Xtrem Hunter

[Carl-NC]

We have plenty of large iron junk in our old farmland. Mostly plough blade parts and related items like harrow tines. Also plenty of iron sheet metal. So all my hoard hunting ends up locating endless quantities of that junk, in some places a piece every 2 metres. So some non-motion discrimination, that is accurate at determining large iron is 'IRON' would be pretty handy.

Same is true in the US. A lot of the big iron pieces will often ID as non-ferrous because the eddy response is stronger than the magnetic response. To better ID iron, you need to analyze the signal through the whole sweep, or use multifrequency.

Many sites that are pasture land, and have been left uncultivated for 100+ years seem to show noticeable variations in ground signal from one spot to another. So using a single-freq machine in non-motion mode gives you the problem of continuously sensing just ground-signal changes ( and of course NOT sensing weakening ground signal, which ultimately reduces sensitivity to wanted targets.) So ... reducing sensitivity to the ground is a desireable feature.
One obvious 'solution' should be the use of multi-frequency ( two is enough, I would think ).

You can solve this either with a ground-grab feature or with slow motion operation (not quite no-motion). With 3 frequencies you can theoretically make a zero-motion detector that cancels ground and discriminates iron.

Another would be the use of search-coil arrangements that inherently cancel ( partially, at least ) the ground signal. So, just as the 'Bigfoot' coil has a figure-8 Rx coil ( and mono Tx ) , a two-box 'equivalent' could be : a three-box. A middle Rx coil, and two Tx coils either side, in anti-phase. Like an existing two-box, but with another Tx the other side of the Rx. The Rx is in induction balance with each Tx individually, but the anti-phase wiring of Tx's means lower sensitivity to the ground ... provided the detector is held level. Multi-freq or single freq should both be compatible with this coil arrangement.

You probably want a [ RX- | TX | RX+ ] configuration instead, as having 2 out-of-phase TX coils produces a far-field null that limits depth. The DOD coil used on the GPZ is an example, and the 19" might even be a good size. I would probably prefer a coplanar coil to an orthogonal coil because it's something you can swing and cover ground faster. Probably the only way I would use a 2-box is with data logging and a mapping program. White's sold a boatload of TM808s to cache hunters, and I thought it was a fairly poor choice for this. My 808 was unable to detect my cache (220 silver quarters) buried 60cm deep.

And I think Audio presentation is important for this kind of machine. It seems that use of stereo audio could bring benefits.
The three-box setup will presumably have 'Bigfoot' behaviour -( different response to targets under the 'heel' and the 'toe' ) , stereo audio may be helpful in picking out the different responses ?

My preference is to use stereo to put AM in one ear and Disc in the other. Even when you want to discriminate iron, it's still very helpful to hear everything in the ground. The AM signal lets you distinguish very close targets.

Also - the choice of operating frequency is worth some thought. It seems there is a concensus that a low-ish freq, like 5 to 8 kHz is the smart choice, presumably making some assumptions that the target is moderately high in conductivity. This may not in fact be the case, and my hunch is that a higher freq may yield better results ... perhaps 12 - 18 kHz range for single freq operation, and (12 plus 36 or 48 ) if going multi-f ( 12/36 or 13/39 for a 3:1 ratio, a la Fisher CZ-series, or 12/48 for a 4:1 BBS system ... or something like Park2 / Field2 on the Equinox, with 18.2kHz as the 'dominant' and 8.2 / 39k as ground rejection additional freqs. ( if I ever found time to make the beast, my 3-box would be on my Fisher F75, 13kHz single-freq. ... I think making such a contraption for my Equinox would be too ambitious )

In the US most hoards will be high conductor coins, like silver dollars or halves. For these, you want a low frequency, even down to 1-2 kHz. The hoards I've seen in the British Museum are mostly small thin coins so a higher frequency (15-20 kHz) will work better. The technology that might work well is that given in US11022712. It could be set up as a 3 frequency TX (say, 1/5/25 kHz) with the weighting shifted low or high depending on what you are searching for.

Thanks for the feedback. I think the important points are

• Ability to handle dynamic ground conditions
• Really good iron ID, especially with big iron
• Super slo-mo or zero motion
• Depth depth depth

On the last point, a TX that can put out an enormous signal would help. Maybe even a harness-mounted battery like the older GPX. You'll have to deal with the channel offsets due to the coil null but that's manageable.

