need mfd

[Geo]

Originally Posted by ma330

HI GEO
I can not see your files.
Please put your files in RAR format
TANK YOU

I mean this...

http://www.longrangelocators.com/for...ad.php?t=18466

[michael]

Originally Posted by J_Player

It turns out this TDA7294 amplifier is even more interesting than I thought.
Aside from being a very low distortion high power amplifier, it runs on a dual power supply that the signal generator IC can share with it.
This means you can use the two 12v batteries like Michael has in his Bulgarian LRL to run both the TDA7294 power amp and the signal generator.
The output from this amp will be higher because of it's 24 volt supply instead of the 12v that the signal generator is using above.
But this is not a problem, the 8038 signal generator is good for up to 30 volts each side of the supply.
So we can plug it into the same supply and send the signal to the TDA7294 all on the same board if we want.
This seems quite convenient for MFD builders.

This amplifier is intended to drive typical speakers from 4-8 ohms. Since the ground usually has much higher impedance, We cannot expect to put the full 100 watts of power into the ground.
But since it can handle up to 100 watts, it seems a good candidate for a step-up transformer to increase the voltage at the probes to get more power into the ground.
Of course, power transistors could do this too. The main difference is this IC is able to maintain a very clean signal without distorting it at power levels, and it is on a single IC.
When we start sending more power out, we can expect the amplifier to heat up, so we need a heat sink that will carry the heat away.
The image below shows a typical heat sink used on an audio amplifier.
But this could be made smaller, especially if you include a fan to circulate air through the fins, similar to how computer fans work.

Because this IC matches up so well to the 8038 signal generator, I show some concepts of how you could hook it up below.
This is not a circuit I tested, but I think it may work if I didn't get any mistakes in the connections.

In the circuit you can see I changed the two capacitors that set the frequency for the 8038 to a bank of 6 capacitors with a rotary switch to select which frequency you want.
You can fill in any capacitor values for your favorite frequencies.
There is also an option to make adjustments to the frequency at pin 4 on the 8038, or you can leave it in the original design.
You can also see where the transformer goes.
You can choose the transformer type depending on the soil conditions.
I think you will have a wide range of soil impedance depending on ground mineralization and how wet the soil is.
For this reason, I doubt any one transformer would be suitable for all soil.
But at least you have some control at the power knob.
Another option would be an adjustable auto-transformer that you can change to suit the soil.
But don't forget the batteries.
When you put out more power, you need bigger batteries.

Keep in mind that Michael's Bulgarian MFD locator uses this same amplifier, but he was able to detect nothing ever, even though he could measure the signal in the ground up to 2 meters distance.
And that is exactly what I think you will detect with this MFD detector... Nothing.
If you think I am wrong and this circuit really can locate treasure, prove me wrong.


Best wishes, J_P

Hi J_P.
I should add that LRL200D at first could detect our hidden test targets more or less. at first the box consisting TDA729 became so much hot, but after that we did something maybe a big mistake .... it's long story.
I'm sure have put the story somewhere in this forum, but couldn't find it with advanced search. you can use keywords: " LRL2000D or STK435 or Notsi" for more than 6 years ago. can you find those posts? I guess are useful.

[J_Player]

Originally Posted by michael

Hi J_P.
I should add that LRL200D at first could detect our hidden test targets more or less. at first the box consisting TDA729 became so much hot, but after that we did something maybe a big mistake .... it's long story.
I'm sure have put the story somewhere in this forum, but couldn't find it with advanced search. you can use keywords: " LRL2000D or STK435 or Notsi" for more than 6 years ago. can you find those posts? I guess are useful.

