TESORO GOLDEN SABRE

[Ultimate_Haze]

hi

to Ivconic
*1e coin = 32 to 36cm in air (~48cm if monostable mode available)
*cola can = 55cm in air (~ 80cm if monostable mode available)

Thanks!That is realy good results.But is this clear detection with slow motion on target?Or just bearly hearble signal?


to Max,
This excplain things.Because I have noticable increase of sens. for larger ithems compared with 27cmDD.But in same time I still have troubles when test with my large coin.Which is 4cm d, thick brass coin.
p.s.can you clear some space in your PMbox?

[metaldetector107]

last TGSL

Dear Ivconic
i changed the diodes only the sound became lower but still sounds continuesly

please help

[ivconic]

Dear Ivconic Max
i have made your last TGSL but when tested i hear i countinuse sound
also when nulling coil i hear some cracks
TX freq is 14.4khz
please help
best regards

Possible bad diode at transient outputs on 4024. Check and replace those 3 x 1N4148 at pins 5. , 6. and 9. on 4024...

[ivconic]

Hello
I made Goldy 3.2 from Apberg sprint draw.

Same as Metaldetector 107.

IC 4.leg Volt is 0.65 .
Tr 2907 and 2n222 Heating during work which is near 4024 .
one of friend said changing all of 2n222 and 2n2907 solving problem .

Regards
Erol

Most probably you will have only to change those transistors with another pair. I suggest you BC557 and BC547 there. If this dont solve the problem than you must do detailed analyse and post more informations here..

[Max]

Hello
I made Goldy 3.2 from Apberg sprint draw.

Same as Metaldetector 107.

IC 4.leg Volt is 0.65 .
Tr 2907 and 2n222 Heating during work which is near 4024 .
one of friend said changing all of 2n222 and 2n2907 solving problem .

Regards
Erol

Hi,
I think you mean the voltage converter ... the ones that give you the negative supply.

OK, there at output you must have something -6.2V if all ok... with components on board, means ic in sockets.

If have much less voltage or positive the negative voltage isn't enough to properly run TGS in working conditions... so something e.g. saturate and you hear steady sound always.

Check transistors, check if you e.g. put one instead of the other... if e.g. swapped the pnp with npn kind and similar mistakes...

Kind regards,
Max

[erolunall]

Hello
I made Goldy 3.2 from Apberg sprint draw.

Same as Metaldetector 107.

IC 4.leg Volt is 0.65 .
Tr 2907 and 2n222 Heating during work which is near 4024 .
one of friend said changing all of 2n222 and 2n2907 solving problem .

Regards
Erol

[metaldetector107]

last TGSL

Dear Ivconic Max
i have made your last TGSL but when tested i hear i countinuse sound
also when nulling coil i hear some cracks
TX freq is 14.4khz
please help
best regards

[ivconic]

That is very usefull info.
Can you post tgsl performance on same ithems with 27 DD?

*1e coin = 32 to 36cm in air (~48cm if monostable mode available)
*cola can = 55cm in air (~ 80cm if monostable mode available)

Hard to say exact distance...i made over 30 coils so far. Not all showed the same performances (no wonder....handmade )
But all coils had performances in noted range.
What differs TGSL from other brands is noticeable depth "limits" over some distance. Quiaozhi could be right when talking about TX power. What makes TGSL exceptionally good and interesting for us here is extra sensitivity on very small coloured items in soil. I've been working with few of my handmades many months on real fields and had a lot of very nice finds. Especially on places where many other brands already "passed" and had worse results. Most of those nice finds were extra small coins and various items. Most of those were 5-6mm size. Another benefit was extra stabillity and splendid discrimination and junk rejection. That's why is so worth of making and working with.
Also that is why i do suggest smaller diammeters coils for TGSL. Smaller than 27cm. Most preferably 20-24cm diammeter.

[Max]

So you are maybe right.
Molzar have the original device maybe he can comare with handmade.
I dont own original TGS.
I can compare with TRS but wont be fare due to diferent coil size.
The thing that worry me is that Max gived over 40 cm with same coil for large coin.
And my results are poor with this last device and this larger coil.Near 30cm.
Hum....
I now its all about the coil and thuning but there is still something I miss here.
Don't wanna discus nexus here its other stuff.
How you think that RX can be optimized in this design?
Please share your ideas.

Hi,
yes the bigger the coil... and you'll get some more depth... BUT remember that big coils need big targets (so in your case big coins).

I say that cause maybe this detail was not considered in latest posts.

If you have to look for small coins I think the best of best is anything from 20cm to 27cm. In TGS I found that the optimum compromise is Ivconic's size... dear old DD 10 or 11' not more.

The coin I used for tests on big coil is big: >32mm diameter, UK half-crown of 1967...copper-nickel alloy... not anymore in production... can see one similar in picture. Mine is that way...

You have to consider that the field shape is different in large coils... then the lines density is different for a fixed amount of power at tx.

Happens, then, you need more exposed target surface to flux in larger coils to gain the response you need... and that's expecially true on small items like coins. With larger objects like a coke can the larger coils work pretty well and you get a very effective increase of range... but we are talking of small stuff here.

The other side effect is the increased ground influence on big coils... so you could end-up on soil with lowered S/N on 12' than with smaller coil say 10' or 11' range.

But the increase on large coin is not speculation... you see it both on air and into the ground... just the approach must then fit in your searching scenario... so if look for smaller stuff stay with smaller coil cause larger will give you more troubles than advantages.

As an example... I use maybe 90% times Ivconic's coil... and (maybe) 5% my larger coil on TGS...

