Roy, W7EL wrote:
"This means that if we put a current into one end of the inductor, it`ll
take about 40 ns for current to reach the other end, right? So we should
expect a phase delay in current of 180 degrees at 6.15 MHz, from one end
to another?"

Hopper`s rule is one foot traveled per nanosecond. 40 feet of wire takes
40 nanoseconds.

The wavelength of 6.15 MHz is 48,8 or about 160 feet and in that space
the phase rotates 360-degrees. 40 feet is 1/4 of 360-degrees or
90-degrees at 6.15 MHz. At 1 MHz, the wavelength is 300 meters. 12,2
meters of wire is about 15-degrees of delay by my $1-dollar Chinese
calculator.

Best regards, Richard Harrison, KB5WZI