Ground Balance Theory

[moodz]

A working GB in a PI metal detector has been around since 1981. Not perfect, but working on the multiple sample subtractive principle used today. I have a few valve radios from the 1940's, which again are not perfect but working. Both use physical principles that can be relied on in order to operate. Of course, both GB PI detectors and radios are far better now than decades ago, and will no doubt be better in the future as technology and understanding advances.

Radiocarbon dating is more accurate now than it was when first proposed in 1949. Initially it was assumed that atmospheric C14 was constant, but now we know that it is variable and corrections need to be applied. Theoretically viscous decay obeys a 1/t law, but refined testing indicates a small variation. This can now be accomodated with improved electronic filtering. How about so called holes in the response? Holes can be shifted or filled in, so that is not a huge problem.

So what key parameter is assumed to be invariant? You alluded to the coil in a previous post, or is it the strict 1/t decay of the viscous signal? The coil inductance must be a variable, as is the susceptibility of the ground, which also varies with temperature, so I agree coil, ground, and electronics are all part of a system.

Eric.

Eric ...you are correct ...the model needs to include the electronics back to the tx switch and supply ...then careful measurements across the end to end system will reveal where GB solution needs to be applied. Then once the end to end system has been characterised the optimal analysis can be selected ...ie dsp / analogue etc.

[Ferric Toes]

BTW, according to some here, Minelab's patents are either prior art or just plain dumb but the same critics readily believe the ground response is "ratiometric" and the ground exponent is -1 when in fact we have to follow certain rules for either to be true. The requirements for the 1/t response are spelt out in various papers and the "ratiometric" characteristic is the accidental result of a simple design feature common to almost all hand held detectors. Break or not follow a few simple rules and the ground response will not be ratiometric and the 1/t response will not apply.

The 1/t response from viscous ground has been verified by several different methods as reported in the many various papers on soil magnetism since the 1960's. It is acknowedged that it can be distorted by TX pulse shape, but for a rectangular pulse that remains at a constant level for a given time prior to switchoff, the decay is t^-1 +/- a small percentage, due to the spread of particle sizes in a real world situation. This decay does not depend on the method of signal processing. It can be observed directly on a scope straight off the preamplifier.

Eric.

[Ferric Toes]

Back to GB ... The analysis proposed thus far is incompetent because it assumes the invariance of a key parameter which is not the case thus a working GB is no more likely to arise than the works of Shakespeare from a roomful of monkeys with typewriters.

A working GB in a PI metal detector has been around since 1981. Not perfect, but working on the multiple sample subtractive principle used today. I have a few valve radios from the 1940's, which again are not perfect but working. Both use physical principles that can be relied on in order to operate. Of course, both GB PI detectors and radios are far better now than decades ago, and will no doubt be better in the future as technology and understanding advances.

Radiocarbon dating is more accurate now than it was when first proposed in 1949. Initially it was assumed that atmospheric C14 was constant, but now we know that it is variable and corrections need to be applied. Theoretically viscous decay obeys a 1/t law, but refined testing indicates a small variation. This can now be accomodated with improved electronic filtering. How about so called holes in the response? Holes can be shifted or filled in, so that is not a huge problem.

So what key parameter is assumed to be invariant? You alluded to the coil in a previous post, or is it the strict 1/t decay of the viscous signal? The coil inductance must be a variable, as is the susceptibility of the ground, which also varies with temperature, so I agree coil, ground, and electronics are all part of a system.

Eric.

[Aziz]

*** WBGB *** WBGB *** WBGB ***

Hey Robby_H,

are you still desperate not knowing anthing about the WBGB?
Or the Moodz-WBGB?

Aziz

[Davor]

The only important point here is that we are all hobbyists here, that we learn a lot and have fun in a process. It is unfortunate fact that a certain company is incapable playing nice, and reverts to trolling places we commune.

[robby_h]

i claim the WBGB title based on latest tests and hard copy patent applications not theories. Why remove the ground signal through processing when you can actively cancel it ....works on all coil topologies including standard monocoils.

As Moodz and Aziz are both claiming the WBGB title then I'm sure most people would agree that it's reasonable to ask if their technology is routinely finding nuggets in ground “thrashed” by other commercial metal detectors? If so, then they certainly deserve the WBGB crown, and congratulations!!!!!!

But if they are not finding significant gold in thrashed areas, then alas, Eric’s observations must surely apply, ie, they are only "theoretical" detectors.

