TESORO GOLDEN SABRE

[ivconic]

I will be anoying again, but i simply must insist on nulling method here.
It is absolutelly wrong to null coil monitoring RX opamp output at 7. pin!
I dont know about other detectors, but can asure you at TGSL is quite different; you must connect bare RX ends to AC milivoltmeter, without any blah,blah resistor and capacitor.Bare ends and nothing else. You will start detector to run only with TX coil connected on it. Monitoring residual voltage on RX coil you must try to achieve less possible voltage.

1) you are using origin oscillator at TGS with which nulled coil will work in future,
2) least voltage achieved when nulled is REAL less possible voltage on that setup with given working frequency,
3) you must use hi-quality mass,filler to fix and harden both coils togather to maintain good null for ever ( after many years of experimenting finally i founded almost same mass used at Fisher and Minelab coils..)

Coil nulled with exact origin oscillator, included on origin detector (pcb) will always work perfectly ONLY with that detector and no one else...On other (same model) detectors, that coil will perform different - not that good.

Reason for this is due huge tolerancy in components quality,battery quality,overall setup etc.etc...
I dont take simulators very seriously just because of this.
I do resolve my handmades one by one, case by case. Although made 26 so far, not all the same. Each one came after is better and better.
Mixing coils for one to another usually give me various results, so i dont mix coils and detectors,though they all should be same...

So...all possible differences and confuses are laying in this, i wrote above..

[Max]

Hi,Max!
I know what are yoy saying. TGS could be pretty unstabile if GEB is not adjusted critically.
I am using trimmer for GEB not potentiometer. Once adjusted well it stays inside preseted for good.
I do not adjust it anymore. If i face some high mineralisation on the field, only way to make TGS calm is to reduce sensitivity.
For example if Sense was at "8" and after few meters,walking, suddenly starts "beep"-ing or chattering due differences in soil conditions i am lowering Sense let's say to "7" or "6" and it calms down and retreive perfect stabillity.
After a while do recheck if it's gonna be stabille on "8" or more again.
But these are very rare cases. In every 10 terrains only one is so "trashy" to provoke TGSL to work erratically.
This behaviour is tied mostly to coil and its design. I noticed different behavior with few different coils.
How i adjust Geb? I have ferrite rod, hot rock, black sand and few old irons in my workshop. I adjust Geb with trimmer not to react on those items yet to react on thin silver piece. It is criticall, cometimes it makes difference in 1/2mm on trimmer...That's why i do not use potentiometer and cables to connect it with pcb..only trimmer.
My field experiences with this mod are very good. Yes it can bang pretty loud if Sense is at maximum and suddenly you pass with coil over some highly mineralized area. But lowering Sense to "6" (for example and passing again it will remain silent. Also switch is very usefull here. In case you come to very trashy field and oftenly have loud bangs there you can easilly switch Off monostabile mode and continue to work without it...rare cases.
Regards!

Hi Ivconic,
thanks for very useful explaination. At first I was using also the trimpot on PCB but some months ago I found that I need the pot on panel... and moved that control there. I found I can null very well using the trimpot... with trial and error procedure, involving the ferrite rod and a medium sized piece of red brick. In most soils I found it worked pretty cool that way, just like you reported... just rare cases when it goes erratic cause of soil or some interference (sometimes I searched near a big ...plant... there are big AC fields around and soil is a bit... hot... for detector and not only). But rare cases... then I found some soils "hot" too causing detector became instable ...I think the soil there is full of small iron oxides, red sand.

I agree that coils are the keys...to maximum depth and stability.

Kind regards,
Max

[ivconic]

yes the musketeer with 10" coil can detect a coin
in ground around 23-25sm, even if you have to lower
your TGL sense, it probably still will be the deeper detector.
and you can still hear from time to time false beeps with the advantage,
not a pain to die..

TGSL is "deeper", no doubts.
Yet Musketeer is also very sweet machine. I had Colt version in the past with TS800 18cm coil. Recently i got Advantage with 10" coil on few days testing. What i noticed is that old Colt with smaller coil was much better and more stabille than new Advantage !??? I couldn't beleive!? Since pcb's are identical i presume all differences must be due different coils!?
Same analogy i intend to use in TGSL case. Intend to make smaller coil than 27cm. Most probably i will make 18-20 cm DD coil and see.
I dont expect smaller coil to go deeper...of course not. Yet i expect excellent performances and more stabillity with it.Although even now, with this 27cm, TGSL is very,very stabille. I am more than satisfied..

Refering Musketeer Colt...once i have found 2.5cm bronze coin at 29cm depth with it and TS800 18cm coil!!!! I was more than delited! Colt was real coinkiller! Pitty i sold it out! How stupid was i?

[Fred]

I will be anoying again, but i simply must insist on nulling method here.
It is absolutelly wrong to null coil monitoring RX opamp output at 7. pin!...

Hi Ivconic,

While i respect your experience and take note of it, i cant understand why it is wrong to measure at pin7 of opamp: this is the only way to take in account the real resistance, capacitance and inductance of circuit, plus amplifying the signal and thus getting more precision.We also avoid instrument interaction.
So i can´t see why this doens´t work ??
Regards,
Fred.

[ivconic]

It just proved to me as ultimate method for nulling TGS coils.
LF353 was made by several manufacturers. I had chance to put ic socket and switch several op-amps there. Perfectly good result on one opamp output is NOT at others, later put in socket. Amplifications in first stage differs from one opamp to another.
By monitoring opamp output while nulling you will get "compensated" but not REAL situation at RX coil. How can i explain?
Simply...after 25 devices and possibly 30 coils it showed and proved to me, which method is most accurate.
I am saying this only in TGS case. I will repeat - i am not claiming anything simillar for any other design.
Fer instance Relic Hawk coil has huge residual voltage. So as few other detectors i checked, yet those are working fine.
But at TGS this method was aproved as best possible so far...at least to me and my amateur working conditions..

