Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #131   Report Post  
Old July 3rd 07, 04:21 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 1,154
Default Guy from university physics dept. makes claims to incite/provokeamateurs!

John Smith I wrote:

[stuff]


Actually, I got those figs wrong, I am late to a meeting, can't find the
paper with the final/optimized lengths/ratios/dia/turns for 10m ... I'll
send post/email 'em later today so as to have it right--just in case
there is one guy with the energy curiosity to kludge one together ...

Most important thing, I can tell, is the ratio of inductance between the
coils--my final length of all coils/radiators if .333% of full 1/2 half
.... a darn good mobile antenna!

JS

  #132   Report Post  
Old July 3rd 07, 05:40 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 17 Jun, 16:13, "Mike Kaliski" wrote:
"John Smith I" wrote in ...

Actually, old news from 3 years ago ...


http://www.eetimes.com/showArticle.j...cleID=21600147


JS


The guy doesn't even seem to realise that height is one of the prime factors
in optimising propogation, particularly at medium wave frequencies and vhf.
Building a tall mast costs plenty of money and if commercial radio stations
could broadcast efficiently from an antenna the size of a bean can, they
would have done it years ago.

This is surely just a couple of coils wound in opposite directions with
capacitive coupling and a capacity top hat to prevent coronal discharge and
maximise current in the top half of the antenna. Basically a form of top
loaded, inductively wound whip antenna tapped somewhere up from the base in
order to pick up a 50 ohm matching impedence at the design frequency. I
don't see any new or innovative principles at work here.

Now if he could make it work efficiently on all frequencies with 50 ohms
impedence and with no requirement for further matching or adjustment of any
sort, I would be impressed. :-)

Mike G0ULI


Mike
The antenna is based on confirmed scientific findings of the masters
and can be proved mathematically as one would expect from such an
antenna.
It is true that what happens to radiation when it is formed is
important
but what is more important is to understand radiation in its formative
stage.
When this is understood then miniturisation comes to the fore that
may
well be more important than the TOA but then even this antenna can be
raised in height. There is a lesson to be learned here. The Yagi was
invented by the Japanese in the early 1920 where America embraced the
invention
and where Japan did not. That same invention proved to be one of
Japans
undoing as they never caught on to the importance possibly by
beurocracy.
This new antenna has been pushed aside by America where I am positive
other Countries are moving fast ahead and now have 3 years lead to
play with.
It is America this time that is complacent. The antenna is there,
the mathematics is there and Maxwells laws are still there, all of
which conform with each other both with this antenna and my Gaussian
antenna but who cares.
Art Unwin KB9MZ.......XG

  #133   Report Post  
Old July 3rd 07, 06:17 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: May 2007
Posts: 182
Default Guy from university physics dept. makes claims to incite/provoke amateurs!


"art" wrote in message
oups.com...
On 17 Jun, 16:13, "Mike Kaliski" wrote:
"John Smith I" wrote in

...

Actually, old news from 3 years ago ...


http://www.eetimes.com/showArticle.j...cleID=21600147


JS


The guy doesn't even seem to realise that height is one of the prime

factors
in optimising propogation, particularly at medium wave frequencies and

vhf.
Building a tall mast costs plenty of money and if commercial radio

stations
could broadcast efficiently from an antenna the size of a bean can, they
would have done it years ago.

This is surely just a couple of coils wound in opposite directions with
capacitive coupling and a capacity top hat to prevent coronal discharge

and
maximise current in the top half of the antenna. Basically a form of top
loaded, inductively wound whip antenna tapped somewhere up from the base

in
order to pick up a 50 ohm matching impedence at the design frequency. I
don't see any new or innovative principles at work here.

