TESORO GOLDEN SABRE

[aft_72005]

Hi ivconic
Don’t worry, my friend removal gall bladder and very well now .only doctor
Said him, don’t eating egg and more eating sugar . anyway I hope you'll recover
full health as soon as.
best wishes.
Aft_72005

[Max]

Hi Nakky and other friends. Very exhausted from gall bladder removal. Most of time i am in bed. Do have strenght only for 10 minutes per day to sit and check new posts here. Splendid jod done here and on RH thread. Looking forward to recover and start building RH. Cheers!

Hi Ivconic,
I hope you'll recover full health soon. I know the feeling of wanna doing something and cannot move for a while...so I understand you very well.

I will enjoy your partecipation in th RH thread... but no problem, first you have to stay fine again.

Best wishes,
Max

[ivconic]

Hi Nakky and other friends. Very exhausted from gall bladder removal. Most of time i am in bed. Do have strenght only for 10 minutes per day to sit and check new posts here. Splendid jod done here and on RH thread. Looking forward to recover and start building RH. Cheers!

[nakky]

Hi Ivconic how are you.Grt Nakky

[Qiaozhi]

URRA!
FINALLY!
My TGS is good.

I am studying the TGS very hardly.Than I decided to build a omega coil. After I nulled the coil with scope and adj. GEB control...bit to bit...until to take almost total silence. With a bit less sens. control...Success...total silent.

Freq. 14.7KHz
Small gold ring - 30 cm in air
nickel coin (2.3cm) - 28cm
Bimetal coin (+ - 3.0cm) 33 cm
Alluminium itens - UAU!


Omega circle (TX = 25cm OD) - 26.3 ohms - 5,49mH
Circle (RX = 13cm OD) - 20 ohms - 6.7mH
Wire - 0.25mm diam.
Small contra circle - 10cm. OD.

Discrimination OK
Strong audio
No improvements at PCB

Now I intend to build a new omega coil with a more large tickness wire for omega circle coil only.Later I'd post the results.
IVCONIC was right omega coil is superb.

DIRCEU

Well done ... very interesting.
But you missed one important detail - how many turns did you use on the TX and RX coils?

[ivconic]

Good job Dirceu!
Cheers!

[Max]

URRA!
FINALLY!
My TGS is good.

I am studying the TGS very hardly.Than I decided to build a omega coil. After I nulled the coil with scope and adj. GEB control...bit to bit...until to take almost total silence. With a bit less sens. control...Success...total silent.

Freq. 14.7KHz
Small gold ring - 30 cm in air
nickel coin (2.3cm) - 28cm
Bimetal coin (+ - 3.0cm) 33 cm
Alluminium itens - UAU!


Omega circle (TX = 25cm OD) - 26.3 ohms - 5,49mH
Circle (RX = 13cm OD) - 20 ohms - 6.7mH
Wire - 0.25mm diam.
Small contra circle - 10cm. OD.

Discrimination OK
Strong audio
No improvements at PCB

Now I intend to build a new omega coil with a more large tickness wire for omega circle coil only.Later I'd post the results.
IVCONIC was right omega coil is superb.

DIRCEU

Nice! Well done.

[Fred]

Hi dirceu,
congratulations,
And thanks for infos!
Good luck using it
regards,
Fred.

[DIRCEU]

TGS - almost ready to run in field

URRA!
FINALLY!
My TGS is good.

I am studying the TGS very hardly.Than I decided to build a omega coil. After I nulled the coil with scope and adj. GEB control...bit to bit...until to take almost total silence. With a bit less sens. control...Success...total silent.

Freq. 14.7KHz
Small gold ring - 30 cm in air
nickel coin (2.3cm) - 28cm
Bimetal coin (+ - 3.0cm) 33 cm
Alluminium itens - UAU!


Omega circle (TX = 25cm OD) - 26.3 ohms - 5,49mH
Circle (RX = 13cm OD) - 20 ohms - 6.7mH
Wire - 0.25mm diam.
Small contra circle - 10cm. OD.

Discrimination OK
Strong audio
No improvements at PCB

Now I intend to build a new omega coil with a more large tickness wire for omega circle coil only.Later I'd post the results.
IVCONIC was right omega coil is superb.

