Fisher PI getting closer

lytle78

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Jul 7, 2006
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Electronic design is complete, I have heard. Mechanical design may be done as well.

Field testing of pre-production prototypes comes next, then if it goes well - production and sale.

Meanwhile I am following things as well as I can - a couple of Facebook groups on beach detecting are onto it.

I know I have posted links to this video (in French) lots of times, but here it is again. the difference now is that (with a lot of help from Google translate) I have prepared a timeline translation/summary for the whole thing. First a couple of definitions, then the timeline.

https://m.youtube.com/watch?v=G8sdp4RG73g&feature=youtu.be#

My work
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Bague OR - gold ring

Tous Metaux - all metal

Discri - discrimination

Discri Coupure du fer - Iron discrim. By silencing

Discri multitons - iron discrim by multitone

0:07 - First test “in the air” Gold Ring - 18K - 2.7 grams - size 11

0:12 - Mode “All Metal”

0:21 - Mode “Discrimination iron cut” - 2 nails (6 cm) crossed

0:29 - Mode “Discrimination multitone” - 2 nails (6 cm) crossed

0:40 - Swing speed test

0:52 - Second test “in the air” - Iron discrim. By silencing

1:00 - The gold is detected beneath the iron - no discussion of recovery speed (it’s zero)

1:10 - The high tone of gold is heard along with the low sound of iron

1:45 - a bag of black volcanic basalt sand from Fuertavantura in the Canary Islands is shown - this has a high Magnetite content as shown next

Until 2:12 - All Metal - demonstrate that all targets - including the volcanic sand react

2:14 - Iron Cut - the ring under the nails responds with normal good tone - the nails and sand are ID’d as ferrous.

2:32 - the sand bag is over the ring and the ring is still a good strong signal - the nails next to it are ID’s as ferrous

2:54 - the same process in multitone ID

3:01 - a Minelab Soverign is introduced and the set up shown

To 3:45 - the Sovereign shows reject of nails and sand bag, acceptance of ring

3:53 - two nails crossed over the ring - no signal

4:17 - the nails removed, the black sand bag put over the ring - weak iron signal

4:32 - CTX. Introduced and set up shown

To 5:30 - CTX gives iron signal over nails, silent over sand bag and gives good signal on ring

5:33 - two nails crossed over ring - CTX gives iron signal, then nails removed and black sand placed over ring - no signal

6:20 - bag removed - CTX gives good signal over ring

6:23 - again only iron signal when nails crossed over ring

6:45 - second (larger) bag of volcanic basalt black sand from Reunion Island introduced

To 6:54 - the ring is placed ON TOP OF the bag - the CTX gives a weak signal side to side - and iron signal front to back - compare this signal to the ring alone (at 5:26 and 6:20)

6:56 - 7:07- the smaller bag is put on top of the ring still resting on the larger bag - CTX gives no signal

7:08 - the Manta - in iron cut mode - sounds on the ring, weak reaction to small bag on top of large bag of black sand, then hits ring strongly after it is placed on top of the large bag and covered by the small bag

7:52 - 8:15 - the Manta still in iron cut discrimination mode - hits ring strongly under both bags - then “cuts” nails to demonstrate discrim is still on

8.36 - Manta demos recovery speed - ring right next to both bags piled up - perfect signal

9:08 - Manta = still in iron cut - hits ring under both bags of sand and covered by crossed nails

To 9:53 further demo of iron cut discrim of the sand bags and nails

9:55 - two shallow holes - two nails in one, the ring under 2 nails in the other

10:58 - Manta in all metal sounds off over both covered holes - the nails give a characteristic “double” signal

11:24 - iron cut - nails silent - good signal from ring under nails

11:57 - first small bag of sand over ring - good signal - then large bag - then both bags - same result.

13:56 Gold coin 2 Escudos (about 22 MM - 7 grams) it is buried about 12” deep and is easily detected in iron cut discrimination after demonstrating that there is no other signal in the sand (coin inserted at 15:26)

17:50 - a large gold signet ring 5.7 grams is buried 40 cm (about 16”) it is easily detected in all metal

To 23:10 (end of video) Manta easily hits the ring in both iron cut discrim and multitone discrim.
 
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This would be an awsome machine no doubt. Although the only thing worth discriminating is iron. I've been following a project where a guy has an oscilliscope mounted on a pi and he can see the varying waveform for different targets. I'm wondering if the manta works the same or similar. Are you aware of any schematics that were ever released? Also, is there any indication on a price point for this machine? I'm using a pi now and just pic my location carefully and all is well.
 
17:50 - a large gold signet ring 5.7 grams is buried 40 cm (about 16”) it is easily detected in all metal.

Love it!
 
