View Full Version : directional detection
Funfinder
02-20-2013, 01:32 PM
To find an object from a distance different detection-methods are possible:
- focusing or amplifying a radiating power source
- measurement of different field strenghts
- calculation of reliable data
And in our LRL case:
- analyzing the field around the object
The most important question is:
what kind of directional antenna works the best and
what kind signal does it detect, electric or magnetic.
electric: natural or/and artifical
(static energy, ion-storms, lightning / EM waves of all kind)
magnetic: natural or/and artifical
(earth magnetic field, magnetite / the magnetic of EM waves)
An AM-ferrite-coil works the best if it is horizontally positioned
and at a 90° angle to the vertically transmitting AM-antenna.
An FM-antenna (the same with satellite signals) must have the
same polarisation.
The usual metal detectors coils works like an electromagnet-wire
concerning the concentrated magnetical strengh in the middle
which then radiates up and below. This is also directional -
directly in front of the coils center (or in the middle) the best detection is possible.
Now lets see what scientifcially knowledge you can contribute.
This is another try to get here in this forum some real advance
concerning "how LRL work".
But it needs scientifical thinking methods and not "dreaming"!
Logically seen a certain antenna-design also leads to the
received kind of signal. Per instance with a telescopic-antenna
AM reception will be difficult.
If you see at the drawing there are squares with A-E and 1-9.
Each of this areas must have a different field-strengh if LRL detection
works! Because the buried metal doesn't radiate by it self, as long as
it is not radio-active and even then the x-rays could get stopped by the ground.
btw. another directional detection method is with reflecting shields like
satellite-dishes or metal pipes. As example you can built directional
WiFi antennas with peanut-cans. But such antennas only work for
very small wave-lenghts, UHF and upwards.
Standing at one of such squares with the pistol-detector represents
a special "field-situation" but starting at each of these points
the detector needs to have the possibility to locate the next
square with the higher energy-level.
Therefore the directional antenna design is crucial important.
A pure static-energy-or EM-field-strenght meter without
a correct directional antenna design always can only detect
or measure the actual situation but without further coordinates.
Of course such a device would be completly useless for long range,
cause any direction could be the right one.
So at least two different coils are needed where the received
energy level between both of them gets compared. Comprende?
So now please take a look at the different antenna-designs and tell me
what kind of signals will be detected!
Good Funfinder, Thanks.
If we go further in those "detecting transmitted signal" theory, there are 3 way of such detecting:
1.) detecting from target reflected signal,
2.) detecting target shadow of signal
3.) triggering target to resonance by TX signal and detecting resonating target
No one of mentioned method are capable to detect small metallic target as coins. First two only for bigger ore deposit in theory. Only a third method has been used in practice and applied in devices for detecting resonating things as underground cables and pipes.
http://img703.imageshack.us/img703/1055/txsignaldetecting.jpg
FrancoItaly
02-20-2013, 05:34 PM
Hi All
Any explanation must take into account the features of the phenomenon, i.e.the relationship with north/south direction and the fact that a single meter of B-field, E-field, infrared, EM in the full range of frequency, they cannot sense the phenomenon. A non shielded trasmitting coil (with RX coil or not) followed by a high gain stage it's very sensible to "sky/compass" effect. This effect is present in all locations regardless of the configuration of the territory. Not shielded coil means that it's sensible to E static fields and north/south direction makes us think of the Earth's magnetic field in some manner it influences the phenomenon.
I favour the atmospheric electric field with solar wind and/or cosmic rays. The very important thing is that the buried target doesn't emit anything but only it disturbs the surrounding environment and this disturb is directional that is for example a signal east-west direction 1 meter along and nothing for other directions. This is a true case of a brass bullet detected by a lrl and a MD. To understand the inner cause of the phenomenon is not so important, I think it would take very sophisticated instrumentation but it is important the way to detect it. The direction of max sensitivity not always it is east-west or north/south and the north/south direction is not equal to south/north direction. I think to a ground battery combined with south/north ionic channel or maybe the lines of force of the atmospheric electric field are curved towards the North.
Best Regards
humhum
02-20-2013, 06:40 PM
Hi All
Any explanation must take into account the features of the phenomenon, i.e.the relationship with north/south direction and the fact that a single meter of B-field, E-field, infrared, EM in the full range of frequency, they cannot sense the phenomenon. A non shielded trasmitting coil (with RX coil or not) followed by a high gain stage it's very sensible to "sky/compass" effect. This effect is present in all locations regardless of the configuration of the territory. Not shielded coil means that it's sensible to E static fields and north/south direction makes us think of the Earth's magnetic field in some manner it influences the phenomenon.
