Factors effecting detection range of VLF coil

[americanelliott]

I am designing a metal-detector for a senior project in electrical engineering. For the coil, I went with the VLF DD design in the Inside the Metal Detector book. We have an oscillator circuit that delivers 500mA at 10kHz (square wave) to the coil. The detection circuit amplifies the receive signal...

[Cryptoman]

I am wondering about the technologies deployed in magnetometers that are used in surface and underground exploration. Where does one start to learn and experiment with this detection equipment class ? Is it realistic to think that magnetometer prototypes can be easily built in a garage or attic environment...