In Alaska, a metal detector will make any gold prospecting trip more productive. They are simple to operate, easy to carry, and can be used in many other adventures, not just your gold prospecting trip to Alaska. They are widely available and can be purchased in Alaska when you arrive. Just remember that many areas produce fine gold and small flakes, but these areas will not usually prove productive with a metal detector. Just the areas with larger gold nuggets will be of interest, and so many locations that are fine for panning and other types of mining will not be worth your time if you plan on going for the big nugget. The most important thing to remember is to have fun while you are using your metal detector in Alaska
How Metal Detectors Work
Metal detectors use electromagnetic induction to detect metal. Uses include demining (the detection of landmines), the detection of weapons such as knives and guns, especially at airports, geophysical prospecting, archeology and ‘treasure hunting’. Metal detectors are also used to detect foreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors. In it’s simplest form, a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of metal, which is electrically conductive, is close to the coil eddy currents will be induced in the metal, and this produces an alternating magnetic field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer) the change in the magnetic field due to the metallic object can be detected. Metal detectors have been around for much longer than most people realize. Towards the end of the 19th century, many scientists and engineers used their growing knowledge of electrical theory in an attempt to devise a machine which would pinpoint metal. The use of such a device to find ore-bearing rocks would give a huge advantage to any miner who employed it. The German physicist Heinrich Wilhelm Dove invented the induction balance system, which was incorporated into metal detectors a hundred years later. Early machines were crude and used a lot of battery power, and only worked to a very limited degree. The Scottish physicist, Alexander Graham Bell, used such a device to attempt to locate a bullet lodged in the back of American President James Garfield in 1881. The modern development of the metal detector began in the 1930’s. Gerhard Fischer had developed a system of radio direction-finding, which was to be used for accurate navigation. The system worked extremely well, but Dr Fischer noticed that there were anomalies in areas where the terrain contained ore-bearing rocks. He reasoned that if a radio beam could be distorted by metal, then it should be possible to design a machine which would detect metal, using a search coil resonating at a radio frequency. In 1937, he applied for and was granted, the first patent for a metal detector. His designs were soon put to the test in a practical way, as they were used as mine detectors during the Second World War. They were heavy, ran on vacuum tubes, and needed separate battery packs – but they worked. After the war, there were plenty of surplus mine detectors on the market; they were bought up by relic hunters who used them for fun and for profit. The hobby of metal detecting had been born. Many manufacturers of these new devices brought their own ideas to the market. Whites Electronics of California began in the 50’s by building a machine called the Oremaster Geiger Counter, and are still at the leading edge of detector innovation today. Another leader in detector technology was Charles Garrett, who pioneered the BFO (Beat Frequency Oscillator) machine, and whose company is still one of the world leaders in design. With the invention and development of the transistor in the 50’s and 60’s, metal detector manufacturers and designers made smaller lighter machines with improved circuitry, running on small battery packs. The metal detector was reduced to a size that even a child could use – and use them they did. Fabulous finds were made; prehistoric gold ornaments, chests of Roman coins, jeweled daggers, arrowheads- all types of metal artifacts were coming out of the ground. Suddenly, there was a huge requirement for those early electronic magic wands which might make a man rich overnight. Companies sprang up all over the USA and Britain who wished to supply the growing demand. Larger portable metal detectors are used by archaeologists and treasure hunters to locate metallic items, such as jewelry, coins, bullets, and other various artifacts buried shallowly underground. Technological changes were taking place at a rapid rate too, and very few of the smaller companies managed to stay in competition with the big outfits. GOLDAK, METROTECH, IGWT, TEC, and, quite recently, ARADO ceased production of hobby machines. Some devotees of metal detecting still treasure their Arado machines, which had a reputation for being difficult to set up, but were reputed to be the deepest-seeking hobby detectors ever made. The biggest technical change in detectors was the development of the induction-balance system, where two coils are set up in an electrical equilibrium to produce a ‘null’ or zero balance. Introducing metal to the vicinity