[TowerTalk] Dipole length vs diameter -- a theory question

[Jim Brown]

On 1/28/2020 2:13 PM, jimlux wrote:
> The K-factor graph can be derived semi-analytically - there are several 
> analytical expressions for the complex impedance of an antenna (and you 
> can solve for where X is zero) over a restricted range. Or, you can 
> numerically integrate the field equations - which is what people have 
> been doing since the late 1800s.

Some of the math Jim is describing here is advanced college level. When 
we encounter design formulas, like the the Handbook, they are the result 
of having written and solved those complex equations. And often, the 
formula is a simplified version, based on certain simplifying 
assumptions (for example, that the wire is straight, round, 
un-insulated, and not close to other conductive objects). A more complex 
equation might take into account the effect of insulation, the effect of 
height above ground and the quality of the soil.

Modeling programs like NEC use various techniques to solve the 
fundamental equations for data that we enter.

73, Jim K9YC