Before buying a Metal Detector most detectorists only think about the cost or the Brand! But few of them really pay attention to the frequency that the machine operates on. In fact, it is one of the most important factors you need to actually pay attention to …
… So what is the Best Frequency for Metal Detectors? A frequency range could be anywhere between 1.5kHz and 100kHz! Yet, the frequency also depends on the conductivity of the target (the higher, the lower should the frequency be), the size of the target (the smaller, the higher should the frequency be) and the depth of the target (the deeper, the lower should the frequency be).
If you don’t know it yet, frequency refers to the number of electronic waves that your machine sends into the ground for detecting metals! For example, a frequency of 10 kHz means that your detector will be able to send and receive waves 10 000 times per second.
In this Post I am about to reveal in-depth helpful information about this Topic! Indeed, you will find out the proper frequencies you will need for valuable targets like Gold, Silver and other Metals …
… Finally, before we dive in, several people are asking on what Metal Detector will give you the most flexibility regarding frequency usage! The one I recommend is a Minelab Model (Check it Right Here on Amazon)
What frequency you will need for Gold?
If you are looking for gold nuggets (which you should be doing at some point anyway!), then you need a detector with a high frequency!
(I am talking here about Gold nuggets which in most cases are very small – However, if you are looking for Gold jewelry that are generally alloyed with other metals, you won’t need a high frequency machine, just a mid-range one would do the job just fine)
In fact, High-frequency machines have shorter wavelengths and therefore are Decent for detecting small objects such as tiny gold nuggets. Moreover, this kind of detectors are, therefore, better for low conductivity targets such as gold and iron.
High-frequency devices are also very accurate when you are holding the coil closer to the surface. It is also more sensitive to ground mineralization interference.
Typically, they use frequencies higher than 14 kHz, helping detect even small gold objects such as rings, coins, and earrings.
Some of the best machines for finding gold include:
- Fisher Gold Bug Pro (You can Learn More About it Here on Amazon!) with an operating freq. of 19 kHz
- Minelab GOLD MONSTER 1000 with an operating freq. of 45 kHz
- White’s Goldmaster GMT with an operating freq. of 48 kHz
- Tesoro Lobo SuperTRAQ with an operating freq. of 17.5 kHz
- Garrett AT Gold (Which is my favorite Gold Detector, you can Check it Here on Amazon!) with an operating freq. of 18 kHz
As you’ve might noticed, the frequency for all these machines exceeds 14 kHz!
Best metal detector frequency for Silver?
If you are trying to hunt for silver, then a low-frequency machine would be a proper pick!
In fact, low-frequency detectors have a longer wavelength and allow you to get a greater depth because the longer waves penetrate the ground far more easily…
… They are also better for detecting high conductivity targets, such as silver! However, these are not good for finding smaller targets and neither are they good for finding low conductivity targets such as iron.
Some of the best low-frequency detectors for finding silver are:
- XP DEUS which can search at four different frequencies
- Garrett Ace 150 operating at a frequency of 6.5 kHz
- Minelab Xterra 305 operating at a frequency of 7 kHz and 18.5 kHz
- Garrett Sea Hunter operating at a frequency of 7.5 kHz
- Minelab Xcalibur 2 operating at a frequency of 1.5 to 25.5 kHz
Best frequency for other metals?
Obviously, detecting machines are not only used for Gold or Silver, they could be used for all sort of metallic items like aluminum, copper, brass …
To do so, you will still need to figure out the proper frequency depending on what you are actually looking for. And this depends mostly on the metal conductivity …
… This conductivity can actually be plotted on a scale, in which ferrous iron falls on the lower side while non-ferrous silver falls on the higher side. Gold and foil fall somewhere in the middle.
For high conductive metals such as silver copper and brass will generally need low freq. around 3kHz (a bit higher or a bit lower). However, for targets with low conductivity like Zinc, Cobalt, Platinum, Tin or even Stainless Steel you will certainly need significant frequencies around 9-10 kHz!
Many machines, such as the Garrett Ace, can predict the type of metallic item that has been found by how well it conducts electricity of the frequency pulses that are sent to the ground …
… This what makes it possible for modern-day machines to discriminate easily between metals and also screen out certain metals such as iron and junk objects if you want to prevent your detector from picking these up!
A frequency that falls in the middle should be ideal for detecting nickel, aluminum and lead!
Some of the good devices that allow you to detect at these frequencies include:
- White’s Spectra V3i HP
- Garrett AT Pro (This one is extremely Popular, you can Check it Here on Amazon!)
- Fisher Labs F75
- Garrett ACE 300
- Teknetics Delta 4000
The Proper frequencies for beach metal detecting
There are many types of machines for those who are looking for stuff in the beach!
The two most commonly used and most successful ones are very low frequency (VLF) technology or the pulse induction (PI) technology!
The VLFs comprise of two separate coils of wire. The outer coil in the detector produces a VLF, which is below 30 kHz, which is directed towards the ground. When this impulse comes in contact with a metal item under the ground, then it gets reflected back at a different frequency.
PI technology, on the other hand, has both the receiver and the transmitter placed on the same coil. Thus, they can also be located in separate loops inside the coil. It then sends out short pulses which creates magnetic fields and then reflect back once the pulse ends.
One of the best beach detectors in this case (in my humble opinion) is the Garrett AT Pro! It operates on different frequencies that go as high as 15 kHz for smaller and/or low conductive targets.
The reason I recommend this one is the LCD screen it comes with! This LCD screen with a button interface makes this VLF machine ideal for dry sand on beaches, occasional wet sand detecting, and it can also do little water detecting as it is waterproof up to 10 feet!