of the coils caused them to unbalance, producing a change of tone in the machine’s speaker. Scientists had long known that every metal has a specific response to stimulation by alternating current. Each metal produces a time lag or ‘phase angle’ in its induced current, in relation to the drive current. This meant that detectors could now be set up to ignore unwanted phase angles, and respond positively only to desired metals. But there was also a downside to the development of the ‘discriminator’ detectors. Introducing discrimination always had the effect of reducing the sensitivity of the machine, so it was less able to find deep objects. In addition, there was the fact that some desirable metals were quite near the area of unwanted metals, such as iron. Gold, particularly in alloy form, was quite close to tinfoil in the overall spectrum, so the discrimination control had to be used carefully. The price to be paid for setting up a detector to ignore iron and tinfoil was the certainty that, sooner or later, the user would scan over, and ignore, a valuable find – perhaps a diamond engagement ring on a beach. Coil designers also tried out innovative designs. The original Induction Balance coil system consisted of two identical coils placed on top of one another. Compass Electronics produced a new design; the two coils were made in a D shape, and were mounted back-to-back to form a circle. This system was widely used in the 70’s, and both concentric and D type (or Widescan as they became known) had their fans. Another development was the invention of detectors which could cancel out the effect of mineralization in the ground. This gave greater depth, but was a non-discriminate mode. It worked best at lower frequencies than those used before, and frequencies of 3 to 20 KHZ were found to produce the best results. Many detectors in the 70’s had a switch which enabled the user to switch between the discriminate mode and the non-discriminate mode. Later developments switched electronically between both modes. The development of the Induction Balance detector would ultimately result in the Motion detector, which constantly checked and balanced the background mineralization. At the same time, developers were looking at using a completely different type of technology in metal detectors. This was the process known as Pulse Induction. Unlike the Beat Frequency Oscillator or the Induction Balance machines which both used a uniform alternating current at a low radio frequency, the pulse induction machine simply fired a high-voltage pulse of signal into the ground. In the absence of metal, the ‘spike’ decayed at a uniform rate, and the time it took to fall to zero volts could be accurately measured. However, if metal was present when the machine fired, a small current would flow in the metal, and the time for the voltage to drop to zero would be increased. These time differences were minute, but the improvement in electronics made it possible to measure them accurately and identify the presence of metal at a reasonable distance. These new machines had one major advantage: they were completely impervious to the effects of mineralization, and rings and other jewelry could now be located even under highly-mineralized ‘black sand’. They had one major disadvantage too: there was no way to incorporate discrimination into a Pulse induction detector. At least, that was the perceived wisdom of scientists and engineers until Eric Foster, who had run Location Technology in Ireland for many years, started a new company in Britain and produced the Goldscan, the first Pulse Induction detector which had the apparent ability to differentiate between metals. This was a new type of ‘junk eliminator’ circuit, which relied on the size of the target as well as its metallic response to give a control that would show positive for a gold ring and negative for a copper coin. Its ability to differentiate between non-ferrous metals was not an exact science, but gave unparalleled depth on mineralized soil or sand. Pulse Induction detectors are now widely used in the construction industry; the Whites PI-150 is an industrial machine which can detect large objects to 10 feet, using a 12 or 15 inch coil. Metal detectors have come a long way, from the simple one-coil BFO, to today’s sophisticated machines. Modern top models are fully computerized, using microchip technology to allow the user to set sensitivity, discrimination, track speed, threshold volume, notch filters, etc, and hold these parameters in memory for future use. Compared to just a decade ago, detectors are lighter, deeper-seeking, use less battery power, and discriminate better. We can expect to see more improvements as designers continue to apply the latest Electronics and Computer technologies to the task of making ever better metal detectors. While these advances push technology to its full potential, new genres of metal detector have made their appearance. BB (Beat Balance) and CCO (Coil Coupled Operation) were unveiled by the electronics press in 2004. Both were invented by electronics writer and designer Thomas Scarborough, and combine unprecedented simplicity with good sensitivity.
