Why is metal detector frequency important? Are there certain frequencies that are better for certain types of metal and searching than others? All of these questions are valid and important. Frequency in metal detectors is a very important thing. And knowing how to use them to your advantage will greatly increase your odds of finding the types of metals you are searching for.
What is frequency in metal detectors?
Frequency is the number of times a signal completes a full cycle per second and is measured in kiloHertz (kHz).
So one hertz (hz) is just that. But 1 kiloHertz is 1Hz multiplied by 1000, using that logic we can conclude that a metal detector running 15kHz is completing 15,000 cycles per second. and so on..
In the graphic below we provide a visual of how the the cycles are represented and what a full cycle looks like.
How Frequency affects your hunt.
Say you are wanting to search for deep targets, a lower frequency is going to do a better job then a higher frequency. Why is that? Since by nature the the wavelength per full cycle will be longer in a lower frequency it allows more time for the wave to penetrate the ground, thus giving it more depth. Lower frequencies are best for Highly conductive metals such as silver as well. Lower frequencies are not good at finding small or tiny metals with a low conductivity level.
If you are seaching for tiny gold nuggest or small types of lower conductive metals you will want to be searching in a higher frequency. While you WILL lose depth, you will also gain the abiltiy to find those tiny low conductive targets. So to sum it up..
The LOWER the frequency, the MORE DEPTH. But misses small lower conductive targets.
The HIGHER the frequency, the LESS DEPTH. But the more sensitive to small lower conductive targets such as tiny gold nuggets.
There is no best frequency for all hunting. Most manufactures of VLF machines stay within the 10-16kHZ frequency, as it seems to be a good middle ground. But having a metal detector that is capable of Simultaneous Multi Frequency may be a better choice for detectorists wanting the best of both worlds. The Minelab Equinox series such as the Equinox 600 or 800 are simultaneous multi freq. units. or the Nokta Makro Multi-Kruzer and Multi-Anfibio are great selectable frequency machines. All of which give you options on what frequency you want to use while detecting!