
This was my favo[u]rite of all the MAKE projects I’ve been working on.
This project uses 2 oscillators in a configuration very much like a Theremin to create a beat frequency (BFO) metal detector.
Range is a few inches for the smaller detection coil, but the detection range can be increased by adding a larger coil.
What I really liked about this project was how the oscillator coil is tuned – using a brass nut on a PVC sleeve.
{ 6 comments… read them below or add one }
Why such a large circuit board? I realize there are signal generation areas of the circuits, but for such few componants, it seems very large for its purpose.
By the way, ive enjoyed the projects on your site and I do a lot of the same kinds of things, so I wanted you to know I wasnt being facetious with my previous question, my thoughts are that, as with the salt in your etchant soultion and the “out of the box” concepts the problem solving process added to your skills, that there may be a purpose for such a large circuit board.
Thanks,
wayne
I goofed up when I printed the etch mask – I printed it at 300dpi, and that was the last piece of transfer paper I had!
You made me smile…..
Glad im not the only one…… 🙂
w/r,
Wayne
how deep in the ground can you pick up a coin?
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