Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old September 3rd 03, 01:08 PM
Ian White, G3SEK
 
Posts: n/a
Default

Reg Edwards wrote:

Now it's up to other people to judge the technical

truth of the matter.

=================================

Justice from 'peers' on THIS newsgroup ??????


I wasn't feeling in need of justice - it's more about encouraging people
to think for themselves.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
  #2   Report Post  
Old September 3rd 03, 04:33 PM
Richard Harrison
 
Posts: n/a
Default

Ian, G3SEK wrote:
"..It`s more about encouraging people to think for themselves."

Why shoulld people worry with reflection coefficients or SWR?

Terman says:
SWR is important because it is easily measured, and SWR directly
indicates reflection in a system.

Reflection coefficient is defined in my dictionary as:
The vector ratio between the electric fields associated with the
reflected and incident waves, at the junction of a uniform transmission
line and a mismatched terminating impedancee.

Other planes and junctions producing an impedance discontinuity are also
cited as producing a reflection and thus a reflection coeficient.

The dictionary quantifies the reflection coefficient as:
(Z2 - Z1) / (Z2 + Z1)
where Z1 = source Z
and Z2 = load Z.

Absolute values are used above for the reflection coefficient when
relating it to SWR.
This is the voltage divider fraction.

Terman says on page 97 of his 1955 opus:
"Reflection coefficient (rho) = (VSWR-1) / (VSWR + 1).
"S" ---sometimes called (VSWR) to distinguish it from the standing-wave
ratio expressed as a power ratio, which is (Emax / Emin) squared.

best regards, Richard Harrison, KB5WZI

  #3   Report Post  
Old September 3rd 03, 05:24 PM
Cecil Moore
 
Posts: n/a
Default

Richard Harrison wrote:
The dictionary quantifies the reflection coefficient as:
(Z2 - Z1) / (Z2 + Z1)


Terman says on page 97 of his 1955 opus:
"Reflection coefficient (rho) = (VSWR-1) / (VSWR + 1).


Please note that if Z1 and Z2 are characteristic impedances of
transmission lines at an impedance discontinuity point, these
two equations yield different results.
--
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
A Subtle Detail of Reflection Coefficients (but important to know) Dr. Slick Antenna 199 September 12th 03 10:06 PM
Re-Normalizing the Smith Chart (Changing the SWR into the same load) Dr. Slick Antenna 98 August 30th 03 03:09 AM
Mother Nature's reflection coefficient... Peter O. Brackett Antenna 8 August 28th 03 06:17 AM


All times are GMT +1. The time now is 05:01 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