DIRCEU

[Shahab]

Hi Max,
I'v just finished my First DD coil but i'm not sure about the it. 2cm coin could be detected at 25cm in air and 2.8cm at 30cm. What could be expected for the showing coins in the picture. Can you advise please.
Hardi

23.5 DD coil

Hi
Excuse me for my question!
Where are you from?

[Max]

Hi Max,
I'v just finished my First DD coil but i'm not sure about the it. 2cm coin could be detected at 25cm in air and 2.8cm at 30cm. What could be expected for the showing coins in the picture. Can you advise please.
Hardi

23.5 DD coil

Hi,
it's not bad result for a smaller DD coil that standard Ivconic's design. I think there's room for some improvement on circuit an eventually nulling.

Have you nulled at 15mVpp or less ? What about wire, is 30AWG ?

I think you can experiment with some nF more or less at RX coil to see if get an increase in the range (probably you'll get that way).

What about disc ? Does it disc out iron completely in disc mode ?

Kind regards,
Max

[Hardi]

Hi Max,
I'v just finished my First DD coil but i'm not sure about the it. 2cm coin could be detected at 25cm in air and 2.8cm at 30cm. What could be expected for the showing coins in the picture. Can you advise please.
Hardi

23.5 DD coil

[Max]

Hi,
Max.
I am londering for thia audio mode for TGS.Did you try some?
This variant with LM388 looks cool.
But I cant find one.Yesterday I have saw LM380N which is also Audio Power Amplif 2,5w.Can I use the same circuit and just replace 388 with 380?
Thanks

Hi,
lm388 is 1.5w but I think there ar eno problems using it instead of lm380...

problem of TGS audio are related not just to amplifiers ... it's all weak cause it's supposed you use it with phones mostly to save battery and got weak signals... or use the internal speaker that's probably enough for most of things outdoor.

Really... I don't like anymore LM380 idea for it and I'm looking at RH audio with lot of interest to see if I can adapt to tesoro's: I see it easy... but for now I'm ok with TGS and wanna see what we can do with RH before returning to TGS mods and upgrades. Probably I will test later on TGSL instead on my pole mounted TGS.

Kind regards,
Max

[tiktak]

Hi,

Hi,
Max.
I am londering for thia audio mode for TGS.Did you try some?
This variant with LM388 looks cool.
But I cant find one.Yesterday I have saw LM380N which is also Audio Power Amplif 2,5w.Can I use the same circuit and just replace 388 with 380?
Thanks

[Max]

What is the best choice for TGSL and TGS: BF245B or TIS75?

Hi,
I think it's really difficault question but best answer is maybe "do not change much"... I've tested all kind of BF245 on it and goes well any case... the TIS75 are very obsolete now so I would suggest you using newer stuff, really easy to find still today like BFs are.

Then you could try experiment different fets there like J107 too, but as I told you, there are not much differences if device works. If some parameter is too far from working (e.g. vgs value) it will just don't work or work totaly unstable... otherwise you'll have just small differences.

Differences are few cause there are other stuff that give much stronger effects than fets kind: fets there are employed in a way (sampler) you'll get spurious transients during commutation... and these effects are always there , no matter of fet kind you use... and they are heavy about stability in any case.

Then also you cannot say this is better than that ignoring which stuff is connected to which other... like ics you use there, sometimes device interactions are more relevant than single device choice, so you can consider any TGS you mount by hand different from the previous, unless you use some "factory" strategy for to reach a "standard"... all same lot for active components...1% maximum tolerance, all same PCB and cleaning procedures, SMT etc etc like Tesoro's factory do.

I will also say that even if you use all these care and smt strategy, hardly you'll get exactly same TGS clones... cause devices are really put to the limit of tweaking here and so hardly you'll get exactly same results from 2 units : this happens also with commercial units, it's not big news sometimes one works better than the other and goes deeper, that's why usually dealers leave users test detectors before buy. Experienced THs knows that could be some difference, in the same model/brand, due to manifacturing process so they wanna see with their eyes before buy. Slight differences, of course, but that could "make the difference" for an experienced TH.

Only brands that could give you strong warranty on e.g. performances are those who have very small production (few hundreds or thousand unit per year): they really tune to the limit and by hand/operator the single unit to match performances declared, and this happens both in the PI and VLF arena. These are really hi-end units and costs are very high too.
I think also some big brands switched to the "factory" strategy when numbers rised up a limit they cannot anymore match with "operator tuning" : that's why probably they produce today just average detectors and not anymore pearls.

Kind regards,
Max