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Hello Guys,

I'm new on this forum and like Alexandre Tartar, I live in north of France.

I was a young prospector in the 90's and asked my father (electronic engineer with good knowledge in magnetic field theory) to build a PI to hunt the beaches. So we have made, in a few months, an home-made PI metal detector 25 years ago, based on the technology of the old White's Surfmaster PI (mono coil). I remember the use of FETs (Field Effects Transistors to make 200 volts pulses). It worked, but unfortunately, my father was afraid by a so powerful magnetic fields and has continued his research on VLF detectors, until today !

After this short presentation, here's my question :

Is the Impulse AQ a bipolar detector ?

Le Jag has explained us on the french forum "detecteur.net"  this technology developped by Alexandre :

Positive and Negative pulse are alternatively sent.

The positive one light the gold ring but magnetize the soil.

The negative one demagnetize the soil.

What about it ?

fisher-research-impulse-aq-metal-detector.jpg

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Subject of course, to correction by Alexandre, The short answer is no, the AQ is not bi-polar. Alexandre has developed bi-polar platforms, but not at this time for the AQ. 

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I will bet a sizable Mexican dinner at La Casita in Globe Arizona that “VE” has nothing to worry about on the possibility of a bi-polar AQ version shortly after AQ going on sale. Fisher is the Tortoise in the fable of the Hare and the Tortoise vs. Alexandre who is the Hare (and a speedy bunny he is indeed!)

If you wait for the BP version, I hope your beaches aren’t visited by too many AQ owners! Lol 

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Hi Rick , if I understood well, you are the owner of an AQ , did you do some tests with it ?

thx , Alain

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Damned ! No chance to see a Fisher Bipolar PI detector on the market until 2032.

...Indeed, my father just sent me the White's US patent 20110316541A1

You can read it at this link (pdf file) :

https://patents.google.com/patent/US20110316541A1/en

(...) Consecutive truncated half sines of current are of opposite polarity as efficiency is enhanced by the bipolar resonance proceeding past the peak of current, providing bipolar waves allowing for earth magnetic field cancellation with as little as one sample of both polarities during the pulse mode sampling time following the truncated half sines of current. (...)

 

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Nice try JEKO - but no cigar for you. The patent is for using half sine current to produce the bipolar response. There are lots of ways to generate a bipolar signal - Minelab’s mine detectors and probably others do it already without infringing the Whites patent.

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That half sine patent has been discussed here as far back as six years ago and still no product in sight. Various prototypes have been developed at White’s over the ensuing years, but so far getting something to work well enough to bring to market has obviously not happened. I keep hoping for a surprise out of left field from White’s based on this patent that somehow turns the market upside down. White’s certainly needs a real winner at this point if they want to remain relevant. The truth is however many patents and great ideas just don’t work out in the real world. The Fisher CZX/Mosca was just one of many, and the Pulse Devil an even better example of a great idea that never happened. An ironic name in retrospect. The devil is, as they say, in the details. :smile:

 

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Thank for your answers and for the link ! 😉

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    • By abenson
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