Hi Michael,
I expect your box would become hot if the amplifier is putting out very much power.
This is why I posted warnings about heat sinks, and better to include a fan to carry the heat away.
The large heat sink you see in my image above is used on some audio amplifier applications to drive speakers, not for connecting to probes that you put into the ground.
One problem with using this amplifier for a ground probe generator is the possibility of accidentally shorting the rods together.
This can easily happen if the rods are dropped, and they fall to the ground where they are contacting each other.
There are other ways that could cause the probes to draw a large current from the amplifier too.
The TDA7294 has a built in thermal overload protection, but I would not rely on it to prevent damage to the circuits inside a Bulgarian LRL.
Your post describing what happened is here: http://www.longrangelocators.com/for...&postcount=223

From what you said in that post, it seems there was a failure which caused the signal generator frequency to become unchangeable.
But is sounds as if you also had a malfunction with the amplifier.
This makes me wonder if the Bulgarian manufacturer was using Chinese counterfeit components that are not capable of performing to the standards of the genuine ICs from the ST microelectronics factory.
I am guessing the amplifier IC failed, and caused the signal generator circuit to fail at the same time.
In any case, it does not cost much to make your own version of a signal generator and power amplifier for a lot less cost than the Bulgarian product.

One question:
In your years of experimenting, did you find that extra power improved your ability to detect from long distance?
Or did you find that your best detection was found when using a simple one or two 9v battery version MFD generator?


Best wishes,
J_P

[michael]

Hi J_P.
Thank you.
I had more and more posts about MFDs; LRL 2000D, homemade transmitter,..... may you put threads link?
what should I add Is that box would become very hot which we had to cool box with wet piece of cloth to decrease temperature.
Afterwards we thought better to open the box, we just simply opened box and closed again, without any handling, after turning on it never warmed up and couldn’t hit test targets it remaind cold even after hours working. I took it to my e.e friend, checked out frequency for all options, got all have single 249 KHZ . my friend checked all parts and found a simple interconnection or something like this. he told op-amp is working well, has no problem, but had no justifying explanation about temperature,....
My friend had a radio generator. He asked me to prepare one STK435 for op-amp to access more and better output, so I did it.
BTW; TDA had a a big heat-sink

Q: In your years of experimenting, did you find that extra power improved your ability to detect from long distance?
A: Honestly it’s hard to state about this, as all places we searched by MFDs had no treasure cos after getting MDL we searched all places.
The hot locations we found by MDL had never been searched before that by MFDs; already we had left them in closet and never used.

Q:did you find that your best detection was found when using a simple one or two 9v battery version MFD generator?
A:Before LRL200D I personally never had MFD, but I had friend who was individual, unbelievably capable to find hidden gold tests everywhere. He had a homemade MFD with 3 probes which put in ground It was working with a single 9V. He could pass all type of my hard blind tests. I personally never could track anything with his MFD.
He would believe that this matter depends on blood types and believed O types are the best in this matter. Himself was O type, me not. Maybe he was right.
god have mercy upon his soul. we missed him.

[J_Player]

Originally Posted by JGeo

Hi J_P.
It is not so simple!!!. Don't think that if you will keep 2 Lrods at your hand then you will find any buried. It needs many experiment.
As for schematic... i attached one LRL with generator and it works.

Regards



Originally posted by J_Player
Hi Geo,
This is excellent information.
Can you post a list of the experiments that are necessary to find buried treasure for ma330?
When he finishes performing the experiments that you show, then he will find treasure the same as you find treasure.

Also, I do not see your attachment for LRL with generator schematic that works.
Can you post that too?


Best wishes,
J_P

Hi Geo,
You did not answer the question for experiments that are necessary.
You have posted that you know what are the experiments that are necessary to detect treasure when using MFD.
No other MFD user has put these experiments in the forum.
The MFD techniques that Carl-NC posted, and techniques that MFD users posted show only the methods to use when holding the rods to find treasure.

Will you be listing these experiments that ma330 needs to perform in order to find treasure with an MFD generator?
Or are these experiments a secret?


Best wishes,
J_P

[J_Player]

Originally Posted by ma330

hi jp
You can design for my post number 38 with IC xr2206 Instead of 8038?
with respect

Hi ma330,
The XR2206 does not fit so well with the TDA7294 like the ICL8038 does.
The XR2206 has a maximum voltage of 26 volts, which is too close to the 24 volt supply.
There is a danger you will burn this IC if you are using freshly charged 12v batteries which can easily exceed the 26v absolute maximum that is allowed.

