What similarity ?, what differences ?

[aft_72005]

Hi ,
My question from LRL mans
What similarity and what differences is between metal detector
And LRL or pistol detector ?
Best regards.

[aft_72005]

Hi ,
My question from LRL mans
What similarity and what differences is between metal detector
And LRL or pistol detector ?
Best regards.

Without reply !!!!!!????

[J_Player]

Without reply !!!!!!????

Maybe LRL experts do not know what the differences are. ?

From the perspective of a person who understands metal detector theory and LRL theories, I can explain what appears to be the diffrerence in theories and maybe operation between LRLs and metal detectors. Maybe an LRL expert who knows the answers can find some errors in my perspective and explain how it really works.

To begin, there are many kinds of LRLs:
A. Dowsing and electronically enhanced dowsing types.
B. Active coil types that broadcast an alternating signal that may be detected by any number of means.
C. Passive electronic types that listen for signals similar to a radio receiver with no transmitter.
D. Hybrid types that use a modified metal detector of some sort combined with "strange" circuitry that is not well explained.

There are many variations of these kinds of LRLs with overlapping between the classifications.
Variations can include using any of the following TX and RX methods:
1. Coils tuned to ELF, VLF and any other RF frequency into the microwave region (most often VLF).
2. Ariel antennas operating at anywhere between ELF to microwave.
3. LEDs, Lasers for TX of a beam to stimulate different areas of ground to be scanned, and coils to detect the response from the ground.
4. Broadcast band receivers used in passive mode or in conjunction with low power transmitters.
5. Electrostatic electronic sensors.
6. Dowsing rods with electronics added, such as low power signal generators connected to the rods or to the ground, or broadcasting in the air.
7. Dowsing rods with samples, magnets or "power loads" added to somehow influence the effectiveness of the rods.

Of all the kinds of LRLs I listed, the most similar to a metal detector is the TX/RX coil style pistol detector.
What is different?

Metal detector theory
Metal detector theory requires the TX coil to produce eddy currents in a target metal that can be detected in a receiver circuit. This depends on using a sensitive circuit and coil that can pick up the eddy currents, and hopefully examine the kind of eddy current to help determine what kind of metal is detected. Metal detectors are limited by the range of the magnetic field that can be transmitted as well as the range of the magnetic field of eddy currents. When the RX circuits are turned up to a high enough gain for maximum range, the problem becomes electronic noise from the internal circuits. If the circuits are optimized for minimal noise, then the second problem of external noise will become prominent --- noise from power lines, EMI, RF in the air, and even noises from the ground due to variations in earth currents interacting with mineralization in the soil. In order to avoid this kind of interference, most detectors have a faraday shield and ground balance circuits to "de-sensitize" the electronics so it will find signals that are not buried in the noise. The remaining signal is focused on the magnetic field with the electric field removed.

PD theory
If we compare a simple TX/RX coil type PD LRL to a metal detector, the first difference is there is no Faraday shield. The PD is also equipped with adjustments that allow it to be tuned much deeper into the noise region, and in some cases beyond stable circuit operation. We hear the experts of LRLs tell how it is necessary to move very slowly and hold the PD steady out in front pointed below the horizon, as well as not to wear clothing that collects static. It would seem they are trying to detect a signal at the extreme sensitivity adjustment, where any user movements could cause false signals. In fact, I expect this sort of detection to pick up a lot of EMI/RF and other interference noise from the air. The signals they are looking to find are not eddy current signals. For a VLF coil to receive a signal more than a meter or so, it must be operating as a radio receiver looking for variations in the broadcast signal. Without a Faraday shield, the electric field is not inhibited, so full RF TX and RX are possible. Possibly the amount of RF that is absorbed in the soil changes, and the diffraction of RF can be sensed. Or maybe there are RF reflections when a target is in range. According to some of the LRL experimenters, there is a hot spot in the location of long time buried metals that interacts with the signal they receive. It is unclear whether this signal must be transmitted, or if it exists separately from a transmitter, and can be detected with a simple passive receiver.


So far I described the theoretical difference between only one kind of LRL and a metal detector. There are many other kinds of LRLs.

