TESORO GOLDEN SABRE

[ivconic]

Thanks Ivconic,

Ordered a length of Belden 8273 to use as coil cable. Should be here tomorrow. Since it has 2 drain leads, I was planning on hooking the TX shielding to one, and RX shielding to other and connect to ground in the box. Or do you think this is overkill? Original cable used was a scrap piece I had off of one of my Minelabs.

Mike

Worth of trying. I used once 2 separate coaxials (simillar to Minelab's) and it worked. Had extra job to readjust GEB cose cable type and it wirements do affects phase in some cases strongly. I think Belden would do the job just fine. Please inform us when test it.

[pulltabmike]

Would you kindly post that schematic as attachment or provide a link to the thread page where you got it? Always confusing what's what in such a long thread.

Cheers!

-SB

Here you go SB Only mods I did to board was to add attachment points for the wiring to the pots.

Mike

[pulltabmike]

Hi,
yes, you have to fix the coils cause vibrations will be detected easy.

In a part of my house I have used in past to test TGS/TGSL even my steps on the floor were detected... not to talk of heavy vehicles etc... any vibration detected like it was a seismic sensor!

Now I test in better conditions so I have not often that problems but sure it's always a good idea having good fixing at coils.

Anyway, I think your results are good enough to invest more time in critical tuning... on soil the tgs is amazing if not too minerals.

Kind regards,
Max

Hi Max,

I was pulling my hair out when nulling the coil, every footstep downstairs was knocking it out Plan on sending my wife shopping when I get around to fine-tuning it!

Mike

[pulltabmike]

12 Volts is 4V less than normal, so you will surely loose some depth cos of that. Are you using zener diod 4v3 or lower than that?
Also what are the supply voltage? I get +8V and - 7V
12-13" is not bad result at all, some of us could not start that good with pcb#1 so ...

Hi Eclipse,

It could be my scope, will double check once I am finished the new board I am building. I used a 4v3 zener diode. I am reading app. +7.8V and -6.3V. Using power supply set at 12V to power board.

Thanks,

Mike

[pulltabmike]

hi pulltabmike....
I will make TGSL 1265 latest version.did you use 0.25mm wire?
Regards....

I used 30 AWG coated wire (0.28mm Wire) that I bought through Amazon.com.

Mike

[pulltabmike]

Hi,
not bad for a start.

"...Any little vibration at the coil makes the detector go nuts!!!..."

This is usually happen when cable is not suitable or not wired up correctly in search head or at detector. Other case is when GEB trimmer is not adjusted properly. To check this you can use ferrite rod and see if detection on it occurs. If yes than adjust GEB trimm softly to stop detection on ferrite, just to hear some rare "cracks" when rod is 2-3" away from coil surface. Doesn't matter if this done in All Metal or Disc Mode, in both ways you can adjust it. In case of Disc mode, keep Disc pot at "1"...
OK, in case you can not "reject" ferrite rod by adjusting GEB trimmer, than coil is not nulled well.
But first recheck cable wirements. You have some draw on these pages how to wire up that correctly. I posted it some time ago...dont remember on which page.
Wish you success, regards!

Thanks Ivconic,

Ordered a length of Belden 8273 to use as coil cable. Should be here tomorrow. Since it has 2 drain leads, I was planning on hooking the TX shielding to one, and RX shielding to other and connect to ground in the box. Or do you think this is overkill? Original cable used was a scrap piece I had off of one of my Minelabs.

Mike

[simonbaker]

Good morning all,
I hope you all do not mind me jumping in, I have been following this project with great interest for a while now, and finally got the bug to build Ivconics TGSL version 2 weeks ago. I have been out of the electronics hobby for about 20 years, so I am quite a bit quite a bit rusty at it I see I have quite a bit to learn! I do have over 25 years experience detecting here in the States. So far, all of my problems have been centered around the coil. I wound a 11" DD, 100 turns TX, 103 turns RX. I am measuring 12V P-P and 14.7 Khz at TX with O-Scope. Aluminum tape used for shielding. My initial air-test depth results are below without the audio boost mod, with the detector at a slight chatter:

US Penny – 12”
US Nickel – 13”
US Dime – 11”
US Quarter – 13”


All of my interference is electrical in nature (my workshop is in the attic of my home) and due to the fact that the coil is not secure. Any little vibration at the coil makes the detector go nuts!!! Once I finish tuning and securing the coil, will test outside. I know the figures above will only improve. For those that have gotten the circuit to where it is now, my hat is off to you, great work

Mike

Would you kindly post that schematic as attachment or provide a link to the thread page where you got it? Always confusing what's what in such a long thread.

Cheers!

-SB

[simonbaker]

12 Volts is 4V less than normal, so you will surely loose some depth cos of that. Are you using zener diod 4v3 or lower than that?
Also what are the supply voltage? I get +8V and - 7V
12-13" is not bad result at all, some of us could not start that good with pcb#1 so ...

Yes, 12-13 with sens not at max is a good detector, find good stuff with it as is. If make better, icing on cake!

Oscillator voltage depends directly on zener voltage and Vgs-cutoff of JFet. (Right now I have 10v p-p.) More zener volts and/or more Vgs-cutoff = more oscillator voltage. You can get distortion though -- but does it matter? One way to increase voltage is put diodes such as LED in series with zener, make volt drop higher. Of course, proof is in field if makes deeper detection. Or substitute JFet with greater Vgs-cutoff.

Regards,

-SB

[simonbaker]

This circuit uploaded in this thread at the past
And again .

