LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old December 4th 03, 06:04 PM
Jim Kelley
 
Posts: n/a
Default



Richard Harrison wrote:

Roy, W7EL wrote:
"So tell you what. If you`ll pull out your equations and calculate the
expected current difference, I`ll replace the coil with one of 100 ohms
reactance and remeasure."

The challenge was directed to Cecil, but anyone can respond. The current
is a function of position along the antenna. Distribution is
cosinusoidal as Yuri said.


That's right. The distribution is the result of the superposition of
the forward and reflected currents. It's basically just one quarter of
a cycle of the standing wave pattern. When the electrical length of a
loading coil represents any significant fraction of the length of the
antenna, the superposition of forward and reverse currents at each end
of the inductor will result in different values. The difference is due
to the phase delay through the loading coil, as Cecil has explained.
Delay is an unavoidable artifact of propagation through wire - whether
it happens to be wrapped into a coil, or not.

73, Jim AC6XG
 
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
Inverted ground plane antenna: compared with normal GP and low dipole. Serge Stroobandt, ON4BAA Antenna 8 February 24th 11 10:22 PM
Smith Chart Quiz Radio913 Antenna 315 October 21st 03 05:31 AM
QST Article: An Easy to Build, Dual-Band Collinear Antenna Serge Stroobandt, ON4BAA Antenna 12 October 16th 03 07:44 PM
Eznec modeling loading coils? Roy Lewallen Antenna 11 August 18th 03 02:40 AM


All times are GMT +1. The time now is 12:31 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017