Basic knowledge of VLF

[jeep6789]

Hello everyone! Out of love for metal detectors, I want to make a VLF detector. I have some questions, please help me to solve them. 1. What waveform is used in the transmitting coil, square wave or sine wave? 2. What is the best sensitivity of the receiving coil, double D or concentric circles? 3. After the receiving coil is amplified by the primary, what processing needs to be done. 4. Is it necessary to use an electronic switch like pi? 5. How to eliminate the interference of soil mineralization? I ask you all for guidance, thank you very much!

[waltr]

Most of this is answered in the book "Inside the Metal Detector" by our Forum sponsor's Carl & George.
https://www.geotech1.com/forums/show...Published-2015

The remaining answers are within this forum. A good VLF project to start with is the TGSL since many of us have built it and it works quite well.

[surfdetector]

https://www.amazon.com/Inside-Metal-.../dp/0985834218

[rajesh]

Hello everyone! Out of love for metal detectors, I want to make a VLF detector. I have some questions, please help me to solve them. 1. What waveform is used in the transmitting coil, square wave or sine wave? 2. What is the best sensitivity of the receiving coil, double D or concentric circles? 3. After the receiving coil is amplified by the primary, what processing needs to be done. 4. Is it necessary to use an electronic switch like pi? 5. How to eliminate the interference of soil mineralization? I ask you all for guidance, thank you very much!

you can start tesoro golden sabre light designed by iv. it help & guide line every thing - 1- sine wave' 2- double D 3- that work very good in ferrous metal