September 6th 09, 11:53 PM
posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Jul 2006
Posts: 625
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Corriolis force
On Sep 6, 5:07*pm, Art Unwin wrote:
On Sep 6, 1:16*pm, JIMMIE wrote:
On Sep 5, 7:29*pm, Art Unwin wrote:
On Sep 5, 6:02*pm, JIMMIE wrote:
On Sep 5, 6:37*pm, "christofire" wrote:
"Art Unwin" wrote in message
...
On Sep 5, 3:17 pm, "christofire" wrote: "Szczepan Białek" wrote in message
-- snip --
If you want to discover what radiates I suggest you read one of the
normal text books on the subject, like Kraus 'Antennas', and stop
making
up your own versions!
To discower what radiates will be better to do experiments with tipping
of
monopole antenas.
* Where do you get this stuff from? Please visit a library - you could do
yourself a lot of good.
Chris
Chris, what I believe he is referring to is that computer programs
support a tipped vertical over one at right angles to earth. Computer
programs are supposed to be based on Maxwell's formula. Is this an
error and how do we fix it. If it is not an error then it supports the
presence of the Coriolis force in collusion with gravity. and not
gravity alone.
* I don't doubt that it is possible to obtain results from a computer
program that appear to contradict conventional theory. *Interpretation of
what comes out is always the responsibility of the operator so, whilst
anyone can enter parameter values and hit 'go', not everyone will interpret
the results correctly. *In this respect it must help greatly to have a clear
understanding of the basic principles of how antennas radiate and how the
modelling programs operate; in most cases how the moment method works. *My
recommendation, as before, is to read an edition of 'Antennas' by Kraus (or
an equivalent), cover to cover, before trying to make sense of the output of
any antenna modelling program. *Of course, I realise that some who 'publish'
here feel this would be beneath them, or too hard ... but, really, it is
neither.
My own take on the effect of tilting a vertical antenna is that if its
length is an appreciable fraction of a wavelength then tilting it will
distort its radiation pattern and will upset the uniformity of its
polarisation, which will impose a further effective radiation pattern. *If
this results in a bit of gain in one particular direction with respect to a
particular polarisation then fine, and this may be of some use in amateur
radio service although it isn't how vertical monopoles are most often used
(i.e. their omni-directional pattern is their strength and there are many
other, better ways, to obtain directional patterns).
However, the theory on which all the well-known modelling programs is based
is the simple stuff described by Kraus, et al, and probably in most cases
follows from the original work that led to NEC
(http://www.nec2.org/other/nec2prt1.pdf). *It takes _no_ account of the
Coriolis force or gravity (outside of its impact on the speed of light). *If
such a program produces output that the operator interprets as depending on
the Coriolis force then, logically, this must be a mistake on the part of
the operator - wouldn't you agree? *However, if you believe the theory on
which the program is based is in error then maybe you shouldn't use it.
More to the point, it is common knoweledge that there is no full
understanding of radiation available anywhere. Thus he is asking probing
questions to fill in the
gaps.
* There is sufficient understanding of radiation and antennas out there, as
widely documented, to have enabled practical radio, radar, and suchlike for
more than a century. *I understand that part of the point of amateur radio
is to encourage experimentation, but I don't understand why experimenters
should wish to shun the accepted, conventional theory and try to come up
with their own, perhaps paraphysical, versions - especially when those
people don't exhibit much understanding of the basics. *Maybe they treat the
subject a bit like art (no pun intended) instead of the science that it
should be.
Personaly I am not willing yet to say antenna programs are at fault
until more explanations come about. Can you explain what he is
commenting upon.?
* It's possible he is being deliberately provocative.
Chris
It is conceivable that the Coriolis effect may act upon EM radiation.
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