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Lytle78, AAaahhh, do you want me to chime in on this thread ? Can you spell "S-H-I-L-L " ? Just kidding :laughing: Your info and enthusiasm is catching. Luv ya like a bro ! :cool:
 
This version will discriminate it out. Just increase the pulse delay to about 25 microseconds And all of the aluminum will go away – but so will most of the gold! LOL
 
Tom, your persistent skepticism is refreshing! But seriously this thing won’t be for everybody it will make funny noises all hi power detectors tend to do that. The discrimination system is it like on a white shirt to Sauro you crank it up and what you discriminate just goes away and you never hear from again – on this one it changes the response sometimes “cutting” iron results in silence - other times it results in funny noises - you have to learn

Likewise PI have been famous for giving “double blips” over iron - this one does that too -except it seems to be a bit better at it than the TDI – based on what I’ve seen in the video and went to LE JAG has told me.

As far as being a shill – not guilty – just aother “fan”. I love the whole story of how Alexandre developed this along with his pals as a private venture for the interest and satisfaction of doing a great thing. And then he succeeded in what he wanted which was to have it picked up a major manufacturer. That manufacturer happens to be first Texas the company for which I have a lot of respect and affection.

But if this thing is as good as I think it might be I might have to become a dealer – why leave money laying on the table ? Lol
 
BRB - No magic oscilloscope or fancy waves – just classic pulse induction technology as first established by Eric Foster – now taken - through very careful engineering - to a new level of power and quiet – and also a new capability in the limited iron discrimination control it offers - oh yes - And the shortest minimal post to lay ever offered in production PI detector – this means MORE GOLD.
 
I'm sure one could use an arduino in place of the oscilliscope above and use it to post process on the fly. Perhaps like so
http://www.instructables.com/id/Arduino-Frequency-Detection/
Then one has basically the same as the manta or perhaps logic is wrong? I'm going to try for the satisfaction of building, I love projects like this and I'm sure it will not compete with the commercial offering of the manta but it will be close enough for me on my currently limited budget.
 
BRB - No magic oscilloscope or fancy waves – just classic pulse induction technology as first established by Eric Foster – now taken - through very careful engineering - to a new level of power and quiet – and also a new capability in the limited iron discrimination control it offers - oh yes - And the shortest minimal post to lay ever offered in production PI detector – this means MORE GOLD.

Well there has to be some kind of magic or else it would not even be possible. This is the only way I can see a pi machine actually having discrimination.
 
Well there has to be some kind of magic or else it would not even be possible. This is the only way I can see a pi machine actually having discrimination.

And ... yes .... lytle78 *is* claiming this is magic :laughing:
 
Well there has to be some kind of magic or else it would not even be possible. This is the only way I can see a pi machine actually having discrimination.

With a proper Induction Balance coil (IB) there is a change in when the phase shifts During the TX pulse with iron verse non-iron. This is one way to have iron discrimination.
 
Good info. I'm trying to grasp it all at this point pooring over the forums at geotech. Its a bit hit and miss there as the information is spread through the forums. I have found a few good diagrams of discriminating pi machines and will probably try a few. Its just fun to tinker. I might try the baracuda also. Pi machines just go deep.

Sent from my LGMS550 using Tapatalk
 
It’s pretty simple. Eric Foster did it decades ago, Minelab does it with the GP and GPX series (with DD coils only and to limited depth). The Whites TDI had various varieties of it.

It all has to do with how ground balancing works on a PI machine. Google Reg Sniff Pulse Induction and you will fine enough reading to keep you busy for a while.

The Manta does something similar, but in ways none of us know because it hasn’t been disclosed, the results are different.

No magic, just good engineering - going all the way back to Eric Foster (google him too - Eric Foster Pulse Induction.
 
The GeoTech forum is what to read and I agree it is VERY scattered so takes a lot of time to read it all.

I have some info on this in the thread on building my detector:
http://www.geotech1.com/forums/showthread.php?24251-My-take-on-the-HH2
This winter I plan on writing the code for iron dis.

Right now my detector work close to the TDI,with GEB, but it is not better than 60% knowing the target is iron or not.
A good read is the threads in "Tinkerer's IB-PI" sub-forum.
 
The GeoTech forum is what to read and I agree it is VERY scattered so takes a lot of time to read it all.

I have some info on this in the thread on building my detector:
http://www.geotech1.com/forums/showthread.php?24251-My-take-on-the-HH2
This winter I plan on writing the code for iron dis.

Right now my detector work close to the TDI,with GEB, but it is not better than 60% knowing the target is iron or not.
A good read is the threads in "Tinkerer's IB-PI" sub-forum.

Waltr,
I know what I will be reading tonight. That looks like a great bit of work has been put into that project. Awsome job! I also want to apologise to op for hijacking this thread although along similar lines of discussion it is somewhat offtopic. Back to manta!!!
 
Their claims of this being better than Erics AquaStar alone makes this a want to have machine. Then the ability to disc out a good bit of iron only increases its desire. I dont care if this machine works anywhere as long as it works IN the water and on the wet sand. I hunt in two tone most of the time with the Nox and PP mode on the Xcal. As long as its not so chatty i cant tell a target from EMI or minerals im good.

One question........ where will the bottle caps hit???:laughing:
 
Time will tell. The discussion has reached a point where waiting for the results to reach the market is probably the best thing.
 
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