LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old April 24th 09, 12:44 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 274
Default Loading coils: was Dish reflector

Roy Lewallen wrote:
Tom Donaly wrote:

There aren't many people who would support a lumped-element analysis on
this newsgroup. Most people know the limitations of using network theory
in these circumstances. The technical arguments against Cecil's approach
were offered a long time ago. This latest is just a flareup that will
soon die down. You shouldn't be confused. The transmission line model of
antennas is well accepted and hoary with age, particularly for
bi-conical antennas (see Schelkunoff). There are a couple of other
types of models with equal validity. If you really want to know the
physical
score, though, you have to get an electromagnetics text that discusses
the integral equations that govern antenna behavior. Pay particular
attention to the parts that explain why numerical methods like EZNEC
have to be used for solutions rather than the symbolic math most
people would expect and want.

73,
Tom Donaly, KA6RUH


I did and do support lumped element analysis for a very small toroidal
loading inductor, and extensively posted the reasons why in this
newsgroup about six years ago ("Current in antenna coils controversy",
2003). Cecil and Yuri were arguing that the coil would replace some
number of "degrees of antenna" and its current therefore would have a
substantial phase difference between input and output ends. I made and
posted careful measurements to support my statement, after which Cecil
invented his "standing wave current" and went off in various directions.

Roy Lewallen, W7EL


I should have specified a large, solenoidal loading coil such as Cecil
is so fond of using. Cecil has since eschewed his "degrees of antenna"
position, but, for some reason, he keeps claiming your tests on the
small solenoid were wrong.
73,
Tom Donaly, KA6RUH
 
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
Dish Network "500" dish with two LNBs Mike Andrews Homebrew 4 February 23rd 07 08:54 PM
Kenwood reflector Kirk Mohror General 0 August 31st 04 01:01 AM
Vet. with a reflector Drbob92031 Antenna 0 November 18th 03 01:42 AM
Reflector for Hammarlund AA5JJ Boatanchors 0 October 22nd 03 04:38 AM
Reflector for Hammarlund AA5JJ Boatanchors 0 October 22nd 03 04:38 AM


All times are GMT +1. The time now is 04:58 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