LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old November 6th 03, 05:16 PM
Richard Harrison
 
Posts: n/a
Default

Cecil, W5DXP wrote:
"My statement was limited entirely to lumped inductors, a purely
imaginary conceptual model."

Sorry I didn`t get the picture. An inductor that provides no phase shift
is similar to a capacitor that holds no charge. Inductors and capacitors
store energies in their magnetic and electric fields. Current lags in
the inductor and leads in the capacitor. Pure reactances have a
90-degree phase shift between applied voltage and resulting current by
definition.

An inductor sans phase shift is salt without savor or sugar without
sweetness.

Lumped inductance means coiled in place of straight wire, to me.
Reference to toroidal coils in this thread implied to me an absence of
external field, for which I chose a shielded coil with a straight-axis
for my example.

I agree with Cecil that a 90-degree antenna which includes only a
45-degree length of wire needs another 45-degree phase-shift in its
length to reach the full 90-degrees.

As the coil is in series with a resistance, and the resistance the coil
experiences depends upon its position between drivepoint
(low-resistance) and far end (high resistance) at the end of the
element, the inductance required to produce the same required phase
shift, varies with its position in the element.

Where the resistance is low, so is the required inductance. Where the
resistance is high, so is the required inductance, and it is all for the
same number of degrees that the antenna is short.

Best regards, Richard Harrison, KB5WZI

 
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 02:03 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