[Skippy]

I'm not so sure about "depth depth depth" ... I don't think the targets are going to be stupid deep, just deep enough to be hard to detect. Hence my thoughts that the 'standard' two-box is too big, and perhaps something 60-70% of the size may be best.
I had wondered which 3-box arrangement would be best; Tx-Rx-Tx, or Rx-Tx-Rx, and which orientation to choose - central coil horizontal, or vertical? The latter question is probably answered by knowing where the sweetspot of a two-box lies. You don't want the two sweetspots just either side of the central coil, I think if they were just the central side of each outer coil it would work better? I've never used a two-box, so have no idea how they behave.

[Skippy]

EMI pickup would also influence the RX coil(s) orientation, I assume a vertical coil would pick up more than a horizontal one.

[ivconic]

Even though this is a "foreign" forum... I won't write some things and I'm very tempted to write.
(Real and true stories about real and true discoveries, lot of photos, video records etc. Nothing from all of that I keep at me, because I don't want any problems with authorities.
I saw, I heard, I saw the evidences... and I kept nothing in my computers and disks, things are too delicate, but if anyone have slightest doubts in such stories; I can say that I saw it!)
Fools who organize "closed" groups on Facebook where they post pictures, videos and loud boastful stories seem especially stupid to me. A true eldorado for the special police!
Alos I already know that the special police visit exactly these forums and collect information from reckless scribes.
And what such a special service fails to notice and read; a couple of "domestic rats" are here always on duty to do this and report it to the police.
This is all about "hikes", "adventures" and real finds. Not single coins, but real hoards, they exist for real and there are finds like that.
Speaking of coins... not terrible. That's "small change". But when we start talking about hoards...
If you are wondering if hoards really exist, if there is a real need for such a detector; the answer is: yes, it's not just a story,
there really are serious hoards and there really is a serious need for such a detector.
When I mentioned in the previous post that I am unable to organize anything like that and host Carl here at my place; I was just thinking about what I'm writing about.
The state has become very restrictive here (too late now), the laws are limited, stupid, vague, they can be interpreted by whoever wants.
And the most lively walk to some rather insignificant hill with detectors; it can turn into an arrest and a lot of trouble. I wouldn't want to do that to myself, Carl, or anyone else.
The worst thing is that the police themselves are not that interested in such phenomena... until someone reports it to them, and then they have to come and check what it is about as a matter of official duty.
The local villagers are very happy to call the police. Because they are afraid that someone will get rich by accident, and not because they think well of the state and the state's wealth.
Peasant mentality. Unfortunately, there are plenty of them.
I write broadly because I cannot write short and direct. You understand why, no need to explain. Read between the lines.
Anyway... such a detector is necessary and interesting, of course!
It is applicable and makes sense in these areas. Previous "experiences" confirm this 100%.
All previous 2box from renowned manufacturers failed on the field. Any better PI easily beats them in performance. But as we know; PI has its flaws.
The magnetometer has no competition when it comes to materials that have magnetic properties. But they are useless when there is only non-magnetic material in the soil.
So... I have no idea which of the known detectors would be suitable for that purpose. For now, Pulse Star II with larger coils is still the only "tool".
But far from being perfect, it also has its flaws.
There is a handmade detector, Bulgarian, they call it "kantar", I don't know exactly what it is, I only saw pictures, it looks like 2box, it is made of wood.
I have heard fantastic stories about it from people. But I have no personal and direct experience.
And then I once heard about the Russian "Korshun". But this is also a DIY device, of an unknown author.
I tried to find out details from Russian colleagues on Russian forums, but unfortunately I didn't find out anything.
That "Koršun" looks like a 2box but has two round coils placed horizontally and works on a slightly different principle. A friend here from another place has it.
He tells fantastic stories about it. But I still haven't found the time or conditions to go and visit it and see what it's all about.
He has a testing ground/bed at home. He says that he finds a small hoard (1kg) with it at 150cm in the ground! Which is fantastic... if true.
He invited me to see for myself, so I'm not ready to write off such claims in advance.
But the circumstances of life are such that sometimes there is no time or conditions even for trivial things, such as a shorter trip and going for a few hours to another place for that purpose.
The mentioned "Korshun" pretty much meets the criteria that Carl mentioned, and in comparison with what I learned from that friend in long Viber correspondences.
Ok, that's it for now. If you're in the mood to continue talking about the technical details here, even starting a new project like that: ok, I'm all for it.

[ivconic]

Even I am now incredibly stupid for writing all this here.
Carl, after a few hours, delete previous post or at least "shade" parts of the post so that no one can't see what it says.

