Zero beating Metal Detector


Posted on Nov 4, 2012

Both oscillators are built using MPF102 or J310 FETs. The Mixer is BF998 dual gate MOSFET. Audio IC amplifier is LM386 which drives a speaker. I have used a stabilized supply for two oscillators and mixer. U1, a 78L05 is doing this job nicely.



Zero beating Metal Detector - image 1
Click here to download the full size of the above Image.

Circuit is being designed on a Single Sided Glass Epoxy Printed Circuit Board. It will be using PCB mounted volume control and a variable capacitor to tune the oscillator. (or varicaps & a pot) However, final design may change. You will have to wind the Loop Coil yourself.




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