Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old June 7th 04, 10:43 PM
Tam/WB2TT
 
Posts: n/a
Default


"Cecil Moore" wrote in message
...
The 'why' is conservation of energy. If there are only two directions
available and energy was traveling in one direction and now it isn't,
it's a no-brainer to realize that it must have changed directions.


Cecil, I think a more convincing argument is that I can take a slotted line
and directly measure a standing wave on it. A wave traveling in one
direction can not do that. Or am I cunfusing things?

Tam/WB2TT


  #2   Report Post  
Old June 7th 04, 11:16 PM
Jim Kelley
 
Posts: n/a
Default



Tam/WB2TT wrote:

"Cecil Moore" wrote in message
...
The 'why' is conservation of energy. If there are only two directions
available and energy was traveling in one direction and now it isn't,
it's a no-brainer to realize that it must have changed directions.


Cecil, I think a more convincing argument is that I can take a slotted line
and directly measure a standing wave on it. A wave traveling in one
direction can not do that. Or am I cunfusing things?

Tam/WB2TT


No. That's right. But the point is - how much energy is actually
moving past the probe? Cecil seems to believe that a standing wave is
more than a superposition of voltages. It would be easy to mistake that
as a superposition of energies. But one can only superpose vector
quantities.

73, Jim AC6XG
  #3   Report Post  
Old June 8th 04, 12:32 AM
H. Adam Stevens
 
Posts: n/a
Default

whoa
system is: source - line - load
If there are impedance mismatches, in the steady state (ie 3 microseconds
after key down);
There will be more energy in the transmission line and the source than there
would be if all the impedances were matched.
This is necessary to satisfy the boundary conditions imposed on Maxwell's
Equations at each end of the transmission line.

The losses are the rent you pay for storing the energy; See bazookas for a
good example.

To the radiated energy moving past the probe one must add the losses.

That's why I prefer antennas with no reflections.
Reflect on that.

If you really want a book Paul Dirac's "Quantum Mechanics" is sweet.
Or Hawking's "The Large Scale Structure of Space-Time."


My cat, Hiram P Maxim (Max for short, he likes sleeping on the S-Line I've
had since '63), just walked over the keys and approves.

73
H.
NQ5H


"Jim Kelley" wrote in message
...


Tam/WB2TT wrote:

"Cecil Moore" wrote in message
...
The 'why' is conservation of energy. If there are only two directions
available and energy was traveling in one direction and now it isn't,
it's a no-brainer to realize that it must have changed directions.


Cecil, I think a more convincing argument is that I can take a slotted

line
and directly measure a standing wave on it. A wave traveling in one
direction can not do that. Or am I cunfusing things?

Tam/WB2TT


No. That's right. But the point is - how much energy is actually
moving past the probe? Cecil seems to believe that a standing wave is
more than a superposition of voltages. It would be easy to mistake that
as a superposition of energies. But one can only superpose vector
quantities.

73, Jim AC6XG



  #4   Report Post  
Old June 8th 04, 01:04 AM
Cecil Moore
 
Posts: n/a
Default

H. Adam Stevens wrote:
That's why I prefer antennas with no reflections.


Dipoles are reflected-wave antennas. You don't like them?
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
  #5   Report Post  
Old June 8th 04, 12:46 AM
Cecil Moore
 
Posts: n/a
Default

Jim Kelley wrote:
Cecil seems to believe that a standing wave is
more than a superposition of voltages.


Exactly, it is also a superposition of currents in phase with
the voltages. V*I*cos(0)=power

Everyone, including you, gets into trouble by completely ignoring
the superposition of currents. When are you (and your boss) going
to stop violating the laws of physics?
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----


  #6   Report Post  
Old June 8th 04, 01:18 AM
Cecil Moore
 
Posts: n/a
Default

Tam/WB2TT wrote:

"Cecil Moore" wrote:
The 'why' is conservation of energy. If there are only two directions
available and energy was traveling in one direction and now it isn't,
it's a no-brainer to realize that it must have changed directions.


Cecil, I think a more convincing argument is that I can take a slotted line
and directly measure a standing wave on it. A wave traveling in one
direction can not do that.


Yes, that is the basis of my earlier challenge. Nobody has been able to
provide a standing wave not composed of a forward-traveling wave superposed
with a rearward-traveling wave. I have offered anyone and everyone $100 who
can accomplish that in a single-source/single transmission line/single-load
system. So far, no takers. One wonders why, considering all the gurus on
this newsgroup. What I get instead are obfuscations of how waves can exist
without energy.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
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
Rho = (Zload-Zo*)/(Zload+Zo), for complex Zo Dr. Slick Antenna 198 September 24th 03 06:19 PM
Derivation of the Reflection Coefficient? Dr. Slick Antenna 104 September 6th 03 02:27 AM
Length of Coax Affecting Incident Power to Meter? Dr. Slick Antenna 140 August 18th 03 08:17 PM


All times are GMT +1. The time now is 04:51 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