TESORO GOLDEN SABRE

[Max]

Hi Max,

Did you not see my previous post?

Hi,
I saw it. My TGS-clone is still a prototype have just tryed a few in test garden.
I have too shame of my last creation that's why I don't post pictures of it...

I've used unconventional case for BandidoII... something you'll never imagine cause the board (1st Gary's design) is really large.

But I think using standard parts to pack TGS-clone... at now is in a rough state, I have few time to pack it well.

I mean... I can post pictures... but, cause of the shame, with same resolution of Esteban's schematics !

Anyway... it works... and BandidoII too... that's what important at the end.

Kind regards,
Max

[Qiaozhi]

Max - how about some photos of your TGS clone, both inside and out?

Hi Max,

Did you not see my previous post?

[Max]

I've just carried out a few tests myself, and cannot so far find any difference if the 0V connection is made within the search head or not.
I intend to do some more scientific tests. More later...

Hi,
I've noticed the side effect of not having gnd connection at rx just on BandidoII, just there I've made such a test.
Maybe with such a small -V rail could be a problem having "propagation" due e.g. to offset along the amplifiers path ?

Anyway, my nulling on coil is everytime around 1mVpp... but there are also gain-to-offset effects to keep in mind... multiplication of problems!

Kind regards,
Max

[Qiaozhi]

Hi,
sorry for latency... yes I have done too.

I leaved rx lead connected to the circuit without gnd connection in BandidoII test... (till now never tryed on Gsabre) seems it works too but not as well as when I connect to gnd. I think that most depends on nulling and offset of preamp.

Bad null and hi-offset preamp. could give problems. I haven't in Bandido any problem like saturations of first stages and the like but used gnd connection cause that way I gained more depth than without it.

Ivconic reported that his coils work better without gnd connection at rx: maybe depends on nulling cause he used a different method than the "standard" reading by scope, as you suggested me some time ago.

Of course rx leads must be connected in the right way... I mean with right phase of rx signal going to preamp. , otherwise disc works bad and also performances aren't good.

Best regards,
Max

I've just carried out a few tests myself, and cannot so far find any difference if the 0V connection is made within the search head or not.
I intend to do some more scientific tests. More later...

[Max]

Thanks - we both seem to be posting at the same time.

Have you tried leaving out the connection? If so, what was the result?

Hi,
sorry for latency... yes I have done too.

I leaved rx lead connected to the circuit without gnd connection in BandidoII test... (till now never tryed on Gsabre) seems it works too but not as well as when I connect to gnd. I think that most depends on nulling and offset of preamp.

Bad null and hi-offset preamp. could give problems. I haven't in Bandido any problem like saturations of first stages and the like but used gnd connection cause that way I gained more depth than without it.

Ivconic reported that his coils work better without gnd connection at rx: maybe depends on nulling cause he used a different method than the "standard" reading by scope, as you suggested me some time ago.

Of course rx leads must be connected in the right way... I mean with right phase of rx signal going to preamp. , otherwise disc works bad and also performances aren't good.

Best regards,
Max

[Qiaozhi]

No center tapped RX. I connected one lead of it just to the gnd wire used for tx coil.

Thanks - we both seem to be posting at the same time.

Have you tried leaving out the connection? If so, what was the result?

[Qiaozhi]

Hi,
already explained by unregistered.

The connection I have is inside the coil. There the two shields wires leads are connected with an RX coil lead to provide a common gnd point there then that joint is connected to the gnd wire coming from the TX pads.

Right schematic is like in BandidoII that shows just RX coil without gnd connection at schematic. But connection exist in original coil made inside the coil itself, so one of RX wires coming from the search coil is actually connected to GND.

Think that as explained all this is to avoid twisted pair effects, having the common gnd connection just at the coils level.

I use that wiring in all my coils.

Kind regards,
Max

Hi Max,

Yes - I already know all this, no problem.
This is not what I'm asking.

My simple question is "When you made your DD and/or OO coils, did you also make a similar connection to 0V within the search head?".