Now if he could make it work efficiently on all frequencies with 50 ohms
impedence and with no requirement for further matching or adjustment of

any
sort, I would be impressed. :-)

Mike G0ULI


Mike
The antenna is based on confirmed scientific findings of the masters
and can be proved mathematically as one would expect from such an
antenna.
It is true that what happens to radiation when it is formed is
important
but what is more important is to understand radiation in its formative
stage.
When this is understood then miniturisation comes to the fore that
may
well be more important than the TOA but then even this antenna can be
raised in height. There is a lesson to be learned here. The Yagi was
invented by the Japanese in the early 1920 where America embraced the
invention
and where Japan did not. That same invention proved to be one of
Japans
undoing as they never caught on to the importance possibly by
beurocracy.
This new antenna has been pushed aside by America where I am positive
other Countries are moving fast ahead and now have 3 years lead to
play with.
It is America this time that is complacent. The antenna is there,
the mathematics is there and Maxwells laws are still there, all of
which conform with each other both with this antenna and my Gaussian
antenna but who cares.
Art Unwin KB9MZ.......XG

Art

There is a place for miniaturised antennas, particularly for military
applications where size and weight of the antenna outweigh other
considerations which are important to commercial and amateur users e.g
bandwidth and efficiency.

The yagi has great front to back ratios and makes for a great if slightly
narrow band antenna for UHF TV reception here in the UK. These antennas are
generally sold tuned to cover the local TV frequency channels rather than
the whole of the UHF TV band. A lot of people will need to buy new antennas
when the switch over to digital TV broadcasting takes place as the digital
channels have been arranged to be at the opposite ends of the band to
analogue TV in most areas.

The yagi was probably the first antenna that did not conform to antenna
theory as it was understood at the time it was developed. Small loops and
E-H antennas also appear to defy logic at first glance but careful analysis
of their performance has revealed how they work with higher efficiencies
than previously believed possible.

Unfortunately for some, there is no magic or defiance of the accepted laws
of physics involved in the way they work.

There are still areas which provide fertile areas for experimentation,
particularly at the extremes of the radio frequency spectrum.

Regards

Mike


  #134   Report Post  
Old July 3rd 07, 06:49 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 3 Jul, 09:40, art wrote:
On 17 Jun, 16:13, "Mike Kaliski" wrote:





"John Smith I" wrote in ...


Actually, old news from 3 years ago ...


http://www.eetimes.com/showArticle.j...cleID=21600147


JS


The guy doesn't even seem to realise that height is one of the prime factors
in optimising propogation, particularly at medium wave frequencies and vhf.
Building a tall mast costs plenty of money and if commercial radio stations
could broadcast efficiently from an antenna the size of a bean can, they
would have done it years ago.


This is surely just a couple of coils wound in opposite directions with
capacitive coupling and a capacity top hat to prevent coronal discharge and
maximise current in the top half of the antenna. Basically a form of top
loaded, inductively wound whip antenna tapped somewhere up from the base in
order to pick up a 50 ohm matching impedence at the design frequency. I
don't see any new or innovative principles at work here.


Now if he could make it work efficiently on all frequencies with 50 ohms
impedence and with no requirement for further matching or adjustment of any
sort, I would be impressed. :-)


Mike G0ULI


Mike
The antenna is based on confirmed scientific findings of the masters
and can be proved mathematically as one would expect from such an
antenna.
It is true that what happens to radiation when it is formed is
important
but what is more important is to understand radiation in its formative
stage.
When this is understood then miniturisation comes to the fore that
may
well be more important than the TOA but then even this antenna can be
raised in height. There is a lesson to be learned here. The Yagi was
invented by the Japanese in the early 1920 where America embraced the
invention
and where Japan did not. That same invention proved to be one of
Japans
undoing as they never caught on to the importance possibly by
beurocracy.
This new antenna has been pushed aside by America where I am positive
other Countries are moving fast ahead and now have 3 years lead to
play with.
It is America this time that is complacent. The antenna is there,
the mathematics is there and Maxwells laws are still there, all of
which conform with each other both with this antenna and my Gaussian
antenna but who cares.
Art Unwin KB9MZ.......XG- Hide quoted text -

