Minelab Electronics Ft16000 Fast Tracker
By Andy Sabisch
From Page 5
February, 1992 issue of Lost Treasure
The GTl6OOO Ground Tracker from Minelab Electronics had become well-known around the world for its performance and ease of operation. The research team at Minelab, headed by Bruce Candy, was not willing to simply rest on the laurels of the GT's design and continued to look for ways to improve on it. After making a number of programming changes to the microprocessor that provides the "brains" for the detector, the FT16OOO Fast Tracker was born.
The Ft16OO0 Fast Tracker is similar to the GT1 6OOO in that it features true automatic ground-canceling capabilities with both motion and non-motion search modes. The FF1 6OO0's circuitry actually senses the mineralization present in the ground being searched and compensates for it on a continual basis. The discrimination circuit, which will be discussed in detail later, is unique in that no loss of sensitivity is experienced even as the level of discrimination is increased to the maximum position.
The detector is mounted on a modified S-shape handle and weighs just under four pounds with the standard searchcoil and battery pack. The control housing is held securely to the shaft with a newly designed bracket that makes removal of the housing for hip-mounting purposes quite simple. The FF16000 comes equipped with a waterproof 8-inch Double-D searchcoil and a 7-foot cord which allows it to be used in shallow water without damaging the electronics. A sturdy nylon carrying bag comes with the detector and is used to hip-mount the control housing.
There are 4 knobs and 4 toggle switches located on the face of the control housing which control the operation of the Ft16000. The VOLUME knob, located in the lower right corner, serves a dual function. It is used to turn the detector on as well as to adjust the strength of the signal heard through either the internal speaker or the optional headphones.
The SENSITIVITY knob, located to the left of the VOLUME knob, is used to adjust the strength of the signal being sent out from the searchcoil. The third knob along the bottom of the front panel is the THRESHOLD knob and this is used to set the background threshold produced by the detector while searching. Above the THRESHOLD knob is the DISC control.
With the knob fully counterclockwise, the discriminate circuit is disabled and the FT16OOO functions as a true all-metal detector. As the control is turned clockwise, the amount of discrimination increases. The FF16000 incorporates a unique discrimination circuit that will only "reject" targets that can be accurately identified.
Small or deeply buried targets often cannot be identified with a high degree of accuracy and as such are frequently rejected by other types of detectors. The FF16000 will respond audibly to all targets the searchcoil passes over regardless of where the DISC knob is set and a different signal will be produced for those targets that fall below the setting on the DISC control. If the target cannot be identified with a high degree of certainty, it will come through with a good clear signal ensuring the operator will not miss recovering a potentially-valuable find through the use of the discrimination circuit.
Above the DISC knob is a three position toggle switch labeled SOUND (Normal/Boost/Enhance). With the switch set in the NORMAL position, the detector will produce a standard signal as the coil passes over a metallic object. The BOOST setting activates a signal booster circuit which increases the ability of the user to hear the extremely faint signals that usually mean the target is deeply buried or very small. The third position, ENHANCE, should be used when searching in an area where the mineralization changes rapidly or a large number of hot rocks are found and produces a "fluttering" sound when a good target has been detected.
The toggle switch to the right of the SOUND switch is labeled SOILNORMAL/DIFFICULT and allows the FF16000 to be used under a wide range of ground conditions. In areas where the mineralization changes frequently or when using the detector along a salt-water beach, the DIFFICULT setting will produce less chattering and falsing. There is a slight loss of sensitivity when searching in this mode; however, in some areas with extreme ground conditions, the NORMAL setting would not be useable.
Above the SOIL toggle are two switches inside a box labeled GROUND BALANCE. The switch on the left is used to select one of three operating modes. The lower setting places the FF16000 into the motion discriminate mode and activates the circuitry that continually adjusts for changes in the ground mineralization present.
The other two positions allow the user to choose either a motion discriminate or non-motion all-metal mode with the ground balance fixed at a pre-selected point. This feature will be discussed later in the field test portion of this article. The switch to the right marked RESET is used to "force" the FF16000 to balance out the mineralization present under the coil.
The FF16000 is powered by 8 AA penlight batteries which are located in a separate compartment on the bottom of the control housing which prevents damaging the circuit board in the event the batteries leak. Mkaline batteries will provide between 30 and 40 hours of use. Regular carbon batteries should not be used as the factory says that they may leak under normal use. Rechargeable batteries can be used with no loss of performance; however, they are not offered as an option by the factory at this time. When 30 minutes of life remains in the batteries, a short tone will be heard every 20 seconds alerting the operator to replace them.
