[TowerTalk] Need some actual Inv V lengths using 14ga THHN

[David Gilbert]

There is indeed a "return path" for a single wire.  The wire 
capacitively couples back upon itself, and the dielectric affects that 
capacitance.  That may sound strange, but think of a capacitive hat 
loading at the top of a vertical or at the end of a dipole.  The wire 
itself is just a different geometry and therefore has less effect, but 
it's the same principle.

EZNEC+ is based upon NEC2 and simply allows more wire segments than some 
other versions.  I can't say whether or not NEC2 handles dielectrics, or 
whether W7EL added a calculation on his own, but if you define a 
dielectric in EZNEC+ it will result in a shorter wire for the same 
effect as a bare wire.  That at least fits the physics of the situation.

Dave  AB7E





On 9/20/2022 6:36 PM, Edward McCann wrote:
> I’ve been looking for several decades for a technical analysis of the Vf of a single bare and insulated wire, hearing nothing but lore from just about everywhere, unbelievable proposals and formulas from some, exhortations from academics that such a search is pissin’ in the wind, since there is no return path, as there is in twin lead or in coax.
>
> 73
> Ed McCann
> AG6CX
> Sausalito
>