The common difference LRLs all have from a metal detector can be summarized as follows:
1. They are claimed to detect metals at long distance using methods that cannot be demonstrated to be working live in front of skeptical witnesses.
2. Most LRLs require long-time buried metals in order to work. LRL experts claim they detect a secondary phenomenon that develops after metal has been buried a long time. But what secondary phenomenon they claim to detect has never been explained in a manner that can be demonstrated or duplicated. Usually the method of operation claimed can be shown to be untrue with simple instruments.
3. Anyone with electronics and construction skills can build a metal detector that works. Nobody can build an LRL that works except a very few people who do not demonstrate the LRL working in front of skeptical witnesses*. The idea that their LRL works exists only in their stories, not in the experience of most people who read their stories.
4. All LRLs seem to require special methods or skills to use them successfully. From dowsing to electronic coil LRLs, there are special instructions that must be followed before any chance of detecting can happen. Also the "environmental conditions" must be favourable in order for them to work. These requirements seem to work to compliment the fact that LRLs cannot be demonstrated in front of skeptical witnesses. These requirements also work to compliment the fact that nobody can build an LRL except the very few people who say they can, but do not demonstrate them working.

Those are some differences between metal detectors and LRLs that I have observed from a technical perspective.
Are there any LRL builders or users that see some errors in my observations, or know some more differences?

Best wishes,
J_P

* Exception: Morgan and Geo demonstrated LRLs they built to other forum member (not completely skeptical). Maybe there are a few others who also did?

[Gwil]

Metal detectors compared to LRLs

(1) Metal detectors operate on well established scientific principles.

(2) LRLs apparently operate on theories that do not appear in any textbook and that would be worth several Nobel prizes if they could be proved correct.

Perhaps one day those Nobel prizes will be awarded. But I have my doubts.

Gwil

[J_Player]

(1) Metal detectors operate on well established scientific principles.

(2) LRLs apparently operate on theories that do not appear in any textbook and that would be worth several Nobel prizes if they could be proved correct.

Perhaps one day those Nobel prizes will be awarded. But I have my doubts.

Gwil

I agree,
Nobel Prizes are awarded to people who demonstrate they have made a great accomplishment.
If it is not demonstrated to be correct to the Nobel Prize committee, then there will be no prize.

Best wishes,
J_P

[detectoman]

hello aft, the lrl difference is; these lrl are put in reception limits, are dm extremely hot"
but whit special support
md have little radio of magnetic irradiation
lrl extended these radio of propagation and reception in waves multiples' armonic
i see, esteban can give you exact detail
i never tried my probable wrongs stuff lrls
im entusiast hobbyst
i am teoric builder, but when i sure any lrl of me is experiment superior, and my buried coins already, i go try all these extrange cacharros

[aft_72005]

Possibly the amount of RF that is absorbed in the soil changes

Hi J_Player


Are you know about absorption type PD ? and what happened when this PD
Seeing targets ?

Best regards

[aft_72005]

Hi detectiman,
Always theory base of practical design , but , important is specially correct
Data .
Best regards.

[J_Player]

Hi J_Player


Are you know about absorption type PD ? and what happened when this PD
Seeing targets ?

Best regards

Hi aft,
Absorption type does not exist. This is only a word that Esteban chose to describe a low impedance passive coil detector that responds to noise and the alledged "phenomenon". It has never been demonstrated that there are any emissions, or that these passive coils are absorbing anything. The description of the response would suggest the coil and amplifier develop a signal when pointed in the direction of long range buried metals. Nothing more. According to Esteban, he concluded the coil is absorbing emissions from the "phenomenon" area of the ground near long-time buried metals.

Here are some references to show the origin of the terminology "absorptive detector":

Esteban explains the ways to detect the "phenomenon" produced by long-time buried metals: http://www.geotech1.com/forums/showp...1&postcount=81
No only gold (buried for many years) produces electrical changes in the vecinity of an electrode (Mineoro's electrode, in this case). Here occurs a disbalance of charges.
Also, the ELECTRICAL variation in a site with buried metal is detectable by a simple FM radio.
You can detect via this methods:
1. radio
2. coil (oscillator)
3. infrared
4. magnetic absorption
5. microvoltmeter
5. association between 2 or 3 the above
Continuous detection (reproducible in the air) maybe is not possible yet, because the involved phenomenon depends of the electrical field produced by the long time buried metals.

Esteban describes how absorption is accomplished with a ferrite in the pistol detector, while the metal detector part is for pinpointing at close range: http://www.geotech1.com/forums/showp...4&postcount=20
Pistol detector based on regular detector works as long range detector (some meters) and is possible in conjunction with other(s) circuit(s).
Morgan has success finding targets with it, I have success with similar instrument... so maybe the problem is errors in schematics or connections.
The ferrite section is the real long range detector in this project.

Pistols with MD can be:
1. Based in regular MD + RF circuit
2. Absorption as the ferrite, in wich case MD is for pinpointing unburied target.
And more and more combinations. Conclusion: an unexploded field with infinite possibilities.