I favour the atmospheric electric field with solar wind and/or cosmic rays. The very important thing is that the buried target doesn't emit anything but only it disturbs the surrounding environment and this disturb is directional that is for example a signal east-west direction 1 meter along and nothing for other directions. This is a true case of a brass bullet detected by a lrl and a MD. To understand the inner cause of the phenomenon is not so important, I think it would take very sophisticated instrumentation but it is important the way to detect it. The direction of max sensitivity not always it is east-west or north/south and the north/south direction is not equal to south/north direction. I think to a ground battery combined with south/north ionic channel or maybe the lines of force of the atmospheric electric field are curved towards the North.
Best Regards
Very correct info and I agree with you Franco , plus I think that when Earth's magnetic field dissolution or impaired from buried metal, around this metal consists generation from all Transmitters frequency. Now this buried Metals is so like Magnet and Receive all freq. , because Earth's have very strong magnetic field . ;)
Funfinder
02-21-2013, 06:31 PM
Thanx everyone for your "realistic" interest.
Now I have created a second drawing for better illustrating the
following conclusions:
The starting point is the electronic circuit itself.
I'm shure we have already enough info that it is either based on electrostatic or on long wave reception in combination with at least "power-level" comparing circuits.
The solution ist very simple:
Instead of using a selective long-wave radio-receiver circuit that
concentrates on just one frequency it observers the magnetical
part of that waves over a large range which will give a 1000x times
higher sensitivity.
It's shure that the magnetical part of those VLF waves get detected!
1. because of the coil-antennas
2. because only the magnetical part interacts on a useful level
with the buried objects and penetrates the ground
Now let's compare it with the Two-Box detector:
Both coils are balanced and if the metal box gets enough
distance to one of the coils the induction starts, reduces the
orginal fields and creates imbalance.
Under "natural conditions" it will be the same.
The LRL passive receiver is balanced to the field-condition.
It doesn't need a transmitter because there are enough
long-wave-transmitting sources available "for free".
If those waves come across a location with buried metal object
they have to interact with it - this is a physical law.
The induction-process works on a steady and longtime basis.
The finetuned passive receiver will detect the same way as the receiver coil
of the two box if the "inductivity situation" of the ground changes -
no matter if it gets stronger or weaker.
And the directional antenna leads there, because if the left coil
starts to get more or less energy it is clear that the changing
field situation must be near the left side!
The metal object works like an antenna with shortcut,
it converts the power of a huge electromagentical spectrum
into it's own energy, it sucks away this free energy and
leaves the surrounded region with a slightly changed
field-condition.
The reason why some of those detectors are sensitive to
north south direction has to do with the magnetical receiver
circuits and the extreme sensitivity that is needed to
detect those very weak field-differences.
The picture below shows the real situation very well:
There are many different EM-fields interacting which makes
the whole thing very complicated.
Perhaps if buried metal object interacts with the electrostatic
force-field this field also disturbs the field lines of the
earth-magnetical field and of the magnetical pulses of all
kind of long-waves.
The crucial point is the receiver circuit itself!
As described already, it has to work on a huge frequency range.
From 5kHz to 100kHz it has to measure the magnetical power
level of this range like a voltmeter.
If such a receiver would be finetuned to 50,972 kHz and observers
only a spectrum of plus minus 5 Hertz the "magnetical induction difference" near a
buried metal object would be almost nothing - no way to detect it.
btw. it's a mistake to think that a buried metal object would
leave the surrounding EM-Fields untouched. It will change it like
a find close to a metal-detectors-coil, just on a much weaker level.
And the EM-fields are not just available above the ground!
Depending on the mineralization, moisture and consistence
ground can transmit EM-waves even better than air - we see this with seismic waves (an earthquake in the air would be harmless).
And ground is not always the huge minus-pole that swallows all electricity or EM-fields. If this would be the case no metal detector could work, because all radiation would be "shortcuted".
Now a good question:
Why such a magnetical long wave LRL-locator won't get confused
by different radio stations (see picture) or only is useful to find
the direction where the radio-station is located?
Answer:
Because it is not finetuned to one single radio-station,
but to a huge long-wave spectrum.
It is almost comparable with a little AM-Radio and the
white-noise level it has, depending if it is used inside
of cave, tunnel, cellar compared with a tower, rooftop or hill.
Or compared with antenna attached or not.
Such a radio will detect the location because it has a
different field-strengh level.
So what is really needed for such a detector?
- high inductive coil antennas, each at least 100 windings, the more the better and also the diameter must be not too small.
Those coils must be really fixed tight and strong.
