Hi

[Hach]

If you can not obtain Minelab TS1000 coil, which is really hard lately; you can make your own coil, with slightly different specs, yet very suitable for this detector.
RX=160 windings, 0.27mm wire
TX=70-75 windings, 0.45mm wire
In this case TX parallel capacitor is 220nF.
Former same as so many times so far explained coil former for TGSL.
I think Don Bowers did much better job in his PDF than me in my PDF, about making such coils.
Look up through the forum for his PDFs , to see the proper dimensions of "D" shapes.
Coil shielding goes to minus rail.

Please can you explain what's best to connect shield between dd coil and what difference between three images and what suitable for SMW

[hooby life]

hi ivconic
i diy this version the ast year . did it the same with it you post now

[ivconic]

[ATTACH]49395[/ATTACH][ATTACH]49396[/ATTACH]
Please can you explain what's best to connect shield between dd coil and what difference between three images and what suitable for SMW

That's for TGSL coil.
SMW needs different setup.
Since Minelab TS1000 coil works splendid with SMW; best way to make diy coil is to copy what's done on TS1000.
It is the two separate coaxial in common pvc (silicone) coating.
Coil shielding goes to TX coaxial shielding and further to minus rail on pcb.
It's the best cable for SMW.
Similar (actually the same) cable is present now days at XP coils.
So it is "double coaxial". Don't know better term for it.

[timekiller]

Hello guys . My pcb is half populated. But I have such a question. The picture above shows the finished PCB, there is 1 extra capacitor 470nf and one 22nf is missing. What is the case with them? Are there any other changes? What is the correct position of the three POT resistor 100 , 10k , 47k ? Thanks for the replies.

[Hach]

That's for TGSL coil.
SMW needs different setup.
Since Minelab TS1000 coil works splendid with SMW; best way to make diy coil is to copy what's done on TS1000.
It is the two separate coaxial in common pvc (silicone) coating.
Coil shielding goes to TX coaxial shielding and further to minus rail on pcb.
It's the best cable for SMW.
Similar (actually the same) cable is present now days at XP coils.
So it is "double coaxial". Don't know better term for it.

I made these two coil attached in pic
TX 75 turn resistance 4.2ohom 20cm wire diameter 0.5mm
I shield it with aluminum extracted from satellite cable.

Rx 170 turn resistance 30.5ohom 20cm wire diameter 0.3mm
Dos it work with Smw?

[ivconic]

I made these two coil attached in pic
TX 75 turn resistance 4.2ohom 20cm wire diameter 0.5mm
I shield it with aluminum extracted from satellite cable.

Rx 170 turn resistance 30.5ohom 20cm wire diameter 0.3mm
Dos it work with Smw? [ATTACH]49402[/ATTACH]

Inductances?
On your place i would try to trim TX parallel capacitor to get ~7kHz.
The rest is just to null the coil.

[Hach]

Inductances?
On your place i would try to trim TX parallel capacitor to get ~7kHz.
The rest is just to null the coil.

I don't have device to measure inductance.
Any advice
Your reply really appreciated
Tomorrow all electronic components will arrive then will assemble the board.

[Nandor]

Hi

Alu-foils can't ouch each other!!! Wrap isolating band all over the coils.

[Hach]

Hello the green spot in attached image
Is it 27kohom or 2.7kohom?!

[Hach]

Also r20 is it 3.9k or 39k
Its not same in schema and pdf pcb!?

[Hach]

Also r20 is it 3.9k or 39k
Its not same in schema and pdf pcb!?

Sorry I mean in schema 3.9k in pcb 1.8k!!
Which one correct?

[ivconic]

Sorry I mean in schema 3.9k in pcb 1.8k!!
Which one correct?

That's good question.
Differences are due possibility to use various coils with it.
Both are correct, since you'll have to check both and see which one is giving you better behavior.
First obey what you see on pcb, those values.
Than when you test detector with coil, checking Disc, GEB ... you'll see if you need to correct that resistor.
So, obey the pcb values , from pcb draw you posted.

[ivconic]

[ATTACH]49422[/ATTACH]
Hello the green spot in attached image
Is it 27kohom or 2.7kohom?!

It is 27k as noted.

[Hach]

Working in progress
Please ivconic check these images
And tell me if transistors in there right places
Also that big tantalum in its+ place

[ivconic]

Ah protoboard!