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High or low, which is the correct frequency ?

This morning I answered a question; ‘which metal detector would you recommend for a beginner’?

I knew that the yellow Garrett brigade would be chomping at the bit to answer and possibly misinform this newcomer to our hobby.

Firstly let me make this clear, this isn’t a dig (pardon the pun) at the Garrett Ace range, we all know they outsold almost all other brands and became incredibly successful. But, that was 15 years ago and things have moved on since. Yes, they can still find plenty of good finds, yes, they are simple to use and yes, lots of people like them.

But there are other alternatives!

My opinion for not buying a Garrett Ace 150, 250, 300I or so on is this, it’s cost verses performance. To understand that, firstly you need to understand frequencies.

If you have been detecting for a while you will no doubt understand the use of frequencies and how they affect your machine. For those who don’t, here is a basic explanation that may help you make the right choice when buying your first machine.

Frequency is just simply the number of waves per unit of time, for example a detector that was set to 10 kHz would send and receive 10 000 times per second. Most detectors use a frequency range of 3 – 100 kHz.

Low frequency has longer waves and is able to penetrate the ground at greater depth. They are better at picking up high conductivity targets like silver, but they are not as good at finding smaller targets or low conductivity targets such as gold. Low frequency machines also struggle to cope with busy iron infested areas or highly mineralised ground.

High frequency has shorter wave lengths, and therefore can transmit and receive more times per second. It is much more capable of finding smaller targets and is more sensitive to low conductivity materials like gold and iron. You might be thinking “but I don’t want to find iron anyway” but if your machine isn’t able to pick up on an iron target correctly it will possibly confuse the signal and give you a nonferrous tone, that will result in you digging unwanted iron targets.

High frequency also offers you higher accuracy for targets that are closer to the surface, for example in a newly ploughed or cultivated field. They also perform better in highly mineralised ground.

So, what we need is a machine that sits somewhere in between the low and high frequency range to give us the best chance. Or ideally, we need a machine that will let us select the frequency to match the terrain or the target type. Or, what about something that uses different frequencies simultaneously (Multi IQ)!

Multi IQ means it is simultaneously transmitting and receiving across its frequency range therefore offering you the best chance to pick up all targets.

Below are some examples of different frequencies of various popular machines


Make	Model	         Frequency kHz
Garrett	150,250	         6.5 fixed
Garrett	350	         8.25 fixed
Garrett	AT PRO	         15 fixed
Nokta	Simplex	         12 fixed
Minelab	Vanquish	 5-40 Multi IQ
Minelab	Equinox 600   	 5-40 Multi IQ 5,10 &15 selectable
Minelab	Equinox 800	 5-40 Multi IQ 5,10,15,20 & 40 selectable
Minelab	CTX	         1.5-100 selectable                           XP	Deus	         3.7-27.7 selectable



The Minelab Vanquish 340 and the Nokta Simplex are both priced similarly to the Garrett 250 & 350, so having read about low and high frequency you can hopefully now see why I would advise against a low fixed frequency machine like the Garrett Ace range when there are more capable machines available at a similar price.

In summary, is the Garrett Ace range any good? Well yes!

But they operate a low frequency, they are not well suited to mineralised ground, wet sand or busy iron infested areas and they may possibly be missing some of those small targets or low conductivity materials like gold.

Hopefully, this will help you with deciding what to buy.


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