Looking back again at this latest posted schematic on page http://thunting.com/geotech/forums/s...12692&page=117

Final LM358 has 12 volt supply instead of 8v -- is that intended?

Other new addition is R55 1M resistor and switch SW2 labeled "Audio" -- is that proven a good addition?

(BTW: Even though takes space, each time someone builds TGS, good to post schematic so we know which one and can discuss and compare.)

Cheers,

-SB

[Max]

Good morning all,
I hope you all do not mind me jumping in, I have been following this project with great interest for a while now, and finally got the bug to build Ivconics TGSL version 2 weeks ago. I have been out of the electronics hobby for about 20 years, so I am quite a bit quite a bit rusty at it I see I have quite a bit to learn! I do have over 25 years experience detecting here in the States. So far, all of my problems have been centered around the coil. I wound a 11" DD, 100 turns TX, 103 turns RX. I am measuring 12V P-P and 14.7 Khz at TX with O-Scope. Aluminum tape used for shielding. My initial air-test depth results are below without the audio boost mod, with the detector at a slight chatter:

US Penny – 12”
US Nickel – 13”
US Dime – 11”
US Quarter – 13”


All of my interference is electrical in nature (my workshop is in the attic of my home) and due to the fact that the coil is not secure. Any little vibration at the coil makes the detector go nuts!!! Once I finish tuning and securing the coil, will test outside. I know the figures above will only improve. For those that have gotten the circuit to where it is now, my hat is off to you, great work

Mike

Hi,
yes, you have to fix the coils cause vibrations will be detected easy.

In a part of my house I have used in past to test TGS/TGSL even my steps on the floor were detected... not to talk of heavy vehicles etc... any vibration detected like it was a seismic sensor!

Now I test in better conditions so I have not often that problems but sure it's always a good idea having good fixing at coils.

Anyway, I think your results are good enough to invest more time in critical tuning... on soil the tgs is amazing if not too minerals.

Kind regards,
Max

[eclipse]

12 Volts is 4V less than normal, so you will surely loose some depth cos of that. Are you using zener diod 4v3 or lower than that?
Also what are the supply voltage? I get +8V and - 7V
12-13" is not bad result at all, some of us could not start that good with pcb#1 so ...

[Friday]

hi pulltabmike....
I will make TGSL 1265 latest version.did you use 0.25mm wire?
Regards....

[ivconic]

Good morning all,

I hope you all do not mind me jumping in, I have been following this project with great interest for a while now, and finally got the bug to build Ivconics TGSL version 2 weeks ago. I have been out of the electronics hobby for about 20 years, so I am quite a bit quite a bit rusty at it I see I have quite a bit to learn! I do have over 25 years experience detecting here in the States. So far, all of my problems have been centered around the coil. I wound a 11" DD, 100 turns TX, 103 turns RX. I am measuring 12V P-P and 14.7 Khz at TX with O-Scope. Aluminum tape used for shielding. My initial air-test depth results are below without the audio boost mod, with the detector at a slight chatter:

US Penny – 12”
US Nickel – 13”
US Dime – 11”
US Quarter – 13”


All of my interference is electrical in nature (my workshop is in the attic of my home) and due to the fact that the coil is not secure. Any little vibration at the coil makes the detector go nuts!!! Once I finish tuning and securing the coil, will test outside. I know the figures above will only improve. For those that have gotten the circuit to where it is now, my hat is off to you, great work

Mike

Hi,
not bad for a start.

"...Any little vibration at the coil makes the detector go nuts!!!..."

This is usually happen when cable is not suitable or not wired up correctly in search head or at detector. Other case is when GEB trimmer is not adjusted properly. To check this you can use ferrite rod and see if detection on it occurs. If yes than adjust GEB trimm softly to stop detection on ferrite, just to hear some rare "cracks" when rod is 2-3" away from coil surface. Doesn't matter if this done in All Metal or Disc Mode, in both ways you can adjust it. In case of Disc mode, keep Disc pot at "1"...
OK, in case you can not "reject" ferrite rod by adjusting GEB trimmer, than coil is not nulled well.
But first recheck cable wirements. You have some draw on these pages how to wire up that correctly. I posted it some time ago...dont remember on which page.
Wish you success, regards!

[pulltabmike]

Good morning all,
I hope you all do not mind me jumping in, I have been following this project with great interest for a while now, and finally got the bug to build Ivconics TGSL version 2 weeks ago. I have been out of the electronics hobby for about 20 years, so I am quite a bit quite a bit rusty at it I see I have quite a bit to learn! I do have over 25 years experience detecting here in the States. So far, all of my problems have been centered around the coil. I wound a 11" DD, 100 turns TX, 103 turns RX. I am measuring 12V P-P and 14.7 Khz at TX with O-Scope. Aluminum tape used for shielding. My initial air-test depth results are below without the audio boost mod, with the detector at a slight chatter:

US Penny – 12”
US Nickel – 13”
US Dime – 11”
US Quarter – 13”


All of my interference is electrical in nature (my workshop is in the attic of my home) and due to the fact that the coil is not secure. Any little vibration at the coil makes the detector go nuts!!! Once I finish tuning and securing the coil, will test outside. I know the figures above will only improve. For those that have gotten the circuit to where it is now, my hat is off to you, great work

Mike

[aft_72005]

Hi Max
I am sure my test area full of electrical noises and interference because
TGSL out put sound with noises, especially when sensitivity pot. At maximum.
I carry it to my home , and test again .
Best regards.