On 14/10/2018 09:49, Spike wrote:
On 13/10/2018 20:43, Jeff Liebermann wrote:

I understand how antenna work and how to predict performance. I can
even do it without 4NEC2 or other antenna modeling program. For
example, the uglier the antenna, the better it works. Antennas that
are more expensive, bigger, and in violation of local building
ordinances, work the best. Experimental prototype antennas always
work while the production versions never seem to work as well. If
there are two ways to assemble an antenna, the wrong way will have
higher gain, lower VSWR, or both. High gain, small size, or wide
bandwidth; pick any two. Using these rules of thumb and others,
anyone can predict how well an antenna will perform by inspection and
without using computer models, Smith charts, or tedious calculations.

WHS

There has been much talk on UKRA in the recent past about the merits or
otherwise of various makes and models of VNAs. It's my view that the
point of having an Amateur licence is to be able to transmit signals
intended to be received by another station. One of the alleged virtues
of a VNA is to be able to set up one's aerial system. However, I
maintain that using cheap torch bulbs is an equally valid indicator of
the state of tune of one's station, and that a distant station cannot
tell the difference between a system set up with the aid of a VNA and
one set up with the aid of a torch bulb or two.



The PP seems unaware of retarded potentials, and has blustered his way
by responding to the question without actually any understanding of
the issues involved.