Directional MD Antenna

[Funfinder]

Something Yagi-style which perhaps could detect
a 2cm coin at a distance of 1 meter, in air! But of
course by metal-detection circuit.

With a very short wavelenght and the reconstructed
interference pattern this should be possible.

The important thing is that the radiation beam must
be very narrow, perhaps even through a metal-pipe.

Of course in this forum are not the engineers of the
big MD-companies but merely some guys with their
little homebrew-PI-problems so I guess I'll have to
do this project on my own anyway, but we will see.

So far this is just an inspiration or a good idea for
stupid people whithout any such ideas! *laugh*

[kt315]

nonsence again.

[Gwil]

I'm merely some guy with some decades of experience in the electronics industry, but none of it involving metal detectors, so I will be mightily impressed when I see a working prototype.

[Orbit]

Something Yagi-style which perhaps could detect
a 2cm coin at a distance of 1 meter, in air! But of
course by metal-detection circuit.

With a very short wavelenght and the reconstructed
interference pattern this should be possible.

The important thing is that the radiation beam must
be very narrow, perhaps even through a metal-pipe.

Of course in this forum are not the engineers of the
big MD-companies but merely some guys with their
little homebrew-PI-problems so I guess I'll have to
do this project on my own anyway, but we will see.

So far this is just an inspiration or a good idea for
stupid people whithout any such ideas! *laugh*

That's perfect I tried it ten years ago did not succeed I was not even persistent .Maybe you'll make it but it is necessary to be persistent !

[Davor]

There are Halbach arrays that may direct magnetic field in one direction, but frankly, are 3dB-s of gain worth it?

[Funfinder]

WOW, Davor, that's It !!! You're ingenious.
First we should start with a directional magnetical antenna!
Finding iron and steel stuff. Next we will see further.
Perhaps 10 identical coils "stacked" up, 3cm distance,
each one extra connected, each one at least 50 windings.
Maybe two such rods in parallel to check the imbalance.

3dB is not the world but already a reasonable beginning.
I know there must be some "yagi-style" way.
Amplification by added antenna stages and with reflectors.

Perhaps some ferrite-shield behind the antennas.

I even think its possible with all-metal mode if we can
concentrate the EM-field straight and sharp forwards.

[Davor]

It should work fine if slavery is re-established. With no slavery you could engage 2 to 3 Bosnian Mountain Horses, and you are good to go.

[Orbit]

I remember that I tried with two coils reverse magnetic field I managed to detect the pi detector detects metals just below the coil and did not detect it at all above the coil the problem was just that the coil pretty heats because of the force magnetic suppression .
HALBACH ARRAY How to double the power of magnets, science experiment

https://www.youtube.com/watch?v=uQWHjj6ofwo