White's TDI SL Oscillogram

[Mark-VA]

Does this look about right?

[Carl-NC]

It's upside-down but otherwise correct. You can flip your pickup coil over to correct the polarity.

[Mark-VA]

Never thought of flipping the coil over. But I tried my original coil with a 1K resistor and this is what I get.

[Carl-NC]

That's even more correct.

[Mark-VA]

[Mark-VA]

Also been thinking about ordering the Wurth 7447480331 and the required op amp to make the current probe. Torn between the TL072, the LT6231 Carl used in is probe or maybe a NE5532 or TL071, Digi-Key has the Wurth inductors at a reasonably price and the Op amps can come from either Amazon or Walmart.com

[Carl-NC]

If you go to the trouble of building the probe, build it with the '6231. It has the bandwidth necessary for MF & PI.

[Mark-VA]

Would that (6231)also work for the original probe post using the single opamp

[Carl-NC]

Which circuit?

[Mark-VA]

[Carl-NC]

I thought that was the circuit you were talking about in post #6.

[Mark-VA]

Yes you are correct.
Sorry about the confusion. I was guessing the Wurth 7447480331 would provide me with a more stable and uniform coil than the three I've wound myself. One worked really well with the single frequency but very unstable on the XP Deus the F-Pulse pin pointer and the TDI SL.
I really like this probe with select-able resistance (SW1a) but at this point I really need a probe that will allow accurate measurements on the XP Deus 2 and the Manticore.
Uniformity is where I'm at in my projects. I need to be able to replicate results each time to provide me with confidence and accuracy.


If this will work for the Deus and Manticore then it is what I need to build.

I'm guessing Wurth 7447480331 would work for L, R could easily be substituted on a bread board with different values or a potentiometer, now the op amp, I'm having trouble deciding on. TL071, NE5532, LT6231 and maybe even TL072. Amazon have several assorted op amp kits for $20 but none with the 6231.

[Carl-NC]

The big circuit is just a more complex and versatile version of the simple circuit. If all you want to do is see what waveforms look like, use the simple circuit. If you want to map the TX field from the surface plane of the coil out to its measurable limit or measure absolute field strengths in Teslas then the complex circuit is for that. In either case, the '6231 will give the best waveform fidelity because of its GBW of 215MHz. Lesser opamps will work, but they will limit waveform slew rate.

[Mark-VA]

Thanks for all your insights into my question.