- Show quoted text -


Mike,
As a Londoner you will appreciate the following. When the war finished
I started my first real schooling at a school that was surrounded by
blocks of debris
but the school was still standing. It was destroyed in WW1 with about
30+ kids dead.
Finally dad got demobbed and came home to our house which was a bomb
damaged house
because the other house was flattened.We as a pair went to Petticote
lane on Sundays
because dad had a interest in radio and I had to get the water
batteries to run it.
One day dad came back from Petticoat lane and brought home with him a
coil of wire
that you plugged into an outlet and that was the new antenna. I had
not had much
schooling up to that time and at the age of 14 had only one year
before one had
to leave and go to work. Mum got me into a school at dockside for
ships
engineers and navigators and tho a year late I at least got two years
of
education despite the war which followed by years
and years of night school I got the education that any college kid
even tho
I was 10 years older. Now I have the mantra that if it is" resonant
and in a
state of equilibrium" it is what I call a Gaussian antenna. So here
at near
the end of my life I finally got to the bottom of the science that
dad
put before me as peace settled on the East End of London. What dad
plugged into the wall was an antenna that was "resonant and in a
state
of equilibrium" and where its resonance was in the AM band.
60 years later his son resolved the question because of the pursuit
of an education.
Shame he isn't alive to hear 'the rest of the story'
Cheers and beers
Art Unwin KB9MZ.......XG

  #135   Report Post  
Old July 3rd 07, 08:23 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 26 Jun, 13:34, John Smith I wrote:
Buck wrote:

...


The section below with pictures made a difference. I saw that the
patent is in concept, that is the arrangement of the coils for the
desired effect and the design of coils which can be helical, squared
off, etc.


Thanks.


Buck


Buck:

Yeah, all that alright.

However, he also claims the "arrangement" he has increases the impedance
of the 1/4 wave shortened antenna to 72-100 ohms. This is interesting
in and of itself, shortened antennas tend to have impedances in the
single digits and are difficult to match efficiently ...

I am just beginning to toy with this version, maybe can get serious this
weekend ...

Regards,
JS


What Buck has stated as well as what the inventor has stated
is in full agreement to what I have always stated and proved.
"The radiator can be any shape or size or angle etc.as long as
it is in equilibrium and resonant which is buried in the laws
of the masters" The question of apurture is purely a reflection
of efficiency which when included in a closed circle shows that
vividly with repect to enclosed area. The same antenna arrangement
is a reflection of Gaussian law and as such can be removed
from any ground assumptions that is inferred by those who have
done this and done that. That same element can be duplicated
to form a dipole of any shape to remove the inefficiencies of
ground and can even be multiplied in number to form an array in
accordance with the Gaussian antenna. It all comes down to actually
understanding the underpinnings of the formation of radiation
rather than learned laws where one is not interested in advancing
for the good of science. Once upon a time I saw an experiment formed
where a bunch of coils placed on a paper plate was placed on top of a
car
where radiation lit a fluerescent lamp..........same buried law.
And then we come to the fractal antenna...........same buried law
of which the mathematics given thoroughly proves tho rejected by ham
radio.
I know you can smell it.
Art Unwin KB9MZ......XG



  #136   Report Post  
Old July 3rd 07, 10:08 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 3 Jul, 10:17, "Mike Kaliski" wrote:
"art" wrote in message

oups.com... On 17 Jun, 16:13, "Mike Kaliski" wrote:
"John Smith I" wrote in


...





Actually, old news from 3 years ago ...


http://www.eetimes.com/showArticle.j...cleID=21600147


JS


The guy doesn't even seem to realise that height is one of the prime

factors
in optimising propogation, particularly at medium wave frequencies and

vhf.
Building a tall mast costs plenty of money and if commercial radio

stations
could broadcast efficiently from an antenna the size of a bean can, they
would have done it years ago.


This is surely just a couple of coils wound in opposite directions with
capacitive coupling and a capacity top hat to prevent coronal discharge

and
maximise current in the top half of the antenna. Basically a form of top
loaded, inductively wound whip antenna tapped somewhere up from the base

in
order to pick up a 50 ohm matching impedence at the design frequency. I
don't see any new or innovative principles at work here.


