LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #5   Report Post  
Old April 5th 07, 09:56 AM posted to sci.electronics.design,sci.electronics.basics,rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jan 2007
Posts: 8
Default VSWR doesn't matter? But how about "mismatch loss"?

Cecil Moore wrote:

billcalley wrote:
Now my head *really* hurts! This is a VERY confusing subject, to
say the least. (And I also thought antenna tuners actually had a
*loss* due to their limited Q...I think I'm going to change careers
now and just become a pet groomer; or perhaps simply give up
completely and work at Radio Shack).


Real-world antenna tuners do have a loss but we previously
specified a lossless system. Of course, real world tuners
and transmission lines suffer losses but we all just live
with those losses while striving to minimize them. The point
is that an antenna tuner reflects most of the reflected
energy back toward the load thus accomplishing a mismatch
gain that offsets some, if not most, of the mismatch loss.
High SWR transmission lines are indeed lossier than flat
matched transmission lines of the same material.
--
73, Cecil, w5dxp.com

Close but no cigar. The (now often automatic) antenna tuner is used to
transform the native impedance to the transmitter to match the conjugate
transformed impedance of the antenna at the transmitter end of the
transmission line. The effective result is that the incident energy
arriving at the antenna "sees" a matched load and goes out to free space
instead of bouncing off the transmission line to antenna interface.
This is also why better antennas have reasonable (not far off matching
impedance) characteristic impedances; they do not require matching networks
physically placed at the antenna itself.
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller


 
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
SolderSmoke #43: LP Filters, Titan, Feedback amps, Return Loss Bridges, "Gonzo Gizmos" [email protected] Boatanchors 2 December 13th 06 06:42 PM
SolderSmoke #43: LP Filters, Titan, Feedback amps, Return Loss Bridges, "Gonzo Gizmos" [email protected] Equipment 2 December 13th 06 06:42 PM
SolderSmoke #43: LP Filters, Titan, Feedback amps, Return Loss Bridges, "Gonzo Gizmos" [email protected] Homebrew 3 December 13th 06 06:42 PM
"meltdown in progress"..."is amy fireproof"...The Actions Of A "Man" With Three College Degrees? K4YZ Policy 6 August 28th 06 11:11 PM


All times are GMT +1. The time now is 11:50 PM.

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