Taking the Plunge with a CZ20

[Anonymous]

I bought my first detector--a CZ20. Do any of you tech guys know how they work? They don't say much in the manual. There are two concentric coils--are they to tune to 5kHz and 15KHz or are they some sort of TR set? This is not an induction balance unit is it? Fisher claims a Fourier transform. How is this done? DSP? Or are they just using the two tones and the differing wavelengths for size discrimination? Is the autotune mode a phase locked oscillator detector? Is the ground balance a frequency offset control to this detector?
It sure would be helpful to know a little about how it works in order to use it effectively. I asked these questions on Surf and Sand, and they said it is just "magic". I agree, nobody really understands the miracle of electromagnetics, but I could be even more worshipful if I had a block diagram.

 

[Anonymous]

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[Anonymous]

Thanks Mr. Bill-- so that means that the two coils are a transmit and a receive coil and the receive coil has a bucking winding to cancel out the direct induction from the transmit coil--if I understand the concept of induction balance. Is the smaller coil the transmit and the larger the receive? I am still struggling to understand, but it sure is an amazing device performance-wise.

 

[Anonymous]

I'm not certain on this but I think the smaller inner coil on the CZ20 is the receive..
Bill

 

[Anonymous]

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[Anonymous]

Thinking about it, the small coil being receive would make more sense than what I said because the target would have its biggest effect then when you were centered over it. Thanks Bill. Lots to think about and much to learn.