Since I had used the GT16000 in the field previously, I quickly read over the manual and watched the instructional video that came with the FT16000. After re-familiarizing myself with the controls, I took it outside to my test garden. Turning the VOLUME control fully clockwise, the SENSITIVITY knob to the 3 o'clock position, the SOUND toggle to NORMAL and the GROUND BALANCE switch to TRACK GB, I proceeded to see how it responded to the various targets.
Ground balancing the FF16000 in the TRACK GB mode can be accomplished in two ways. The easiest is to allow the ground tracking circuitry to automatically compensate for the mineralization present by simply sweeping the coil across the ground for about 30 seconds. After several sweeps, the coil can be raised and there should be no discernible change in the threshold. The other method is to hold the RESET toggle switch in the upper position while raising and lowering the coil.
Very quickly the threshold will become constant as the coil is being moved meaning that the detector has ground balanced itself. Once either method has been used, the ground balance circuitry will continue to sense the mineralization present and make any changes necessary to maintain maximum sensitivity if the TRACK GB mode has been selected.
All of the targets produced clear signals, even on the seven-inch plus coins, and by selecting the BOOST mode, I found that the coil could even be raised off the ground while still detecting the targets. By increasing the DISC control to five or six, I was able to hear a noticeable difference when passing over a nail at four inches; however, a bolt at seven inches continued to produce the same clear signal as a coin would even at a setting of eight.
As I mentioned earlier, the FF16000 will not audibly reject a target unless it can identify it with a high degree of accuracy. The depth of the bolt combined with the mineralized soil had caused it to produce a good signal.
The first place my wife and I took the FT16000 to was a nearby stream that had produced a fair amount of gold in the late 1800s and still sees weekend prospectors searching its banks on a regular basis. We hiked in about 3/4 mile from the road and selected a promising stretch of the creek to search.
Since we were searching in the stream, we opted to hip-mount the control housing to avoid accidentally dropping it in the water. In order to avoid passing up any gold, we turned up the DISC knob fully counterclockwise which selected the ALLMETAL mode. Placing the SOIL and SOUND switches in NORMAL, I ground balanced the FT16000 and began to search among the rocks on the streambed.
Almost immediately I received a solid signal and carefully pinpointed the target. After removing several handfuls of mud and gravel and placing them in a plastic gold pan, I checked the hole and saw that the target was out. Quickly panning down the material, I found the lead portion of a .22 caliber bullet.
The next few targets produced loud signals and were modem pieces of trash close to the surface. Near the head of a small pool, I received a faint signal that I almost missed. Switching the SOUND toggle to BOOST, I swept the coil over the area again. This time the response was quite loud and well-defined. From almost 8 inches, I recovered a .38 caliber shell casing that had obviously been there for some time.
I tried searching in the BOOST mode; however, while the response to targets was much more pronounced than in the NORMAL mode, the threshold signal wavered noticeably which was somewhat distracting. By searching in the NORMAL mode and rechecking questionable signals in the BOOST mode, I found that I could differentiate between signals caused by bumping the coil or changes in mineralization and good targets quite easily.
My wife tried using the FT16000 near some exposed bedrock farther upstream and she was able to locate a number of targets in the area. While she found some small pieces of wire, a few more shell casings, and three lead bullets at depths of up to 7 inches, neither of us was rewarded with any gold nuggets on this trip. With the sun going down and our 20month-old son thoroughly soaked from playing in the creek, we decided to call it a day and head for home.
I mentioned that I was field testing the FT16000 to Dave Colwell who runs East Coast Prospecting and Mining Supply in Ellijay, Georgia, and asked him if he would be interested in providing some input. Dave is extremely proficient in the use of detectors for both general TH'ing and electronic prospecting applications and I felt he could provide some insight into the FT16000's performance in the field.
The following weekend, Dave and a friend went to a site near Dahlonega which held a number of tailing piles from the large dredges and hardrock mines that had operated nearby. Dave's friend had obtained permission from the current landowner to search the area and had recovered several nice nuggets on previous visits.
Due to the uneven terrain that was to be searched, Dave opted to use the FT16000 in the hip-mount configuration. Setting the SENSITIVITY control to 2 o'clock, SOUND and SOIL to NORMAL, and selecting the MOTION TRACK GB search mode, Dave quickly ground-balanced the FT16000 and began searching along the base of one of the tailing piles. The first few signals produced nails from an old building nearby, so Dave headed in the opposite direction towards the creek.
