TGSL-EDU

[ice413]

I test my TGSL-EDU with the Hantek 6022 and got these values: See pics. In pic #2 you can see where i put the probes.
I really dont know what to measure, so please, give me a hint where to put my probes, and what numbers
i should aim on.
scope:
where i put the probes:

[Silver Dollar]

Well channel 2 should be after the preamp;




The level should be 4 mv at the coil so 4 * preamp gain at preamp out.
Looks like the gain is X20 so 80 mv at the preamp out.

You have to be on the correct side of the null though. I think you can tell
by waving a piece of ferrite. It will have a favorite side where it will gain in
amplitude only. I think you want to be on the other side so waving ferrite will
cause a phase shift to the favorite side before amplitude gain. Waving silver
(like a silver dollar) will cause an amplitude gain only as it likes our null side.

So you want to be 4 mv on the silver side for best operation. This is all easier
to see on a concentric. A "DD" is too sensitive to make the tiny changes needed
to see this... (at least mine is)

Here's some pictures of a concentric I did a few days ago;
Nulled


Ferrite


Silver

[bernte_one]

hey silver dollar

nice pictures, thanks good to understand

[ice413]

Great and thanks.
I'll test again tonight.

[Koala]

Well channel 2 should be after the preamp;
[ATTACH]31353[/ATTACH]

[ATTACH]31354[/ATTACH]

The level should be 4 mv at the coil so 4 * preamp gain at preamp out.
Looks like the gain is X20 so 80 mv at the preamp out.

You have to be on the correct side of the null though. I think you can tell
by waving a piece of ferrite. It will have a favorite side where it will gain in
amplitude only. I think you want to be on the other side so waving ferrite will
cause a phase shift to the favorite side before amplitude gain. Waving silver
(like a silver dollar) will cause an amplitude gain only as it likes our null side.

So you want to be 4 mv on the silver side for best operation. This is all easier
to see on a concentric. A "DD" is too sensitive to make the tiny changes needed
to see this... (at least mine is)

Here's some pictures of a concentric I did a few days ago;
Nulled
[ATTACH]31355[/ATTACH]

Ferrite
[ATTACH]31356[/ATTACH]

Silver
[ATTACH]31357[/ATTACH]

Can you not just swap the RX and TX connection if you can't detect large silver. Just a thought I could be wrong

[Bandit1611]

Hi All,

I am excited i just got my TGSL-EDU kit from Silverdog.

I do have a few questions regarding the following:
1) i would like to add a head phone jack and a volume knob to the circuit. does anyone have a schematic of how to do that with the TGSL EDU Boards?
2) the GB Pot is a pcb mount, does this ever need to be adjusted while using the detector in the field? if so would it not be better to have this on the control panel?
3) to do the test points for verifying the circuitry is correct, should i build up the whole board or build each of the modules? i think i should be building the whole board but i wanted to make sure before i start down that path.

Thank you

[Koala]

Hi All,

I am excited i just got my TGSL-EDU kit from Silverdog.

I do have a few questions regarding the following:
1) i would like to add a head phone jack and a volume knob to the circuit. does anyone have a schematic of how to do that with the TGSL EDU Boards?
2) the GB Pot is a pcb mount, does this ever need to be adjusted while using the detector in the field? if so would it not be better to have this on the control panel?
3) to do the test points for verifying the circuitry is correct, should i build up the whole board or build each of the modules? i think i should be building the whole board but i wanted to make sure before i start down that path.

Thank you

I use the GB (on my IDX) all the time to maximize depth in a wide range of conditions.

If you only detect on one type of ground you will not need to adjust it. If you move from field to beach to areas with coke on the ground plus loads more different locations then you will be setting the GB often. I find a multi turn POT a nice luxury but not necessary

I always use a headphone jack so you can change headphone in the field. Surprising how often they fail cable is always being bent as you dig. I always carry a spare set. Don't bother with a volume control. You can always use headphones with a volume control.

Cant answer 3 as TGSL-EDU is not my detector

[Ozoz_xba]

Well channel 2 should be after the preamp;
[ATTACH]31353[/ATTACH]

[ATTACH]31354[/ATTACH]

The level should be 4 mv at the coil so 4 * preamp gain at preamp out.
Looks like the gain is X20 so 80 mv at the preamp out.

You have to be on the correct side of the null though. I think you can tell
by waving a piece of ferrite. It will have a favorite side where it will gain in
amplitude only. I think you want to be on the other side so waving ferrite will
cause a phase shift to the favorite side before amplitude gain. Waving silver
(like a silver dollar) will cause an amplitude gain only as it likes our null side.

So you want to be 4 mv on the silver side for best operation. This is all easier
to see on a concentric. A "DD" is too sensitive to make the tiny changes needed
to see this... (at least mine is)

Here's some pictures of a concentric I did a few days ago;
Nulled
[ATTACH]31355[/ATTACH]

Ferrite
[ATTACH]31356[/ATTACH]

Silver
[ATTACH]31357[/ATTACH]

On the scope it looks that phase shift is just aproxx 20 degree, ,should be DD coil 20 degree and concenteic 200 degree(2 hundred) degree?