LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #22   Report Post  
Old October 12th 14, 09:07 PM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default OK, let's discuss dipoles vs length

Ian Jackson wrote:
In message ,
writes
Ralph Mowery wrote:

wrote in message
...
I've done a lot of modeling with V's and inverted V's. Except for a slight
diffenence due to ground effects at low heights, there is no difference
between them.

As the angle goes from 180 degrees, i.e. a dipole, the impedance goes
down and and the pattern spreads out.


I have not played with the programs , but often wondered what the effect is
on antennas that are suported on the ends and the middle is dropped in a U
or V shape and not the inverted V shape. Many antenna books and articals
seem to show the flat top and inverted V paterns, but I have not seen any
with the actual V type.


Like I said, there is no difference in free space between a V and an
inverted V.

There are slight differences when close to ground.

Assuming it's a halfwave dipole, I would have thought it was better to
concentrate on getting the centre (where the current is) as high as
possible, rather than the ends. [Obviously this depends on whether you
have a suitable sky-hook available for and at the centre.] However, I
believe that there is at least one commercial loaded dipole (essentially
for portable use, I think) that has a short mast, and the ends of the V
are up in the air.


Model it let me know what you find.

Also, regarding the radiation pattern, as the ends are dropped, doesn't
the signal that starts coming off the ends have an increasingly
vertically-polarised component?


As I recall, yes, the vertical component increases with decreasing angle.


--
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
Real Oil Drillers Discuss MC 252 dave Shortwave 2 May 15th 10 10:24 PM
Discuss about books chandru Shortwave 0 July 12th 08 11:34 AM
OT , You may need to discuss this . [email protected] CB 2 November 30th 07 12:51 AM
Anyone care to discuss... Professor CB 11 April 23rd 05 07:35 PM
Art Bell to discuss BPL on C-to-C AM TONIGHT (??) 3/20/04 Jim Hampton Policy 0 March 20th 04 10:59 PM


All times are GMT +1. The time now is 10:20 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