- a nonselective but wideband long-wave passive receiver stage
- electronically very stable and high sensitive circuits for reliable
signal level comparation-tasks
- adjustable sensitivity for wide varying country, weather, ground and other EM-field strengts
- the possibility for fine-adjustment close to real outdoor conditons
(trimpots easy adjustable directly while already in nature)
Any questions?
Shure, there always will be more to discover, but personally I'm convinced
that if LRL works, it will only work reliable this way!
And it's pure logical, its like a gigantic high sensitive 2box-detector with moving receiver while the radiation comes from all sides naturally.
And I'm shure if we isolate the "passive receiver" circuits from many
of those homebrew LRLs we have the proof that they are using
a simple long-wave receiver with magnetical-antennas!
Even the ferrite coil antenna works on the same principle.
What really count's is to understand that this "phenomenon"
is not based on one tiny and weak frequency, but on the sum
of a huge range of a large long-wave EM-field-area.
For an usual metal-detector it would costs an unbelievable
huge amount of battery-power if it would receive and transmit
on 100 or more frequencies at the same time!
In nature this is different - the most of the usual long wave radiation
is pretty weak and the source very distant, but it multiplys extremly
if "melted together".
We see similar effects at the aurora borealis (the northern light) and its proven that sunstorms even can interupt completly powerful radio-communication. If those energy-fields are summing up they are really powerful and of course easy detectable, too.
A final word about how good will it work in practise:
2 factors are important:
- enough powerful free available long-wave radiation
- stable and sensitive enough receiver
Most of the time the second point will be the problem!
Some long waves are available everywhere, but will they
give enough detection contrast???
A very sensitive and stable receiver will have no problem,
but a homebrew DIY box will need a certain amount or power
of given LW-radiation or it will detect no difference or nothing at all.
And if there is snow or rain the EM-field gets weakend even more.
But such detectors may function good enough in the evening time
and if weather is good.
How to built it?
The easiest way would be modifying a high sensitive LW-radio.
It needs 2 high inductive magnetical-coil antennas and a little circuit
to see at what antenna is more or less energy at the moment
and while pointing the detector into different directions.
How to make such a receiver "unselective"?
Simple remove any "resonant circle" (coils, capacitors) that tunes the receiver to
a certain frequency. But I hope we can get more precise info
about this topic. The receiver also should stop somewhere at max.
200kHz because the magnetical energy of higher frequencies
has much more trouble to penetrate the ground.
And finally it is important to go outside to calibrate this receiver
because calibrated at home it will not work outside and vice versa.
Good luck! :cool:
FrancoItaly
02-22-2013, 11:17 AM
Hi Funfinder
I don't agree with you, my lrl has no magnetic parts, only a small inductor (3 turns, diameter of 1 cm) and mainly a stylus antenna, only 20 cm works fine. A not shielded coil (PD pistol) means sensitivity to static charge and the working frequency seems to be unimportant and this seems to exclude RF emission. It's true that RF waves have B-component and E-component but I experienced the same behavior in many different places between them, close to the sea and in the mountains and it is unlikely that radio emissions cover evenly the territory. I think that the penomenon it's simply this: we move the lrl from from left to right and vice versa, the lrl sense a change of the E-field and this changes the amplitude of an oscillator or better a high gain amplifier in oscillating mode. If this oscillator is "hard" to "modulate" we sense only the sky/compass effect.
Best Regards
Funfinder
02-22-2013, 09:51 PM
Hi FrancoItaly
and thanx for your reply.
An unshielded coil has nothing to do with electrostatic charge.
For static power only a electrode is needed, the larger the surface area, the better.
As we know already from tests, those electrostatic-receivers aka
electro-meters does not work as LRL.
What is your definition of sky/compass effect?
Do you have had already real success with your static-LRL
and can you scientifically prove that it really works?
We have here already since 7 year all kinds of "my LRL works"
claims but it is high time that we stop all those rumors and
find a real scientifical basis!
So if your LRL really works, FrancoItaly, at least you have to
describe exactly why you think that it can work just by
simple electrostatic.
btw. static charge is not horizontally so it can't work from many meters ahead.
I built two very sensitive static-detectors on my own and all what they
are detect are artifical high voltage and powersources from a distance,
the ignition-sparks of motors, high-voltage lines etc.
And the static difference is already extremly huge if the detector moves
from 1m30 high to 1m40 upwards the ground so it is absolutly
impossible that a buried metal object is detectable that way!
The field change of a buried metal object is much weaker than
the change of the moving charge detector!
And not to forget:
E-meters are existing since a very long time, as example for
weather forecast (are thunderstorms close etc.) and so far no one
used them successfully for treasure-hunting!
btw. this static crap detection also is the reason why alot LRLs
do not work. I guess this OKM Bionic uses static, too - so its no
wonder that people are very unhappy with this thing!
