give it metal detectors with a penetrathion depth of 1m

[Carl-NC]

There is probably no way to detect a coin at 1m. I have seen a very high-powered PI detector with a 32cm coil detect a US nickel at roughly 50cm. The Garrett ATX will detect a US nickel at 43cm. I don't know that any of the projects posted here can do anywhere near that, probably more likely 30cm max. With some heavy mods they might get close to 40-50cm but you will need a really good understanding of PI to get there, and a big battery.

[MartinB]

Well Carl, the Garratt ATX looks like a great machine but carries a hefty price tag of just under 3,000 GBP. Way beyond my capabilities, but is there anyone out there up the challenge of replicating one? Even if it cost a couple of hundred dollars to construct, it would be worth it.

[Riss]

which of the detectors described in this forum has the greatest detection depth. can the PI detector with the 1m coil detect a coin at 1m?
Levin

Let's leave the technical part aside . I have come to the conclusion that you have no experience in digging holes. Get out your best shovel and dig a hole 50 cm (20 inches) deep and note how long it took you to dig it. Then a hole 71 cm (28 inches) - for how long, and one 1 meter deep - for how long. You must have dug 3 separate holes! -only with a spade and a pickaxe, otherwise the coin may be damaged during excavation . I hope you have great physical strength and endurance , because in real conditions the last 10 cm are dug very carefully, which takes extra time . What if the soil is heavy and dense (difficult to dig) ? Well - get and a special shovel for digging up the soil…what if the soil is wet and sticks to the shovel… We all look forward to your next post the results of this science experiment, nothing but the results of the experiment!

[ivconic]

In the USA, you don't have the remains of ancient Roman and late Roman as well as medieval fortresses, towers, and settlements.
And here in this part of Europe we have a lot of them.
Next to the main places, between the main places; there were numerous smaller towns, villages, rest stations and horse exchanges.
Some claim that along the route of the Roman road "Via Militiaris" (which passes 30 km from me) there was one such place every 6 Roman miles.
And in the mountains and hills there are also places where people retreated in times of wars, unrest and barbarian invasions from the east.
All listed are places of great interest.
In such places, finding a coin at a depth of more than 20-25 cm is an extraordinary success and does not happen often.
80% of coin finds in such places; does not exceed a depth of 10-15 cm.
And in the valleys of the rivers, next to the banks of the rivers, there are "peaceful" settlements.
There, the river flooded and deposited layers of soil, and the finds are very deep there. Sometimes over several meters.
I am more inclined towards mountainous and hilly terrains, I rarely visit river valleys.
But in both cases it is about surfaces that are very densely "seeded" with various metal pieces, sawdust, rust, as well as crushed ceramics.
In the valleys of the rivers, in the fields, to all of that, we need to add very aggressive chemistry left over from the regular annual fertilization of the fields.
In such described conditions, finding a coin is a challenge.
And finding it at greater depth is a very rare phenomenon.
Depth does not go along with other good features on the detector. Well, the rule of thumb is that a "deep" detector has no other good features.
Deep Detector is only good for Youtube video ads. In practice, it is mostly unusable on the mentioned surfaces.
In the described conditions; coins are not found by the "deep" detector. Coins are found by a detector that has a very good GEB, DISC and Recovery Speed.
And that is the harsh truth that 90% of detectorists today do not understand.
Now after this story, all those YouTube depth tests should seem totally pointless to you, right?
I don't know about you, but to me they are totally pointless.
Of course, in such conditions, as I have described and I have on my fields; an additional mm to cm of greater depth is always desirable.
But it is also the most difficult task to project such a detector, which will satisfy all these conditions.
Good PI detector BUT with perfect GEB&Discrimination; would be the closest thing to an ideal detector for such conditions.
But such a PI is an oxymoron, of course.
I don't need to mention that I already had the ML GP3000 for a long period of time and that I also carried the GPX 5000 there for shorter periods.
They proved to be almost unusable.
Explorer SE is very deep, but it is too "slow" for such conditions.
The Fisher CZ series and 12xx series performed relatively solid.
But the XP models performed best.
This story, I hope, well illustrates the reasons why "depth" by itself means nothing.

[ivconic]

On the fields and plains (Vojvodina, Serbia), "ultra shallow" detectors like the Tesoro Silver Sabre, Golden Sabre and similar types performed very well.
Every year after the season of plowing the fields; such detectors pick up all the good finds from shallower surfaces.
They are particularly successful in finding the smallest silver coins.
And who has ever tried to search on such surfaces; knows that the smallest silver coins are the hardest "targets" in such conditions.
We can talk about "depths" seriously, only when it comes to very "clean" soils with a very uniform composition.
Sahara ... for example. That's where deep detectors are successful!

