Minelab Sd 2100e
By Chris Gholson
From Page 30
May, 2002 issue of Lost Treasure
Whoever said, Legends never die, may have been talking about the Minelab SD 2100e.
Although this detector dropped out of the limelight a few years ago, with the release of the SD 2200D and the GP Extreme, its remarkable nugget finding abilities were not forgotten.
Fortunately for nugget hunting enthusiasts everywhere, Minelab Electronics has decided to bring this classic detector back into the mainstream.
Aside from its curved shaft, reduced battery size and new name, the SD 2100e still retains all the great features found on its predecessor, but sells for about $1,000 less than the original price.
The SD 2100e is packed in a single box containing the detector and the following parts: 11 double D coil, armrest, upper and lower shafts, headphones, battery and cable assembly, mains battery charger, vehicle battery charger, instruction manual, and warranty card. Assembly takes no more than a few minutes.
The SD 2100e does not have an external speaker; all sound is heard through the headphones, which plug into the jack located in the top of the battery pack. Nor is it equipped with a discriminator, so all metallic targets will need to be investigated. The SD 2100e is fueled by a 6V rechargeable, 4.5A/hr gel cell battery, which should provide enough power for 6-8 hours of use when fully charged. The gel cell battery does not need to be fully discharged before recharging and will not develop a memory.
The Tune control is a 10-turn Variable Frequency Control located on the back of the control box that allows the operator to minimize the effects of electromagnetic interference from power lines, radio transmitters and other metal detectors. The Tune feature is designed to reduce background noises and has no effect on depth penetration or sensitivity, therefore there is no optimum setting in areas that are interference free.
It is important to mention that only constant sources of interference such as power lines and other detectors can be tuned out. It is a waste of time trying to tune out every plane flying overhead.
The pitch of the background threshold and target response sound can be adjusted to suit an individuals own hearing by using the Tone control. This control is also located on the rear panel and is protected by a plastic plug. The best method for adjusting the Tone is to place a small metallic object on the ground, remove the plastic cover and insert the supplied screwdriver. Turn the screw while sweeping the coil over the target until a desirable pitch is found. Be sure to replace the plug when youre done to prevent dirt from entering the control box.
The Search Switch and the Balance 1 and 2 knobs found above and below it are the most important controls on the SD 2100e, as they are used to set the ground balance.
Ground balancing the SD 2100e is a simple 3-step process which consists of flipping the Search switch into the up position and adjusting the Balance 1 knob while pumping the search coil over the ground. The knob is turned until there is very little or no variation in background sound as the coil is raised and lowered. The Search switch is then flipped into the down position and the same process is carried out with the Balance 2 knob. Once this has been accomplished for both knobs, the Search switch is placed into the center position and the detector is balanced.
Here are two bits of advice on ground balancing: 1) In extremely mineralized or noisy soil, it will be advantageous to detect in the Balance 1 position. This setting reduces sensitivity towards small targets, but will eliminate a vast majority of the ground noise making it possible to hunt in even the worst conditions. 2) Some hot rocks can be tuned out by ground balancing directly above them, however, this may in turn cause the surrounding soil to become hot. You will find that hunting in this manner is far less effective than simply balancing to the soil and dealing with the hot rocks as they come.
I decided to test the SD 2100e on my favorite stomping grounds - the Bradshaw Mountains of central Arizona. Rising to an elevation of over 7,000 feet, the Bradshaws cover an area of nearly 600 square miles and are one of Arizonas most famous goldfields. Although many of the known nugget patches in the region had been picked over, I still had a secret spot up my sleeve that I was dying to hunt with the SD 2100e.
After an hour of kidney-shaking driving on the rough, washed out dirt road, I was relieved that both my truck and I had finally reached the secret gully in one piece. The 15 foot wide waterway, which cuts its way through the eastern flank of the mountains, had definitely produced its fair share of placer gold. While most of the pieces found had been small, it had provided my father and I with no less than 3 ounces of raw nuggets. Apparently, the narrow gully with its many bends and jagged, crack-filled schist bedrock had created the perfect natural nugget trap. The only drawbacks were the abundant hot rocks and pockets of noisy black sands.
