Technical Assistance Web Page
Single Layer Air Coil Inductance Calculator
For Use In Building Loading Coils For Mobileering On H.F.
d = Coil diameter (in), n = Number of turns, l = Coil length (in)
1) For 10 ~ 40 meter band you want inductance between 40 uH to 45 uH. For 10 ~ 80 meters you should have an inductor of 75uH to 85 uH
2) This calculator will get you close and is not intended as a final formula