Furthermore, this detector also has an auto/manual ground balance along with a wide range of other setting that makes it ideal for both novice and professional detectorists.
By the way, this minelab detector does a fine job on the beach! You can check it out!
The Proper frequencies for highly mineralized soil!
Mineralized soil is known to be the worst enemy for us as enthusiastic hobbyists!
This is because mineralization in the soil causes much frustration and confusion in the incoming signals!
Ground mineralization refers to the amount of magnetism present in the soil because of particles in the soil that have metallic characteristics, thus producing a magnetic response which gets picked up by your metal detector.
That’s why; you will need a machine that operates at different frequencies at the same time and that has good discrimination capabilities! Indeed, you need to set at least 3 frequencies, one which is pretty low, another one which is pretty high and another one which is somewhere in between … Then, if you start to receive some annoying broken signals in a continuous way that correspond to a frequency you are setting, just drop that frequency and carry on! By doing so, the false signals will significantly decrease!
Grounds across the world vary in mineralization and there are many metal detectors that are specifically designed to overcome this problem. Some of the main features a detector needs to have to combat ground mineralization are ground balance and pulse induction technology. However, even VLF devices work well in mineralized soil.
Some of the devices that work well in mineralized soil include:
- Blisstool V5
- Minelab FBS machines
- Garrett GTA 350
- Whites XLT Spectrum
- Minelab Equinox 800 (When it comes to technology, this one is one of the Best! You can check it Here on Amazon!)
- Fisher 1232-X
For more info about these kinds of machines, you can have a look at these adapted devices of mineralized ground!
How Ground conditions influence your machine’s frequency?
Indeed, it can have a significant influence on your detector’s frequency!
This is because a detector is (at the end of the day) a very sensitive equipment and maintaining an optimum level of detection depends on many factors!
It may surprise you to know that even plant vibrations and temperature fluctuations can affect your detector’s frequency and overall sensitivity.
These effects are actually more pronounced when you are operating at a higher frequency, which can typically result in reduced performance and increased chances of false triggering!
Even high moisture and salt content in the soil will throw off the frequency. In fact, this creates false metal signals, making it difficult for you to distinguish between actual metal and any other soil product.
For more information about this topic, you definitely should check this article on how the ground conditions affect your detection capabilities! You will learn there some helpful info …
Does the frequency also depend on the coil?
The frequency of your detector also depends a lot on the coil you are using. A coil is similar to say purchasing the tires for your car!
Or you can even compare it to what shoes you wear depending on the weather outside. In fact, coils are made for different search conditions and using different coils for different conditions will increase the efficiency of your machine.
When you work with a multi-purpose multi-frequency device, it is important that you not only choose a proper sized coil and type, for example, DoubleD or Concentric (mono) but choose its operation frequency as well!
You should ideally use low-frequency coils (anywhere between 3 to 7.5 kHz) to look for large targets. The lower the frequency of the coil, the deeper your detector can look into the ground!
At the same time, do not use large sized coils (12 x 13″ with 18.75 kHz frequency) to look for large targets. High frequency will not penetrate too deep and as a result, coils of large diameter will not help you find what you are looking for.
A high-frequency coil (18.5 kHz) is best if you are hunting on the beach or looking for small coins for example!
Highest frequencies that metal detectors could support …
Detector frequencies typically fall in the range of 3 to 100 kHz! This means that the highest frequency it generally could support is 100 kHz.
Usually, though, people prefer to use mid-range frequencies to increase their chances of finding more targets.
Simultaneous multi frequency detectors – What you should know
I’ve already talked about that earlier in this Guide, but here I want to address that a bit more in-depth!
Actually, most devices operate on a single frequency! Low frequencies usually have single digit frequencies that are under 10 kHz and are good at finding highly conductive targets such as large metal items and coins.
Higher frequency detectors are over 30 kHz and are extremely sensitive to smaller items and low conductive metals. However, they struggle with ground penetration.
Then there are also selectable frequency detectors known as simultaneous multi-frequency machines!
They allow you to select from one of the several possible ones. They are able to analyze the signal from two or even more freq. at one time! The process could be done either simultaneously or sequentially and at a very high speed.
However, the end result is usually the same and the results from two or more frequencies have to be compared in order to get information that typically cannot be had by analyzing only one single frequency by itself.
There are many Minelab detectors that work on simultaneous multi-frequencies. The Minelab CTX 3030 (Check its current Price Here on Amazon!) is the most advanced one of them …
… Also, you can check this List of Simultaneous frequency detectors! There are some fine choices in there …
High or low frequency Machine! What’s best for beginners?
If you are a beginner to this great hobby then you should opt for buying a metal detector that works between 5 kHz and 10 kHz!
This is just the right frequency for beginners to start with. As you slowly get the hang of detecting, you can graduate to a high-end and specialized device …
… Then you can also increase its frequency eventually!
The most commonly used technology in beginner’s devices is VLF as it will easily allow you to distinguish between different metal types and it works best on any type of ground that has high mineral content as well.
Some of the best ones for beginners include:
- Garrett Ace 300
- Fisher Labs F22
- Tesoro Compadre
- White’s Coinmaster
- White’s Coinmaster Pro
- Bounty Hunter TK4 Tracker IV (This one is probably the Cheapest in this List, You can Have a Look at its Current Price Here on Amazon!)
- Garrett AT Pro
Was this Post longue, hopefully not! Yet, I really wanted that you understand deeply this topic …
… I feel annoyed quite a bit when hobbyists (especially beginners) only talk about the best brand and don’t pay enough attention to other important factors related to detectors including its frequency the coil size/type as well as other important details!
Hopefully, you’ve got the most out of this guide and that you are more aware of the proper freq. that you should opt for next!