Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old August 30th 09, 10:54 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default radiators

Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,
apparently
a break off from the standard ham statements of bigger is better as
well as more wire is better.
I have searched and searched for the reason why such a statement is
spread around as if it is has a factual or a mathematical statement to
back it up. For instance a quad radiator is not straight! Nor is a
loop or nor a helical as well as many others. At the same time it is
recognized that all is not understood about radiation and never has a
radiator been constructed that complies in its entirety with Maxwell.
I have untold books on antennas but none (not including ARRL stuff)
provide any sort of reason that this could be true.
Is anybody aware of a recognized author stating why this should be
considered true when current leaning is towards point radiation which
obviously seen as a break away statement..
  #2   Report Post  
Old August 30th 09, 11:15 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default radiators

Art Unwin wrote:
Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


I highly doubt he ever said anything of the sort.

apparently
a break off from the standard ham statements of bigger is better as
well as more wire is better.


And the physical reality that antenna performance is directly related
to size in wavelengths.

snip rest


--
Jim Pennino

Remove .spam.sux to reply.
  #3   Report Post  
Old August 31st 09, 12:29 AM posted to rec.radio.amateur.antenna
tom tom is offline
external usenet poster
 
First recorded activity by RadioBanter: May 2009
Posts: 660
Default radiators

Art Unwin wrote:
Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


Hmm. Please provide a reference where this was stated. I doubt that's
what was actually the verbiage used.

cognized that all is not understood about radiation and never has a
radiator been constructed that complies in its entirety with Maxwell.


According to only you.

I have untold books on antennas but none (not including ARRL stuff)
provide any sort of reason that this could be true.
Is anybody aware of a recognized author stating why this should be
considered true when current leaning is towards point radiation which
obviously seen as a break away statement..


Again, please provide a reference that "current leaning is towards point
radiation".

I sure I won't get a real answer here. As usual.

Just like his bailout on providing a description on his antenna earlier
this weekend.

fraud.

tom
K0TAR
  #4   Report Post  
Old August 31st 09, 12:46 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default radiators

On Aug 30, 5:15*pm, wrote:
Art Unwin wrote:
Tom, W8ji *apparently is an expert with antennas *having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,



I highly doubt he ever said anything of the sort.


As long as you turn a blind eye to what he states
then you are in good shape! But then somebody in this group
will point you to Tom's statement and you can then respond as
to what he really meant which is not what he stated.




apparently
a break off from the standard ham statements of bigger is better as
well as more wire is better.




And the physical reality that antenna performance is directly related
to size in wavelengths.


It depends on your definition of "size". I prefer the term
encapsulating volume.
All physics laws are based on the presence of equilibrium. Thus you
may deform a radiator to the smallest volume as long as you retain a
state of equilibrium, regardless of the number of wavelengths at
issue. This is why "point radiation" is still discussed.
As an aside, the number of wavelengths used has nothing to do with
Maxwells equations
which accounts for ALL forces presence in the forming of radiation and
not the simple
radiator coupling and re radiation approach alone. It all comes down
to root L.C. in a equilibrium environment as the determinate factor
in his equations.

So, the bottom line is that you disagree with the statement made by
Tom as being incorrect.
It will be interesting what the rest of the group have to say as they
wade in.



snip rest

--
Jim Pennino

Remove .spam.sux to reply.


  #5   Report Post  
Old August 31st 09, 12:53 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default radiators

On Aug 30, 6:29*pm, tom wrote:
Art Unwin wrote:
Tom, W8ji *apparently is an expert with antennas *having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


Hmm. *Please provide a reference where this was stated. *I doubt that's
what was actually the verbiage used.

cognized that all is not understood about radiation and never *has a
radiator been constructed that complies in its entirety with Maxwell.


According to only you.

I have untold books on antennas but none (not including ARRL stuff)
provide any sort of reason that this could be true.
Is anybody aware of a recognized author stating why this should be
considered true when current leaning is towards point radiation which
obviously seen as a break away statement..


Again, please provide a reference that "current leaning is towards point
radiation".

I sure I won't get a real answer here. *As usual.

Just like his bailout on providing a description on his antenna earlier
this weekend.

fraud.

tom
K0TAR


You are correct Tom. I have no interest in exchanging insults with
you.
My interests are in radio to which you supply nothing. There you go,
I have now answered you once and that is it.


