--- In ultralightdx@..., D1028Gary@... wrote:

Hi Phil,

Thanks for your comments, and I'm happy that you are joining in the
loopstick experimentation for the PL-310/380 DSP models.

There is of course a formula for determining the inductance of a conductor,
namely
4l
L= 0.0002 [ 2.3 log ( ---- -- 0.75)] uH
d

where "L" is the inductance in microhenries, "l" is the length of the
conductor in cm, and d is the diameter of the conductor. This formula is for a
single wire, and does not apply for ferrite-wound coils (which undoubtedly
will have a more complex formula). If you wish to calculate inductance this
way, I certainly admire your dedication :-) Almost every experimenter I
know simply uses their LCR meter to check coil inductance.

See:

https://www.amidoncorp.com/specs/2-35.pdf

for some formulas on how many turns to use on a given rod for a desired inductance.

(use with grains of salt....it's difficult to get this dead on, but it gets you started)

best wishes,

Nick