LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old December 27th 07, 07:51 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Dec 2007
Posts: 72
Default Standing-Wave Current vs Traveling-Wave Current

Cecil Moore wrote:
Roger wrote:
Cecil Moore wrote:
Assume a constant power source and you will get the results
that Roy is talking about.


No, because you would find two waves of equal voltage and current
traveling in opposite directions, always arriving at exactly out of
phase, at the source.


No, because a *constant power source* is pumping joules/second
into the system no matter what voltage or current it requires
to move those joules/second into the system. It's like the
power source in "Forbidden Planet".

Now the question here is "Do the waves bounce off one another?"


Waves do NOT "bounce" off one another. At a physical
impedance discontinuity, the component waves can
superpose in such a way as to redistribute their energy
contents in a different direction. (Redistribution of energy
in a different direction in a transmission line implies
reflections.) In the absence of a physical impedance
discontinuity, waves just pass through each other.

www.mellesgriot.com/products/optics/oc_2_1.htm

micro.magnet.fsu.edu/primer/java/scienceopticsu/interference/waveinteractions/index.html

There is a third possibility. The interaction of the two waves can
establish a very high resistance, so high that no current flows-zero.

Does this place us at a logical impasse, with current reversing and
voltage doubling at in one argument (at the open end), but not doubling
at the source end? No, the voltage will double at the source end when
stability is reached after one full cycle (in the 1/2 wave example).

Logically then, we must recognize that our source voltage WILL NOT
remain constant following the arrival of the reflected wave. Certainly
this is what we find when we retune our transmitters after changing
frequency.

What would be the logic of insisting that the input voltage be held
constant to the 1/2 wave example after it is shown that the reflected
wave must interact with the incoming wave give a very high impedance at
the source?

73, Roger, W7WKB

 
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
Standing Wave Phase Tom Donaly Antenna 135 December 15th 07 04:06 PM
Standing wave on feeders David Antenna 12 May 21st 07 05:22 AM
Dipole with standing wave - what happens to reflected wave? David Antenna 25 September 6th 06 01:39 PM
Newbie ?: I've Built A Simple 1/4 Wave Dipole for 2 Mtrs. Could IMake a1/2 Wave? WolfMan Homebrew 4 September 29th 04 02:40 PM
What is a traveling-wave antenna? jopl Antenna 7 April 16th 04 10:56 PM


All times are GMT +1. The time now is 04:12 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