Now if he could make it work efficiently on all frequencies with 50 ohms
impedence and with no requirement for further matching or adjustment of

any
sort, I would be impressed. :-)


Mike G0ULI


Mike
The antenna is based on confirmed scientific findings of the masters
and can be proved mathematically as one would expect from such an
antenna.
It is true that what happens to radiation when it is formed is
important
but what is more important is to understand radiation in its formative
stage.
When this is understood then miniturisation comes to the fore that
may
well be more important than the TOA but then even this antenna can be
raised in height. There is a lesson to be learned here. The Yagi was
invented by the Japanese in the early 1920 where America embraced the
invention
and where Japan did not. That same invention proved to be one of
Japans
undoing as they never caught on to the importance possibly by
beurocracy.
This new antenna has been pushed aside by America where I am positive
other Countries are moving fast ahead and now have 3 years lead to
play with.
It is America this time that is complacent. The antenna is there,
the mathematics is there and Maxwells laws are still there, all of
which conform with each other both with this antenna and my Gaussian
antenna but who cares.
Art Unwin KB9MZ.......XG


Art

There is a place for miniaturised antennas, particularly for military
applications where size and weight of the antenna outweigh other
considerations which are important to commercial and amateur users e.g
bandwidth and efficiency.

The yagi has great front to back ratios and makes for a great if slightly
narrow band antenna for UHF TV reception here in the UK. These antennas are
generally sold tuned to cover the local TV frequency channels rather than
the whole of the UHF TV band. A lot of people will need to buy new antennas
when the switch over to digital TV broadcasting takes place as the digital
channels have been arranged to be at the opposite ends of the band to
analogue TV in most areas.

The yagi was probably the first antenna that did not conform to antenna
theory as it was understood at the time it was developed. Small loops and
E-H antennas also appear to defy logic at first glance but careful analysis
of their performance has revealed how they work with higher efficiencies
than previously believed possible.

Unfortunately for some, there is no magic or defiance of the accepted laws
of physics involved in the way they work.

There are still areas which provide fertile areas for experimentation,
particularly at the extremes of the radio frequency spectrum.

Regards

Mike- Hide quoted text -

- Show quoted text -


Interesting that you mentioned efficiency. Radiation in itself is very
efficient
i.e. in the 98% region It is how we use it is where the efficiency
goes down.
But if initial efficiency starts of with 98% and with a superconductor
we
gain two percent it becomes very obvious that loss of efficiency even
if
large is minor when compared to the reduction in size. As far as
narrow bandedness is concerned of the yagi this has little to do with
efficiency
but with what we do with the radiation which by coupling as a method
of
focussing to get a major lobe. True this is an advantage to some but
the
penalty is narrow banded because of compromises that are forced upon
one where
the desirables do not appear in sync with each other. So yes a very
small
antenna may be less efficient but how much does that loss in
efficiency
match up to the advantage in size and where the final shape provides
desirables that are in sync with each other. Amateurs have long
thought that
bigger is better and if it doesn't fall down then it is not big
enough!
All of which is not based on radiation itself but on the basis of
Yagi
technique on how we use that radiation. Times have changed from the
old
days where gain was everything. Miniturization has become so important
as well as equal surrounding coverage that the cell phone has become
an instantaneous replacement for long distance transmission in the
commercial world. As I read in this latest quarterly magazine for the
antenna trade
the biggest hold up today in communications is to design drivers with
low impedance levels such as 5 ohms where this in fact misuses modern
day science.
We now can obtain miniturised design with minimul reduction of
bandwidth and minimul
loss of comparitive efficiency where higher impedance feed is so more
electrically efficient
that it makes low impedance a lost cause. I am quite sure that other
countries are not discarding such logic and thus taking advantage of
the intervening years
for advances in the military field where secrecy can be adhered to.
Well at least for a while.
Best regards
Art Unwin KB9MZ.....XG