So we cannot simply plug in the XR2206 like we can for the ICL8038.
But there is a worse problem. The XR2206 is hard to find.
The only available supplies I have seen are Chinese counterfeit ICs which I do not use.

If you can find XR2206, then you will do well to make a circuit design that has a 12 or 18v supply for this IC.
I think it is easier to use the same ICL8038 that Carl-NC recommends.


Best wishes,
J_P

[J_Player]

Originally Posted by michael

Hi J_P.
Thank you.
I had more and more posts about MFDs; LRL 2000D, homemade transmitter,..... may you put threads link?
what should I add Is that box would become very hot which we had to cool box with wet piece of cloth to decrease temperature.
Afterwards we thought better to open the box, we just simply opened box and closed again, without any handling, after turning on it never warmed up and couldn’t hit test targets it remaind cold even after hours working. I took it to my e.e friend, checked out frequency for all options, got all have single 249 KHZ . my friend checked all parts and found a simple interconnection or something like this. he told op-amp is working well, has no problem, but had no justifying explanation about temperature,....
My friend had a radio generator. He asked me to prepare one STK435 for op-amp to access more and better output, so I did it.
BTW; TDA had a a big heat-sink

Q: In your years of experimenting, did you find that extra power improved your ability to detect from long distance?
A: Honestly it’s hard to state about this, as all places we searched by MFDs had no treasure cos after getting MDL we searched all places.
The hot locations we found by MDL had never been searched before that by MFDs; already we had left them in closet and never used.

Q:did you find that your best detection was found when using a simple one or two 9v battery version MFD generator?
A:Before LRL200D I personally never had MFD, but I had friend who was individual, unbelievably capable to find hidden gold tests everywhere. He had a homemade MFD with 3 probes which put in ground It was working with a single 9V. He could pass all type of my hard blind tests. I personally never could track anything with his MFD.
He would believe that this matter depends on blood types and believed O types are the best in this matter. Himself was O type, me not. Maybe he was right.
god have mercy upon his soul. we missed him.

Hi michael,
Another post you made is here: http://www.longrangelocators.com/for...&postcount=222

But I do not see your other posts for a transmitter and for STK435.
It is interesting, the TDA7294 in your Notsi locator had a heat sink, but this heat sink was enclosed inside the box which did not allow the heat to escape.
When this amplifier is used for stereos, we usually see holes put in the case so air can circulate to allow the heat to escape into the air.
I have seen other designs where the heat sink is attached to the outside of the stereo box so fresh air could circulate at the metal fins to remove the heat.
If you stopped seeing any heat, then it means the IC stopped producing power that causes heat.
If your EE friend says the TDA7294 is not damaged, then it is possible that heat destroyed the microprocessor where the signals are generated, and where the control for the TDA7294 comes from.

If you are lucky, maybe you can get a replacement for the processor that is already programmed to work with the 2000D.

The STK435 is another amplifier that was designed to run stereo speakers.
This is a dual amplifier, with a 7 watt right channel and a 7 watt left channel.
Since you only need a single channel, you can use only half of this IC.
Or you could connect it to make two separate outputs that could drive 4 ground probes.

7 watts is usually enough power to run most stereo speakers that people use in their home or in their car.
It is also more power than most MFD generators need.
This IC will not develop nearly as much heat as the TDA7294 amplifier at 100 watts.
Since the consensus among MFD users is high power is not important, it does not surprise me that this amplifier was adequate for your experiments.

Best wishes,
J_P

[Geo]

Originally Posted by J_Player

Hi Geo,
You did not answer the question for experiments that are necessary.
You have posted that you know what are the experiments that are necessary to detect treasure when using MFD.
No other MFD user has put these experiments in the forum.
The MFD techniques that Carl-NC posted, and techniques that MFD users posted show only the methods to use when holding the rods to find treasure.

