MAG Building Poll

[Willy Bayot]

Hi Willy, how much distance must you keep between the PPM and AC power lines? Thank you Willy.

Our system is designed with a powerful bandpass filtering and sensor tuning at around 2KHz and, moreover, its signal processing rejects all random noise from the environment. Thus, the AC power line are not too much disturbing.
I have already made some surveys along roads in the middle of my village with power lines going over or under without any disturbance.
The only influence is from DC power lines which generate a large magnetic field which then drastically changes and covers the much weaker earth magnetic field. This is the case from our electrical railway network which is powered in 8KV DC. It means that I can not go closer than a few hundred meters from a railway line.

Willy

[Willy Bayot]

Hi Willy
I was watching this thread, and saw at http://users.skynet.be/fa352591/index.htm sensor picture much larger coils than those mentioned earlier, also with two bottles...
I am experimenting a little winh PPM with poor results, basically with your earlier designs, and I wonder would it be better to use such larger sensors to get more signal...
Can you please tell us specs of those coils
regards
msolc
p.s. when I loose that little nerves left, will simply buy your kit

Hi,

The two bottles are there just because of the physical dimensions of the coils and because I bought a large bunch of those bottles.
In principle, more proton-rich fluid gives more proton precession signal. Thus, maximizing the volume of fluid is the best bet.
Larger coils with thicker wire (i.e. larger polarization current) also give a better SNR.
For underground surveys, the sensors NEED to be noise-cancelled due to the large environmental noise found in most ground locations, thus, the double coil sensor is a MUST.
At first, we limited ourselves on the size and weight of the coils because we were afraid that they would be too heavy to carry by an walking operator. Then, we found some practical sensor assembly which makes the sensor easily carried without much effort during a long survey. Thus, we decided to enlarge the sensor coils for the units of the KIT and SEMI-KIT. The only limitation now is the currently high price of copper wire which makes a sensor rather costly to manufacture.
Note that we are still using here smaller double coils with a single bottle per coil and they still give good SNR results.

The coils have a total length of 172 mm (about equal to twice the height of a small bottle) and the diameter of the end plates is
70 mm.
7 layers of AWG18 wire.

Note that the sensor coils are the easiest and less critical parts to make for a PPM as DIY. If you indeed loose your nerves on your own electronic circuits, you could still buy the tested set of boards alone from us and integrate it into your own box. This would only cost you around USD1400 instead of USD2000 for the whole semi-kit.

Willy

[Wirechief]

Hi John,

Yes, we do it now and have sold a few of them to individual users and we have more on order from our second production series in progress.

Yes, the most adequate professional use of a magnetometer is by utility companies and other public work companies to detect buried utilities and tanks. Also, to be used by ecological organizations to clean up fields contaminated by buried barrels full of hazardous material. This is the type of market we would prefer if we find local system integrators ready to integrate our kit into a professionally-looking, wheather-proof instrument.
If you have any specific ideas in that direction, let's open an Email exchange.

Willy

Hi Wlly, even though I work for a fairly large scientific commercial company, I have no ideas of any commercial enclosure makers as you are seeking. We make most everything in house except for the molds of the housings for the instruments we sell. But I will be attentive to this type info for you if I hear of anything. I think you have to pursue a commercial interest for this instrument if it is going to grow and make you a solid business Willy. Unfortunately if you were to depend on the general public to go anywhere with this project it would be a very limited venture.
My thought is to use it for hunting large meteorites and for seeking out large treasure caches left behind by the Spanish Conquistidors of yesteryears. If it could be installed in a fish for ocean treasure hunting that would be cool too.
I'm glad that our AC power lines is not much of a problem for the PPM, it shows it is a great design. Ok Willy I will tell the people I meet in the metal detector business about the PPM and maybe get a few sales for you that way. But I will stay in touch and I wish you the best Willy. Thanks very much.

John Tomlinson,CET
John's Detectors

[Willy Bayot]

Hi Wlly, even though I work for a fairly large scientific commercial company, I have no ideas of any commercial enclosure makers as you are seeking. We make most everything in house except for the molds of the housings for the instruments we sell. But I will be attentive to this type info for you if I hear of anything. I think you have to pursue a commercial interest for this instrument if it is going to grow and make you a solid business Willy. Unfortunately if you were to depend on the general public to go anywhere with this project it would be a very limited venture.
My thought is to use it for hunting large meteorites and for seeking out large treasure caches left behind by the Spanish Conquistidors of yesteryears. If it could be installed in a fish for ocean treasure hunting that would be cool too.
I'm glad that our AC power lines is not much of a problem for the PPM, it shows it is a great design. Ok Willy I will tell the people I meet in the metal detector business about the PPM and maybe get a few sales for you that way. But I will stay in touch and I wish you the best Willy. Thanks very much.

John Tomlinson,CET
John's Detectors

John,

The problem is not with the material nor the enclosures. Our semi-kit already uses a water-proof NEMA box and keypad and IP68-rated connectors. These are easily found at Digikey's web shop. The real problem is with the manual work involved in assembling those with our set of boards and enclosing the sensor coils inside a proper non-metallic box. As retired engineers, we do not wish to use our (precious) time for that type of work and we prefer to concentrate on the design and test of our current and new instruments.

The sensor coils could indeed be installed inside a fish for treasure hunting but again there, we do not want to spend our time on that task.
Actually, the moderator of this forum (Christian) has bought two of our kits and is busy integrating them, one for underground surveys and the other for underwater surveys (designing and building a fish).

We actually do not really wish to build a solid business out of that if all our time is spent at tasks which we do not like. We've had enough of this in our professional career. We prefer now to concentrate on pure R&D activities as we were doing before retirement. That means designing and testing prototypes and starting small production series.

For the treasure caches presumably left behind by conquistadores, they could possibly be detected if they were contained in enclosures with ferrous marterial like wooden coffers reinforced with iron bands all around as were the safes built at those times. It could also detect potential gunneries (rifles, swords or even cannons) left in the caches.

Willy

[Wirechief]

John,

The problem is not with the material nor the enclosures. Our semi-kit already uses a water-proof NEMA box and keypad and IP68-rated connectors. These are easily found at Digikey's web shop. The real problem is with the manual work involved in assembling those with our set of boards and enclosing the sensor coils inside a proper non-metallic box. As retired engineers, we do not wish to use our (precious) time for that type of work and we prefer to concentrate on the design and test of our current and new instruments.

The sensor coils could indeed be installed inside a fish for treasure hunting but again there, we do not want to spend our time on that task.
Actually, the moderator of this forum (Christian) has bought two of our kits and is busy integrating them, one for underground surveys and the other for underwater surveys (designing and building a fish).

We actually do not really wish to build a solid business out of that if all our time is spent at tasks which we do not like. We've had enough of this in our professional career. We prefer now to concentrate on pure R&D activities as we were doing before retirement. That means designing and testing prototypes and starting small production series.

For the treasure caches presumably left behind by conquistadores, they could possibly be detected if they were contained in enclosures with ferrous marterial like wooden coffers reinforced with iron bands all around as were the safes built at those times. It could also detect potential gunneries (rifles, swords or even cannons) left in the caches.

Willy

Howdy Willy, ok mighty fine business and I see now. Yes it is not in your interest to do the manual part of it. I don't blame you and if you can dispense with the labor of it all then you will be able to pursue new projects without any delay. But I think it is really great that you and any others involved put the PPM out to us at a much reduced price compared to Geometrics. Are you having to do all the labor end of it yourself Willy? I will chat to you later Willy and take care. Many thanks.

John Tomlinson,CET
John's Detectors