what is the most important ? inductance or resistance ?

[ashkelon]

hello
i made new small coil 20cm for my pi. i tryed one by one turn and found the best detecting coil.
now i want to make bigger coil 40cm and i use calcoils program.

20cm coil, 200 microhenry and wire resistance 1,05 Ohm
in order to make 40cm coil which measurement must i use? inductance ? resistance ?

if i use same inductance 200microhenry , 12,5 turns and 1,35 Ohm for 40cm coil
if i use same resistance 1,05 Ohm , 9,5 turns and 120 microhenry for 40cm coil.

[WM6]

if i use same inductance 200microhenry , 12,5 turns and 1,35 Ohm for 40cm coil

Yes, inductance.

[mikebg]

Ashkelon, all parameters are important. Most important is resonance frequency of TX network. If you use coil shielding, you should reduce inductance because 40 cm coil has near twice more large coil-shield capacitance than 20 cm coil.