As I see it, there are three answers to this question...

(1) Yes my technology is routinely finding gold nuggets in real magnetically mineralised ground thrashed by other commercial metal detectors.

(2) The GB technology has only been tested using a lump of magnetite or hot rocks or a sample of well blended ground.

(3) The technology is still on the drawing board or has only been tested on the bench.

If the answer is (2) or (3) then I think most would agree that it can be safely filed away with the countless other "theoretical" detectors that have appeared and then vanished over the last 13 years or so of Geotech.

BTW, according to some here, Minelab's patents are either prior art or just plain dumb but the same critics readily believe the ground response is "ratiometric" and the ground exponent is -1 when in fact we have to follow certain rules for either to be true. The requirements for the 1/t response are spelt out in various papers and the "ratiometric" characteristic is the accidental result of a simple design feature common to almost all hand held detectors. Break or not follow a few simple rules and the ground response will not be ratiometric and the 1/t response will not apply.

And BTW again, has anyone else noticed that those who make the most extraordinary unbelievable claims are also Minelab's biggest critics??

[Davor]

Back to GB ... The analysis proposed thus far is incompetent because it assumes the invariance of a key parameter which is not the case thus a working GB is no more likely to arise than the works of Shakespeare from a roomful of monkeys with typewriters.

It apparently works well for some machines, say Whites, QED... Actually bugwhiskers opened a bit different approach to solving it in a way that also improves S/N.

As for the monkeys, should any of them respond to a name Christopher ...

[Tepco]

That quote is an oxymoron ...Knowledge of the Truth is the real advantage ...The use of that knowledge is the power. My quote ...LOL.

Back to GB ... The analysis proposed thus far is incompetent because it assumes the invariance of a key parameter which is not the case thus a working GB is no more likely to arise than the works of Shakespeare from a roomful of monkeys with typewriters.

May sound like one, but from standpoint of evolutionary biology or etiology or...what not, this man is right, mentioning just for what our hardware is built, not for what it should be. This quote is bit out of context, whole story is different and most probably true.


In second part, i completely agree with, this is the main problem, you most probably already managed to find some regularities (post 255), i'm stumbled upon them too, this is what should be discussed here, real advantage.

[Aziz]

Back to GB. GB? Going back?

[moodz]

“The human mind was not designed by evolutionary forces for finding truth. It was designed for finding advantage” Albert Szent-Györgyi , 1893-1986, Hungarian Nobel Prize winner.


Now, how about going back to ground balance?

That quote is an oxymoron ...Knowledge of the Truth is the real advantage ...The use of that knowledge is the power. My quote ...LOL.

Back to GB ... The analysis proposed thus far is incompetent because it assumes the invariance of a key parameter which is not the case thus a working GB is no more likely to arise than the works of Shakespeare from a roomful of monkeys with typewriters.

[multieagle]

...

What we observe is not nature itself, but nature exposed to our method of questioning.—Werner Karl Heisenberg

An experiment must always example the parameters of the trap made to test it. Yes, I like that.

[Tepco]

....
As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.
Albert Einstein, "Geometry and Experience", January 27, 1921
US (German-born) physicist (1879 - 1955)

“The human mind was not designed by evolutionary forces for finding truth. It was designed for finding advantage” Albert Szent-Györgyi , 1893-1986, Hungarian Nobel Prize winner.


Now, how about going back to ground balance?

[moodz]

... and you are free to complicate to your heart's desire. Or not.

What became clear hereis that the ground exponent is exactly -1, and all other values from literature are merely quirks of measurement.

I like the Heisenberg's motto about measurements:

What we observe is not nature itself, but nature exposed to our method of questioning.—Werner Karl Heisenberg

....
As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.
Albert Einstein, "Geometry and Experience", January 27, 1921
US (German-born) physicist (1879 - 1955)

[Aziz]

Howdy,

look what happens, if you are the "World's most crazy metal detector designer".
I do have an ulti ultimate super-duper hyper negative IQ.
(see below )


BTW, I also have a complete cup/t-shirt series of my WBGB-saga. A WBGB-song too.

Aziz

[Davor]

I like the crazy part, but be sure to strike out the patenting part - there is no such thing as protection in a patent that will ever work in the inventors' benefit. Too many people lost their time, money, families, lives ... everything - after filing a patent.

Patents are merely toys in the hands of big players, and they are extremely fussy about their toys.

See what patent did to bugwhiskers. That was some protection.