Topband: dipole height

[Rick Karlquist]

Tom W8JI wrote:

> If dominant noise comes from a null direction, the difference between gain
> in the desired signal direction to null of the noise will set the
> performance. For example, with a thunderstorm off the rear, F/R is most
> important.
>
> If noise is unevenly distributed, then it becomes very complex.
>
> Most people out in a rural area are probably in a situation where whatever
> QRM or noise bothers them, comes from random, differing, directions. Some
> people in congested areas have significant noise from one direction, and
> they need a deeper null in that specific direction. Going for
> exceptionally
> high F/R is meaningless unless there is somewhat-consistent strong QRM
> from
> the rear.

This is why anecdotal reports of great receiving antennas should be
taken with a grain of salt.  If the user had a dominant noise source
in one direction, a receiving antenna with modest RDF, but with a null
in the direction of the noise could work miracles.  Of course, that
same antenna in other locations might not do anything special.

Rick N6RK