how to build a 50 cm concentric search coil

[arti]

l have a seben extreme metal dedector and l need to build a 50 cm concentric search coil cause it doesnt work good in non ferrous metal but it works great in ferrous metals so i need to build a 50 cm search coil in order to increase the depth for gold. Does any one help me telling,

1.how many wire turns to use for the outer TX
2.how many wire turns to use for the inner TX
3.how many wire turns to use forthe RX

or does it have any other problem in this search coil which l have ( 25 cm seben extreme metal dedector )how to fix it.

kind reagrds

[kt315]

seben is some kinda one from chinese made deDectors' name, with one tipo schematic, I guess. can you give pics inside, PCB, I could be said more correct?

[Qiaozhi]

l have a seben extreme metal dedector and l need to build a 50 cm concentric search coil cause it doesnt work good in non ferrous metal but it works great in ferrous metals so i need to build a 50 cm search coil in order to increase the depth for gold.

The best way to "fix" a Seben Extreme metal detector is to replace it with something else.
Simply fitting a 50cm search coil will not increase the depth for gold. You will lose sensitivity to small items, and more than likely increase the likelihood of finding deep iron.
However, if you do wish to experiment with different coils, you can use the Coil Calculator at the top of the Coils Forum.

[arti]

Thank you for your reply!

l will give you some pictures of PCB but is it possible to replace any circuit component in order o fix the depth for gold without building other 50 cm search coil (its own 25 cm search coil).

[arti]

thank you
is it possible to replace any circuit component in order o fix the depth for gold without building other 50 cm search coil (its own 25 cm search coil).

[kt315]

po-russki eto zvuchit tak - Iz govna konfetku sdelat'. sorry for my perfect russian, can not translate in english (( I am not able...