When searching for any type of treasure, it is important to have an accurate metal detector. If you use the wrong type of detector or are using a detector not built to handle certain soil conditions or saltwater, you will encounter issues and likely miss some treasures.
Some experts speculate that only 15 to 20 percent of the world’s gold has been discovered. There is gold to be found in many locations. This article will discuss how the best and most accurate metal detectors for gold will help your hunts and increase your potential for finding gold.
And below, please take a moment to view some of the top detectors for gold on the market—be it gold rings, nuggets, coins or even gold prospecting in general:
|Garrett AT Max||$$$||Waterproof to 10 feet|
|Fisher F22||$$||9″ Triangulated Concentric Coil|
|Garrett Ace 400||$$$||8.5 x 11" DD coil|
|Minelab Vanquish 540||$||Search Modes: Coin, Relic, Jewelry, Custom, All Metal|
VLF vs PI Metal Detectors
When choosing a metal detector for gold you need to decide which technology will work best for your specific needs: VLF or PI.
VLF, or very low frequency, is also known as induction balance. It is the most popular technology in metal detectors today. VLF metal detectors have 2 distinct coils: a transmitter coil and a receiver coil. The transmitter coil is the outer coil loop and within it is a coil of wire.
Electricity is sent along the wire, in one direction then another, thousands of times per second. The number of times the current direction changes each second establishes the frequency of the machine.
The receiver coil is the inner coil loop containing another coil of wire. This wire is the antenna which picks up and amplifies frequencies coming from buried target objects.
The current that moves through the transmitter coil creates an electromagnetic field and each time the current changes directions the polarity of the field changes. As the magnetic field pulses back and forth into the ground it interacts with conductive objects.
This cause them to generate weak magnetic fields of their own. The polarity of the object’s magnetic field is opposite the transmitter coil’s field: as the coil’s field is pulsing down, the objects field is pulsing upward. The metal detector can then determine about how deep an object is buried based on the strength of the magnetic field. A closer object will have a stronger magnetic field.
A VLF metal detector distinguishes different metals with phase shifting. Phase shifting is the difference in timing between the transmitter coil’s frequency and the frequency of target objects. Objects that easily conduct electricity are slow to react to changes in current, called inductance.
An object that poorly conducts electricity is quick to react to changes in current, called resistance. Higher inductive objects will have a bigger phase shift because it takes longer to change its magnetic field.
A PI, or pulse induction metal detector, uses a single coil as both transmitter and receiver. Powerful, short bursts (pulses) of current are sent through a coil of wire. Each pulse creates a brief magnetic field. When the pulse ends, the magnetic field reverses polarity and collapses suddenly, creating a sharp electrical spike.
This spike lasts microseconds and causes another current to run through the coil. This is called the reflected pulse and is very short. Another pulse is then sent and the process repeats.
If a PI metal detector is over a metal object, the pulse creates an opposing magnetic field in the object. When the pulse’s magnetic field collapses, causes the reflected pulse, the object’s magnetic field makes it take longer for the reflected pulse to disappear.
It works similarly to an echo: in a PI metal detector, the magnetic fields from objects add their “echo” to the reflected pulse making it last a fraction longer than normal. A sampling circuit within the detector monitors the length of the reflected pulses. It then compares it to the expected length and the circuit can determine if another magnetic field has caused the reflected pulse to take longer to decay.
The sampling circuit sends the signal it monitors to the integrator which reads the signals from the circuits, amplifies and converts them to direct current (DC). The DC’s voltage is connected to the audio circuit where it is converted into a sound indicating a target has been found.
Reflected pulse lengths are difficult to distinguish in PI machines, so they do not discriminate, or filter out unwanted metals, as easily as a VLF machine can. They are, however, much better than VLF machines in highly mineralized soils and wet, saltwater environments.
Most PI detectors work better in areas where magnetic hot rocks are found and can find items much deeper than a lot of VLF machines.
What a Gold Detector Is (and Isn’t)
A gold metal detector is just what it sounds like: a metal detector specifically designed to find gold. These machines are calibrated for gold hunting. All metal detectors work by sending electromagnetic fields into the ground, then analyzing the return signal.
The transmitted electromagnetic field includes loops of electrical currents called eddy currents, within conductive metals. Eddy currents have their own electromagnetic field, which the detector receives and then analyzes. Machines specifically for gold take this process further.
Gold metal detectors measure inductance and conductivity. Inductance is the amount of eddy current produced by a target and conductivity refers to how easily those currents flow. Measuring the size of eddy currents and their speed allows gold detectors to calculate a “time constant” of a target. All targets have a time constant and it varies from target to target. Aluminum foil, for example, has a short time constant, while gold, coins, and rings have longer time constant. Steel, iron and other ferrous metals have even longer time constants.
Gold metal detectors can specifically be calibrated to find targets within this middle range. The size, shape, and distance of a target combined with environmental variables means this method is not foolproof, though.
All these factors can influence a metal detector’s time constant calculation. In order to compensate for these factors, gold detectors can be calibrated while in use to search for a narrower or broader range of time constants.
