LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old April 12th 06, 11:05 PM posted to rec.radio.amateur.antenna
John Popelish
 
Posts: n/a
Default Current across the antenna loading coil - from scratch

Cecil Moore wrote:
John Popelish wrote:

Cecil Moore wrote:

What does it mean to the E-fields and H-fields to say
the voltage is leading the current?



It means that the current at both ends of the coil was delayed
(relative to its phase if the coil had not been there). It means that
there was a voltage difference across the ends of the coil that drove
that current through the coil.



In order to avoid any delay through the coil, you propose a delay
in the one inch of wire at the bottom of the coil? Does that really
make sense to you? How is this magic delay accomplished?


Exactly the way it is accomplished if you apply AC to an LC "L" low
pass filter that droves a resistor load. The short antenna acts as
the capacitor (in parallel with losses and radiation) in the circuit.
It is resonated with the series inductor so both the inductance and
capacitance cancel, so the source drives only the losses and
radiation. Power factor corrected.

If you don't believe me, simulate it with EZNEC. Connect a source to
a parallel combination of C and R. Record the phase of the current
with respect to the voltage (the current will lead). Then add a
series inductance that cancels the capacitance, and the current will
be delayed till it matches the phase of the applied voltage. Power
factor corrected.
 
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
Imax ground plane question Vinnie S. CB 151 April 15th 05 05:21 AM
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna RHF Shortwave 1 January 24th 05 09:37 PM
FS: sma-to-bnc custom fit rubber covered antenna adapter Stephen G. Gulyas Scanner 17 December 7th 04 06:42 PM
FS: sma-to-bnc custom fit rubber covered antenna adapter Stephen G. Gulyas Swap 17 December 7th 04 06:42 PM
Current in loading coil, EZNEC - helix Yuri Blanarovich Antenna 334 November 9th 04 05:45 PM


All times are GMT +1. The time now is 05:39 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