In http://www.youtube.com/watch?v=1OrPCNVSA4o...
Big one is your 150V to coil from inverter and small one is your nanopulser with coax cable.

So, what plays the role of the compass needle in the Dally's device?

Also, in the NMR simulation at http://www.drcmr.dk/JavaCompass/  ,the big magnetic field is constant an unidirectional, however Dally's current "to coil from inverter" is AC, which is neither constant, nor unidirectional

So, what plays the role of the compass needle in the Dally's device?

Also, in the NMR simulation at http://www.drcmr.dk/JavaCompass/  ,the big magnetic field is constant an unidirectional, however Dally's current "to coil from inverter" is AC, which is neither constant, nor unidirectional

The AC or DC doesn't matter on main signal as long as you follow same principles. In most cases it is AC with other signal following polarity.

Who told you NMR can happen only in hydrogen..? It can happen in any matter.

It would be more correct to write that NMR can happen in any matter that has  intrinsic magnetic moment and angular momentum, in other words a nonzero spin. 
Not all matter has .

Hi everyone

If you allow a small, but I think an important point.
Pay attention to the quality of mounting scheme nanopulser.
At a high frequencies and short pulses, it is necessary to take steps to eliminate spurious emissions on the momentum,  parasitic generating, etc.

@ itsu.  this design board is not suitable for such devices. Need use the board with a continuous conductive ground.
After installation of the transistor and diode DSRDs, the scheme may bad work.
I usually use a workpiece from FR-4 material. Use a sharp knife-cutter. I cut with a knife by a metal ruler. I has long been using this method for modeling boards RF and microwave range.
For a high frequency or very short pulses, such assembling on the standard boards is not suitable.
However, you done that even in this version is still working.
It would  be desirable to have everything worked reliably, for yours version of replication. 
You every success!

Regards
Vasiliy

Concerning the permeability of the small toroid, i followed your formula in post #236, and i made the calculations with the inductance in uH and the dimensions in mm, is that the way to do it?

See video i made of that here: http://www.youtube.com/watch?v=4pCmJMAjLHg&feature=youtu.be

An air web with very short leads or a construction over a copper laminate ground is a good advice for circuits operating at ns or GHz.

Regarding your permeability measurements - they are OK, but that's not everything.  You still do not know the saturation points of your toroids.

To measure it, wind two CW layers of one winding with 1-2mm dia. wire (the second layer advancing in the opposite direction along the outer circumference of the toroid) and apply very short pulses (green) at high frequency to this winding using one of your power MOSFETs, driven by your TL494 circuit, while measuring the drain current through a 0.1Ω current sensing resistor.

These current pulses should be sawtooth shaped (blue), however as you start gradually decreasing the frequency the TL494 (or increasing its pulse width (purple) ), the sawtooth tips will start curving up on your scope (red).
Note the instantaneous current when this distortion happens, divide it by the number of turns in the winding and by the circumference of the toroid, and you will have the saturation point of the ferrite.

P.S.
If your pulse tops start flattening out (instead of curving up), that means that you are reaching the V/R limit, e.g. you current sensing resistor has too much resistance or your supply voltage is too low or you don't have enough turns.

Thanks verpies / Vasiliy for confirmation on the permeability measurements.

Also verpies thanks for the next step    the saturation point.

(It makes me feel like going forward half the step of the previous one; going forward, but never reaching the goal).

I understand we must work in saturation mode (post #228), so we should be able to see that in the created nano-pulse,

(sloping line indicates on the transformer in saturation mode.)

right?

Anyway,  concerning the design error of the IRFU320 MOSFET nano-pulser, for those who are intrested, i made some additional scope shots showing the problem:
http://www.youtube.com/watch?v=hNxkLCMlpS0&feature=youtu.be

I am sure the problem is in the design of the diagram.

I will remove the both transistors and use a max4420 MOSFET driver to drive the MOSFET.
If that's not going to work i will have to look for KT629A transistors

Regards Itsu
 

Quote

sloping line indicates on the  transformer in  saturation mode

Regards Itsu

Well, at least in our system of notation so accepted

Regards

I am sure the problem is in the design of the diagram.

What happens to the polarity of the pulses if you flip the switch S2 ?