Hi

[Nandor]

Hi

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

[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.

[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]

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?

[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.

[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.

[hooby life]

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

[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

[MartyJ1963]

Thank you sir,,You're a star! Regards,,,Marty.

[ivconic]

Thank you Ivconic. Could you please tell me best frequency for the S.M.W Coil?,,,I am still learning (but getting better) about DD/Concentric tuning at the moment on my O'scope. I am ok now at building VLF Coils to spec now I have a decent LC Meter (DE-5000), sometimes this new meter confuses me though because it tests at different frequencies (1khz/10khz/100khz/10hz/120hz) and apart from know to test Electro Capacitors at 120hz I don't know which frequency really to test my VLF Coils because different frequency settings give slightly different values,,as I said, still learning but enjoying this great hobby. Thanks again,,Regards,,Marty.

7.3-7.7kHz

[MartyJ1963]

Thank you Ivconic. Could you please tell me best frequency for the S.M.W Coil?,,,I am still learning (but getting better) about DD/Concentric tuning at the moment on my O'scope. I am ok now at building VLF Coils to spec now I have a decent LC Meter (DE-5000), sometimes this new meter confuses me though because it tests at different frequencies (1khz/10khz/100khz/10hz/120hz) and apart from know to test Electro Capacitors at 120hz I don't know which frequency really to test my VLF Coils because different frequency settings give slightly different values,,as I said, still learning but enjoying this great hobby. Thanks again,,Regards,,Marty.

[ivconic]

@Ivconic-Thanks for sharing the extra information,,much appreciated as always. Really looking forward to building this but I have to order some new pcb clad yet, as I only have 100mmx70mm, so will gather the rest of my parts in the meantime,,Thanks again, Regards, Marty.

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.

[MartyJ1963]

@Ivconic-Thanks for sharing the extra information,,much appreciated as always. Really looking forward to building this but I have to order some new pcb clad yet, as I only have 100mmx70mm, so will gather the rest of my parts in the meantime,,Thanks again, Regards, Marty.

[ivconic]

Looks very nice, thanks for sharing your work!

No sweat.
There is always something "rolling" and "hanging" in my workshop.
It's the life style more than anything else.
SMW is simple and obscure but very usable and worth to be made.
It is the funny Fisher 1235/ White's Classic combination.
Funny on paper but very serious performer on the field.

[Nandor]

Looks very nice, thanks for sharing your work!