The circuit oscillates at approx 140kHz and a harmonic of this frequency is detected by an AM radio.
Simply tune the radio until a squeal is detected.
When the search coil is placed near a metal object, the frequency of the circuit will change and this will be heard from the speaker.
The layout of the circuit is shown and the placement of the radio.
The TRUTH about Metal (GOLD) Detectors.
A Gold Detectors club in the US created a challenge with 12 members with skills ranging from 12 months detection to over 25 years. They used 5 different detectors to find 30 different items, hidden in sand and under pieces of cardboard.
The results were these: All detectors performed almost equally but the interpretation of the beeps, sounds and readings on the detector were
quite often mis-read and the winner was a member with 1 year experience.
The moral of the story is to dig for anything that is detected as it may not be a "ring-pull."
With these findings you can clearly use a very simple, cheap, detector and get results equal to the most expensive equipment.
The only thing you have to remember is this: You need the right frequency for the type of soil to cancel out the effects of minerals etc.
That's why there is a range of frequencies from 6kHz to 150Hz.
All the other modes of producing and injecting the pulse add only a very small improvement to the detection process.
The energy put into the injecting pulse also has an influence of the depth of detection.
A Gold Detectors club in the US created a challenge with 12 members with skills ranging from 12 months detection to over 25 years. They used 5 different detectors to find 30 different items, hidden in sand and under pieces of cardboard.
The results were these: All detectors performed almost equally but the interpretation of the beeps, sounds and readings on the detector were
quite often mis-read and the winner was a member with 1 year experience.
The moral of the story is to dig for anything that is detected as it may not be a "ring-pull."
With these findings you can clearly use a very simple, cheap, detector and get results equal to the most expensive equipment.
The only thing you have to remember is this: You need the right frequency for the type of soil to cancel out the effects of minerals etc.
That's why there is a range of frequencies from 6kHz to 150Hz.
All the other modes of producing and injecting the pulse add only a very small improvement to the detection process.
The energy put into the injecting pulse also has an influence of the depth of detection.
Informative post! Is Underground metal detector good enough for both occasions like security detecting or finding gold?
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ReplyDeleteThe world’s first company specialized in detecting gold, raw gold, minerals, groundwater and security systems ECT provides these products with the cheapest prices, the fastest shipping methods and the easiest way to buy a product from the source directly to your door wherever you are in the world. original site
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