Electrostatic detectors does not work for treasure-hunting,
thats a proven fact! And at a long distance hundred times not!
back to the real working long-wave design:
Now it is also clear why sometimes an usual metal detector
"destroys" the phenomenon, as it was described already often.
The usual MD emits a very strong long-wave-field compared to
the very weak "naturally" one which overloads the LRLs detection
circuits and may neutralize the very weak longwave-induction field
around the buried metal object.
And I have discovered something else:
Perhaps such a longwave LRL detector also works with just one coil!
Cause if a person walks around he will meet different field strenghts
and if he gets closer to the buried find the field either will start to
get stronger or weaker - and in both cases this would cause to
signalize and so the user by walking around will get an impression
what direction or place is connected with this changed field source.
Two coils would provide an even better coordination, but a single
coils also should do the job and already is somehow directional.
In that case even a horizontally positioned coil could work because
it would receive the field from all directions on an identical level.
btw. we have to think about the roots of physics:
Why do electrons spin around the atomic-kernel?
Do they have some kind of perpetuum mobile? :D :lol:
Do they spin forever and ever and ever without losing energy?
The answer is complicated, but it has something to do with
temperature. Supra conductive material near absolute zero
work because the electrons are not in an "excited" state.
The electrons of atoms are spining stronger the more they
are energized! As example by temperature radiation (infrared).
And we are living usual in an energized world, we have
temperatures that are high above absolute zero.
The buried metal can't remain completly silent, because it
gets highly activated by all kind of natural energy.
Its time to understand the whole laws of electro-physics
from a real low-level basis and not by playing around with
all those ominous circuits that only leads to self-deception.
FrancoItaly
02-23-2013, 12:35 PM
Hi Funfinder
I don't tell that lrl is a static E-field receiver, I have builded many instrument with very high impedance and they were useless as they sense also walls and threes.
Look at my tread "the point of the situation" where I posted the schema of my lrl. This is a low impedance circuit but the stylus antenna makes me think that are involved E-field components of some unknow field. If the gain of the lrl it's too much when we distance ourselves or we approach the North South direction the lrl emits a signal, this is the compass effect and this happens everywhere. The same effect when we lower or raise the lrl. If we move an unshielded coil in an not uniform E-field I think that a voltage is induced in the coil. The lines of force of the static atmospheric electric field they are perfectly vertical or they are slightly curved towards the North ? In the second hypothesis a change of voltage emerging on the surface of the Earth (from a buried target) it may be revealed by the lines of force i.e. 2 meters away and 1 meter above ground. I cannot tell that my lrl works 100%, in my test field it senses 5 silver coin buried about 1 years ago at 2 meters and I find a brass bullet at 1 meter but I have many signals not confirmed by Metal detector. All these signals are well located and away from these signals there are no other signals (sky/compass effect).
Best Regards
Funfinder
02-24-2013, 03:36 AM
Hi,
I absolutly like your contribution here - very good technical based and on a "real" interested basis. With persons like you here we have a chance to find out finally all what counts to get a real and reliable working LRL!
> I don't tell that lrl is a static E-field receiver,
So there is not much left besides long waves!
> Look at my tread "the point of the situation" where I posted the schema of my lrl.
This thread is very interesting, I have read it.
> If we move an unshielded coil in an not uniform E-field I think that a voltage is induced in the coil.
Well, this is a good question (how strong is this induced power etc), but It doesn't really counts. Cause the signal-line has to remain after movement, and induced power would not remain.
The LRL detector isn't moved all the time, it must work correct also if it stands still.
The tree and wall effect is simple electrostatic, flashes love to strike trees because they reach a higher region and contain humidity or even mineralic salts. Walls often are mineralized, too.
For electrostatic often only the pure distance counts.
> The lines of force of the static atmospheric electric field they are perfectly vertical or they are slightly curved towards the North ?
Depending on the charge of the sky they are not always pure vertical, especially if thunderstorms are close nearby.
> in my test field it senses 5 silver coin buried about 1 years ago at 2 meters and I find a brass bullet at 1 meter but I have many signals not confirmed by Metal detector.
This is the problem. You may find the coins because you unintentionally lower the detector just by a minimal distance because you want to get a positive test result.
This is simple to check - let a person try to find the coins who don't know where they are located.
It also could be the case that the ground over or around the coins is different, not that strong comprimated then the surrounding ground.
Seen from a professional angle of view a electrostatic-meter is not a electrostatic-meter, means not all are the same useful.
First such a device should show the exact electrostatic value.
