headphones with a 90-degree plug is preferred over the straight-plug design based on the jack location.
Field Test I had the opportunity to be part of the development project team for the X-Terra's and as such, was able to spend a considerable amount of time in the field using the X-50 in its various incarnations. Minelab's engineers should be commended in that they started with a platform based on feedback from their customers and then were able to fine tune the design throughout the testing phase to address virtually all issues that were raised by testers worldwide.
Keeping in mind what the intended market segment is for the X-50, I focused my testing activities on local coin hunting, colonial-period relic hunting and some beach hunting along the Carolina coastline.
The first few sites I took the production model to were local schoolyards that despite having been hunted regularly over the years, still held an occasional surprise or two in terms of older goodies. Selecting Pattern 2, I adjusted the Ground Balance and leaving the other adjustments at Preset, I started off in the older section of a nearby elementary school. The first three good signals all indicated 30 and as expected, turned out to be zinc pennies a few inches deep. A deeply buried solid 42 signal got my hopes up but it turned out to be only a clad quarter at just over 7 inches. Near the tree line at the back of the school, I started to pick up a number of larger rectangular tabs which registered 18 and 21, so with the use of the REJECT touchpad, they were quickly and easily eliminated. An hour netted a handful of clad coins as well as three wheat cents and 1936 Mercury dime at just over seven inches, all of which had produced solid, repeatable signals. This success was repeated at a number of other local parks and schools with some deeply buried targets producing clear signals that a few other detectors, brought along for comparison, either could not detect or produced signals that were marginal at best. A positive characteristic of the X-50 is that good targets will produce consistent sounds and target ID values while trash will typically produce a broken or "clipped" audio response and erratic ID values on the LCD screen which makes it easy to ignore the trash and focus on the "goodies".
The Atlantic coastline in the Carolinas is a challenge to any detector due to the heavy concentration of black sand, so I packed up the truck and took the X-50 to Folly Beach near Charleston which has produced well in the past. Starting in the dry sand near the dune line, I was able to run the sensitivity near MAX with only the slightest evidence of false reading, which in itself was noteworthy compared to most VLF detectors I've used here before. Unfortunately while coins at depths of up to nine inches+ were common, gold jewelry wasn't, so I opted to try the wet sand area that was being exposed as the tide went out. Here I had to drop the sensitivity to "10" and keep the coil off the ground a bit, no minimize false readings, but I was able to hunt the area and more importantly, find several targets including coins and a small 14KT gold charm in the surf line. The optional Double-D coil should improve the X-50's performance in this application and I am looking forward to returning with the coil when it is released.
Relic hunting to me is the real "acid test" for most detectors. Not only are most good targets deeply buried, they are often found in trash infested, mineralized sites, so the combination of good detection depth, target separation, discrimination and ground compensation is needed for maximum success. The first site I hit was one I and others had hunted before but tended to avoid due to the trash and severe ground conditions present. Ground balancing was a snap and did require a setting of "10" vs. the preset value of "6" so the ground was "hot." Initially hunting in All-Metal with the sensitivity boosted to "15", I switched back to Pattern 1 whenever a non-ferrous target was detected to see if using discrimination would mask good targets near ferrous trash.
In every case, a non-ferrous signal in All-Metal produced the same, consistent signal in Pattern 1. I continued to hunt in Pattern 1 which eliminated the ferrous trash and allowed me to focus on non-ferrous targets. Two hours at this site turned up three pre-1900 coins, two flat buttons, a skeleton key and a fired musket ball. Other than a few pieces of non-ferrous modern trash, all my signals had been "keepers." I hunted a few other sites dating back to the 1700's and the X-50 performed surprisingly well in terms of detection depth, target ID accuracy at depth and target separation in high-trash areas. Combining these performance traits with the X-50's lightweight gives relic hunters another detector to give serious consideration.
Summary The X-Terra 50 was developed to meet the needs of detectorists that wanted high performance, light weight, good balance at a moderate cost and versatility--and that is exactly what Minelab's engineers produced. At less than three pounds, the X-50 can be used for hours without fatigue. It has a fast recovery speed which combined with its lightweight and unique operating frequency, makes it ideal for competition hunts. It is extremely easy to adjust and provides above average performance. The ability to literally change detectors simply by changing search coils is another unique Minelab feature and will allow users to fine tune the X-50 to fit their exact needs for a specific type of hunting and specific ground conditions. Keeping in mind that the X-50 is not intended to replace any of the high-end models in the Minelab line, it does exactly what it was designed for and then some. The online version of this field test contains more details on the X-50 & its performance.
The X-Terra 50 retails for $699 and comes with the nine-inch 7.5 kHz concentric coil and skid plate. Optional accessories from Minelab include Koss headphones, a durable rain cover and, to be introduced, search coils of different operating frequencies, sizes and designs; i.e., Double D or concentric.
For the name of your nearest dealer, more information on the new X-Terra series or the rest of the Minelab line, contact Minelab USA at 871 Grier Drive, Suite B-1, Las Vegas, NV 89119, call them at 702-891-8809, or visit their web site at www.minelab.com and be sure to mention you read about the new X-Terra X-50 in Lost Treasure magazine.