Will you be listing these experiments that ma330 needs to perform in order to find treasure with an MFD generator?
Or are these experiments a secret?


Best wishes,
J_P

Hi J_P.
There is not any secret, very simple you(and everyone) must learn how to use the Lrods. Lrods needs calm and much stability when you walk. Also you must keep them very light and very horizontal. Wind is not a friend of rods. Every man must spend some hours to experiment with them so to start to have success.

Regards

... i forgot to say that depended of the generator power you must wait between 5 and 30 minutes when you connect the probes to earth until to take the Lrods.

[J_Player]

Originally Posted by Geo

Hi J_P.
There is not any secret, very simple you(and everyone) must learn how to use the Lrods. Lrods needs calm and much stability when you walk. Also you must keep them very light and very horizontal. Wind is not a friend of rods. Every man must spend some hours to experiment with them so to start to have success.

Regards

... i forgot to say that depended of the generator power you must wait between 5 and 30 minutes when you connect the probes to earth until to take the Lrods.

Hi Geo,
This is excellent news.
We now have some improvements that we can add to the Carl-NC procedure to use MFD.
I think it is finally time to make the updated graphic and procedure that includes your modifications to successfully find treasure when using MFD.

Before I post the updated graphic, maybe you can say what you think is the best amount of power to have coming from the signal generator that you see posted above using the ICL8038.
For me, I think the TDA7294 is not needed, and does not give better results than the power from only the ICL8038.
But maybe you think a small amplifier can help like the STK735 or similar?

Best wishes,
J_P

[Geo]

Hi J_P.
The power of the generator is important but it is not for the time. You must make a MFD and to try it at different terrains. What you ask for is a flow of current!!!!!. Current more than 10ma is OK, but believe me is not easy. For some reasons the Ohm's law don't work good here

Regards

[J_Player]

Originally Posted by Geo

Hi J_P.
The power of the generator is important but it is not for the time. You must make a MFD and to try it at different terrains. What you ask for is a flow of current!!!!!. Current more than 10ma is OK, but believe me is not easy. For some reasons the Ohm's law don't work good here

Regards

Hi Geo,
Of course ohms law will not work good here.
You are sending power to ground probes that have telluric currents moving in the ground.
We expect we could see some voltage offset between the probes even if there is no generator connected to them.
Of course this external voltage source from the ground can interfere with any ohm's law calculations you make if you are only considering the current that flows from your MFD power source.

But the solution is simple.
If you want to inject a measured amount of current into the ground, then you don't need to make an ohm's law calculation.
You can simply build a current-controlled amplifier.
You can put a control that adjusts how much current to send out, then the amplifier will make whatever gain is necessary to reach the current that you set.
We know the resistance of the ground can change a lot depending on the mineralization and the moisture content.
We but with a current-controlled amplifier, we will not need to make any adjustments for soil.
It will all be done automatically by the amplifier.
We can simply set the control for how many milliamps we want to send out and we will get this exact amount no matter where we plug in the probes.
Of course, we will need to measure both positive and negative phase current to average the power, because the telluric currents can cause a zero cross offset.
The only thing that would stop us from getting the amount of current needed is if the ground resistance is too high.

The remaining question is what is the recommended amount of AC current to send into the ground?
And how much voltage is necessary to deliver this current to the ground?

Best wishes,
J_P

[ma330]

hi
What helps to connect the generator to lroad to find the target ?with mfd?

[J_Player]

Originally Posted by ma330

hi
What helps to connect the generator to lroad to find the target ?with mfd?

The best way I know to connect the generator to L-rod is to connect with a wire.
You will need one wire for each L-rod.
The method below helps to connect the generator to the L-rod.
Or you can solder the wire directly to the copper handle.

Best wishes,
J_P

[ma330]

Originally Posted by J_Player

The best way I know to connect the generator to L-rod is to connect with a wire.
You will need one wire for each L-rod.
The method below helps to connect the generator to the L-rod.
Or you can solder the wire directly to the copper handle.

