Topband: Shortend Vertical model questions

[K9AY]

> Yet, isn't there a "watch out for" when using large differences of
> conductor diameters ?  (like a 6" vertical and #14 top loading
> as to the real world numbers)  > 73 Billy AA4NU

Yes, this is a situation to avoid.  For a short vertical like the one under
discussion, the easiest way to avoid the problem is to model the larger
vertical section using 3 or 4 wires the same size as the top loading wires,
spaced so they represent a "cage" or "skeleton" the size of the larger 
conductor.  Use the same number of segments for each of these wires,
since another NEC issue is that close-spaced wires must have the pulses 
aligned to get the most accurate results.  

73, Gary
K9AY