Esteban explains why he calls the magnetic/electric detection "absorption" rather than response to an anomaly: http://www.geotech1.com/forums/showp...&postcount=127
J_P: From what you have posted, it appears that your machine is only showing different "beeping responses" when the target is removed, which has convinced you that your machine is absorbing emissions. However, I am not convinced. I do not believe there are any emissions from the "phenomenon" area except an increase in radionuclides for long time buried metals. And it also seems that your machine is not capable of counting radionuclides. Therefore, I speculate that you are detecting an anomaly of some sort, -- not emissions.
Esteban: I use "emission" because some very sensitive instrument that enlarge a short pulse 100,000,000 times show the target in wide angle, so is difficult to centrate due the anomaly. But the anomaly only is detectable or better detectable when target is buried for many years and near surface, 10-30 cm. When small target is very deeply maybe you obtain few detection or only a beep, except if the mass is a treasure.
I use "absorption" because I consider that a loop with a toroid can absorb some magnetic-electric anomaly around such targets

Esteban shows photos of a classic "absorption" ferrite sensor in an experimental LRL: http://www.geotech1.com/forums/showp...96&postcount=1

Esteban describes absorption of "phenomenon" with experimental magnetic device detected bronze that Mineoro could not find: http://www.geotech1.com/forums/showp...7&postcount=86

Esteban explains how absorption works to detect local magnetic and electric field using the pistol detector: http://www.geotech1.com/forums/showp...2&postcount=22
Qiaozhi: Are you attempting to detect differences in the local magnetic field or the electric field?
Esteban: The both. Devices based in magnetics (passive type, absorption mode) must be low impedance loop/low resistence coil for to no catch interferences and detect only non ferrous, but have not much distance, only few meters. Except based in magnetics type MD coils (active). Based in this same type but with many turns coil catch ferrous...
But based on electric field go more far (antenna, microvoltmeter type).
Qiaozhi: But your detector is a handheld pistol-type. How can this detect a potential difference in ths soil? Or is this using a different technique?
Esteban: Because, is the form for this kind of detector, is not equal in form that regular MD, except if there are an IB detector coil attached in a box with handle. Just this is the job of the electronic LRL: to detect the difference in the soil, and his more sensitive since you don't approach in the soil, so is free of effect soil and capacitance.

Esteban tells distances of detection when using different LRLs: http://www.geotech1.com/forums/showp...9&postcount=51
IR (infrared) + FM radio = 7 m in distance, depth for coin max. 50-70 cm.
Absorptive can catch 20 m or a little more, but depth is other theme. I think treasure at more 4 m depth can't be detectable at this distance (30 m), but in vecinity yes.

http://www.geotech1.com/forums/showp...76&postcount=4 IR + FM radio + magnetic absorption antenna = 25 m


============
The concept of "absorption" means a low impedance coil usually on a ferrite is connected to a receiver/amplifier with an RF detector circuit, similar to an AM radio receiver. Whatever signal is received is passed through a threshold detector and made to beep when it becomes stronger than the threshold setting. This is called "absorptive detection".

Best wishes,
J_P

[Esteban]

New antenna born! Here is important the position of secondary core wich takes the "info" from loop-primary coil-ferrite. System no patented yet? Who knows? Have others... Of course, coil (loop) can be aluminium round, square, rectangular. I'll post photo soon...

[WM6]

New antenna born! Here is important the position of secondary core wich takes the "info" from loop-primary coil-ferrite. System no patented yet? Who knows? Have others... Of course, coil (loop) can be aluminium round, square, rectangular. I'll post photo soon...

Hi Esteban

I dont know if it was patented exactly as you draw, but it was used many times in different schematics as air TR coupled., ferrite rod TR coupled, or ferrite pot transformer coupled.

[Esteban]

Hi Esteban

I dont know if it was patented exactly as you draw, but it was used many times in different schematics as air TR coupled., ferrite rod TR coupled, or ferrite pot transformer coupled.

Hi WM6.

Note that here the difference is the core with possibility to adjust into a X point in the ferrite bar. Here elements, no yet assembly.

[Esteban]

In this other method, antenna only acts as "guide" of signal. A movable core is positioned in best point according "phenomenon caused by gold signal".

[WM6]

Hi WM6.

Note that here the difference is the core with possibility to adjust into a X point in the ferrite bar. Here elements, no yet assembly.

Yes, Esteban, by using ferrite bar tunning of such antenna can be more comfortable for our lab conditions.

What dimension of ferrite rod you use?

[Esteban]

Yes, Esteban, by using ferrite bar tunning of such antenna can be more comfortable for our lab conditions.

What dimension of ferrite rod you use?

The more large I have in this moment: 18 cm long, 1 cm diameter.