Even with a gold metal detector, finding gold is part skill and part luck. You need a good balance of the two to be successful at finding gold. Gold metal detectors have helped prospectors move from only finding gold in rivers (panning or sluicing) to finding gold on land.
Top Gold Detectors on the Market
The following list shows some of the best gold metal detectors there are, their technology type, and their operating frequency:
- Fisher Gold Bug Pro – VLF Machine – 19.2 kHz
- Fisher Gold Bug 2 – VLF Machine – 71 kHz
- Garrett AT Gold – VLF Machine – 18 kHz
- Garrett ATX – PI Machine – 730 Pulses per Second
- White’s Goldmaster GMT – VLF Machine – 48 kHz
- White’s Goldmaster 24k – VLF Machine – 48 kHz
- Tesoro SuperTRAQ – VLF Machine – 17.8 kHz
- Minelab Gold Monster 1000 – VLF Machine – 45 kHz
- Minelab SDC 2300– PI Machine – 3000 Pulses per Second
- Minelab GPZ 7000 – Hybrid between VLF and PI
- XP Deus – VLF Machine – Multi Frequency – 4, 8, 12, & 18 kHz
Each of these detectors is specifically calibrated to find gold in the most difficult soil conditions. Most areas where gold is found contain highly mineralized soil from old mining activities and high mineral content in soils. This can cause a low frequency detector to go haywire. But these gold-specific metal detectors can handle these soils while remaining accurate. Each company has spent year refining their technologies and ensuring a great user experience.
Metal Detecting Tip for Gold Hunting
One tip to always remember when looking for gold nuggets or flakes is to search where gold has already been found. Smaller bits of gold are often left behind by those panning or sluicing. It pays to know the area and where these old mining activities took place.
Combing the beach is a great way to find lost gold jewelry and coins. It is worth noting that not all metal detectors, even those specifically for gold, work well in wet sandy soils or saltwater areas. Saltwater is highly conductive and can interfere with a metal detector’s ability to locate targets.
The same goes for areas with highly mineralized soils, which is typically where gold is found. Last time I metal detected near a river in southwestern Idaho known to contain gold, my detector kept going haywire from the mineralized soil (I was not using a specific gold metal detector: lesson learned!).
The frequency of metal detectors is one of the most important features. Frequency is the number of waves per unit of time measured in kilohertz, or kHz.
For example, a metal detector with an operating frequency of 10 kHz will send and receive 10,000 times per second. Low frequency waves have longer wavelengths and search deeper.
These are better for finding high conductivity metals like silver but are not good for gold. High frequency waves have shorter wavelengths, are more sensitive to ground mineralization interference, and are better at finding low conductivity metals like gold and iron. The closer to the surface a high frequency wave can detect an object the more accurate the results.
Finding the Right Search Coil
It is important to choose the right search coil for gold prospecting. Larger coils will get more depth, but smaller coils are more sensitive and have better target separation. There are 2 types of standard search coils: concentric and Double-D (wide-scan).
A Double-D coil is characterized by 2 D shaped coil bundles configured in an elliptical shape like 2 opposing letter Ds. These coils are better in heavy ground mineralization and more stable in saltwater areas. Wider scanning of the ground is achieved by Double-D coils than concentric coils.
Most metal detectors operate in the “Goldilocks” frequency zone, between 6 and 8 kHz. This gives a good balance of depth and sensitivity. Many newer model gold metal detectors work on a higher frequency than all-purpose metal detectors.
The higher the operating frequency, the higher the likelihood of finding gold. All major metal detector manufacturers make metal detectors specifically for gold.
5 Awesome Gold Detectors You’ll Love
The Minelab SDC 2300 is a great example of a PI machine made to hunt gold. This detector uses a technology called Multi Period Fast Pulse Induction, or MPF PI. This gives significant performance improvements over more conventional PI detectors.
Most PI detectors require the transmission signal to be completely “shut down” before the receiving signal can be sent and processed. MPF technology produces an almost instant transmission waveform switch off allowing for receiving signal processing immediately afterward. The receive process allows for a higher sensitivity when searching for small gold pieces.
The SDC 2300 also has reduced electromagnetic interference susceptibility and improved performance in saltwater conditions. Reduced ground noise with Minelab’s Enhance/Fine Gold setting minimizes soil signals and false detection from hot rocks.
This helps with gold nugget detection and makes prospecting less confusing and more efficient. This detector has Automatic Ground Tracking and Fast Ground Balance, so it is always optimized for the soil conditions.
Fisher’s Gold Bug 2 has the highest operating frequency of any VLF detector on the market today, at 71 kHz. This means the Gold Bug 2 is highly sensitive to even the smallest big of gold. This model also has fantastic discrimination so it can better filter out iron and hot rocks. Iron and gold tend to ring through very similarly on most metal detectors so it is helpful to have a gold detector that can filter out iron signals.