Best wishes,
J_P

tank you j-p
How to help connect the generator to find the target? Is it this? And use it simultaneously with the mfd?

[Geo]

Originally Posted by J_Player

Hi Geo,
Of course ohms law will not work good here.
You are sending power to ground probes that have telluric currents moving in the ground.
We expect we could see some voltage offset between the probes even if there is no generator connected to them.
Of course this external voltage source from the ground can interfere with any ohm's law calculations you make if you are only considering the current that flows from your MFD power source.

But the solution is simple.
If you want to inject a measured amount of current into the ground, then you don't need to make an ohm's law calculation.
You can simply build a current-controlled amplifier.
You can put a control that adjusts how much current to send out, then the amplifier will make whatever gain is necessary to reach the current that you set.
We know the resistance of the ground can change a lot depending on the mineralization and the moisture content.
We but with a current-controlled amplifier, we will not need to make any adjustments for soil.
It will all be done automatically by the amplifier.
We can simply set the control for how many milliamps we want to send out and we will get this exact amount no matter where we plug in the probes.
Of course, we will need to measure both positive and negative phase current to average the power, because the telluric currents can cause a zero cross offset.
The only thing that would stop us from getting the amount of current needed is if the ground resistance is too high.

The remaining question is what is the recommended amount of AC current to send into the ground?
And how much voltage is necessary to deliver this current to the ground?

Best wishes,
J_P

Hi J_P.

I used earth resistance meter to check the ground resistance and to calculate the current but no good results.
Anyway i wrote at my previous post that we need current >=10ma. At my devices this was able only with a small power amplifier and a H.V. tranformer at the output. With voltage >80v i had the good results.

Regards

[J_Player]

Originally Posted by ma330

tank you j-p
How to help connect the generator to find the target? Is it this? And use it simultaneously with the mfd?

Hi ma330,
Most people who use MFD do not connect a signal generator to the rods.
They only connect from signal generator to 2 ground probes.

The rods usually have no electrical connection.
There are only a few MFD generators that use ground probes and also have an electrical connection to the rods.
One of these is the Dell Systems Omnitron that you can see here: http://www.geotech1.com/cgi-bin/page...r800/index.dat

On the Omnitorn, the rods are connected to a more simple circuit than the circuit above.
The Omnitron generator for the rods uses a 555 timer IC with a control knob that adjusts the frequency.
This simple IC does not make a sine wave. It only produces a square wave, and at very low power.
This is a separate generator which is the same as the second generator IC that is connected to the ground probes.
Both can be used simultaneously.
Or only the ground probes can be used for times when you do not want to use the second generator for the rods.

I have never heard of any reports from anyone who says they found treasure when using the Dell Omnitron generator connected to the rods.
My belief is connecting a frequency generator to the rods will not help you to find treasure.
I think that none of the circuits above will help you to find treasure.
But other people say they find treasure, so I show the circuits that they say will work.

Best wishes,
J_P

[J_Player]

Originally Posted by Geo

Hi J_P.

I used earth resistance meter to check the ground resistance and to calculate the current but no good results.
Anyway i wrote at my previous post that we need current >=10ma. At my devices this was able only with a small power amplifier and a H.V. tranformer at the output. With voltage >80v i had the good results.

Regards

Hi Geo,

Geologists have measured the resistance of the ground many times with good accuracy.
They use very expensive amplifiers and calibrated meters to find the resistance of many kinds of soil.
Here is the interesting thing:
Geologists found that the ground can have a resistivity that ranges from 100 ohm-cm to 1,000,000,000 ohm-cm.
This means that if they put their ground probes 1 meter apart, they can measure from 0.159 ohms for wet, salty topsoil to 1.59 megohms if there is no moisture content in the soil.
For an amplifier that is to send 10 ma constant current to the ground, we see that it must be able to deliver a voltage that varies between 1.59 mv to 15,900 volts for different soil conditions.
This seems like a very expensive signal generator.

