Two ultrasonic articles

[Max]

Max, you need to made a few effort and type on the web the words infrared antenna. The light consist in photons and a train of photons is a beam. Each photon is a nanoantenna and a beam is a large antenna. This is the reason you can transmit voices in others via this beam. If you can transmit, you can receive.

Hi,
sure... but aren't we talking of 62Khz signal there ?

So how the hell such short wavelenght thing will help you detect LF signals ????

Do not understand. Now you're talking about phonons ???

Isn't that a little presumptuous issue... when devices are nearly made of old parts and junk ?

Kind regards,
Max

[Max]

I don't know why the most "sense of humor" is used on RS forum...

I think that such images don't contribute in it. And consume bytes.

Regards

Ok... from now on... I will post just stamp-sized schematics and trashy-lrl pictures... to save bytes!

Kind regards,
Max

[Esteban]

Ok... from now on... I will post just stamp-sized schematics and trashy-lrl pictures... to save bytes!

Kind regards,
Max

Ok, continue posting it... you made a great work! Congrats!

[Max]

Ok, continue posting it... you made a great work! Congrats!

uhm... don't like polemics too ???

Ok... no cartoon , no polemics... seems you're not generalist... I hope you at least like sports!

Ok Estaban, coming back to the topic... the IR beam is an antenna and there's are phonons , right ?

Why the use of RF receiver then , like the passive ferrite ?

I mean, why don't use just an optical solution if so...?

And in the case of spontaneous potential why don't use just electrometer ?

Kind regards,
Max

[Esteban]

Hi,
sure... but aren't we talking of 62Khz signal there ?

So how the hell such short wavelenght thing will help you detect LF signals ????

Do not understand. Now you're talking about phonons ???

Isn't that a little presumptuous issue... when devices are nearly made of old parts and junk ?

Kind regards,
Max

For the same reason a IR very short wave beam can carry LF like voices, for example, why not for other purposes?


Regards

[Esteban]

uhm... don't like polemics too ???

Ok... no cartoon , no polemics... seems you're not generalist... I hope you at least like sports!

Ok Estaban, coming back to the topic... the IR beam is an antenna and there's are phonons , right ?

Why the use of RF receiver then , like the passive ferrite ?

I mean, why don't use just an optical solution if so...?

And in the case of spontaneous potential why don't use just electrometer ?

Kind regards,
Max

Any system you want works as LRL... the theme is: wich is the best. The great advantage with IR is the very precise detection.

Regards

Esteban

[ivconic]

I don't know why the most "sense of humor" is used on RS forum...

I think that such images don't contribute in it. And consume bytes.

Regards

"I don't know why the most "sense of humor" is used on RS forum..."

Now, this is mother question of all questions here!
Question and answer in one sentence.
Esteban, no matter the dissidences about lrl, you are still our very good friend here. God bless You!

[Max]

For the same reason a IR very short wave beam can carry LF like voices, for example, why not for other purposes?


Regards

Hi,
but that's not big news... you can modulate an higher frequency signal (carrier) to transmit enough informations about the wanted signal... like voice or video signals.

You need e.g. an higher frequency of carrier for good amplitude modulation...

As an example that happens when you digitize an analog signal you'll transmit with e.g. rf waves: Shannon's theorem say you must sample at more than twice the frequency of the interesting signal to transmit... that allow you completely rebuild at demodulator the original digitized signal...

But then... all well known, what's new ?

You wrote of an IR antenna and phonons... not carring LF by modulation over IR.

Where's the e.g. modulator in the LRL scenario ?

Suppose you send e.g. short IR pulses using some 555 timer + transistor + IR LED. Then use some photodiode or phototransistor to get the back scattered IR beam... ok... where's target influence in that ???

I think it's not so simple describing an LRL as saying that you carry LF signals on an IR beam.... like in a wireless headphone set...

You modulate on/off the IR source and that's all... you'll get back scattered IR signal at same 555 frequency not LF or anything else... so where's the role of target in that ?

And also, if the target of interest is (and actually IS) buried in the soil how the hell that small, weak IR emission will penetrate soil at e.g. 30 or 50cms to be scattered back by target ?

Cause otherwise you mean it's not target that scatters back the radiation but soil itself I think... but how and why ?