  #137   Report Post  
Old July 4th 07, 01:11 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: May 2007
Posts: 182
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

snip
Mike,
As a Londoner you will appreciate the following. When the war finished
I started my first real schooling at a school that was surrounded by
blocks of debris
but the school was still standing. It was destroyed in WW1 with about
30+ kids dead.
Finally dad got demobbed and came home to our house which was a bomb
damaged house
because the other house was flattened.We as a pair went to Petticote
lane on Sundays
because dad had a interest in radio and I had to get the water
batteries to run it.
One day dad came back from Petticoat lane and brought home with him a
coil of wire
that you plugged into an outlet and that was the new antenna. I had
not had much
schooling up to that time and at the age of 14 had only one year
before one had
to leave and go to work. Mum got me into a school at dockside for
ships
engineers and navigators and tho a year late I at least got two years
of
education despite the war which followed by years
and years of night school I got the education that any college kid
even tho
I was 10 years older. Now I have the mantra that if it is" resonant
and in a
state of equilibrium" it is what I call a Gaussian antenna. So here
at near
the end of my life I finally got to the bottom of the science that
dad
put before me as peace settled on the East End of London. What dad
plugged into the wall was an antenna that was "resonant and in a
state
of equilibrium" and where its resonance was in the AM band.
60 years later his son resolved the question because of the pursuit
of an education.
Shame he isn't alive to hear 'the rest of the story'
Cheers and beers
Art Unwin KB9MZ.......XG

Art

Even though I was born some years after the war ended, I do have some old
magazines and articles that mention such an antenna. I believe that there
were two or three (perhaps more) rival designs around in the 50's possibly
into the early 60's that claimed to improve radio reception dramatically.
The arrival and shift of interest into television seems to have sounded the
death knell for these devices.

As I recall, some of the pundits at the time were rather disparaging about
these miracle antennas and indeed most designs were proved to be fraudulant,
but one design did actually work and genuinely provided improved
performance. I would guess that this was probably the one your dad acquired.
I believe the design that worked did so because it achieved a genuine
impedence match wereas the others were just devices that hooked up the radio
to the house mains and used that to provide an antenna. Not very safe at
all!!! One device proved to be just a high resistance wirewound resistor
connected to the mains.

So the genuine device did achieve provide a proper match and achieved a kind
of what might be termed equilibrium with the receiver. These devices weren't
particularly cheap to buy either. Looking at antenna prices today, I see
that hundreds of dollars can be spent on a couple of dollars worth of
fibreglass, aluminium and a bit of wire, so things haven't changed that much
I guess. That is surely why rec.radio.amateur.antenna exists and is so
popular; to provide an alternative to those people that do want to think for
themselves rather than blindly following the path commercial manufacturers
dictate.

Regards

Mike G0ULI


  #138   Report Post  
Old July 4th 07, 01:36 AM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 18 Jun, 12:01, Jim Lux wrote:
J. Mc Laughlin wrote:
Dear Group:


Details of the patent applications may be found on the USPTO's site.


Robert J. Vincent (Electronics Technician II, Physics-URI)


Application 20060022883; published Feb. 2, 2006
Application 20070132647; published June 14, 2007


I think that ends in ..649
filed 25 Jan 2007

one might note that claims 1-23 were cancelled...

The second application is basically a revision of the first amd has more
details of why it has priority over earlier applications (presumably
over other inventors?)

The first is a continuation application as well.