But, let's look at what the geologists use for their power supply... they usually do not send out more than 300-400 volts, and they have a large range of voltage they can adjust their ground resistivity supply for.
When they are set at 400v to measure the highest resistivity soil, they will only send out 2.5 uA.
They have an auto-ranging meter which can switch from milliamps to microamp scale without a problem and give them the correct resistivity readings with very good precision.
Of course, this kind of supply is only for making ground resistivity measurements.
A geologist has no reason to force 10ma through 100cm of 1.5 megohms ground.

But there is a second part of the puzzle:
Geologists also know that the ground can have electrical properties that cause it to act like a capacitor when they are using AC on their ground probes.
When they make their induced polarization surveys, they watch for the phase angle that is caused by the ground.
And they will often sweep through a large range of frequencies to determine the time constant of the ground "capacitor effect".
This is not actually capacitance as we understand from charged plates that are separated by a dialectric.
It is caused by buried particles, or by pores in rocks which can become polarized when they feel the charge from the power the geologist sends into the ground.
These absorb some of the power that is sent, which causes them to become polarized.
Then when they remove the power, the particles slowly lose their polar charge and relax back to a neutral equilibrium.
The polarizing and relaxing process happens over a time constant, depending on the size of the particles or pores in rock structures.
This helps geologists to identify where there may be an ore body or porous rock structures of various pore sizes.
In order to cause this polarization, they use power supplies usually 1000-3000v, sometimes over 10Kv, and usually powered by petrol engine generators that can be several KW.

But for our purposes, we don't care about polarizing pores in rocks, or ore bodies.
We can think of this effect as unpredictable capacitive reactance that can be present in some ground, but not in other ground.
You can see how this would make it difficult to measure how much power your sine wave frequency is putting out.
It cannot be done with ohms law.
We must now consider the phase angle and the power factor.
This effect will be different for every different location of ground.
It all depends on what is below the ground.

If it was a simple DC probe, it would be easy to figure the current, but with AC, I am thinking what is important is how much energy you transfer to the ground.
This would be watts of real power that is corrected for power factor, not simple rms current.

But this is only my guess.
From all the reports I read, most people who report success with MFD say they are using a 5v or a 9v signal generator.
Some are even using a simple 555 with no amplifier... only a capacitor to make an AC couple to the ground probes.
Should we believe their MFD generators are working?
Who knows?

Best Wishes,
J_P

[Geo]

Hi J_P.
I know how to measure the earth resistance (it was my job before some years).
I measure it with the attached meter.
Resistance near to my city was between 0.5 and 40 Ohm.
When i say that it is not so easy i mean that with 10V audio signal and with 1_Ohm earth resistance i had not any current flow.

Regards

[ma330]

How can I do for this IC output volume control?Please show in what way?
This IC is suitable for boosting the output frequency of 8038?

[Geo]

At one MFD i used the TDA2030 IC. At the output i connected a 12V/220V transformer.
You can download the datasheet from it...

[J_Player]

Originally Posted by Geo

Hi J_P.
I know how to measure the earth resistance (it was my job before some years).
I measure it with the attached meter.
Resistance near to my city was between 0.5 and 40 Ohm.
When i say that it is not so easy i mean that with 10V audio signal and with 1_Ohm earth resistance i had not any current flow.

Regards

Hi Geo,
This seems very strange.
The resistance you measure will depend on where you place the ground probes, the depth of your ground probes, and on the distance they are separated.
Geologists have never had a problem to measure the ground resistance when they test using an audio frequency signal.
They know that when they put a voltage to the ground to measure resistance, the current that flows depends on electrolytes in the soil.
So they avoid electrolytic reactions by using AC so they will not have problems with getting an accurate measurement.
But they also put a higher voltage than 10v into the ground when they measure the resistivity, and they spread their ground probes a larger distance than is usually used by MFD experimenters.
They send enough voltage to overcome any telluric currents so they will be insignificant in their measurements.
Then they measure the voltage that is flowing through the ground between the ground probes to determine what the resistivity of the ground is.
They do not connect an inexpensive digital ohm meter to a pair of test probes to measure ground resistivity.
When they make AC measurements, their signal processor can cancel any telluric current offset between the probes if it rises to a significant level. Their resistivity test equipment will also cancel any error readings that come from power lines or stray ground currents up to 100db to filter them out.
See below for the equipment that the geologists in the USA use.

