TESORO GOLDEN SABRE

[WM6]

Additionally to tictac:

As ivconic say there is practically impossible to get double basis frequency if you consider here suggested data. If you consider all suggested data, you can measure 28kHz only by wrong procedure (e.g. f-meter input can be overloaded by wrong connection, mean, your TGS can be entirely ok and parasitic mirror frequency can arise in input stage of f-meter, which can be in different way coupled during measurement on MD output).

Only in case that your coil dimensions (diameter) are smaller than suggested, you can solve problem by adding some windings as previous noted.

[Qiaozhi]

Might be the frequency 14.25kHz, only you measured second harmonic?
If you respected datas i posted earlier (255x137 and wire 0.25...107w and 102w...or simillar) than it is almost impossible to achieve 28.5kHz frequency! Impossible!
Which type of frequencymeter you are using?
To many open questions at your work and posts Tiktak.... Many times i didnt wanted to involve myself in some more detailed discussion here cose there is some basic knowledge and skill you MUST have before attempt to make any of present devices. Not to mention TGS, which is rather complex to build, and it is not most suitable for a beginner as starting project. Although schematic looks simple, although coil also looks easy to made....it is not the case for sure. TGS with coil, presented here is very difficult to make properly.Not for beginers at all. Anyone can draw pcb,solder components and make some coil....but it will not work! Trust me.
Do not understand me wrong here. I am just saying what is real situation, facts.
Zillion of question, always same question,always same problems with this TGS.
This thread tends to be hugest thread on internet ever!
To make TGS right and properly, you must undestand its working principles first.
Also, many of you - you must return back to very first pages and carefully read all posts. Everything is already elaborated pretty detailed here, step by step.
Very Best Regards!

Hi Ivconic,
I agree.
This project is not one that should be attempted lightly. There are mainy gotchas along the way that will inevitably lead to huge frustration, both for the person building the detector, and for the other forum members.

tiktak - The TX frequency you have determined is probably a measurement error. As Ivconic has noted, this is the second harmonic, which looks suspicious. Have a look at the TX waveform with a scope and directly measure the period from there.
If your comparators are in sockets, then that's most likely the cause of the instability, regardless of whether you claim to have had this working previously. It is bad practice to use sockets for comparators if the input signal hovers around the switching level, especially when there's no hysteresis. Do you have access to an oscilloscope? If not, then you will probably never be able to really fix this problem.

[ivconic]

Might be the frequency 14.25kHz, only you measured second harmonic?
If you respected datas i posted earlier (255x137 and wire 0.25...107w and 102w...or simillar) than it is almost impossible to achieve 28.5kHz frequency! Impossible!
Which type of frequencymeter you are using?
To many open questions at your work and posts Tiktak.... Many times i didnt wanted to involve myself in some more detailed discussion here cose there is some basic knowledge and skill you MUST have before attempt to make any of present devices. Not to mention TGS, which is rather complex to build, and it is not most suitable for a beginner as starting project. Although schematic looks simple, although coil also looks easy to made....it is not the case for sure. TGS with coil, presented here is very difficult to make properly.Not for beginers at all. Anyone can draw pcb,solder components and make some coil....but it will not work! Trust me.
Do not understand me wrong here. I am just saying what is real situation, facts.
Zillion of question, always same question,always same problems with this TGS.
This thread tends to be hugest thread on internet ever!
To make TGS right and properly, you must undestand its working principles first.
Also, many of you - you must return back to very first pages and carefully read all posts. Everything is already elaborated pretty detailed here, step by step.
Very Best Regards!

[WM6]

HI,
Also my TX frequency is 28,5 kHZ for both devices.
How can I reach 14 kHz by adding or taking off some windings?

By adding between 3/5 - 4/5 existing windings, if your measurement was correct and you measure basis frequency and not only some parasite frequency.

[tiktak]

Hi

HI,
Also my TX frequency is 28,5 kHZ for both devices.
How can I reach 14 kHz buy adding or taking off some windings?
Max please look the numbers from my previous post and tell me are this the numbers for 255 DD.
Thanks.
I use 100 w 0,25mm wire.
Thanks

[tiktak]

Hi,

HI,
Thanks to all folks for advices.
I will try to check all the moments you have point me.

1.ICs are fitted with socets!I think that this is not the probleme because I use same way on my first device!

2.I draw my PCBs on hand and they are not 100% the same.This could be the reason.But my first device PCB is hand drawn too.But they are the same.

I will check all again and will post here.

[Qiaozhi]

Hi Qiaozhi,

I made my DD coils with a left shift.The problem was to be able to get the right angle with a minimum residiual voltage.

Interesting... I'll do some more checks, probably sometime next week. The DD coil I made had some relatively thick wire (0.56mm), and this does it make it more difficult to null. Perhaps using thinner wire would make it easier to find a point where the phase-shift is to the left.

Also an amplitude variation dependent of metal implies that the coils are not perfectly nulled,or else all metals would make amplitude to rise.I think this means o good coil with good discrimination is NOT a perfectly nulled coil.

That's true. I have stated previously that Tesoro coils are not perfectly nulled. Usually there is around 15mV residual across the RX coil.