The Tesoro SuperTRAQ comes with Tesoro’s patented SuperTRAQ Computerized Ground Tracking System. This means users can continuously and automatically compensate for mineral changes within the soil. Although this model runs at a lower frequency than the Minelab SDC 2300 and Fisher Gold Bug 2, it still operates at a higher frequency than most VLF machines. Plus, Tesoro offers a lifetime warranty on all their detectors.
Minelab’s GPZ 7000 uses a new technology called the Zero Voltage Transmission (ZVT), which is a hybrid between VLF and PI. The search coil (14”) uses 2 windings (1 transmission and 2 receivers) called a Super-D coil. This model also has a specific Gold Mode with 3 settings: High Yield, General, and Extra Deep.
High Yield finds medium or small nuggets, General is best for detecting large or medium nuggets, and Extra Deep is best for detecting in highly mineralized soil but is not as sensitive to smaller nuggets. This machine also calibrates itself to the ground every few seconds with tracking ground balance.
These machines all have something in common: they have fantastic ground balancing. The importance of this cannot be understated when searching for gold. As mentioned, most gold rich areas are known to have highly mineralized ground conditions which cause standard detectors to overload and give false readings. Each of the machines listed here compensates for this by offering continuous ground tracking and balancing to adjust for changes.
The Garrett ATX is an all-terrain PI machine that is great at finding gold nuggets. It operates at 730 pulses per second and is rugged enough to take into desert areas, mountain areas, and rivers (it is also waterproof to up 10 feet).
Designs like this do not limit where you can search without damaging your machine. In almost all locations where gold is found, the bedrock is the place to search. Using your metal detector close to and often right on top of bedrock and scratch the search coil and could potentially damage the detector housing if it is dropped. A rugged design takes this worry away.
When you find a nugget, be sure to keep searching in the same area. Gold tends to be found near gold, so always check and recheck an area where you have already found it. If you know of an area where shallow gold has been found, deeper nuggets could still be present.
Always be sure to read and familiarize yourself with your detector’s manual to learn how best to ground balance and discriminate for the best results. Rivers are often great sources of gold nuggets. Be sure your search coil is waterproof (most are) and if the water is deeper, that your entire detector can be submerged. Some machines, like the Garrett ATX, are fully waterproof.
Another thing to remember is that previously searched areas may still yield more gold nuggets. It has been well-documented that detectorists will search an area with one detector, and some time later when they upgrade or switch to a different metal detector, they return to the same area and find more gold where they thought it was searched out.
This is because there isn’t a single detector designed to find every size and type of gold. There is always some gold left behind. But this is not a bad thing! This means areas that have been highly searched may still yield results.
VLF machines are made to find small, but shallow, gold nuggets. The search coil needs to be within a few inches of the nugget to hear an audio signal. You must work slowly, and it is recommended to use headphones to hear the faint signals from small nuggets and flakes.
For best results with a VLF detector, look for areas of exposed bedrock where the ground has been removed or is only a couple of inches deep. VLF machines will typically miss deeply buried or larger gold pieces.
PI machines will search deeply and find both medium and large gold pieces. If the area is only filled with small pieces, a typical PI machine may miss them. Newer models with more advanced technology, like the Minelab SDC 2300 or Garrett ATX, will work better on smaller pieces of gold. Traditional PI machines miss a lot of small gold, and unfortunately, about 95 percent of gold is small.
Besides mineralized soil, many gold prospecting areas are full of trash. If this is a problem in your search area, a VLF detector can weed out some of the iron and trash signals like nails, cans, and wire. Again, some deeper nuggets can read as iron and if you are in doubt about a target, always dig!
Serious prospectors typically own both a VLF machine and a PI machine. This way they have a detector that will work in each situation. If they are searching large or medium nuggets (larger than .3 grams), they use PI. VLF machines are best at finding nuggets .3 grams or less.
If you only want, or can only afford a VLF detector, you can always use the “Scrape and Detect” method. Detect the top layer of ground and remove all targets. Remove a 3 to 4 inches of soil in the previously detected area. Re-detect and remove all new target signals. Repeat these steps until you reach bedrock or go past the gold bearing layers.
Always thoroughly detect the bedrock as this is where most of the gold will be hiding. In fact, in some areas, approximately 99 percent of all gold is on the bedrock. Removing the overburden, or soil, will expose the bedrock and increase your chances of finding gold.
Always be sure to observe laws regarding significant surface disturbance. You won’t want to use this method if the bedrock is many feet below the topsoil.
There are many important factors to consider when prospecting for gold. Always research your search area and determine what type of soil is present. This will help you determine what type of metal detector you need. Keep in mind most PI detectors are more expensive than VLF detectors.
Both will work very well in finding gold nuggets or flakes. Always search in areas where gold has been known to exist. You can have all the fanciest equipment in the world, but you must search in the proper area to yield results. It is important to use a gold-specific metal detector to maximize your results.
These machines are specifically built to compensate for highly mineralized soils, saltwater conditions, hot rocks, and gold detection. It can be frustrating to search for days and not find a single nugget, but if you stay focused and determined, have the right equipment, and a good area, you will most certainly find gold!
- If you enjoyed this article, please “like” our Facebook page!