Kind regards,
Max

[J_Player]

Hi,
but that's not big news... you can modulate an higher frequency signal (carrier) to transmit enough informations about the wanted signal... like voice or video signals.

You need e.g. an higher frequency of carrier for good amplitude modulation...

As an example that happens when you digitize an analog signal you'll transmit with e.g. rf waves: Shannon's theorem say you must sample at more than twice the frequency of the interesting signal to transmit... that allow you completely rebuild at demodulator the original digitized signal...

But then... all well known, what's new ?

You wrote of an IR antenna and phonons... not carring LF by modulation over IR.

Where's the e.g. modulator in the LRL scenario ?

Suppose you send e.g. short IR pulses using some 555 timer + transistor + IR LED. Then use some photodiode or phototransistor to get the back scattered IR beam... ok... where's target influence in that ???

I think it's not so simple describing an LRL as saying that you carry LF signals on an IR beam.... like in a wireless headphone set...

You modulate on/off the IR source and that's all... you'll get back scattered IR signal at same 555 frequency not LF or anything else... so where's the role of target in that ?

Hi Max,
It is hard for you to understand what Esteban is saying because he is not good for explaining fine details in the English language. Maybe I can help to explain what he is describing about using IR to locate treasure.

First, Esteban is saying two things: He says that IR can be used to find treasure (based on his observations in his experiments). And he is also making conclusions to describe what he believes is the principle on which the IR is detecting the treasure. Let's separate these observations and conclusions so they do not become mixed and cause confusion.

From the observations and experiments, Esteban found that when he powered an IR LED with a 400 Hz square wave, the amplitude of the power going to the IR LED would change when it was pointed at a long time buried treasure. Here are some details that you can understand:
Build a 555 timer circuit set to 50% duty cycle at a very stable 400 Hz, with a sharp rise and fall time. It does not have to be exactly 400 Hz, but it must be stable over time and with temperature changes. Use the 400 Hz to drive an IR LED directly, or with fast driver transistors if needed. Be careful not to overdrive the LED and cause it to heat up. In the LED power input circuit, connect a high impedance sample and hold with comparator circuit to sense if the amplitude of the 400 Hz is changing as the LED is pointed in different directions. The time constant should be similar to what is used in metal detectors for finding a treasure, but should be adjustable in case you decide to scan very slow or very fast. The output to this comparator that senses a variation in amplitude should be sent to a circuit that can cause beeps when rising above a preset threshold. An alternate method is to simply connect a high impedance audio amplifier to the LED input power and listen to the relative loudness of the 400 Hz transmitted signal.

The observation that Esteban is talking about is when he powers an IR LED with a clean 400 HZ square wave 50% duty cycle, the amplitude of the power sent to the IR LED will increase when it is pointing at long time buried treasure. The variation is small, and easier to find with a comparator circuit than simple listening. This is simple to do. No Rx needed.

Now for the conclusions part. This is not so simple. In fact I have never heard a believable explanation of the mechanism how IR can find treasure from Esteban or from other sources. I read a lot of information of how IR can be used for similar things, but no mechanism explained how the IR power input will change in amplitude when pointing at a halo area. One thing for sure, from the circuit that Esteban described, there is no data being transmitted from the 400 Hz carrier, and there is no Rx circuit to be tuned. This is just a simple IR LED transmitting circuit where we watch the transmitted power signal. I would prefer to form my own conclusions about how it works after considering what Esteban concludes, as well as reading other sources for the behavior of IR beams.

Best wishes,
J_P

[Max]

Hi Max,
It is hard for you to understand what Esteban is saying because he is not good for explaining fine details in the English language. Maybe I can help to explain what he is describing about using IR to locate treasure.

First, Esteban is saying two things: He says that IR can be used to find treasure (based on his observations in his experiments). And he is also making conclusions to describe what he believes is the principle on which the IR is detecting the treasure. Let's separate these observations and conclusions so they do not become mixed and cause confusion.