[Fred]

It just proved to me as ultimate method for nulling TGS coils...

Ok Ivconic TNX!
I want to make new coil for my TGS someday and i will try this method.
I intend to make a TGSL from your PCB too

regards,
Fred.

[simonbaker]

Hi,
about connectors I use these you can see at Maplin:

http://www.maplin.co.uk/Search.aspx?...y%20Connectors

Are multiway, low frequency connectors.

You can mount the socket on panel and then wire cable to the plug: they are good cause you fix the plug with a ring-screw after inserted in socket... much like Tesoro's original plugs do (though Tesoro's use bayonet mount).

The 4-ways kind are good for coils like TGS.

They cost few... and are strong enough for MD applications... though are more exposed to corrosion... than some original MD parts.

The noise is not a big issue in these connectors if wiring is done right way: There's no difference between Tesoro's ones and these about noise at these low frequencies.

From what I know some small manifacturers prefer using these than more fancy things... in PIs too... cause are excelent for the purpose and costs are reasonable.... and are worldwide available.

Kind regards,
Max

Thanks everybody for the connector information.

I hope for two things:

1) inline connector, male-female, instead of mounted in case. What are good connectors for this?

2) Also compatible with Tesoro coils. Is this realistic?

Questions:

1) do Tesoro coils come with cable permanently attached or by connector?
2) can TGSL be designed to use real Tesoro coils, or is that nuts?

Thanks for your experience.

SB

[ivconic]

"...2) can TGSL be designed to use real Tesoro coils, or is that nuts?.."

TGSL is already designed to use real Tesoro coils....designed for TGS
BTW labeling those manufactured at Tesoro as "real" makes me feel our coils here suppose to be "unreal" !?

Ok...jokes aside, it is quite expectable TGSL to work very descent with original Tesoro coil designed for Tesoro Golden Sabre. Why not? Nothing really changed in TGSL except the fact that Notch stage is removed. Not a big deal. So if you have original coil for TGS for sure you can use it. No problem!
Regards!

[simonbaker]

Also instead of trimpot 100K (threshold) between +8/-5V there
is 330K connected directly to -5V. Did you find this value to be
good enough and there is no need to place trimpot?

Speaking of this there are 2x100K (R48 and R51) used instead of just one
200K. Can I use 200K instead, 0.25W. Perhaps they need to be 0.5W, i dont have a clue why did you switch those

(R48 and R51)

TGSL does not have battery check, why are these resistors and op amp circuit still in schematic and PCB?

[simonbaker]

"...2) can TGSL be designed to use real Tesoro coils, or is that nuts?.."

TGSL is already designed to use real Tesoro coils....designed for TGS
BTW labeling those manufactured at Tesoro as "real" makes me feel our coils here suppose to be "unreal" !?

Ok...jokes aside, it is quite expectable TGSL to work very descent with original Tesoro coil designed for Tesoro Golden Sabre. Why not? Nothing really changed in TGSL except the fact that Notch stage is removed. Not a big deal. So if you have original coil for TGS for sure you can use it. No problem!
Regards!

Ha, ha, yes "real" is insult but not intended, your coils are super-real !.

[Max]

Thanks everybody for the connector information.

I hope for two things:

1) inline connector, male-female, instead of mounted in case. What are good connectors for this?

2) Also compatible with Tesoro coils. Is this realistic?

Questions:

1) do Tesoro coils come with cable permanently attached or by connector?
2) can TGSL be designed to use real Tesoro coils, or is that nuts?

Thanks for your experience.

SB

Hi,
1) inline connector ? why not... will work too. There are similar low freq connectors that made this... you could also checkout cannon (used for audio, microphones) connectors... they are high quality , but remember the metal part of them must not swing otherwise you'll get false signals cause of that.

2) difficault to find... for example I have original 9x8'' from tesoro... and I changed original connector....5 ways (with ring-screw not bayonet). It's a problem with it if you haven't an original tesoro detector... difficault to find socket for it.

3) all tesoro coils have connector... soldered to cable. You can swap coils... cause of that connector stuff. It's rare today a detector has just one coil attached... and no connector.

4) already explained by Ivconic: you can, and it works. But , I have to say, on 9x8'' I have performance that are good but sure not as good as with the 11'' homemade for TGS.
I found also that my 9x8'' works better when on my BandidoII than with TGS.
9x8'' is very nice, expecially at pinpointing and disc... less on depth.
So... you can buy one and enjoy it but I think too an homemade suited to particular TGS is much better than a standard coil, expecially at depth.

Kind regards,
Max

[simonbaker]

Thanks for cable connector info.

I'm checking TGSL schematic and my eyes do not see a transistor TR3, is that correct?

[tiktak]

Hi,

Hi,
Ivica.
Exelent work as aweys!
Great.I am almost ready with the PCB.I will try it soon.
But I am curies what you found?

3) you must use hi-quality mass,filler to fix and harden both coils togather to maintain good null for ever ( after many years of experimenting finally i founded almost same mass used at Fisher and Minelab coils..)

What is it?
Thanks

[tiktak]

Hi,

Hi,
I can see some diferances.
What do you think Ivconic?

[tiktak]

Hi,

Hi,
Shape,wiring?