Many people use consumer metal detectors to look for coins on the beach. Most metal detectors are only good to detect metal within a foot or so below the ground. The detection depth depends on the type of metal detector, type of metal in the buried object, size of the buried object, type of metals in the ground, and other objects in the ground.
There are four major types of hobbyist activities involving metal detectors:
* Coin shooting – looking for coins after an event involving many people, like a baseball game, or simply looking for any old coins
* Prospecting – looking for valuable metal like gold and silver
* Relic hunting – looking for items that are historically significant, like weapons used during a war
* Treasure hunting – looking for items that are rumored to be hidden
Before any user of a metal detector can confidently operate their machine, they need to know several vital steps that apply to most metal detector uses. The first step is “tuning” in your detector to the ground. This means that the detector is adjusted so that it recognizes the ground as a medium for targets to be in. Most new digital units have a “self-tuning” feature installed. For the ones that don’t, you must manually tune them in. After this is achieved, you’re ready to begin searching for your target, whether it’s a coin, gas line, or what have you. Placement of the loop above the ground is critical for desired performance. Hold the detector at arm’s length with the loop barely touching the ground. For most purposes, a “motion” mode is used. This means the loop must be moving at all times for it to function correctly. With the detector now ready to go begin to sweep it back and forth along the ground. Each sweep should take close to a second from one side to the other. Additionally, each sweep should overlap the last forming a tight sweep pattern. This way you will be less likely to pass over the target. While you are searching with your detector, a slow even pace should be established.
Anyone who pans for gold hopes to be rewarded by the glitter of colors in the fine material collected in the bottom of the pan. Although the exercise and outdoor activity experienced in prospecting are rewarding, there are few thrills comparable to finding gold. Even an assay report showing an appreciable content of gold in a sample obtained from a lode deposit is exciting. Regardless of whether you are a new prospector or a pro, the gold pan is still the most indispensable companion you can have. It is one of the first tools used in locating gold and is one of the last used, even in commercial mining to check the value of ore being processed. The Gold Pan is used wherever gold occurs in approximately 75% of all the countries in the world. Until the last twenty years the most popular pan to evolve was the steel pan. These pans came with and without ridges and typically rusted easily. Probably the most efficient pan for the novice and expert today is one molded from tough, space age plastic. It is far superior to the steel pan for several reasons. Firstly, it is rust and corrosive proof. Secondly, it can be textured with a fine “tooth” surface to hold the gold better. Third, it is about one quarter the weight of a steel pan, and fourth the green color can be made a permanent black so that even the tiniest flakes of gold can easily be seen. The common sizes of pans today are the 8 to 12 inch pan, used primarily for sampling, or clean up. The 14 inch pan is the most popular, multi size use. The 16 to 18 inch pan is used by the more experienced panners. The larger pan load requires greater stamina and technique. An accomplished experienced gold panner can process about one cubic yard of material in an 8 hour day. But with the development of the hand sluice, the dredge, and the rocker, even the novice today can process about a cubic yard per hour.
How to Pan for Gold
1): Fill the gold pan about half full of gravel, then submerge it deep enough in water (stream or tub) so it is just under the surface of the water. Next give the pan several vigorous shakes back and forth and from side to side, but not too hard as to wash material out of the pan, you want to shake the gravel so the heavy gold sinks to the bottom of the pan and the less dense rocks and minerals float to the top of the pile in your pan.
2): Change from the shaking motion to a gentle circular movement, so the remaining material starts turning in a circle. This process will cause most of the dirt and clay to dissolve and wash out of the pan. If roots and moss surface, work them over your pan with your fingers to dissolve any lumps. Pick out the larger rocks, pebbles, and debris after making sure that they are washed clean of any mud or sand. You want to try and recover as much gold as possible but you will lose some in the process so don’t be to gentle in the operation. Do this until you have the larger rocks and pebbles washed out of the pan.