From the observations and experiments, Esteban found that when he powered an IR LED with a 400 Hz square wave, the amplitude of the power going to the IR LED would change when it was pointed at a long time buried treasure. Here are some details that you can understand:
Build a 555 timer circuit set to 50% duty cycle at a very stable 400 Hz, with a sharp rise and fall time. It does not have to be exactly 400 Hz, but it must be stable over time and with temperature changes. Use the 400 Hz to drive an IR LED directly, or with fast driver transistors if needed. Be careful not to overdrive the LED and cause it to heat up. In the LED power input circuit, connect a high impedance sample and hold with comparator circuit to sense if the amplitude of the 400 Hz is changing as the LED is pointed in different directions. The time constant should be similar to what is used in metal detectors for finding a treasure, but should be adjustable in case you decide to scan very slow or very fast. The output to this comparator that senses a variation in amplitude should be sent to a circuit that can cause beeps when rising above a preset threshold. An alternate method is to simply connect a high impedance audio amplifier to the LED input power and listen to the relative loudness of the 400 Hz transmitted signal.

The observation that Esteban is talking about is when he powers an IR LED with a clean 400 HZ square wave 50% duty cycle, the amplitude of the power sent to the IR LED will increase when it is pointing at long time buried treasure. The variation is small, and easier to find with a comparator circuit than simple listening. This is simple to do. No Rx needed.

Now for the conclusions part. This is not so simple. In fact I have never heard a believable explanation of the mechanism how IR can find treasure from Esteban or from other sources. I read a lot of information of how IR can be used for similar things, but no mechanism explained how the IR power input will change in amplitude when pointing at a halo area. One thing for sure, from the circuit that Esteban described, there is no data being transmitted from the 400 Hz carrier, and there is no Rx circuit to be tuned. This is just a simple IR LED transmitting circuit where we watch the transmitted power signal. I would prefer to form my own conclusions about how it works after considering what Esteban concludes, as well as reading other sources for the behavior of IR beams.

Best wishes,
J_P

Hi,
ok... now I understand what he's doing with IR led.

Now is more simple for me to wire up some 555 and look at that voltage...

(don't understand why he made all that stories and doesn't focus on practical stuff! )

to see if it changes when pointed to something underground: I think I have also a suitable test site for that... with old scraps of metals (copper, lead and the like... also old silver)

But I have a few questions about the IR emitter...

First... which kind of emitter... there are >750nm but is needed a particular wavelenght ? Or any kind is fine for to test ?

If we use a simple IR LED emitter isn't the incident outdoor light (and generally speaking EM radiations from e.g. sun) have an effect on power the led get from the driving circuit ?

I think external light can alterate the readings on e.g. voltage drop on the junction... or not ?

I mean... like with zahori there's a risk of being fooled by unwanted environment "signals" like a reflected light beam or a particular angle you hold the IR led vs e.g. Sun direction can give.

Kind regards,
Max

[Fred]

I no way i can find a reason why a led or any transmiting only device could be afected by a distant factor

[J_Player]

I no way i can find a reason why a led or any transmiting only device could be afected by a distant factor

Hi Fred,
You can't find any reason is because you have not looked in the right places for a reason. For example, here are a couple of examples of why a transmitting only device can be affected by a distant factor:

1. A radio transmitter is monitored in the broadcast studio for power transmitted at the transmitter site, and found to have a sudden increase in power. Shortly afterward the transmitter stops broadcasting. Later investigation shows that a maintenance electrician 15 miles away at the transmitter tower accidentally connected the 250 volt supply line to the 120 volt power supply at the transmitter. The insurance investigator determines that the excessive voltage caused overheating and failure of the power transformer. Thus, the transmitted power did indeed fluctuate independently of what the VU meters at the studio showed was being sent out as a modulated carrier by microwave link to the transmitter.

2. An employee of a test facility finds that people listening to him talk on his mobile phone complain of strange intermittent fluctuations in signal strength and electronic noise every day while he is at work, but have no problem hearing him from his mobile phone when he is not at work. The employee at the test facility investigates the mobile phone problem and finds that there are charged subatomic particles from his nuclear test facility that are bombarding the circuitry in his mobile phone whenever he is conducting a test. The oscilloscope connected to the output at his mobile phone shows that these weird distortions of the transmitted signal occur at the exact moment when he causes servomotors move radioactive materials outside their shielded container to irradiate test samples at the test site more than a mile away in the desert. Of course, he never thought these particles would cause variations in his mobile phone circuitry, because the actual nuclear test site is more than a mile from his laboratory. Anyway, he had extra thick lead panels installed on the walls and ceiling of the test site enclosure room, and found that the strange electronic noise can no longer be heard by people listening to him talk on the mobile phone. -- Another example of transmit-only power being affected by a distant factor.