Maybe you have a problem with your amplifier circuit.
Or maybe your meter is not making accurate measurements for the current.
If the problem is not from the amplifier or the meter, or from the electrical properties I talked about above, then there is only one remaining explanation....

Maybe a Jinn lives near your city.
I have read the reports how Jinns will cause equipment malfunctions for treasure hunters.
I even read reports where PI metal detectors failed to work when Jinns were near.
Maybe this is the reason why your amplifier cannot send any current through a 1 ohm load.


Best wishes,
J_P

See equipment that geologist uses to measure ground resistivity below

[Geo]

Originally Posted by J_Player

Hi Geo,
If the problem is not from the amplifier or the meter, or from the electrical properties I talked about above, then there is only one remaining explanation....

Maybe a Jinn lives near your city.
I have read the reports how Jinns will cause equipment malfunctions for treasure hunters.
I even read reports where PI metal detectors failed to work when Jinns were near.
Maybe this is the reason why your amplifier cannot send any current through a 1 ohm load.


Best wishes,
J_P

See equipment that geologist uses to measure ground resistivity below

Hi J_P.

There is no reason to continue this discussion. You Have a tendency to mocks the others. But we did not see any construction from you. Only theory and theory.

Regards

[J_Player]

Originally Posted by Geo

Hi J_P.

There is no reason to continue this discussion. You Have a tendency to mocks the others. But we did not see any construction from you. Only theory and theory.

Regards

Hi Geo,
You have it wrong.
This is not a theory.
I have worked with several geologists in California.
I watched their crews using the exact test equipment that you see above and other models similar.
I can tell you I did not see them use a 10v multimeter to measure the earth resistivity.
They know they cannot get an accurate measurement unless they use more sophisticated instruments with the methods I explained.
This is not a theoretical idea for how to measure ground resistivity. It is what I saw during every resistivity survey.

None of the instructions I posted for MFD methods are theory either.
These are the exact instructions that were given by manufacturers and users of MFD equipment who say they are finding treasures.
You can also see that Carl-NC posted the same instructions that he got from real MFD users and manufacturers.

What you have been telling us is that ohm's law does not work for your equipment.
I explained a lot of ways above how you could have false readings, but you do not want to believe.
You can check with any geologist to see why they do not use a simple multimeter to measure the resistivity of the ground.
These are not theories.
These are actual field practice methods that geologists use, who have many years of experience working with soil that has different salt content, different kinds of electrolytes, and different moisture content.

The only thing that is maybe theory is to try to guess why your amplifier does not send current to the ground.
The only theory I can think is that there is a problem with the amplifier, or the ground has a higher resistivity than what your meter measured, and does not allow a measurable current to pass.
If there is not a problem with the equipment or the methods of measuring, then it must be caused by outside forces.
If you don't believe this can happen, send a PM to michael.
He did not believe it could happen either, until he saw how it happens.
He will be happy to tell you all about it.
I do not believe michael will give you any false information.


Best wishes,
J_P

[ma330]

Originally Posted by Geo

At one MFD i used the TDA2030 IC. At the output i connected a 12V/220V transformer.
You can download the datasheet from it...

hi geo
The transformer at the output frequency will cause instability.Strongly.Oscillating about 1 kHz to more
To solve this problem, what solution do you recommend?

[Fred]

Originally Posted by Geo

Hi J_P.

There is no reason to continue this discussion. You Have a tendency to mocks the others. But we did not see any construction from you. Only theory and theory.

Regards

Hi Geo,
Irony can be healthy sometimes.