Hi

[ivconic]

Additional infos,
i used toggle switch 2x3 with center position neutral, to switch ON the detector either with C30 in circuit, either C30 out of circuit.
C30 in circuit brings up the "bell tone", similar as at Garret's. Very effective at some type of targets.
Saves me from using another switch for tone option.
Also there is a diode bridge acting as battery reverse polarity protection.
This is particular case, not general, since i made this detector for one friend who is often careless and already burned several detectors with reversing the polarity at 12v/1.3A battery.
So i had to figure out how to prevent that.
Ok, there is small and insignificant voltage drop at bridge... not presenting any problem and not affecting detector behavior at all.

[ivconic]

After so many years i am still making SMW, every once in a while, whenever i have chance to obtain TS coil (rare lately), since i am to lazy to make diy coil anymore. Pretty fed up of that labor.
So i finished this one last week. It is working "by the book", excellent, indeed deep and sharp!
I had extra housing, laying in a drawer for long time, so i draw pcb to match that housing.

[ivconic]

Hiya Ivconic,,,Thanks for sharing the SMW layout,,,Could you let us know the Coil Data for this pcb please and Frequency,,Thanks in advance. Regards, Marty.

Coil specs close to specs of Minelab TS1000 coil.
1mH TX and 15mH RX.
Although SMW is tolerant and can be trimmed also with bit different coil specs too.
Frequency can be 6 to 8kHz.
Capacitor is 100nF.

[MartyJ1963]

Hiya all,,,Thanks again Ivconic for the SMW Layout,,,,Can anyone tell me the value of the Capacitor in the picture please? I've been Looking forward to making this S.M.W for a couple of years now for my collection,,Also, if anyone knows the TX and RX frequencies so I can have a go at making the coils,,,Much appreciated, Regards,,,Marty.

[MartyJ1963]

Hiya Ivconic,,,Thanks for sharing the SMW layout,,,Could you let us know the Coil Data for this pcb please and Frequency,,Thanks in advance. Regards, Marty.

[ivconic]

C30 and C32 are not present on pcb draw.
Those are optional.
Try them, if you like them; keep them.

[ivconic]

Ok that s good.
Which best version of smw you suggest to me ? The deepest ?

The prime one.
Ok, now you pulled out from me the latest bijou!
Which i never intended to share here!
Let it be the treat for this month:

[hooby life]

Jewelry as such earnings, chains with small links and similar; are presenting horrific targets for most of the common detectors.
Any awkward shapes that disperses the eddy currents like that.
SMW is not the exception. It will struggle with such targets.
But it will perform very good on targets like coins, rings and similar.
SMW is one of the "deepest" diy i ever made. General purpose nature. Usual targets in our hobby.
In my case; coins. Ancient coins, mostly made of bronze and similar alloys.

Ok that s good.
Which best version of smw you suggest to me ? The deepest ?

[ivconic]

Thanks ivca
That mean test with another target like gold coin or ring..

Jewelry as such earnings, chains with small links and similar; are presenting horrific targets for most of the common detectors.
Any awkward shapes that disperses the eddy currents like that.
SMW is not the exception. It will struggle with such targets.
But it will perform very good on targets like coins, rings and similar.
SMW is one of the "deepest" diy i ever made. General purpose nature. Usual targets in our hobby.
In my case; coins. Ancient coins, mostly made of bronze and similar alloys.

[hooby life]

Despite the fact that earning is usually in circular form (maybe not in your case, can't tell without photo); still most of the earnings are "open loop" in eyes of the detector.
Much harder to detect than "closed loop" targets.
Due simple reason; dispersion of the eddy currents.
Now, if we take the same earning and weld the ends, to form the "closed loop"; detection of it will be much easier and better.
Point is in shape and form.
Magnetic features of the given metal comes on second place.

Thanks ivca
That mean test with another target like gold coin or ring..

[ivconic]

I test with earning gold . size about 1cm my be 0.5gram

Despite the fact that earning is usually in circular form (maybe not in your case, can't tell without photo); still most of the earnings are "open loop" in eyes of the detector.
Much harder to detect than "closed loop" targets.
Due simple reason; dispersion of the eddy currents.
Now, if we take the same earning and weld the ends, to form the "closed loop"; detection of it will be much easier and better.
Point is in shape and form.
Magnetic features of the given metal comes on second place.

[hooby life]

Now seriously.
0.5 gram of gold... what shape, size?
if just a grain; than Minelab marketing and sale experts would be real yoyos to place such hot prices on their products, right?
Who would even think to buy any of their product if such grain can be easily detected with obscure diy as SMW is?
On the other side; 0.5 gram of gold can be hammered in a coin form, presenting larger "area" and yet possible to be detected even with general purpose machine.
I really can not tell about 0.5 gram gold. Never had such target to experiment with.
What i can tell is that once i detected hammered gold coin, 0.7 gram weight, at ~15cm depth with SMW.
Of course it was not pure gold, it was gold alloy, some medieval Turkish coin.
That's what i can tell only.
But if we talking about grains and ore... well... Minelab is one of the possible solution, SMW is not.

I test with earning gold . size about 1cm my be 0.5gram

[ivconic]

Im biginer ivca soory .smw is my first diy md .

Now seriously.
0.5 gram of gold... what shape, size?
if just a grain; than Minelab marketing and sale experts would be real yoyos to place such hot prices on their products, right?
Who would even think to buy any of their product if such grain can be easily detected with obscure diy as SMW is?
On the other side; 0.5 gram of gold can be hammered in a coin form, presenting larger "area" and yet possible to be detected even with general purpose machine.
I really can not tell about 0.5 gram gold. Never had such target to experiment with.
What i can tell is that once i detected hammered gold coin, 0.7 gram weight, at ~15cm depth with SMW.
Of course it was not pure gold, it was gold alloy, some medieval Turkish coin.
That's what i can tell only.
But if we talking about grains and ore... well... Minelab is one of the possible solution, SMW is not.

[hooby life]

Im biginer ivca soory .smw is my first diy md .

[ivconic]

I have hime made 27 cm DD coil . test with 0.5 gram gold nothing .