In the case of the IR LED, I suspect you will have to look into things that can influence the transmitted power from ground where long time buried metal is located. This means your search should include educating yourself about all the geotechnical properties that may change in the vicinity of a long time buried metal object, and see if you can find something that would cause a very slight change in the power of a square wave powering an IR LED. According to Esteban, the distance that this effect can be detected for an IR LED is not very far. The IR is used in conditions when good pinpointing accuracy is necessary, not long range detection.

Best wishes,
J_P

[J_Player]

First... which kind of emitter... there are >750nm but is needed a particular wavelenght ? Or any kind is fine for to test ?

If we use a simple IR LED emitter isn't the incident outdoor light (and generally speaking EM radiations from e.g. sun) have an effect on power the led get from the driving circuit ?

I think external light can alterate the readings on e.g. voltage drop on the junction... or not ?

Hi Max,
Esteban did not comment anything about the effects of the sun on the IR LED. He said he and others found long time buried objects at close range when using common IR LEDs, which are not very powerful for detection. (I believe close range means maybe up to 2 meters maximum, or 1 meter for small items). But he is sure IR laser will be better. He did not experiment with different frequencies other than what common IR LEDs were on hand. One exception is he once used a common (cheap) Chinese laser pointer modulated at very low freq., and found a button at 20 cm depth.

If you intend to experiment in with different light emitters, I would suggest trying several bright IR LEDS at different frequencies, as well as the IR lR lasers. Also note there are some very powerful white LEDs used in flashlights (torches) which may have IR versions of similar power. Then also consider the green laser pointers, modified to run at full power. Be careful, these green lasers become dangerous when at full power, and have a short lifespan.

Also, for experimenting purposes, I would suggest collimating any LED to focus it into a better beam. I imagine that the pinpointing ability and probably the range will improve if the light pattern is more of a beam instead of spread out in a large area.

Best wishes,
J_P

[J_Player]

For Fred: Another more realistic reason why a led or any transmiting only device could be affected by a distant factor:

I no way i can find a reason why a led or any transmiting only device could be afected by a distant factor

Remember, Esteban's description of the IR LED detection is not at long distances, but at distances found with a good metal detector or slightly better. Here is an example of how a PI detector transmit signal is affected by a target at the similar distance as Esteban describes the IR signal:

Suppose you were to build Carl's Hammerhead PI detector, and modify the timing circuits so you will no longer look at the signal after the transmit pulse is stopped. Suppose you only look at the signal during the time when the search coil is energized and brought up to full power, and you extend the pulse length to a longer period to allow a reaction from the target. But you are monitoring only at the power being put into the coil by the batteries and FET. If you watch the wave form of the voltage or current rising into the coil, you will see a constant pulse rising from 0 v to the maximum, repeating itself at every pulse. Then when you move the coil near a large metal target, you will see the waveform changes. Why? Counter emf generated from the eddy currents in the target will impede the current being sent to the search coil, and cause it to slow down, and will show a different wave shape. This effect may be small, depending on the target, and may change due to different target metal compositions. So it will be a good idea to use electronics to sense slight variations in the transmitted pulse as it rises in order to see the change when a target is near the coil.

This is an example of a distant factor affecting a transmitting only device for a PI metal detector coil.

If we put forth the argument that the PI transmit coil is also the receive coil, then this same argument could be used for the IR led when in the proximity of long time buried metal. Could it be that the IR LED is acting as a transmit and receive sensor just as a PI coil is? If so, then the only missing piece of the puzzle is to identify what physical property of a long time buried metal and surrounding soil will cause a change in the current/voltage moving in the IR LED circuit.

Best wishes,
J_P

[Esteban]

"I don't know why the most "sense of humor" is used on RS forum..."

Now, this is mother question of all questions here!
Question and answer in one sentence.
Esteban, no matter the dissidences about lrl, you are still our very good friend here. God bless You!

Ivconic, thanks. Keep the good works!