LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #8   Report Post  
Old April 1st 14, 07:52 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default Radials

Channel Jumper wrote:

Radials on a elevated antenna only works if the radials are placed at or
near the bottom of the antenna and are arranged at a 45* angle.

Any other angle and you might as well not have any radials at all!


Utter nonsense.

The radials do have to be at or near the bottom but the angle of the radials
mostly determines the antenna impedance.

With the radials at 90 degrees the impedance will be around 40 Ohms and
at 45 degees very close to 50 Ohms.

One can download the demo version of EZNEC and observe the effect of
radial angle for themselves.

On a 10 -12 meter antenna, these radials would need to be at least 1/4
of a wavelength long - 9 feet and preferably 18 feet long to do any
good!


The ideal radial length for ANY ground plane antenna is slightly longer
than 1/4 wavelength, no matter for what frequencey.

If you coil them up they do not work as intended, but they might help a
little.


If you coil them up, you are inductively loading them, shortening the
physical length just like a loaded vertical.

If you make them electrically around 1/4 wavelength, loaded radials will work
just fine.

Ground plane antennas have been made with 4 hamsticks; 1 for the vertical
element and 3 for the radials and they work.

They major drawback to such is the limited bandwidth of loaded antennas.


snip remaining babbling nonsense



--
Jim Pennino
 
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
radials for Cushcraft AV5 Daniel Ferrato - IK2SGL Antenna 3 August 23rd 19 01:33 AM
radials Jeff Arrowsmith Antenna 9 April 16th 13 11:20 AM
Radials Rick Antenna 5 February 28th 07 06:13 AM
Radials hasan schiers Antenna 0 March 22nd 06 10:42 PM
Radials for 6-BTV rhymer Antenna 5 May 31st 04 01:55 AM


All times are GMT +1. The time now is 05:43 AM.

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