Optimize RX ? lower noise front-end... fix instability and noise propagation on board... use different parts... put one-shot at end of audio path: that way you could increase gain and leave tx power as before... the reduced noise will increase S/N... you can run at increased gain, max sensitivity with no or minimum chatters and then get far/weak signals more easy... that could mean a gain of >5cms detection range (maybe!) on 20-25mm range coin on 10' coil.

That's not bad... that way you could break the 40cm range on 1eur with a 10' coil... but you may ask Ivconic about advantages and troubles related e.g. to the one-shot (monostable) at the end of chain... like poor pinpointing etc

Kind regards,
Max

[Qiaozhi]

Second...i have my doubts about TGS. Dont know how to explain..but it is optimised for cetain coil diammeters. Looks like... at least. Very good performances can be achieved with smaller coil also...let's say 20cm and 24cm diammeters...27 of course...but 32cm...hmmm.. i havent succeed so far. And i gave up already.

This might something to do with the relatively low power of the transmitter. Perhaps a more beefy TX would work better for large coils, although it would most likely make things worse for the smaller ones.

[Ultimate_Haze]

That is very usefull info.
Can you post tgsl performance on same ithems with 27 DD?

[ivconic]

Huh, that reminds me on my experiences. I also tried to make good 32cm coil without success. I achieved extra good performances with 27cm coil....but with 32cm not so good!? How come? First i think it is about wire. I used same wire as on 27cm. Second...i have my doubts about TGS. Dont know how to explain..but it is optimised for cetain coil diammeters. Looks like... at least. Very good performances can be achieved with smaller coil also...let's say 20cm and 24cm diammeters...27 of course...but 32cm...hmmm.. i havent succeed so far. And i gave up already.
Also i agree with Quiaozhi, chart results looks rather optimistic...or those were achieved only in air. If those represent air distances, than are ok. But if those represent depths in soil...than i can only say WOW!

Speaking of coil sizes....up from recently i am happy owner of Musketeer. It came with 18cm coil (TS800). But...also i managed to get 36cm,39cm and 45cm DD Excelerator coils for it. So....
What to say? Same thing - i am not thrilled with what i gained with larger coils, comparing to what i gained with smallest one. Smallest one, 18cm is working over any expectations! Yet deepest is 36cm coil, but considering fact it is double size than smallest one...than those results i gained with it are not to be thrilled about.
Eventuall comparing chart of results gained with all mentioned coils would show that 36cm coil is deepest (optimum), than 39cm on second place, than 45cm and last would be 18cm (but for sure deepest if coil size is only criteria).
But...also 18cm coil is absolute champion when comes to comfort, pinpointing and sensitivity on smallest items. Other hand 45cm coil is best for covering large area and going very fast forward. 36cm and 39cm are in the middle.
I can name now air results if any benefit from those:

* 18cm coil, 1e coin = 28cm in air,
* 36cm coil, 1e coin = 42cm in air,
* 39cm coil, 1e coin = 40cm in air,
* 45cm coil, 1e coin = 41cm in air .

* 18cm coil, cola can = 65cm in air,
* 36cm coil, cola can = 85cm in air,
* 39cm coil, cola can = 87cm in air,
* 45cm coil, cola can = 125cm in air.

So... you can easilly see and understand tendecies here.
Actually you can not expect huge depth increase on smaller and smallest items if using larger coil diammeters.
Rule of thumb is not the absolute rule here.
Larger coils are more suitable for locating larger objects and cover more area when swinging over soil.
Smaller coils are more suitable for detecting smallest objects and present best choice for accurate pinpointing.
I guess same thing is with TGS too.

[Qiaozhi]

The thing that worry me is that Max gived over 40 cm with same coil for large coin.

You will have to ask Max about that.
40cm is nearly 16", which is a better claim than made by Nexus!
You should really compare to the commercial model.

[Ultimate_Haze]

hi

Your depth results seem reasonable. The French chart that was posted here is very optimistic. No doubt these results were obtained in an air test with all metal mode and maximum sensitivity. This is why MD manufacturers do not like to publish depth charts, as they are all somewhat subjective.
Max (I think) has some good results, but this was achieved after a lot of tweaking. If your homemade device compares to the commercial version, then I would be happy.

So you are maybe right.
Molzar have the original device maybe he can comare with handmade.
I dont own original TGS.
I can compare with TRS but wont be fare due to diferent coil size.
The thing that worry me is that Max gived over 40 cm with same coil for large coin.
And my results are poor with this last device and this larger coil.Near 30cm.
Hum....
I now its all about the coil and thuning but there is still something I miss here.
Don't wanna discus nexus here its other stuff.
How you think that RX can be optimized in this design?
Please share your ideas.

[Qiaozhi]

Hummmm.
Nothing new.........
Only finaly one nice picture of how the coil is wired.
Here is a question.I have made 5 coils 31cm.All is ok inductance,resistance...
But depth is poor.No meter what I try,how I null,even 30sm depth is not shore for large coin.Compared with other results here...Sheeee
So I am wondering isn't there a mistake that I have made while soldering.
Voltages are V+ 7,93 V-6,25.Is this ok?
In rx stage there is little pick in V- its 6,36.
So now I will try just 27.To make shore that device is ok.

This last version is realy silent.And audio is now stronger!I use 32ohm speaker.Because here 16ohm can't be found.

Your depth results seem reasonable. The French chart that was posted here is very optimistic. No doubt these results were obtained in an air test with all metal mode and maximum sensitivity. This is why MD manufacturers do not like to publish depth charts, as they are all somewhat subjective.
Max (I think) has some good results, but this was achieved after a lot of tweaking. If your homemade device compares to the commercial version, then I would be happy.