Did BFO can ???

[Geo]

BFO has no ability to ignore mineralization. As you make the coil bigger and try to go deeper, the ground causes more problems.

Carl,
Even if you ignore the mineralization parameter, a bfo detector has not the ability to go deeper than the half of a PI.

Regards

[GOLDENSKULL]

Hi,

I want to dig at least 2-3 meter...
Did white's surfmaster pi can detect a medium metal object in 2-3 meter
depth ?

for deep search white's surfmaster pi is better or deltapulse ?

[WM6]

Hi,

I want to dig at least 2-3 meter...
Did white's surfmaster pi can detect a medium metal object in 2-3 meter
depth ?

for deep search white's surfmaster pi is better or deltapulse ?

With proper coil you can reach 2-3m depth.

For 2m use coil of about 120x120cm for 3m about 180x180cm (coil have to be adapted to MD circuit /dumping resistor - scope/)

The only problem is to mantain such big coil in field.

[GOLDENSKULL]

Thanks WM6,

For deep search 2-3 meter with large coil, white's surfmaster pi is better or deltapulse ?

[GOLDENSKULL]

For big coil construct the Delta Pulse with a 1x1 or 2x2 m coil.
Very good and stable detector for large objects at big depth. Also you can Try the (PS-G lite clone) from Georgi Zhelev, it has one kind of discrimination and it has designed better for big objects at big depth.

Hi Geo,

please put more information and schematic of (PS-G lite clone) from Georgi Zhelev ...

Thanks...

[WM6]

Thanks WM6,

For deep search 2-3 meter with large coil, white's surfmaster pi is better or deltapulse ?

It depend on how to construct one or other, but both are in proper configuration capable to detect bigger objects at depth of 2-3meter.

[GOLDENSKULL]

Did anyone have White's Surf PI Pro schematic ?

[Melbeta]

Depends on what you are looking for....

Did anyone have White's Surf PI Pro schematic ?

Golden Skull,
Metal Detectors are not universal metal locating instruments. Each is designed for its own purposes. So if you want to go looking for gold nuggets in a stream area, since a gold nugget is usually small, then you can use a BFO detector, which is a beat frequency oscillator, as the minerals in the ground slow down the oscillator, you can turn up the beat frequency, and it will go faster, and then compensate for the ground minerals pulling down the beat frequency. In those cases, I would set it on mineral search, rather than metal search, and then search for black sands, which are the minerals, then when you find a large concentration of black sands, then you dig down to where the gold is, then set it on metal setting, and then search for the gold nugget.

Now if you are looking for a buried treasure, then go with a 2-box unit, which will go down deeper, and find large buried treasures.

But a VLF or a PI (pulse induction) detector will far surpass a BFO! The BFO is an old technology machine, and in my thinking, it is only good for finding black sand (minerals) today, when you can have better metal detectors available today.

If the area is heavy with ground mineralization, then go with a Pulse Induction machine, as they are great on wet mineralized beaches.

So tell the forum first, what it is you want to go after, and 2 to 3 meters, in my language are probably 6 to 9 feet deep, and that is deep. So also remember, when going that deep, the target cannot be a small coin, as it will not see it at all. The target HAS to be a big target, or the coils will not see it at all....

So tell what you are after first, then you will get more specific information, that you can use to make what you want to use to do the job....

[GOLDENSKULL]

Golden Skull,
Metal Detectors are not universal metal locating instruments. Each is designed for its own purposes. So if you want to go looking for gold nuggets in a stream area, since a gold nugget is usually small, then you can use a BFO detector, which is a beat frequency oscillator, as the minerals in the ground slow down the oscillator, you can turn up the beat frequency, and it will go faster, and then compensate for the ground minerals pulling down the beat frequency. In those cases, I would set it on mineral search, rather than metal search, and then search for black sands, which are the minerals, then when you find a large concentration of black sands, then you dig down to where the gold is, then set it on metal setting, and then search for the gold nugget.

Now if you are looking for a buried treasure, then go with a 2-box unit, which will go down deeper, and find large buried treasures.

But a VLF or a PI (pulse induction) detector will far surpass a BFO! The BFO is an old technology machine, and in my thinking, it is only good for finding black sand (minerals) today, when you can have better metal detectors available today.

If the area is heavy with ground mineralization, then go with a Pulse Induction machine, as they are great on wet mineralized beaches.