I'm going to guess that the examiner came back on the first app and
said: Uh,uh, you need to update to establish why a)you're first and b)
why you're novel

If you've got significant time available, compare the two applications
and it may be revealed





73, Mac N8TT


--
J. Mc Laughlin; Michigan U.S.A.
Home: - Hide quoted text -


- Show quoted text -


Jim,
I just looked at the patent application and I feel the University
has not been a service to the inventor. The university did not supply
or did not have the mathematical underpinning of the design. The whole
patent
evolves about one antenna arrived in experimental form. As normal
additional claims were made in an effort to cover other possibilites
of that empirically found antenna without the mathematical
underpinnings
to guide for additional claims. Yes he has numourous claims but
without
the underminnings the claims are severely hampered. I would have
thought
that any University after being presented emperical results would
have
followed the lines of any scientific institution until the
underlining
mathematics could be solved to provide a firm basis for the
application
based on science or mathematics of which the antenna was just one
sample to validate the request. At least the University gave him an
avenue to pursue the patent in the hope that something of value would
rub of
as some sort of esteem but without scientific backing from extensions
of
laws of past masters I cannot see that comming about. For instance he
has made no reference to the makings of radiation, it's pulsatic form
or a connection to all other laws of the masters other than laymans
terms of what a inductance does other than refering to the current
bucking.
Both of the patents will come out together and the combination will be
instructive.
My request publishing date will be held back until at least the first
review since
I wrote it myself together with the request for examiner help, a given
proviso
that is provided for inventors who have not handed all power to an
attorney
and who relies on direct comunication with the examiners by the
inventor himself.
This way the claims which is really the only guts that count with a
patent are a
cooperative development between the examiner and the patentee which
gives it
a perceived advantage if litigation is followed. In one past
application
there was numourous intercomunications between the examiner as well as
his boss
before a particular claim was formulated as the first claim that
satisfied all
based on given information and around which other claims were made.
Since my claim was not of a commercial nature some errors were agreed
to
but as a learning exersize which is how I treat anything I do, it was
a extremely
good learning experience. One patent I pulled or let it run out before
review
because of so many doubting thomases and now I can't even remember
what is was
and what I did with the paperwork. That also was a learning experience
that I will not duplicate. As far as the tests applied to the new
invention
from the University where the testing was against another antenna
under the
same conditions. This totally nullified ground conditions and other
environmetal
conditions that can change the attributes of the test in both an
disadvantegous
way as well as advantageous allowing for a apples
and apples comparison where very questionable observables were
cancelled out.
With reference to Jim Lux comments with respect to the testing
procedure.
I certainly see that as a reputable test if one accepts the validity
of the
specs assigned to that which it is being compared to. Which is tested
in the
very same environment and using the very same equipment. As an
engineer I see
no better way to test an antenna for the military. Trust but verify
which
is often beyond the amateur who often relies on smell.
Best regards
Art Unwin KB9MZ.....XG.


  #139   Report Post  
Old July 4th 07, 01:14 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 440
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

"art" wrote
... I have always stated and proved. "The radiator can be
any shape or size or angle etc.as long as it is in equilibrium
and resonant which is buried in the laws of the masters"

____________

A distinction needs to be made between the ability of a conductor of any
size/shape to efficiently produce EM fields from the r-f current flowing
along it, and the capability of the associated transmitter and transmission
line to deliver that r-f current.

A good conductor of EVERY size/shape (including even a point source) will
radiate virtually ALL the r-f power that can be made to flow into it --
which quantity equals the product of the square of the r-f current at the
feedpoint, and the resistive term of the impedance there (ie, the radiation
resistance).

If the radiating structure (antenna) is not self-resonant, there will be an
impedance mismatch between it and the transmission line connected to its
feedpoint. This means that the antenna will not accept all of the
transmitter power that could be delivered it to by the transmission line.
But whatever power does transfer into the antenna will be radiated with the
same high efficiency as if the match was perfect.

There are many examples of non-resonant (highly reactive) antenna structures
that, with proper system design, radiate a very high percentage the power
available from the transmitter. Common examples of this are the monopole
radiators used by MW AM broadcast stations -- very few of which are
self-resonant.

High radiation efficiency is achieved in these non-resonant antennas by the
use of a matching network at the antenna feedpoint, which cancels the
reactance of the monopole, and transforms the r-f resistance term there to
match the Zo of the transmission line in use.