I decided to begin my search in one of the more productive stretches of the gully. This spot had given up many nuggets, but it was shallow and had been detected heavily in the past. After 30 minutes of searching, I came up with only two bits of wire, both of which appeared to have been washed down by the recent cloudbursts. This stretch had obviously been cleaned out.
Still hopeful of coming home with a few nuggets in my pocket, I pushed further down the gully to where the overburden thickened. This stretch had received less attention in the past because of its lack of exposed bedrock and annoying hot rocks. As I rounded a bend I spotted a half-dead Cottonwood tree standing near the edge of the bank. The gnarled roots and thick trunk had allowed for the formation of a rock bar about 6 feet in length. Any gold that had made it around the bend could have been easily slowed by the tree and deposited in the rock bar. On the downstream side of the bar I immediately picked up a sharp signal. Pinpointing the target was not a problem, but getting it out of the hole proved to be more of a challenge. Finally, the 7 deep, elusive target was out of the hole and into my hand. Low and behold my treasure had turned out to be nothing more than a tattered piece of lead.
Although a bit disheartened I wasnt about to give up on the rock bar just yet. As I passed the coil along side the tree's base the constant hum of the threshold was broken, almost as if I had crossed over a hot rock. I got down and cleaned the area of anything that could possibly give off a response and rechecked with the detector. Sure enough, the target was still there. I dug deeper along side the roots until I hit a thin layer of reddish clay atop the bedrock. Another quick pass of the coil confirmed that it was still hidden somewhere within the jointed bedrock. Not wanting to damage a potential nugget, I abandoned my pick and switched over to a flathead screwdriver. As I picked out one of the larger cracks, a glint of yellow caught my eye. My SD 2100e had finally found its first gold! The 4 gram nugget was smooth and rounded; it had obviously received a good beating on its journey down the gully.
I finished working the rock bar without any more luck. The discovery had rejuvenated my spirits and aroused my curiosity about what might be lurking in the deeper gravel even further downstream. Although the presence of gold in this portion of the gully was certain, the large boulders and thick overgrowth made working this area a time consuming affair. More trash had accumulated here, most of which was buried between 6-9 inches. Other potential targets turned out not to be targets at all, but rather dreaded hot rocks buried just beneath the surface. However, I am proud to say that the sore back and bloodied knuckles I received from digging all those deep holes was not in vain. Just as the sun began dipping over the backside of the mountains I uncovered yet another precious gold nugget. Much like the first, it had only been a whisper from the surface. Although not as large, it was chunky for its size, tipping the scales at just over 2 grams.
The field test had been a success. I managed to walk away with about 7 grams of gold in my pocket, but, more importantly the SD 2100e proved to be every bit as good as the original SD 2100. With it I was able to punch down through the black sand and hot rock rich gravel and locate nuggets that other machines might have missed.
The supplied 11 double D coil handled itself nicely in the field and while its configuration definitely gives an edge in bad ground, there is no doubt in my mind that the gully would produce more gold if I were to rework it using a monoloop coil. This would mean putting up with considerably more ground noise, but would offer the chance of finding smaller and deeper gold.
My overall opinion of the unit is positive. Like all of the big Minelabs, the SD 2100e excels at finding larger nuggets at depth, however, target tests conducted in the field demonstrated that this machine is fully capable of sensing gold weighing less than a gram. Its lack of complicated gadgets and simple, 3-step manual ground balance make the SD 2100e by far one of the easiest gold detectors to learn and operate.
With a two-year parts and labor warranty, and suggested retail price of only $1950, the SD 2100e provides exceptional performance and depth at an affordable price. This is a no-nonsense detector made for chasing gold in nasty, mineralized ground and I feel confident recommending this machine to anyone with a passion for nugget hunting.
For additional information on the new SD 2100e, or to find your nearest dealer, contact the factory at Minelab USA Inc., 2700 E. Patrick Lane, Suite 11, Las Vegas, NV 89120, call 888-517-2066 or 702-891-8809, or visit their website at www.minelab.com