Crazy ferrite idea

[simonbaker]

Idea I have wanted to try for a while:

Suppose we make a ferrite core for our TX and maybe also RX coils?

For example, take a bunch of black sand, mix with glue, and spread across inner area of the coil on a piece of cardboard or something.

Possible advantages:

1. Magnify magnetic fields
2. Swamp any ground mineralization effect

Possible disadvantages:

1. Hysteresis in the ferrite would lower the coil Q, waste energy.
2. Dumb idea.

Any thoughts or experimenters willing to try?

Regards,

-SB

[Max]

Idea I have wanted to try for a while:

Suppose we make a ferrite core for our TX and maybe also RX coils?

For example, take a bunch of black sand, mix with glue, and spread across inner area of the coil on a piece of cardboard or something.

Possible advantages:

1. Magnify magnetic fields
2. Swamp any ground mineralization effect

Possible disadvantages:

1. Hysteresis in the ferrite would lower the coil Q, waste energy.
2. Dumb idea.

Any thoughts or experimenters willing to try?

Regards,

-SB

Hi,
the usefulness depends on what kind of MD you're trying to make... if e.g. a very directional two-boxes it will work.
A member posted a schematic of such a thing... that uses 2 ferrite one at tx side and the other at rx side... like in AM radio receivers.

The problems will be more than advantages in other kind of mds... like e.g. PI (cause of hysteresys losses and non-linearity) or VLF-IB... where you're supposed to balance ground signal and mineral component by electronics... and adding grains of magnetic materials will create a number of problems when near real soil.

Of course, any md can be made to outperform on the bench and one can also try a special pi or vlf-ib that way on the bench to say if works... and it could I think... cause one could e.g. focus fieldlines in particular shape etc but on soil there will be great troubles for sure.

In two-boxes the antennas are far from soil... and so you can use e.g. air core loops or ferrite-loops without much difference... where near to soil
things are never that easy.

There's also an energetic problem... you'll lose energy with hysteresis so must spend more battery for unuseful task... the more power the more energy wasted...

I know, anyway, that some old BFOs and off-resonance were made that way... with the use of ferrite rods as sensitive "head" (kind of hammerhead I would say) remember me old magazines from 60's and 70's... but that circuits (one work at 455Khz, others at 470Khz if I remember well) were not much more than educational projects... much like radioworks... I remember one off-resonance that was made with IF transformers... 455Khz like am radio stuff...

PS: Esteban do you remember that project of 455Khz off-resonance ? I think you could have that schematic... it was from an italian (or was spanish?) magazine I think. Unfortunately I could not locate anymore that project cause was on my friend's father magazine that my dear friend borrow me... but now that stuff is lost forever!

Kind regards,
Max