[ivconic]

And for the end there remains the last case; this is where the very correct position expressed by Riss comes into play.
And those are big forests. It rarely happens that there is a settlement in such a forest.
But lately, most detectorists are determined to go to such places and look for "accidental" finds, because the known sites have long been searched and emptied.
So today there is a greater chance of finding something valuable in such forests, as an "accidental" find.
There the soil is relatively "clean" and this is where a deep detector could come into play.
But... take my word for it; while walking through such a forest and searching with some "depth" detector;
inside you pray to God that such a detector does not find anything deep for you!
Because if it finds; the long, painfull and difficult agony of excavation follows!
The first 20 cm of the layer is loose soil with small veins from plants and small stones. Easy.
And then a much harder layer begins, with stones embedded in strong clay soil, as if someone was building an impenetrable wall with mortar and concrete.
And all this is made more difficult by thick and even thicker veins and tree roots.
Every 5cm deeper is more and more agony!
The worst part of the whole story is that there is no such thing as 100% reliable discrimination.
Discrimination with the detector is to a good extent accurate only up to 20-30... even 40 cm deep.
After that, the discrimination accuracy drops rapidly with each centimeter of depth.
So you're digging something you're not sure what you're actually digging.
It very often happens that the famous horseshoe is found at a depth of over 50 cm!
After two hours of hard physical work. In some incredible way it got there.
Often, at depths of over 50 cm and 1 m, some undefined rusty iron mass is found, which is worth nothing.
And while you dug it up; you are so broken and tired that that day of searching is over for you.
Who searched and has such experiences; he knows what those torments and agonies are.

[ivconic]

All this story is primarily related to finding coins, small jewelry and smaller pieces of precious metal.
Of course, there is also a continuation of the story, which is the search for large items, deposits and hoardings.
And in that case, everything that is written still applies.
With a note; that any better detector will suddenly become "deep" when dealing with such large pieces of findings.
Deus with a 22.5 cm coil very successfully finds such finds at depths of up to 1 m and a little more than that.
Because in 99% of cases it is iron or alloys with iron.
And such a mass gives a very strong signal even with coils with a smaller diameter.
Ever since I've had Deus, which is since 2012. I've had several cases of such digs. Up to 1m and something over that.
If the "target" is big enough; each better detector becomes "depth" or "deep" detector.
And we often mentioned the "halo effect" over the years.
If the target is of such a composition and if it remains in the ground long enough, a so-called halo effect develops around
the target and the target becomes "shallow", "bigger" and easier to detect.
In most cases, these are worthless findings. Much joy when detected - greater disappointment when dug up.
Several great discoveries of very valuable finds, which I remember for my entire "career", are in 100% of cases accidental and lucky finds.
I am not aware of any such deliberate finding.
And here, in a couple of posts, I briefly wrote everything that is important for the detectorist to keep in mind.
And from this story, I hope it is clear to you how much and what the role and importance of "depth" actually is.

[Levin]

What is the best metal detector of the metal detectors shown here in the forum in terms of penetration depth and discrimination
Levin

[Carl-NC]

The PI projects will give you the most depth, maybe 30cm on a coin, but they have no discrimination. The VLF projects can discriminate but can't go as deep. I'll leave it to others to suggest a "best" project because I don't know, but you probably won't be happy with any of them based on what you want.

[Riss]

What is the best metal detector of the metal detectors shown here in the forum in terms of penetration depth and discrimination
Levin

As I expected - you have no desire to dig holes . Then why are you asking again and again about a deep detector ? I remembered - a friend muttered to himself : ,, I have to cut hay for the donkey again...’’ Someone asked him -ok, but what's your donkey for? The answer was -how so for what ?- to transport the hay !

[Carl-NC]

Levin, the question of whether you want to dig a 1m hole is of no concern to me. But what you are asking for is well beyond the capabilities of current technology. Even detecting a coin at 50cm would take a monumental effort and would almost certainly have no discrimination. I suggest you get on general detecting forums and see where the state-of-the-art is right now. You are very unlikely to build anything better.

[Orbit]

[КУОТЕ=Царл-НЦ;н412103]Левине, питање да ли желите да ископате рупу од 1м ме не занима. Али оно што тражите је далеко изнад могућности тренутне технологије. Чак и откривање новчића на 50 цм захтевало би огроман напор и готово сигурно не би било дискриминације. Предлажем да уђете на форуме за опште откривање и видите где је тренутно најсавременије стање. Мало је вероватно да ћете направити нешто боље.[/КУОТЕ]

[Orbit]

The PI projects will give you the most depth, maybe 30cm on a coin, but they have no discrimination. The VLF projects can discriminate but can't go as deep. I'll leave it to others to suggest a "best" project because I don't know, but you probably won't be happy with any of them based on what you want.

[Riss]

We still have extremely low technological development and limited knowledge. We cannot create a VLF directional antenna , which would improve the depth of metal detectors . Even if we create a detector registering a coin at 1 meter , an even greater challenge is creating the technology to quickly mine the coin from that depth without risk of damaging it . And in the layer with depths of 20 cm - 1 meter there are many valuable objects... Because the treasure hunter's efficiency is the area and depth , shaken per unit time ( the searched volume of soil ) , I personally would work with my old detector , but I would give a lot of money for fast mining technology (machine ) . In real work a lot of time is wasted to mine the coins - in a geometric progression from the depth of the hole. And so , Levin - did you dig the three holes? How many such holes can you dig in for 8 hours ?

[kt315]

What is the best metal detector of the metal detectors shown here in the forum in terms of penetration depth and discrimination
Levin

begin from TGSL. no penetration depth but you will get a fun.
also, i strictly recommend you to order a book ITMD just now. it will give you good perspective.