Which is more crucial-Inductance or resistance ?

[Peter Jones]

when building smaller coils (this for a basic "DD" coiled detector) which measurement of the original coil should I try to acheive ?

[Esteban Cabrera Grinok]

Maybe reluctance...

I know an italian metal detector circuit that works by variable reluctance principle.

[Peter Jones]

What I mean is when making a different sized coil should I aim to match DC resistance with the original coil or should I try to match inductance?

[Carl]

IB or PI? In an IB design the transmit frequency is often dependent on the coil inductance, whereas resistance plays a secondary roll in determining the Q. In a PI, resistance affects maximum pulse current and inductance (and self-capacitance) affects the turn-on tau and damping.

Also keep in mind that most single-frequency IB designs use narrow-band coils on both transmit and receive, and sometimes have caps inside the coil to achieve this.

- Carl

[Roy]

Surely the answer is whatever gives you the desired response...