3): Now wash away the lighter sand and gravel. Hold the pan just under the water and tilt it slightly away from you. Begin to swirl the water from side to side, with a slight forward tossing motion. Take care, but with sufficient force to move the surface and the lighter gravel out over the edge of the pan. Leveling the pan out from time to time and shaking it back and forth will cause the light material to come to the surface and the gold to settle to the bottom. Keep working the pan until you are down to black sand and color(gold).
4): Now you will want to start carefully working the black sand. Now is the time to slow down and be careful. Leaving just a little water in the gold pan, lift the pan out of the water and use your tweezers to pick out any nuggets and large flakes and place these in your poke. You can use a magnet to separate the magnetite (black sand) from the gold. Continue panning the con down until it is about a third gold. As you pan you will notice that the gold will form in a tail behind the black sand. At this time you can clean up the gold with your tweezers and eye dropper. Keep panning until you are out of gold or out of black sand in the bottom of the pan.
Learning How to Pan for Gold
The easiest way to learn how to pan for gold, is to watch someone else do it first. You can’t appreciate how vigorously you have to shake the pan at the beginning until you see a master gold panner in operation. Many of the commercial gold panning tours in Alaska will teach you how to pan for gold, and will get you into the color in about an hour. If you want to learn prior to coming up to Alaska, you should consider joining a local gold prospecting club. You will get the chance to practice and also see what other people are using. If you don’t ave the time or desire to join a club the next best thing is to buy a video or book. I normally buy this type of specialized material from Amazon gold panning.
Gold Panning Kits
Many prospecting stores sell a gold panning kit. These kits normally consist of a gold pan, book and/or video, and a bag of sand with gold ore. The store will place a number of gold flakes and small nuggets in the bag of sand/gravel so that you will know the amount of gold you should be recovering. With these gold panning kits it is recommended that you pan the pay-dirt over a small tub or child’s play pool so you can recover the sand and gold you missed while you learn. It isn’t a bad way to go but not nearly as exciting as learning on a stream in the great outdoors.
Note, some of this information is out of date. Please check with GPAA for latest status of these claims.
These are just a few of the mining claims owned by clubs in Alaska. Access is normally restricted to members only, but you can always join if it is something you want to do during your prospecting trip to Alaska. These claims can be worked with gold pans, sluice boxes, dredges, and placer wash plants. The larger scale operations will require people to work together with the group dividing the gold up at the end of the trip. When you prospect on your own on these Alaska gold claims, you will get to keep whatever you find.
Cripple Creek – Near Nome, Alaska. Members are allowed access the the gold bearing gravels of Cripple Creek and can take part the larger scale operation where they can share in the proceeds for their time at the camp. The club provides food, shelter, transportation, mining equipment, and the expertise to bring home gold. Mining the beach and inland gravel benches is very popular with many of the guys and gals on Alaska Expeditions. Over the years we have developed highly specialized sluice boxes, recovery equipment and classes for training those with little or no experience to recover gold from the beach sands right in front of our Cripple River Camp as well as from bench gravels up the stream. Normally visitors will also have the chance to prospect and mine the famous Gold beaches of Nome.
Deadwood Creek – Near the town of Central, Alaska (north of Fairbanks) GPAA has 13,000 feet of access claimed along the creek and there and surely enough room with good gold for several people. Several small cabins are available for use by members when working the area. The roads are passable even with motor home or trailer, but major supplies are 170 miles away.
Mills Creek – On the Kenai Peninsula – abut 1.5 hours south of Anchorage. The local heavy snowfall and high-elevation typically keep prospectors out until the first part of June. Mining operations can normally continue until snow and freezing temperatures shut everything down in mid-October. The GPAA mining claims are at the mouth of Mills Creek where it joins Canyon Creek. No facilities exist at the Mills Creek claim block. Camping is available in the immediate area and supplies and lodging can be secured in Cooper Landing or Girdwood.