[Carl-NC]

I'm not so sure about "depth depth depth" ... I don't think the targets are going to be stupid deep, just deep enough to be hard to detect. Hence my thoughts that the 'standard' two-box is too big, and perhaps something 60-70% of the size may be best.
I had wondered which 3-box arrangement would be best; Tx-Rx-Tx, or Rx-Tx-Rx, and which orientation to choose - central coil horizontal, or vertical? The latter question is probably answered by knowing where the sweetspot of a two-box lies. You don't want the two sweetspots just either side of the central coil, I think if they were just the central side of each outer coil it would work better? I've never used a two-box, so have no idea how they behave.

I would expect a typical hoard in Europe to be on the order of a meter deep. Not because someone buried it a meter deep, but because in the centuries since there has been some soil build-up. If that's true, then it's Good News for treasure hunters because most of the hoards found so far were probably not so deep, and there are more hoards out there beyond the limits of the detectors currently being used. The TM808 is pretty good at detecting large deep metal, I don't think it's so good at detecting deep coin hoards. Like I said, my TM808 could not detect a modest size cache at a modest depth.

Here is how orthogonal coils work:


The TX field lines bend downward vertically and cut through the surface of a deep target, creating eddy currents. Shallow targets are actually hard to detect because the flux lines are more horizontal. You can add another RX coil on the other side of the TX; it won't add any depth but will cancel EMI and ground.

[ivconic]

I don't have permission from the owner to post pictures of that new Korshun.
Although I only have two low-res images, it doesn't show much anyway.
But that's why I have some text from much earlier in which the details are glimpsed.
The text talks about a very old model of a Russian minesweeper.
This new "Korshun" with phenomenal performance is something completely new and different, it has mcu and LCD but
the coils are similar and the settings are the same as in the pictures in this word document.
The scant information I have is that a Russian engineer who worked in a military factory; now is out of that business and to rarely produce a piece of two of those detectors.
At very high prices. And that's all I have of the info.
Here is the doc:

[ivconic]

...I would expect a typical hoard in Europe to be on the order of a meter deep. Not because someone buried it a meter deep, but because in the centuries since there has been some soil build-up. If that's true, then it's Good News for treasure hunters because most of the hoards found so far were probably not so deep, and there are more hoards out there beyond the limits of the detectors currently being used. The TM808 is pretty good at detecting large deep metal, I don't think it's so good at detecting deep coin hoards. Like I said, my TM808 could not detect a modest size cache at a modest depth...

I know many cases of discovery.
Most of them are in the range of up to 1 meter deep. But there are also a decent number of cases at much greater depths.
It is necessary to point out that this area is probably the oldest on the planet in terms of old civilizations and their traces and remains.
Yes, it is true; most hoards are deliberately buried deep!
It is about gangs of robbers who ran rampant in a certain age and then brought their loot to the mountains and deliberately buried it deep.
They even made false road signs, coded inscriptions on rocks, used various landmarks and often set various deadly mechanical traps.
Everything you've seen in the Indiana Jones movies; is quite real and exists, of course in a different form and with many different details.
Serbia (and Bulgaria, I believe) are full of signs and "maps" drawn on the rocks. There are also a lot of discoveries.
The most recent example from last winter was the discovery of a pair of hoards from the Bronze Age. At depths of 90 and 110 cm.
An acquaintance brought his mobile phone and showed me a bunch of pictures, photos, but he didn't let me transfer any of them to my computer.
And I thank him for that, it's better for me and for him that it's like that.
And another visitor played me several videos from his phone, I was shocked, amazed by what I saw.
Of course, he didn't want to give me a copy of even one of those recordings. I also thank him for that.
Because having such material can only bring trouble.
But Carl... if you had seen it with your own eyes, as I had; you would realize some things that are hard to accept as reality.
There are no such things in the USA, nor will you have the opportunity to see anything similar there.
And it is a real shame that it is so.
The things I have seen are so fantastic that it is a risk to even talk about it here, 99.99% of those who read it would not believe it at all.
There is only one problem; I did not participate in any of those discoveries... unfortunately.
And that's why I still have money problems! But such people come to me often because I am known in the area as a repairman of such equipment.
Unfortunately, most are not willing to leave their equipment with me long enough for me to copy it.
And most of the breakdowns are easy and trivial, so everything is usually over in a couple of hours. During this time, many are in the mood to talk and then show recordings and videos.
And my hair stands on end from what I see then.
The 2 box principle that you showed in the sketch is known and explained many times.
But I think that the aforementioned Korshun works on a similar but not the same principle. I'm not sure though.
As far as depth is concerned, 1 meter is easily conquered with Pulse Star II and coil 45cm and 1x1m. We are talking about serious hoards here, not a handful of worthless coins.
The average depths involved in the cases I have seen are from 1.5 meters to 4-5 meters.
And the hoards in question are serious "masses" of mixed metal objects, mostly coins, but also a lot of jewelry and parts of weapons and costumes made of precious metals.
Don't waste your time on devices whose "success" is a depth of only 1 meter... that was overcome a long time ago.