It should contain at least 2 different detection circuits so acurate measurements can taken place (left-right, up-down or front-back).
We have e-fields from 100-300 V/m at good weather to 25.000-35.000 V/m at thunderstorms.
The planet earth is a huge spherical-capacitor, the voltage goes between ground and ionosphere.
If clouds are moving over the sky they change the charge field.
This is in german language but you can see there a schematic to
built a "field-mill", a professional electrostatic-meter:
http://www.qsl.net/dh1stf/aufbauae/aufbauae.htm
btw. the whole site is about electrostatic. http://www.qsl.net/dh1stf/ (http://www.qsl.net/dh1stf/)
Another main reason why a e-field meter device can't work portable for treasure hunting also is the changing ground-contact.
It would need a metal ground-plug and even that would be unreliable.
The e-field directly goes through the buried stuff, and little
coins can't change it in voltage.
If electrostatic would work we could built metal detectors with
high voltage flyback-coils - creating little flash-arcs that will
lead us to the buried metal. To bad it does not work that way,
but at least the lightning so doesn't strikes our shoes. :lol:
Again back to the long-wave principles:
Below we se a real working schematic for a simple
long wave receiver:
The diode "grabs" the amplitude modulation and changes
it into low level audio frequency (ca. 0-7kHz)
On the left this is a ferrite coil with 3x 5 windings and
1x usual 100 windings (L1), it works by transformation,
depending on the coil and variable capacitor (C1, ca. 5-200pF)
you can receive long wave or middle wave (AM) with it.
In our case we don't need any radio-station-audio
and we also don't need a narrow frequency spectrum.
So the receiver must provide the full range of the needed
long-wave band and the detection circuit has to be adjustable
so it only gives a signal if the level of this overall signal
reaches a special high or low energy-value.
The below circuit only gives a little impression,
we need one that contains a much better amplification
and the needed signal-level output for exact detection
of any, even very weak field-changes.
FrancoItaly
02-24-2013, 12:15 PM
Hi Funfinder
you quote "The LRL detector isn't moved all the time, it must work correct also if it stands still" it's no true, my LRL is a motion instrument but recently in a place where there was a strong signal my LRL issued a flickering sound with no movement.
For the moment I'm not interested to know well the theory of LRL or to build other circuits (I have builded more than 30 instruments) but I want to improve the only LRL that works (for me). For those who want to experience should know that it takes a lot of amplification to catch the "phenomenon". You also quote "You may find the coins because you unintentionally lower the detector just by a minimal distance because you want to get a positive test result", all my test are performed also by a friend of mine with the same results and there is no doubt that the signals are real
Best Regards
Funfinder
02-24-2013, 06:36 PM
Hi FrancoItaly,
the fact is that the density of the earths-magnetical field is not everywhere the same. If this field must interact or avoid metal objects it distorts and changes alot, you can see it on my 2nd drawing.
Your LRL works on the same principle as a moving coil inbetween an U shaped permanent-magnet. It will induce electricity, that's why you have to move it most of the time.
This also explains the compass effect because if the coil is aligned to the north-south direction the induction-process will be stronger.
And it will detect the buried metal because it interacts with the magnetized or anti-magnetized field around the buried object, this field is a result of interaction of the earth-magnetical field and buried metal object.
You are right, a huge level of amplification has to be involved to detect differences inbetween such very weak signals.
In your case the coil will induces a raise of some micro or pico volts.
Your LRL seems to be a highly amplificated analog Volt-Meter with special signal-output. By waving the coil around you get electric induction by the available magnetic fields and you can recognize differences.
It's good if also your friend is able to detect the coins, don't take it personal, but I have to exclude all kind of self-deception sources, this is the only acceptable and responsible scientifical method.
Now what you can do is to mount your LRL on a wooden plank and move it on a same distance from the ground over the area from 3m away.
Well, the magnetical field lines would offer the opportunity to catch a distortion from a larger distance. And they are going straight through mountains so if you stand in front of them and it contains ore-veins it should be possible to detect them by the distorted or weakend field-lines in the front or back.
Of course the power of the magnetical field lines are changing alot throughout the world, it has also to do with sealevel, mineralic bedrock situation, mountains and the distance from the poles.
Funfinder
02-25-2013, 05:22 AM
btw. @ FrancoItaly
Do you get a reaction from your LRL if you wave around a permanent magnet
close nearby or if its lying on the ground and you walk over it? I assume so.
FrancoItaly
02-25-2013, 10:32 AM
Hi Funfinder
At the moment are not in Italy, but next week I'll do these tests, but my LRL don't have any coil, only stylus antenna 20 cm elongated...
Best Regards
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