Very good points John, the subject first started out some time ago when
I stated that thge yagi array was really an in efficient way of
providing communication point to poit because it can be seen that the
radiation field points all over the place. The comments first came back
that little energy was exposed outside the main lobe which then people
stated it wasn't a measure of yagiefficiency bringing gain and a lot of
miscellaneous stuff until they got to the point that the yagi was
efficient and the real efficiency revolves around radiation itself.
Then sniping started and I took off for a while.
When I came back I modified the question
to what people thought the question should be because that was what
they had an answer for but again they got screwed up because the
subject still remaines the yagi with respect to radiation fields
knowing full well that radiation cancellation enters heavily when
determining final radiation fields which is why one should not bring in
gain to the picture. So cutting out the clutter of environment and
dielectrics used etc the question is phrased around the transfer
arrangement that the Yagi uses to translate a electrical power input
for the production of a time varying field which is the most simple
basic aproach since we are dealing only with the eIR equation in
obtaining the energy change over efficiency with respect to the Yagi
antenna alone.No nead to show off your perceived knowelenge about
antennas or to change the subject so that one doesn't have to show
their ignorance of factors outside of Ohms law which is all one needs
to know. But sadly in this newsgroup people get upset if one doesn't
know the answer to the question prefer to divert things to a question
that they do know the answer to and do this by questioning the
intelligence of the poster first before their own intelligence becomes
the question. From the very beginning I gave the hint where it can be
reasoned out without a lot of uninportant clutter but unfortunately all
ignored it as possible drivel. Is it any wonder that antenna talk and
aspiring amateurs shy away from this newsgroup and where it attracts a
different sort of clientele in line with present day activities? My
goodness a dipole is a basic element in any antenna array with respect
to effiency but an arrays efficiency is based on the additions to the
driven dipole of other elements used to produce the near field to
produce perceived benefits which is outside of this question. I realise
that all hams do not have to be electrical engineers but it does seem
the purpose of some is to complicate things beyond the comprehension of
those who we wish to have in the fraternity in an attempt to elevate
them selves in fraternity fashion. Oh well I can't change the world!
The yagi has held its own since the 1920 so it must be sacrelidge to
examine it furthur to expose more efficient means of producing near
fields. For myself I have written around a new form to be published by
the PTO and was intending to discuss its merits with this group first
but I now realise that information iand knoweledge is not what is sort
after, only targets to throw stones at.



John Smith wrote:
Jerry Martes wrote:
...
How do you define efficiency?

Jerry



Jerry:

You make that sound like such a simple question.

Antenna efficiency is a complicated and often misused figure.

All antennas suffer from losses. A simple horn antenna for example will
not be as efficient as a perfect aperture of the same size because of
phase offset. The real efficiency of an antenna combines impedance match
with other factors such as aperture and radiation efficiency to give the
overall radiated signal for a given input. The best and mostwidely used
expression of this efficiency is to combine overall efficiency with
directivity (of the antenna) and express the efficiency times
directivity as gain.


The above is NOT mine, but taken from the web...
http://www.tmcdesign.com/antenna%20c...nformation.htm

So, we need to know if we are discussing antenna efficiency, or
radiation efficiency, or the skin effect as related to the ether
efficiency, etc. grin

Good that you are asking him!

Regards,
JS