[ivconic]

And this is the official version of the military detector, the price of which is huge!
It is the same detector as the Korshun I wrote about.
Only that the picture shows the factory model, digital, the last word of technology.
Although it is a military product, it can be purchased individually.
But the problem is the price.
It is both the most powerful and the deepest metal detector I have ever seen in my life.

[Riss]

It's a full moon now- the great treasures are mined at full moon… ( nothing is accidental )
Videos for creative inspiration… For translation - artificial intelligence knows Bulgarian language better than me . Historians and archaeologists with a narrow specialty ancient history of Egypt and its connections with south-eastern Europe confirm that these are not fabrications. There is much more shocking information in the Vatican archives … but they are inaccessible…

https://www.youtube.com/watch?v=mSW5itcxo8I
https://www.youtube.com/watch?v=wDqY4g921g0
https://www.youtube.com/watch?v=o9qWRBDPRBw
https://www.youtube.com/watch?v=VQxaRs5tqEg
https://www.youtube.com/watch?v=i35GokqwPxY
https://www.youtube.com/watch?v=0XQboAB2qOE
https://www.youtube.com/watch?v=BnjeSpCM_A4
https://www.youtube.com/watch?v=HdGuJPeqa0w
https://www.youtube.com/watch?v=nlMwTqjHq8c – Bastet , Egyptian princess, buried in southern Bulgaria , ancient knowledge of Egyptian priests
https://www.youtube.com/watch?v=VZn4HDMaERc - Tsarichina village - ancient knowledge
https://www.youtube.com/watch?v=F9ryaIMoWZ0 - also
https://treasures.zonebg.com/tsb1.htm
https://www.geotech.ru/safety_equipm...loiskatel_mg1/
https://www.technoac.ru/catalog/prod...loiskatel-mg-1
http://logsys.ru/metallodetektor-glubinnyj-mg-1i/
https://www.arms-expo.ru/armament/samples/1770/72365/
http://www.bnti.ru/des.asp?itm=7060&tbl=07.01.01.
https://www.youtube.com/watch?v=PUHg3k29fc0 MG1
https://reibert.info/threads/prodam-...ik-imb.199105/
https://www.ebay.com/itm/274239082258 Metal detector EBINGER TREX 150
https://www.youtube.com/watch?app=desktop&v=7yOBB7WBc3A - TREX 150 , video
Rx-Tx-Rx - I tested it at least 17 years ago - I did not like it… only for pitches with some iron junk.

[ivconic]

The story of Вълчан Войвода is very interesting. I manage to understand Bulgarian without translation about 60-70%.
We have a similar character: Pop Martin Himović.The leader of the bandit gang.
Are these stories real? It's hard to say. Throughout history, it is possible to find mention of such names, but not events from new urban legends.
Over the years, I have also collected several volumes with transcriptions of old stories, signs, descriptions, etc.
Some seekers from Bulgaria come to Serbia on the trail of those stories.
That's how I found out about the "Kantar" detector, which is made of wood and according to the principle of operation, it is a 2box.
There is some simpler electronics inside, and the balance is achieved by mechanically adjusting the position of the antennas.
And all that is not empty talk; it also testifies to a couple of successes in searching with that detector. With very good results.
I assume you are from Bulgaria? Have you heard of "Kantar"?
It is the name for an older type of scale, because it resembles such a scale in appearance.

[ivconic]

Pop Martin Himović was a Serbian priest, a renegade in the mountains with his gang of bandits during the Turkish occupation of these areas.
This video shows that he and Valčan Vojvoda (Вълчан Войвода) were friends.

[ivconic]

Carl here are some achieved depths:

Maximum detection depth 5 m
Depth of detection of the OFAB-250 aviation bomb 3.1 m
Depth of detection of an artillery shell of 100 mm caliber 1.8 m
Depth of detection of an artillery shell of caliber 152 mm 2.2 m



This is older model.
The one I posted earlier is latest model and with depths up to 10 meters.
And price is 12 000 euros.
Now... we don't talk here about diy made by any of us; we talk here about a device produced by Russian military technology. Top of the world technology.

[ivconic]

[ivconic]

geotech.ru !!!