This results in an impedance match capable of passing nearly all the power
available from the transmission line, despite the fact that the antenna
itself remains non-resonant, and without setting up high standing waves on
the transmission line.

The only significant losses.then are the attenuation of the transmission
line, the loss in the matching network, and the loss in the r-f ground
system. In normal broadcast station practice these losses are small enough
for the groundwave field at 1 km to be 90% or better of the theoretical
value for a perfect radiator of that electrical height and applied power,
over a perfect ground plane.

Bottom line (N.B. Art): antennas do not need to be resonant to perform as
very efficient radiators.

RF

  #140   Report Post  
Old July 4th 07, 02:25 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Guy from university physics dept. makes claims to incite/provoke amateurs!

On 4 Jul, 05:14, "Richard Fry" wrote:
"art" wrote... I have always stated and proved. "The radiator can be
any shape or size or angle etc.as long as it is in equilibrium
and resonant which is buried in the laws of the masters"


____________

A distinction needs to be made between the ability of a conductor of any
size/shape to efficiently produce EM fields from the r-f current flowing
along it, and the capability of the associated transmitter and transmission
line to deliver that r-f current.

A good conductor of EVERY size/shape (including even a point source) will
radiate virtually ALL the r-f power that can be made to flow into it --
which quantity equals the product of the square of the r-f current at the
feedpoint, and the resistive term of the impedance there (ie, the radiation
resistance).

If the radiating structure (antenna) is not self-resonant, there will be an
impedance mismatch between it and the transmission line connected to its
feedpoint. This means that the antenna will not accept all of the
transmitter power that could be delivered it to by the transmission line.
But whatever power does transfer into the antenna will be radiated with the
same high efficiency as if the match was perfect.

There are many examples of non-resonant (highly reactive) antenna structures
that, with proper system design, radiate a very high percentage the power
available from the transmitter. Common examples of this are the monopole
radiators used by MW AM broadcast stations -- very few of which are
self-resonant.

High radiation efficiency is achieved in these non-resonant antennas by the
use of a matching network at the antenna feedpoint, which cancels the
reactance of the monopole, and transforms the r-f resistance term there to
match the Zo of the transmission line in use.

This results in an impedance match capable of passing nearly all the power
available from the transmission line, despite the fact that the antenna
itself remains non-resonant, and without setting up high standing waves on
the transmission line.

The only significant losses.then are the attenuation of the transmission
line, the loss in the matching network, and the loss in the r-f ground
system. In normal broadcast station practice these losses are small enough
for the groundwave field at 1 km to be 90% or better of the theoretical
value for a perfect radiator of that electrical height and applied power,
over a perfect ground plane.

Bottom line (N.B. Art): antennas do not need to be resonant to perform as
very efficient radiators.

RF


All very true. But the bottomline is not just efficient antennas but
also
having the radiation field where you want it at an inexpensive way,
that is compatible with your lot size and in cluster form i.e. array.
The antenna from the University is resonant tho less efficient than
ideal
But many hams with small lots place in high esteem an antenna that tho
a
bit less in efficiency gets the job done. But with all that said
I have no problem with anything that you have stated. Lets face it,
if a ham can get on the air with a small antenna tho losses may be 1-2
db
he has achieved all he wanted to do and other hams who are positioned
in the right
places will certainly view his signal as an equal.
Best regards
Art

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
KB9RQZ Makes One Post After Another Then Claims Others Are LYING When His Own Words Are Quoted VERBATIM [email protected] Policy 3 September 26th 06 01:57 PM
the 'language' of physics GOSPELS FAR FROM THE TRUTH --Mor... [email protected] Shortwave 18 August 7th 05 02:59 AM
Physics according to toad Cmd Buzz Corey Policy 5 May 28th 05 04:57 PM
NY TIMES says new super-small Hammie Antenna defies physics Nicolai Carpathia CB 16 June 12th 04 08:08 PM
Ye canna change the lars o' physics Dave VanHorn CB 5 August 2nd 03 08:34 PM


All times are GMT +1. The time now is 11:27 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017