Subtraction

[Danno]

Hi All,
Just curious how many different ways there are to do signal subtraction, would be interesting to see if Deus II is doing something new or using older methods like the DFX.

I am guessing and accurate ground balance is necessary to get accurate results on salt and iron based minerals.

[kt315]

ITMD is good thing to begin from. but... this is just my personal opinion.

[kt315]

hi

small view -> Link to copyrighted material removed.

[Danno]

hi

small view -> Link to copyrighted material removed.

small view of what?

[Qiaozhi]

small view of what?

It was copyrighted material, which has since been removed by youtube. So don't bother looking for it.

[Carl-NC]

Just curious how many different ways there are to do signal subtraction, would be interesting to see if Deus II is doing something new or using older methods like the DFX.

I'm aware of 2 major ways of doing GB with MF. First is to treat each frequency as a separate VLF detector and do traditional phase-rotation GB on each one. Then do a weighted subtraction on the resultant resistive signals to notch out salt. V3 does it this way. I believe that this has also been done backwards: first do salt balance using phase rotation, then notch ground with subtraction. I don't recall where I've seen this.

The second way I'm aware is to take the MF signals and create composite signals with weighted subtraction. This results in a ground-nulled composite signal, then the resistive signals are used to notch salt. The old analog CZs did it this way.

It's impossible to say how any of the new designs are doing it as everything is in software. BTW, ITMD1/2 doesn't really cover any of this. ITMD3 will.

[Danno]

I'm aware of 2 major ways of doing GB with MF. First is to treat each frequency as a separate VLF detector and do traditional phase-rotation GB on each one. Then do a weighted subtraction on the resultant resistive signals to notch out salt. V3 does it this way. I believe that this has also been done backwards: first do salt balance using phase rotation, then notch ground with subtraction. I don't recall where I've seen this.

The second way I'm aware is to take the MF signals and create composite signals with weighted subtraction. This results in a ground-nulled composite signal, then the resistive signals are used to notch salt. The old analog CZs did it this way.

It's impossible to say how any of the new designs are doing it as everything is in software. BTW, ITMD1/2 doesn't really cover any of this. ITMD3 will.

Thanks Carl, when is ITMD3 being published? I have 2.

[Carl-NC]

Don't know, still lots to do. Probably next year.