Shift left, shift right, non ferrous increase or decrease, etc.

[MaverickITA]

Dear friends,
you know Tesoro coil produce RX phase shift to left, relative to TX, with all metal.
Non ferrous cause an increase, ferrouse a decrease in amplitude.

It is due to the direction of the windings only?

What determines phase shift and what non ferrous and ferrous response exactly?

Thank you in advance.

[Gwil]

This may possibly help:

http://www.geotech1.com/forums/showt...et-experiments

Gwil

[kt315]

http://www.geotech1.com/forums/conte...metal-detector

[MaverickITA]

http://www.geotech1.com/forums/conte...metal-detector

Yes the book is very good.
I have already bought it but I do not found the answer to my question.
Can be I missed something?

[MaverickITA]

I have also another question (only one?):
when you build a DD coil, it is better to put TX over RX or the opposite?

[Qiaozhi]

Dear friends,
you know Tesoro coil produce RX phase shift to left, relative to TX, with all metal.
Non ferrous cause an increase, ferrouse a decrease in amplitude.

It is due to the direction of the windings only?

What determines phase shift and what non ferrous and ferrous response exactly?

Thank you in advance.

The amount of relative phase-shift for ferrous and non-ferrous can be adjusted somewhat by changing the coil overlap, but the direction of the phase-shift and amplitude changes will stay the same. These are a function of the relative tuning between the TX and RX coils. The best way to get a better understanding of coil construction is to do a few experiments.

Energy is induced in a nearby conductive target in the form of eddy currents. Depending on the resistive and reactive properties of the target, the signal at the RX coil (as a consequence of Lenz's Law) will either have a reduced amplitude (due to absorption) or an increased amplitude (due to redistribution). See Chapter 7 and page 88 of ITMD.

[Qiaozhi]

I have also another question (only one?):
when you build a DD coil, it is better to put TX over RX or the opposite?

For all practical purposes, it makes no difference.

[MaverickITA]

The amount of relative phase-shift for ferrous and non-ferrous can be adjusted somewhat by changing the coil overlap, but the direction of the phase-shift and amplitude changes will stay the same. These are a function of the relative tuning between the TX and RX coils. The best way to get a better understanding of coil construction is to do a few experiments.

Energy is induced in a nearby conductive target in the form of eddy currents. Depending on the resistive and reactive properties of the target, the signal at the RX coil (as a consequence of Lenz's Law) will either have a reduced amplitude (due to absorption) or an increased amplitude (due to redistribution). See Chapter 7 and page 88 of ITMD.

I am going to read it better.

[MaverickITA]

For all practical purposes, it makes no difference.

Thank you.

[kt315]

I always write - read ITMD BEFORE you open new thread and asking something. do not open new thread if you did not read ITMD. ask what you see unclear in ITMD,
give a mention on page and together we ll find out the answer.

[MaverickITA]

I always write - read ITMD BEFORE you open new thread and asking something. do not open new thread if you did not read ITMD. ask what you see unclear in ITMD,
give a mention on page and together we ll find out the answer.

You are right, I am goingo to do more attention.