simple powerful schematic please

[rajesh]

simple

[Geo]

Hi Geo!
Yes, I know all these things about coils, but not sure how to mount them.
The way I do it is very hard,but seems better. Feel sory for your coil ( and
mine too he-he). Wish you a luck with new coil.
Bye!
P.S. Tomorow I'll try again.

Hi Hush
You need a scope. When you move a little the wrap you see that there is a phase shift. So you try to have the small signal with zero phase shift.
My coil was a little large for the housing so when i put it in the housing i had phase shift
Good luck

[Hush]

Hi Geo!
Yes, I know all these things about coils, but not sure how to mount them.
The way I do it is very hard,but seems better. Feel sory for your coil ( and
mine too he-he). Wish you a luck with new coil.
Bye!
P.S. Tomorow I'll try again.

[Geo]

Hello Geo!

With DD 250 mm coil works the same at all metal and at disc mode.
DD 280 mm and OO works perfectly, but not setisfy with sensitivity.
Haven't scope, but I have very good digital multimeter which I used for nulling.

Thanks for answer, cheers!

Hi Hush. Try to reverse the leads of the one wrap. If you have not shield at the coils then maybe you have big phase shift and work as discrimination. I had a 32cm DD coil and i used it with my TGS. I had a very good sensitivity at all metal (for a 30mm coin... more to 40 cm) but at disc i had problem. Very bad depth or no detecting gold and bronze. When i test it with the scope i saw a very big phase shift between 2 wraps. Now i construct a new coil
Regards

[amtech2005]

simple powerfull schematic please

As KT315 recommended in the earlier post the Groza III . Complete with parts or assembled and tested. It is a deep search vlf detector with excellent discrimination but I have no Idea on the $ Price ?? The web page link might be an outline example for the Geotech Forums New " Design Group" ?? amtech2005

[Hush]

Oh forgot to tell you, no shield , coil is just on probe table. Want to make few coils which I shell change just on one machine.
Cheers!

[Hush]

Hello Geo!

With DD 250 mm coil works the same at all metal and at disc mode.
DD 280 mm and OO works perfectly, but not setisfy with sensitivity.
Haven't scope, but I have very good digital multimeter which I used for nulling.

Thanks for answer, cheers!

[Geo]

Hi hush.
Do you work at all metal or at Disc????
Does your coil have shield, and if yes do you leave a gap???
If you have a scope you must look for signal null and for zero phase shift between the 2 wraps

[Hush]

Hi,
depends on size of coin too. I mean that if your coin is 30mm diameter is not so big deal detecting it at 35cm (in air) with e.g. a 25cm diameter coil.

If that's your purpose you can mount TGS, look the "Tesoro Golden Sabre" thread in tech forum... you'll understand why: there is schematic and everything you need.

If you mean something smaller as coin ...say 2cm diameter ...well things become a bit more complex and TGS will not detect at that depth (unless you can perfectly optimize it- not so easy - I got 36-37cm for 1eur on air).

Almost 95% of discriminating detectors of any brand will fail detecting a 2cm coin at 35cm depth on air! Just a few can detect (again, on air) the coin and disc it right too. There are maybe 5 or few more commercial VLFs that could do really on soil.

If you mean using PI you can detect the 2cm coin at more than 35cm on air... many of them can do... cause are more powerful... but then you haven't any good disc on them (till now) and so you'll dig up lot of trash... iron, nails, rusty cans etc etc

So... if you mean big coins at medium depth...follow my advice: build TGS... you'll save a lot of money and it will find your coins.

Best regards,
Max

Hi Max!
I finished TGS and TGS Light, pcb made by Vladimir- good pcb but reversed be careful people, and some transistors pins too! I have to solder IC reversed
but never mind, it works good, bravo Vladimir thanks!
Also I made 3 coils for them OO coil 250mm, DD 280 mm and DD 250 mm.
Last coil was DD 250 mm and doesn't work well. I made it for just for 2 hours,
TX coil 105 winds 5.9 mH, RX coil 110 winds 6,4 mH, works at 14,1 kHz.
Must to say that I made first 2 coils with much more attention and different
way then you and Ivconic- winding without any crossing wires and exactly lenght of 6 mm, and trust me that was not easy.But no miracles. DD coil 280 mm catch silver coin 30mm just at 30-31cm, discrimination works exelent but
I'm not satisfy.OO coil is even worst, but this last one catastrofic- disc does't works properly. It can't catch silver coin at all, just some bronze coin at 8-10 cm. So I decide to ask you to take few minutes forme, and answer
on few questions.
1. What do you mean exactly, when you said "the good coil"? On what should
I pay attention when making coil to be good? In past I've made coils only for PI detectors, and they works exelent, but it is much more easy to make coil
for PI. The wire gauge is larger, and is easy to winding wire next to wire without crossing, and it is very important for PI trust me.
2.Condensator at RX coil is second important thing to get some more cm.
If I understend well, condensator used for nulling coil should be used for PCB
right? Then I shouldn't get some more cond parallel or serial? When changing
capp freq changes too. Is exactly freq more important for sensitivity , or something changes too with different capp?
3. On what should I pay attention else to get similar results like yours?

Yes, I know, lot of questions, but I am sure a lot of people are interest in that. Well, if you will be so kind to answer me, I will be very grateful.
Sorry for my very poor English , ciao!
P.S. By the way, what is the weather on the Mars?

[kt315]

utekai again released up his website. all about Groza-III.

http://www.utekai.info/masterskaja/t.../thunder1.html

[tiktak]

Hi

Hi,
Have anyone made this GROZDA detector?
I wanna try this and need help!
Thanks

Probvay niakoya GROZDANKA........chak s CPU ne sa ama stavat.

[rumensat]

there is no such thing - simple and powerful

all is important from coil to schematic, elements and program in cpu

[Max]

hi all
can you send me a simple and powerful metal detector schematic please i have checked geothunting diagrams but i dont know which one is good
so please i am looking for detector schematic with capability of finding a single coin up to 35cm and more
thank you again
i am waiting forward

Hi,
depends on size of coin too. I mean that if your coin is 30mm diameter is not so big deal detecting it at 35cm (in air) with e.g. a 25cm diameter coil.

If that's your purpose you can mount TGS, look the "Tesoro Golden Sabre" thread in tech forum... you'll understand why: there is schematic and everything you need.

If you mean something smaller as coin ...say 2cm diameter ...well things become a bit more complex and TGS will not detect at that depth (unless you can perfectly optimize it- not so easy - I got 36-37cm for 1eur on air).

Almost 95% of discriminating detectors of any brand will fail detecting a 2cm coin at 35cm depth on air! Just a few can detect (again, on air) the coin and disc it right too. There are maybe 5 or few more commercial VLFs that could do really on soil.

If you mean using PI you can detect the 2cm coin at more than 35cm on air... many of them can do... cause are more powerful... but then you haven't any good disc on them (till now) and so you'll dig up lot of trash... iron, nails, rusty cans etc etc

So... if you mean big coins at medium depth...follow my advice: build TGS... you'll save a lot of money and it will find your coins.

Best regards,
Max

[kt315]

35 cm... sweetty words... every cm costs aprox. $100 for a brand, by the way. it's REALLY a Battle Field!