That´s interesting,small detail tha make the difference.
The experience i have with CC coils is not good, as i had to make too many nulling turns , thus ruining the detection range.
Omega coil worked well, but it was a coil i made for other detector and i never tested phase shift or nulling with the TGS.

Regards,
Fred.

That's another experiment for us to try.

[nelson]

Hi Qiaozhi. Yes you are rigth, i missed that reply.
Sorry, and thanks
Take care
Nelson

I guess you missed my previous reply to this question:
http://thunting.com/geotech/forums/s...postcount=2273

[Fred]

Hi Qiaozhi,

I think Max said that he could confirm there was a phase-shift to the left with a Tesoro factory-made concentric coil, but do not remember what he found with the DD..

I made my DD coils with a left shift.The problem was to be able to get the right angle with a minimum residiual voltage.
Also an amplitude variation dependent of metal implies that the coils are not perfectly nulled,or else all metals would make amplitude to rise.I think this means o good coil with good discrimination is NOT a perfectly nulled coil.

For the concentric coil, a left-phase shift means that the target is detected as it enters the RX coil, whereas a right phase-shift will only detect the target as it leaves the RX coil, which makes it more difficult to pinpoint amongst the trash..

That´s interesting,small detail tha make the difference.
The experience i have with CC coils is not good, as i had to make too many nulling turns , thus ruining the detection range.
Omega coil worked well, but it was a coil i made for other detector and i never tested phase shift or nulling with the TGS.

Regards,
Fred.

Hi, in post #2180 I had stability problems with GS, now they are solved and GS works well and is very stable. Maybe some of my experience will help someone with similar problems.
1. coil. It has to be absolute solid, use some form and lot of epoxide glue, if you swing coil and it hits grass or something and bends a bit, it will give lots of false signals.
2. Battery. In my case problem was a battery, I use 10 AA chargeable cells, two of them were bad and with 9,... volts my GS dont work. Fully charged with 13 volts all metals and disc both
work well, if accu drops under 12v it goes unstable in all metal, and under 10 also in disc mode.
3. wiring. My GS worked much stable after I used inside a case for RX and TX shielded leads and banded all other wiring together.
4. audio. I never had a problem with weak audio, but i also use as a Max 16ohm 8cm speaker from old mac computer.

[Max]

Hello

One friend said adding 2.2k paralel to 2.2k R increasing deepth 5 cm

This 2.2k At right bottom side of pcb connected 2n2907

he wrote he found 2 cm coin at 60 cm undreground.

with tgs and ivconics coil 257mm 140mm. DD .

regards
Erol

Hi,
2cm diameter at 60cm ? Impossible... so I think if he found it maybe there's something else in soil (at fewer depth) he maybe miss during excavation and then when he bring detector again it detected the coin there (say after 30-40 cm already dug... in the hole digging more deep).

This is a possible scenario... happened to me with some small targets cause I found some copper scraps (small) were dispersed in the ground just 30cm above the "good" stuff...

In one of this excavation I removed for 30cm depth about 60cm diameter large hole... without finding anything at first (2 small copper scraps I found just later with lot of efforts there) but clearly pinpointing 4 good targets (silver) in the bottom of the hole just easy. SO EFFORTS WERE GOOD SPENT THAT TIME!

Kind regards,
Max

[Max]

WONDER HOW GARRETT'S TARGET IMAGING WORKS . HIGH POWER DSP ?? ANYWAY SPEAKING OF COIL POSITION !!! WHY DOES A TWO-BOX HAVE THE REAR COIL OUT OF PHASE WITH THE FRONT COIL ???? AZIZ , MAYBE YOU NEED TO DESIGN A MULTI-PHASE SEARCH COIL FOR STANDARD DETECTORS. THIS SHOULD BE ON OUR DESIGN GROUP THREAD NOT HERE ... HAVE A GOOD DAY !! ...................EUGENE

Hi,
don't know of target imaging stuff... but the coils in 2box are 90° out cause this way there's minimal (ideally zero) magnetic coupling between them... so rx receive "zero" signal in absence of target.

Kind regards,
Max

[erolunall]

Hello

One friend said adding 2.2k paralel to 2.2k R increasing deepth 5 cm

This 2.2k At right bottom side of pcb connected 2n2907

he wrote he found 2 cm coin at 60 cm undreground.

with tgs and ivconics coil 257mm 140mm. DD .

regards
Erol

[Qiaozhi]

How i can measure RX frequency, to know if RX coil is resonating at 16.XXX Khz?
Regards
Nelson

I guess you missed my previous reply to this question:

http://thunting.com/geotech/forums/showpost.php?p=72453&postcount=2273

[amtech2005]

TESORO GOLDEN SABRE

WONDER HOW GARRETT'S TARGET IMAGING WORKS . HIGH POWER DSP ?? ANYWAY SPEAKING OF COIL POSITION !!! WHY DOES A TWO-BOX HAVE THE REAR COIL OUT OF PHASE WITH THE FRONT COIL ???? AZIZ , MAYBE YOU NEED TO DESIGN A MULTI-PHASE SEARCH COIL FOR STANDARD DETECTORS. THIS SHOULD BE ON OUR DESIGN GROUP THREAD NOT HERE ... HAVE A GOOD DAY !! ...................EUGENE