Serbian "Most Wanted"

[Ruben2000]

Tx 1 MH rx 14.75 mh
does not pierce into the ground I've tried
Asenka no one helps me double tone smw 555

Hello hooby life.
My DD 27cm coil, TGSL mold I built it with the specifications of:
Tx 1mH
Rx 15mH
And approximate frequency of 7.3Khz.
I made this coil with an inductance meter that I built, with these specs:
Tx = 43 turns, 0.45mm, 3ohm, 1.013mH
Rx = 161 turns, 0.25mm, 37.2 ohm, 14.948mH.
C1 = 68 nF
C6 = 47O nF

At that time I did not have an instrument to measure inductance, but now I have received my instrument purchased from Aliexpress and I have measured my coil and it measures very differently than described above.

[Ruben2000]

These are the measurements of my coil with my new instrument. And that must be the problem for which it does not discriminate.

[Ruben2000]

Any suggestions would be welcome!!

[Ruben2000]

I am going to have to build a new coil.

[Ruben2000]

[QUOTE = hooby life; 288028] Hola rubun2000
?Cu?l es la especificaci?n de su bobina?
Tx 1 mh rx 14,75 mh
Frecuencia aproximadamente 7,5 khz [/ QUOTE]
Hello hooby life.
This can also help you.https://www.geotech1.com/forums/atta...8&d=1614119402

[Asanka Sanjeewa]

Dear my friend,
Here the photos, if you want discriminate important think is coil mH value. if you made many many size coil you need to select tx 1 mH and rx 14-15 mH. HERE THE CHANGED RESISTORS
PUT TWO RESISTORS 1K5 FOR 1K8
2K7 FOR 2K2
1M FOR 1M3
DO NOT USE RX 22NF CAPACITOR
sorry my coil is 40 cm *22 cm [one coil part ]

Hi Asanka.
Could you share the mold of your large coil so that you can build one just like it?
I would also like to know what resistors you have changed or what changes you have made and what capacitors you used to tune.
I also asked cnckecgo for help and nothing!

[Asanka Sanjeewa]

okay brother, i will try to help you , please tell me which thik wire [swg gauge ] did you use for TX and RX COIL and did you remove or change resistors and capacitors ? Also did you use this PCB pattern, Am i correct ?

Tx 1 MH rx 14.75 mh
does not pierce into the ground I've tried
Asenka no one helps me double tone smw 555

[zakari]

hi asanka
what kind coil did you used
can you explain about tx and rx coils and shapes

best regard
zakari

[Ruben2000]

Dear my friend,
Here the photos, if you want discriminate important think is coil mH value. if you made many many size coil you need to select tx 1 mH and rx 14-15 mH. HERE THE CHANGED RESISTORS
PUT TWO RESISTORS 1K5 FOR 1K8
2K7 FOR 2K2
1M FOR 1M3
DO NOT USE RX 22NF CAPACITOR
sorry my coil is 40 cm *22 cm [one coil part ][ATTACH]55147[/ATTACH][ATTACH]55148[/ATTACH][ATTACH]55149[/ATTACH][ATTACH]55150[/ATTACH][ATTACH]55151[/ATTACH]

Hello Asanka, that of putting a bridge instead of C1 if the detector works?
I have never tasted it that way !!
I will do tests after I finish building my new coil.
Thanks for the details!!!

[Asanka Sanjeewa]

Hello zakari and Ruben 2000
smw is deeper machine among all IB metal detectors. But discrimination is not good. If you want to good discrimination you need to make admiral metal detector. It's simple and cheap home made project. I use ruben's share PCB version. I t is good and super discrimination than other PCB version.some pcb version are not good. also i did not use RX capacitor. When i remove RX capacitor detector works well. Ruben2000 your coil induction value correct. I think problem is your pcb version or unbalancing coil. If you want good work IB md you need to good coil balancing and check the null point. I did not use coil pattern and coil cover because my coil is big.I made equiangled square coil cover using PVC conduit tube and bends. also not shield it.not ground test yet. i made it as a temporary coil because how to work to search this PCB pattern. Here the my coil pattern. It is simillar Russian volksturm coil pattern. Happy hunting

[Ruben2000]

Hi Asanka,
What do you mean by balancing the coils well and having a good null?
Isn't equilibrium and null the same?
Could you explain that to me in more detail?
Sorry for asking you this but I don't know much about IB MD.

[Asanka Sanjeewa]

Hi ruben2000, It is difficult to explain , sorry friend

Hi Asanka,
What do you mean by balancing the coils well and having a good null?
Isn't equilibrium and null the same?
Could you explain that to me in more detail?
Sorry for asking you this but I don't know much about IB MD.

[Ruben2000]

Hi ruben2000, It is difficult to explain , sorry friend

Thanks anyway friend Asanka.
I am going to do the null of my coils; I do it in the same way as for the TGSL, measuring on pin 8 of the LF347 in the millivolt range; the goal is to get the lowest millivolts by moving one of the coils, this is where the best null is. If I am wrong in my explanation, please have someone clarify it for me.

[Ruben2000]

This is my new coil with the inductance and ohms measurements. [ATTACH] 55193 [/ ATTACH] [ATTACH] 55194 [/ ATTACH] [ATTACH] 55195 [/ ATTACH] [ATTACH] 55196 [/ ATTACH]

[Ruben2000]

Details of my DD 27 cm coil. TGSL model.
TX = 45 turns = 0.511 mm.
RX = 171 Turns = 0.286mm.