Metal Detector Circuit

Here’s an explanation of the 5 basic types of metal detectors for those that aren’t too tech-savvy.

Need a metal detector, but don’t know anything about a metal detector circuit? Don’t worry. Here’s an explanation of the 5 basic types of metal detectors for those that aren’t too tech-savvy.

Transmit & Receive (T & R)

This type of detector works by telling between items containing iron and those that do not. Unfortunately, this detector does not work correctly where the soil has natural deposits of minerals.

This type has since then been phased out. But, these antique models are still around for those metal detecting enthusiasts who enjoy collectables.

Beat Frequency

These detectors use sound waves given off of an object to detect metals.

Though this type of metal detector is better than T & R models, beat frequency detectors can’t tell the difference between the different kinds of metals found buried in the ground. This can lead to a lot of false-positive signals.

You’re more likely to find this type of detector relatively inexpensive. A new metal detector with beat frequency capability could run you $100 or less.

Very Low Frequency (VLF)

VLF metal detectors are able to distinguish between different metals, including gold and silver. This kind of metal detector is popular among those looking for gold treasures.

To detect iron and silver, you’ll need a mid-range VLF detector that tracks the frequency of up to 4 kilohertz. A kilohertz is a measuring unit for sound waves.

Gold nuggets can be detected using a VLF metal detector of at least 18 kilohertz. The best models at detecting gold stockpiles transmit frequencies up to 71 kilohertz.


With this type of hybrid detector, the system that was used with the old Transmit & Receive metal detectors is combined with the VLF technology.

This means that these detectors are capable of detecting in highly mineralized soils without getting too many false-positive signals. Detecting trash and junk is greatly reduced with this type of detector, too.

Pulse Induction (PI)

These detectors do a good job of metal detecting on beaches, especially underwater. As long as it has a waterproof casing. PI detectors are not bothered by highly-mineralized areas like you find in black sand, saltwater, coral, etc.

This detector works by firing a high-voltage signal pulse into the area that is being searched.

Metal detectors don’t have to be complicated. You don’t need to know anything about how the metal detector circuit works. All you need to know is what you’re trying to search for and which one will work best for your type of buried treasure hunting.

COTD Metal detectors