IGSL

[ivconic]

BTW...

[der_fisherman]

Andy, Here is the post where the grounding discussion was going on last summer. see post #372 http://www.geotech1.com/forums/showt...=16122&page=15

Plus, I made 2 videos in an experiment where I made two coils, One with the coils connected to the shield inside the coil shells and one with the shields and ground wires connected only to ground on the PCB.

Plus see these two videos The first is the "wet grass" configuration:

http://www.youtube.com/user/dobybowe.../5/7UBOca3btMw
http://www.youtube.com/user/dobybowe.../6/XhRboS639no

Hi Don,

thanks for the tip and the reading, but I am even more confused now about null, discrimination and GEB, it all seems to hang with the nulling, and as I haven't yet even received my kit yet from SilverDog, it is of course not yet built!!! So a lot of the terminology was over my head.

I do have a dual beam scope, meters and also an impedance meter for both C and L......I think I have everything needed, except the "understanding".....

So many differences of opinion from learned intelligent colleagues here.....thanks to you all.

Is there a clear, cut and dried setup for an IGSL double D coil?

Is there one for a TGSL that also applies to IGSL?

I have not as yet found one that agrees with you, but I am still reading.....

It would appear that the differences of opinion also result in different setups and different performances!! (SOOOO TRUE)

Once I have my electronics built and I can start on the coil nulling, maybe I will understand better......

If you have any further tips, please drop me a line as I feel I need help big time, thanks. Nothing is too tiny, everything happily accepted.

Regards

Andy

[ivconic]

"...Once I have my electronics built and I can start on the coil nulling, maybe I will understand better......"

True!

[ivconic]

Details.....

[Qiaozhi]

Andy, Here is the post where the grounding discussion was going on last summer. see post #372 http://www.geotech1.com/forums/showt...=16122&page=15

Plus, I made 2 videos in an experiment where I made two coils, One with the coils connected to the shield inside the coil shells and one with the shields and ground wires connected only to ground on the PCB.

Plus see these two videos The first is the "wet grass" configuration:

http://www.youtube.com/user/dobybowe.../5/7UBOca3btMw
http://www.youtube.com/user/dobybowe.../6/XhRboS639no

You commented earlier that the "wet grass" problem may be isolated to the use of a USB cable. I suspect this is true; as a commercial Tesoro (Bandido) works absolutely fine. However, occasionally you will find a faulty Tesoro coil that is intermittemt in wet grass. This is caused by a bad shield connection in the coil housing.

[WM6]

You would need to change the number of turns on the coil in order to make this useful for analyzing the field around a metal detector coil. Unfortunately, with the current design, it would need a different measurement coil for each TX frequency. For example, using a 1" (25.4mm) circular coil to measure the 14kHz TX signal from a TGSL would require 35 turns (assuming the same top value of 1uT, and an output voltage of 500uV).
In order to use the same coil for all tests, you would need a microcontroller to scale the results correctly according to frequency and magnetic field intensity.

Thanks for thorough comment Qiaozhi.

I do not understand what is main goal of solving disputed connection/orientation DD coil windings dilemma?

- to get better possible sensitivity?
- to get ideal phase shift?
- both of them?

Knowing answer, test (what we get by changing) cannot be a big problem.

[nakky]

Ivconic nice work .

Grt Nakky

[der_fisherman]

Wet grass fix.

[selim]

igsl finish

[der_fisherman]

Thanks for thorough comment Qiaozhi.

I do not understand what is main goal of solving disputed connection/orientation DD coil windings dilemma?

- to get better possible sensitivity?
- to get ideal phase shift?
- both of them?

Knowing answer, test (what we get by changing) cannot be a big problem.

I did answer, but not with your text, sorry.
The wet grass fix.

[ivconic]

Ivconic nice work .

Grt Nakky

Thanks Nakky!
Look Selim's work! I like it!
Very good work Selim!

[Wiltran]

IGSL

Ivconic, your MD looks professional! BTW do you bend your own aluminum pipe? I tried to bend alu. pipe with bad results!

[ivconic]

Ivconic, your MD looks professional! BTW do you bend your own aluminum pipe? I tried to bend alu. pipe with bad results!

No i am not..
Huge issue! Chronic issue!
I manage to obtain shaft or two... from time to time..

[WM6]

Nice work Selim. Congratulation.

[der_fisherman]

Beautiful, well done....thanks for the pics.