[Max]

Yes - I know all this.
What I'm asking about is what configuration has anyone used for either a DD or OO configuration with the Tesoro circuits. i.e. Did you connect one side of the RX coil to the screen within the search head, or perhaps used a centre-tapped RX coil, etc. ??
Also, did anyone notice any difference in operation if the RX coil is not connected to the screen within the search head?

No center tapped RX. I connected one lead of it just to the gnd wire used for tx coil.

[Qiaozhi]

Max - how about some photos of your TGS clone, both inside and out?

[Qiaozhi]

Tesoro uses a diff. ampl. The ground for the RX is made in the coil.
This way the twisted pair eff. from the cable is used to cancel out ext. noise.
For opencentere ore DD ore OO coils this is al the same.... I think...

Good luck

Yes - I know all this.
What I'm asking about is what configuration has anyone used for either a DD or OO configuration with the Tesoro circuits. i.e. Did you connect one side of the RX coil to the screen within the search head, or perhaps used a centre-tapped RX coil, etc. ??
Also, did anyone notice any difference in operation if the RX coil is not connected to the screen within the search head?

[Max]

Question for Max:

The Tesoro concentric coils have a direct connection between one wire of the RX coil and the screen. The screen is also used as one of the wires for the TX coil, and is connected to 0V on the PCB.
When you made your DD coils, what scheme did you use with regard to this screen connection in the search head. In other words, did you connect one side of the RX coil to the screen, as in the Tesoro concentric coils.

If anyone else has made their own DD or OO coils for a Tesoro detector (clone or original) I would be interested in your experience in this area.

Thanks.

Hi,
already explained by unregistered.

The connection I have is inside the coil. There the two shields wires leads are connected with an RX coil lead to provide a common gnd point there then that joint is connected to the gnd wire coming from the TX pads.

Right schematic is like in BandidoII that shows just RX coil without gnd connection at schematic. But connection exist in original coil made inside the coil itself, so one of RX wires coming from the search coil is actually connected to GND.

Think that as explained all this is to avoid twisted pair effects, having the common gnd connection just at the coils level.

I use that wiring in all my coils.

Kind regards,
Max

Tesoro uses a diff. ampl. The ground for the RX is made in the coil.
This way the twisted pair eff. from the cable is used to cancel out ext. noise.
For opencentere ore DD ore OO coils this is al the same.... I think...

Good luck

[Qiaozhi]

Question for Max:

The Tesoro concentric coils have a direct connection between one wire of the RX coil and the screen. The screen is also used as one of the wires for the TX coil, and is connected to 0V on the PCB.
When you made your DD coils, what scheme did you use with regard to this screen connection in the search head. In other words, did you connect one side of the RX coil to the screen, as in the Tesoro concentric coils.

If anyone else has made their own DD or OO coils for a Tesoro detector (clone or original) I would be interested in your experience in this area.

Thanks.

[nelson]

Ok TikTak, have a good trip and post your results when you get back.

Regards

Nelson

Hi,
Max.
The resistance with 141 and 150 is too high but the sound now is louder than the readings from my previous!
So I will try as you say 120 and 135 and will fix this two new coils in housings and will be gone for some time to make real field tests.
The surfice is covered with rocks and cant keep coil close to ground on MY HUNTING AREAS!!!
But anyway no stupid questions for some time..........

So wish me luck!I am shore that TGS will performe MUCH better then the chinees toy that I have.But I wanned to make IVCONICS 28DD too.......
See you when I return.
Be well!

[Max]

Hi,
Max.
The resistance with 141 and 150 is too high but the sound now is louder than the readings from my previous!
So I will try as you say 120 and 135 and will fix this two new coils in housings and will be gone for some time to make real field tests.
The surfice is covered with rocks and cant keep coil close to ground on MY HUNTING AREAS!!!
But anyway no stupid questions for some time..........

So wish me luck!I am shore that TGS will performe MUCH better then the chinees toy that I have.But I wanned to make IVCONICS 28DD too.......
See you when I return.
Be well!

Have a good trip ! I wish you'll be lucky with your TGS.