On Thursday, February 13, 2014 7:19:34 AM UTC-6, W5DXP wrote:
On Wednesday, February 12, 2014 9:55:39 PM UTC-6, Jeff Liebermann wrote:

Did you ever reach a conclusion or a consensus?



I reached a conclusion based on the inductance calculator at:



http://hamwaves.com/antennas/inductance.html



When I plug the 75m Texas Bugcatcher loading coil into that calculator, it gives an axial propagation factor of 3.5333 radians per meter. Multiplying by 1.4553 gives a propagation factor of 5.142 degrees per inch. Multiplying by the length of the coil, 6.5", yields an electrical length of 33.4 degrees. At 4 MHz, the propagation delay would be 23.2 ns. Because the loading coil is used in a standing wave antenna, the standing wave phase delay and traveling wave propagation delay are unrelated, i.e. a phase delay measurement will not yield the correct propagation delay or number of degrees occupied by the loading coil during normal transmit operation.



Since the complaint was that hams are not technical enough, I thought I would introduce a technical subject and see what happens.

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73, Cecil, w5dxp.com

Is this related to the great K3BU-W8JI "current across the coil" debate?
Seems some came to the conclusion that the location of the coil had a
lot to do with whether the current was equal at each end of the coil..
IE: in one exact location it could be equal, but in other locations it
could vary at each end.

I forgot now, it's been so long.. I never really worried about it too
much, because even if it were proven that the current dropped across
the coil, it would not change the design of the antenna.
Just more along the lines of something to know or keep in mind.