Tuning Selectivity Factor

Hi.
Which tuning coil yields a better selectivity Q factor by itself on a resonant LC circuit, one made with a thin or a thick conductor ?

What about the capacitor; which type/attributes contribute to better selectivity ?

Q=R*SQRT(C/L) so L value must be as low as possible,C must be as high as possible to obtain highest Q for Parallel Resonance Circuit.
The conductor thickness has less importance compare to conductor quality due to RF Current Nature.Because RF Currents flow vicinity of Outer Part of the Conductor so -for instance- using a Silver Plated copper wire will be better than simple copper.In old days, Transmitter Coils were made with Silver Plated Copper Tubes..

The ratio of L:C plays a big part in performance. It's not necessarily easy to calculate what ratio is optimum in your application.

Ohmic resistance has an effect on Q. Higher resistance causes lower Q.