So tell the forum first, what it is you want to go after, and 2 to 3 meters, in my language are probably 6 to 9 feet deep, and that is deep. So also remember, when going that deep, the target cannot be a small coin, as it will not see it at all. The target HAS to be a big target, or the coils will not see it at all....

So tell what you are after first, then you will get more specific information, that you can use to make what you want to use to do the job....

Hi Melbeta, and all friends...Thanks,

I must say i want search more on minerals and sand grounds, not in beaches, in depth 2-3 meter for meduim and large buried treasures not for single coin,
what MD is better for me to building... ?

[Geo]

Hi Geo,

please put more information and schematic of (PS-G lite clone) from Georgi Zhelev ...

Thanks...

Here it is
http://geotech1.com/forums/showthread.php?t=16325

[Melbeta]

Well, I would say go and ask some MD dealers....

Not knowing just precisely what it is, that you are looking for, I would say go visit some metal detector dealers, look at their machines, bring along something that is metal, and more likely nearer the conductivity of the metal that your future target will resemble, and is near the "medium" or "large" sized treasure you are going to look for, and see how their machines respond to it, in an air test, from 2 to 3 meters away.

Experience is the best teacher, for a person who has no idea of what he wants. Go and see what metal detectors, at various dealerships actually do with a piece of metal. And if you can actually give them some idea just what it is, that you want to search for, and the depths, you might find the ideal machine...

Keep in mind, that a metal detector, creates an electronic electromagnetic eddy field (which I have read in books written by Charles Garrett), which flows over, and on the surface of the metal object. Now that eddy, as I understand it, is running around on the surface of each individual coin, it does not see the coins as a mass single object. Now it is the magnetic eddy field, that the receive circuits, actually see.

Now if you can imagine that an separate eddy field is running round and round, on each individual coin, that is not likely going to be seen 2 to 3 meters (6 to 9 feet) in the ground! But if the coins are all inside a large iron chest, well that is another story. The detector does not see the coins inside the iron chest, it sees instead, the actual iron chest surface area. So the eddy will flow around the iron chest, not the coins hidden inside it.

So now you see why I asked you what the treasure is?????

If it did indeed see the mass of coins as a large object, rather than each single coin object, it would see them deeper. Imagine all of the coins are now connected together, and I will say rusted together, or corroded together into one mass, especially with the same metal if possible, as a method of description, it will see a larger mass object, as each coin sees to have merged into another coin, like they are one large coin, through the method of metal to metal attachment. So I repeat, if the coins are now fixed together, such as like they would corrode (corrosion) into a larger single sized object, the eddy will run, not on each individual coin, but over the entire mass of metal, and it will now look more like a large piece of metal, not a bunch of coins, and you will see all of those individual coins also deeper.

Circumstances in the ground, not only the target, but the mineralization of the ground, determine the outcome. I will summarize now...

I will say simply "bigger is better", if you are going deeper into the ground. And bigger coils are also better, if you are going deeper into the ground. And a machine that does not respond to the mineralization of the ground, is also a deeper seeking metal detector. Thus a pulse inductor detector begins to sound better and better. Now you can understand the interest in the vintage old Minelab Relic Hawk?

So if the treasure is a ceramic container, full of dollar size coins, rather than the same container full of penny sized coins, it will see the container with dollar sized coins deeper. It does not see the ceramic container, it goes through that container, and sees its contents. So if it is a steel safe buried, it will see that deeper. It will not see the coins inside the iron safe! Just the iron safe.

So now you can understand, that a detector sees larger sized targets, that are a mass target, rather than a collection of individual targets, deeper.

So you can understand, that larger coils see the same sized object deeper than smaller sized coils, but with less sensitivity, and less response, then the smaller coils. Now you understand the problem better.

One has to know (1) what the target is,(2) what its size is, (3) what its metal content is, (4) what its depth is, and (5) the mineralization of the ground that the target is located within, BEFORE one selects a likely metal detector. Or before one selects a certain sized search coil. Or before one selects a two box detector over a Pulse Inductor or VLF detector.

In your case, I think you must first "get a feel for the market", and get some experience seeing what metal detectors will do, with some metal targets that might resemble your eventual target, before your questions can be accurately be assessed and solution rendered...

[GOLDENSKULL]

Thanks Melbeta,

I will go to build and test my BFO MD with Micro...