Strange things are going on! That's my point and that puzzles me! Because ...

But this implies (illustration b) that removing the LC circuit completely should result in having infinite impedance for ALL received frequencies, thus we should hear all nearby transmitting radio stations at once, but we don't. Why?

Because now we don't have the energy amplifying feature of the LC circuit anymore!?

So, who is willing to adjust this reality in order to comply with the textbooks?

Zeit,
In general textbooks are there to teach, and it is for the reader to learn from a written explanation.
Not understanding the text or explanation, does not directly imply that the text or explanation is wrong.

An LC circuit is also called a tuned circuit because it has a specific time constant which equals a specific frequency.  Therefore it acts as a frequency filter. It might appear that it amplifies, but in reality it doesn't add anything to the signal, no FE input. Your earpiece will load the LC circuit and lowers its selectivity effectiveness and de-tune it, the reason your picture uses a crystal earpiece because it has high impedance.  A standard dynamic earpiece as you use for your cell phone wouldn't work here because of its low impedance and it contains a coil which would change the freq of the LC circuit in a big way.

When it comes to hearing all stations without filter seems to be well explained by MarkE above. I would guess you would still hear a strong/near station above all else. It is all a matter of composite signal strength

Red_Sunset

I see! MarkE and Red_Sunset have decided to adjust reality to the textbooks. I never thought something different could ever happen!

So then explain this: Free energy from air TEST

First explain where this energy (charging a capacitor for free) is coming from and why it should perhaps(?) be considered as NOT free. Second explain, why a crystal-radio (also working with an antenna and ground) should not make use of that energy?

Actually this arrangement consists of two Avramenko Plugs connected together, principle explained here: The Work that is Created by Means of Potential Field - Alexander V. Frolov

As I said earlier: Reality is adjusted to fit the textbooks. How can extracting energy be pointless, when it is obviously done and shown in the Milkovic video?

As one can see, it is not so easy to deceive Zeitmaschine, especially if one evidently can't even debunk a simple free energy lever device scientifically.

Now - just for fun -  let me debunk the power of the wind (scientifically).

A windmill or wind wheel can't work, despite we can see it working every day!! The wind commonly blows in one direction (like gravitation). So if we take a sheet of paper, then this paper is blown by the wind in one direction a few meters. Hence we can get some useful energy out of it. But after that few meters we have to put that sheet of paper back to its start position and that means pushing it against the force of the steady blowing wind, so all energy gained in the first step is lost in that second step and thus the overall energy gain is zero. Quod erat demonstrandum!

Now show me a working windmill and I'm sure it's fake, maybe it works with a hidden motor.

Zeit,

I know you are taking me around in circles and I will play your game a bit longer

1..  Energy out of the air, sure that is very possible.  But that is not likely the same energy than your radio signal (energy), the one you are receiving from the sender antenna. I have no reason to believe different to my knowledge.
Re energy out of the air,  Tesla proposal for wireless power transmission relied on input energy from solar winds into the ionosphere, as far as I gathered,  that looked very possible as a tapping method in a theoretical sense.  Several practical aspects are  intimidating to my view.

2.. Your fun for wind energy,  energy extraction out of anything requires movement.  Wind is a circular circuit between hi & lo pressure, there is actual air movement between these pressure points. The heat from the sun is the pump that is driving it.
You do not need to move the paper, tape it to a rotor and it will spin

In comparison to any other field you are referring to, magnetic or gravity, the apparent consistency of the field is static. 
This difference can be demonstrated, just for comparison by trying to get lift in a FIELD vs. wind, 
example, try to install a magnetic Narca foil in the magnetic field, and see what happens?  Doesn't work as intended.
The same problem in a gravity field ?  Now try the same in the wind, that works fine?

You will notice that the apparent difference is that a field has no physical property compared to a wind flow.
There is a good reason these fields are called "Conservative",  and the wind is not conservative

Regards, Red_Sunset

"The law of conservation of energy does not count towards this, because we do not want energy from nothing, but from an already present energy field." these fields are FORCE fields, not ENERGY fields.
A force can be applied indefinitely without expending energy.

Cart and horse:  When evidence is found that challenges established understanding, then that evidence should be evaluated. 

People can imagine all sorts of things that have no bearing on reality.  Simply imagining something does not create evidence for that thing.

I see! MarkE and Red_Sunset have decided to adjust reality to the textbooks. I never thought something different could ever happen!

So then explain this: Free energy from air TEST

First explain where this energy (charging a capacitor for free) is coming from and why it should perhaps(?) be considered as NOT free. Second explain, why a crystal-radio (also working with an antenna and ground) should not make use of that energy?

Actually this arrangement consists of two Avramenko Plugs connected together, principle explained here: The Work that is Created by Means of Potential Field - Alexander V. Frolov

As I said earlier: Reality is adjusted to fit the textbooks. How can extracting energy be pointless, when it is obviously done and shown in the Milkovic video?

As one can see, it is not so easy to deceive Zeitmaschine, especially if one evidently can't even debunk a simple free energy lever device scientifically.

Now - just for fun -  let me debunk the power of the wind (scientifically).

A windmill or wind wheel can't work, despite we can see it working every day!! The wind commonly blows in one direction (like gravitation). So if we take a sheet of paper, then this paper is blown by the wind in one direction a few meters. Hence we can get some useful energy out of it. But after that few meters we have to put that sheet of paper back to its start position and that means pushing it against the force of the steady blowing wind, so all energy gained in the first step is lost in that second step and thus the overall energy gain is zero. Quod erat demonstrandum!

Now show me a working windmill and I'm sure it's fake, maybe it works with a hidden motor.

It's always fun to see someone take the ordinary and try and represent it as extraordinary.  Bravo.

"The law of conservation of energy does not count towards this, because we do not want energy from nothing, but from an already present energy field." these fields are FORCE fields, not ENERGY fields.

Says who? If so, then what is causing the electrons to orbit the nucleus of an atom (visualized)? There must be an energy source for that to do. Can a static force field cause continuous quantum fluctuations in space? Or do we rather need an energy field for that? When I put something on my table then the gravitational field creates a force pushing that thing against the table. But what is causing the counter force in the table? When I press my fist against the table periodically with the expense of energy, then what energy is causing the also periodically acting counter force? Just asking ...

People can imagine all sorts of things that have no bearing on reality.  Simply imagining something does not create evidence for that thing.

Denying the existence of evidence is not much of a help either. Why does the Serbian Ministry of Science (see screenshot below) financially support the production of pendulum pumps, when those pumps do not work as claimed?

I think the your time has come to construct a setup in order to run a test protocol to confirm your conviction.  That is the most convincing approach you can take.

I would prefer to construct a setup in an electrical way (like Moray in 1936). Handling of heavy steel beams is not my thing. So I have to gather information how to do it without much abortive attempts. That pendulum stuff is a very good source of such information.

By the way: The best evidence for the existence of free accessible energy are the amounts of distractors in the relevant forums. If one would claim in the forums he can make himself invisible, no one would really care, I guess. But as soon as the phrase »free energy« appears in the forums, hell breaks loose.

To manage your risk exposure, make a list of all important and critical pieces of the puzzle, evaluate them as, 1- Proven by theory,   2- Proven by test,    3- assumed,    4-unknown 

Actually my list of pieces becomes shorter and shorter over time. At the beginning the list contained thyristors and transistors and diodes and custom wound coils and electronic oscillators and exotic materials. Now I'm down to two capacitors and two transformers off the shelf.

Keep us updated for a sanity check.

Unfortunately the functionality of the Universe is rather insane than sane.