hi im guessing im way off can you assist me

[metal mania]

Hi firstly I need to say I'm a complete noob when it comes to electronics best to get that out of the way I feel now this is the problem I need help on there's this detector a cheapie but real good discrimination doesn't complain about salt.

the problem is it only has a 6 inch coil say i wanted to build a custom 12 for it would I do this.

1.disassemble the 6 inch
2.count turns on the receiver and sender coils
3.build a new on with double the turns on each.

please stop laughing now and explain how I would really do it.

ps keep it as low tech as you can with as few tools needed as necessary.


thanks in advance

ps please cease laughing

[Qiaozhi]

the problem is it only has a 6 inch coil say i wanted to build a custom 12 for it would I do this.

1.disassemble the 6 inch
2.count turns on the receiver and sender coils
3.build a new on with double the turns on each

No - it's more complicated than that.

Firstly, you haven't said whether this is a mono or an inductance-balanced (IB) coil.
If it's a mono, then you may have a chance, but if it's an IB (and you're an electronics noob) then you're in for a shock.
In both cases you need to find out the inductance and resistance values of the individual coils using an inductance meter, and then use an air-core coil calculator (such as the one at the top of the Coils thread) to calculate the number of turns required for the diameter of the new coil.
Finally (for an IB) you will need to balance the coils to match the detector electronics. This is best done with an oscilloscope. If it's a DD coil, the balancing process is generally simpler to achieve. However, concentric coils are more difficult to make, because it requires a separate nulling coil that adds another of complication.