On Sep 14, 3:18*pm, "Richard Fry" wrote:
"Art Unwin" wroteThese were shore based installations probably in Hawaii or some island.
With respect to resonance, moving away from such as well as changing
from 15 degrees (Frank's 30 degrees divided by two) would provide a pattern
of distinct advantage which the navy is constantly looking for. *For a whip
tipped at an angle of 15 degrees can provide a forward pattern of gain which
can be a big deal
__________
Art -
The graphic linked below is the work of George H. Brown of RCA Labs, from a
1936 paper published in the Proceedings of the IRE.
It is a plot of surface wave field intensity vs.monopole height, including
the distance to the "fade zone" where nighttime skywave radiation returns to
earth to via reflection from the ionosphere to interfere with the surface,
or ground wave.
In it please note:
1. Maximum field strength does not occur at electrically resonant heights of
the monopole (that is, where its feed point terminal reactance is zero).
I will look at the URL later Now I put the resonance as second to
equilibrium
as with equilibrium the need for a ground plane is negated In general
terms broadcast stations want equal radiation
around the point of installation knowing that the decibel is not
discernable in their audiance ears
2. The characteristics plotted are not related to azimuth, therefore the
performance of a broadcast monopole will not be enhanced by "tipping." *If
it was, AM broadcast stations would have been doing so starting 70 years
ago.
That is what Harrison said. He also said we have one method of
radiation so why do we need another?
Brown had no reason to isolate horizontal propagation from vertical
propagation and because construction
is way more simple relative to Earth there is no reason to reinvent
the wheel. The Yagi method of radiation
is a very good approximation even tho it disregards the weak force as
it deals more with total gain versus the polarity
of the field. Present day science have more demands on radiation than
Brown would realize. My wife nearly died last year because of a slight
misdirection
at the hospital when a needle nicked the liver when the medical people
placed to much reliance on provided measurements that were beyond the
capabilities of the equipment. As science grows so does understanding
and so does use of radiation which has requirements
way beyond a radio station
Regards
Art
http://i62.photobucket.com/albums/h8...fVerticalMonop...
RF