Switching to the BOOST mode, he noticed an appreciable increase in detection depth; however, the oscillation of the threshold signal became distracting and he removed his headphones. A weak signal near some large rocks sounded promising so Dave carefully removed some dirt and rechecked the area. The signal was still in the hole but getting stronger.
After several minutes of removing the hard-packed dirt and rocks, the FT16000 indicated that the target was out of the hole. Sifting through the dirt, he found a complete .22 caliber bullet which had been over 6 inches deep. A few more hours of searching near one of the old mine shafts produced a number of items including shotgun shell casings, lead fragments, rusted tools and other implements, and a few boot tacks.
With the temperature climbing into the mid-90s, Dave and his partner headed back to the car. While none of the objects he had recovered were particularly valuable, the FT16000 had handled the changing mineralization well and located some small targets at up to 6 or 7 inches deep.
Dave summarized his experience with the FT16000 by saying, "The detector is extremely simple to operate and even a beginner can keep it properly ground-balanced. The hipmount feature makes it comfortable to search for long periods of time by keeping the weight of the control housing off of your arm. While I didn't find any gold with the FT, based on some of the targets I did find, I'm sure I would have if the coil had gone over some."
During the field test, several people asked me why you would want to search in any mode other than the TRACK GB mode which continually compensates for the changes in ground mineralization. Answer: normally, the TRACK GB mode would be the preferred mode to search in; however, the two FIXED modes work extremely well for certain applications.
To try out the FIXED modes, I went to a small stream about 40 miles east of Atlanta where a fair amount of fine gold has been found over the years. I set the SENSITIVITY knob to 3 o'clock, VOLUME to maximum, SOUND and SOIL to NORMAL, and the GROUND BALANCE toggle to FIXED GB NON-MOTION. I adjusted the THRESHOLD control to produce an audio signal some what louder than what I would normally hunt with and used the RESET toggle to ground balance the FT16000 on a sand bar in the middle of the stream.
The detector was now ground balanced for the mineralization present in the ground directly under the coil and would not readjust itself as the mineralization changed. As I searched along the creek, I listened for any decrease in the threshold signal which would indicate an increase in mineralization content. A concentration of black sand would cause this type of response, and while not all black sand contains gold, it is a sign worth investigating. Along the inside bed near a large rock, the threshold dropped noticeably over a small, well-defined area.
Putting the detector on the shore, I shoveled some of the sand and gravel from the bottom into a gold pan. Panning the material down, I saw that there was a fair amount of black sand and a thin ribbon of minute gold flakes in the bottom of the pan. Taking samples from just outside the area that the PTl 6000 had pinpointed revealed virtually no black sand and not a single flake of gold.
I repeated this process several more times over the next few hours, and when I was finished, I had pinpointed some areas that would be well worth dredging or sluicing based on the sampling I had done. The FT16000 works well in locating pockets of black sand that would warrant further investigation.
The FT16000 was designed to build upon the performance of its predecessor, the GT1600 and it does. The microprocessor tracks the ground mineralization and corrects for any changes much quicker than the GT and there is a slight increase in detection depth, particularly on coin-sized and larger objects. It is extremely simple to operate and it allows even a novice to hunt those areas where mineralization has forced others to give up in frustration.
With the control housing mounted on the shaft, the balance of the unit puts much of the weight on the user's forearm. If it's going to be used for an extended period of time or in uneven terrain, the hip-mount configuration is highly recommended. The audio threshold signal that is heard while searching is not constant as seen on many other detectors, but warbles or oscillates slightly. This takes some practice to become accustomed to, and it becomes more pronounced when searching in the boost mode.
While the FT16000 was designed primarily with the needs of the electronic prospector in mind, its ground-canceling capabilities make it an effective beach and relic detector in its own right. With the optional 6inch round and 12-inch elliptical coils, it can meet the needs of a wide range of TH'ers.
The FT16000 sells for $849 and comes with a 2-year parts/1-year labor warranty with all service work done in the United States. For a catalog detailing the entire line of Minelab detectors and the name of your nearest authorized dealer, contact the importer at Down Under Treasures, P.O. Box 91538, Henderson, NV 89009, or call them at (702) 565-1353 and mention that you read about it in Lost Treasure!