  #6   Report Post  
Old August 31st 09, 01:21 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2007
Posts: 1,336
Default radiators

On Sun, 30 Aug 2009 14:54:05 -0700 (PDT), Art Unwin
wrote:

Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


He might have been talking about small antennas:
http://www.w8ji.com/radiation_resistance.htm
"Small antennas require extraordinary care to obtain high efficiency."
The 2004 Dayton PowerPoint presentation is at:
http://www.w8ji.com/Dayton/Limited%20Space%20Antennas.ppt
Using Google, I couldn't find any statement resembling the "straight
radiators" claim.

Ummm... fractal antennas are anything but straight and have the best
gain for their size of any antenna.
http://www.fractenna.com

Also, efficiency isn't everything. For example, the efficiency of the
typical mobile HF antenna is fairly lousy because the antenna is a
small fraction of a wavelength long. Still, it's the best that can be
done on HF without trailing a long wire to a balloon, and dragging a
grounding plate.
http://www.k0bg.com/eff.html



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #7   Report Post  
Old August 31st 09, 01:27 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jan 2008
Posts: 141
Default radiators


"Art Unwin" wrote in message
...
Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,
apparently


Art,
The only place I have ever read that on Tom's site is related to Beverage
antennas- the statement is true, and for obvious (to most of us) reasons.

Dale W4OP


  #8   Report Post  
Old August 31st 09, 01:35 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2007
Posts: 1,336
Default radiators

On Sun, 30 Aug 2009 17:21:34 -0700, Jeff Liebermann
wrote:

On Sun, 30 Aug 2009 14:54:05 -0700 (PDT), Art Unwin
wrote:

Tom, W8ji apparently is an expert with antennas having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


Using Google, I couldn't find any statement resembling the "straight
radiators" claim.


Oh wait. Maybe he was referring to the mounting pole:
http://picasaweb.google.com/lh/photo/HC8B4F-AnCQF6I_u0k3MYg

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #9   Report Post  
Old August 31st 09, 01:45 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default radiators

Art Unwin wrote:
On Aug 30, 5:15Â*pm, wrote:
Art Unwin wrote:
Tom, W8ji Â*apparently is an expert with antennas Â*having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,



I highly doubt he ever said anything of the sort.


As long as you turn a blind eye to what he states
then you are in good shape! But then somebody in this group
will point you to Tom's statement and you can then respond as
to what he really meant which is not what he stated.


I highly doubt that will ever happen either.

apparently
a break off from the standard ham statements of bigger is better as
well as more wire is better.




And the physical reality that antenna performance is directly related
to size in wavelengths.


It depends on your definition of "size". I prefer the term
encapsulating volume.


Yeah, sure.


snip rest

--
Jim Pennino

Remove .spam.sux to reply.
  #10   Report Post  
Old August 31st 09, 03:23 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 1,339
Default radiators

On Aug 30, 7:21*pm, Jeff Liebermann wrote:
On Sun, 30 Aug 2009 14:54:05 -0700 (PDT), Art Unwin

wrote:
Tom, W8ji *apparently is an expert with antennas *having lectured
at Dayton and has authored many technical articles around antennas,
states that radiators must be straight for maximum efficiency,


He might have been talking about small antennas:


That may have been at the back of his mind but he did not stipulate
that

http://www.w8ji.com/radiation_resistance.htm
"Small antennas require extraordinary care to obtain high efficiency."


Very true for electrically small antennas with emphasis on
electrically.

The 2004 Dayton PowerPoint presentation is at:
http://www.w8ji.com/Dayton/Limited%20Space%20Antennas.ppt
Using Google, I couldn't find any statement resembling the "straight
radiators" claim.


I never said this is a quote from the Dayton lecture. Tom has numorous
dissertations with regard to antennas


Ummm... fractal antennas are anything but straight and have the best
gain for their size of any antenna.
http://www.fractenna.com

That is what Chip states for his company but I have no idea how a
fractal would work on top band. Most on this group deride the claims
of Chip with more than a handful of insults



Also, efficiency isn't everything. *For example, the efficiency of the
typical mobile HF antenna is fairly lousy because the antenna is a
small fraction of a wavelength long.


Exactly because it takes a WL or multiple there of to attain
equilibrium
*

Still, it's the best that can be
done on HF without trailing a long wire to a balloon, and dragging a
grounding plate. *


No. You are incorrect in my eyes! A multiple of a wavelength does
not require a ground plain and can be condensed into any shape or form
whilst retaining the required equilibrium. This is per the laws of
Maxwell when considering all forces involved in radiation for maximum
efficiency.
Regards
Art



http://www.k0bg.com/eff.html

--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558


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



All times are GMT +1. The time now is 01:44 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017