LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #5   Report Post  
Old March 11th 09, 10:43 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Nov 2006
Posts: 85
Default Polarization Loss?

Fun stuff!

I actually found this behaviour in experimentation (or rather I noted
what was already in the theory books). I was looking at mobile FM ops on
70cm and had found that horiz polarization yielded a much lesser
peak/null phase addition problem ("picket fencing") than on vertical
(the antenna aperture being wider in the horiz plane). I went to
circular in an attempt to test if there was a large enough component of
major polarization shift from multpile refectections, and promptly lost
most of the first reflection. On the whole it was about a 3dB loss
(9-12dB having been the horiz vs vert improvement) but that was very
terrain amd obstruction dependent.

It was a pity because the mobile antenna looked real trendy! (A skew
planar loop)

Cheers Bob VK2YQA

Clifford Heath wrote:
Bob Bob wrote:
Be aware that in a reflective/multipath environment you get a
polarization reversal.


Interesting thought. That means that with two antennas,
one clockwise and one ccw, you could adaptively mix the
two signals to cancel the 1st reflections.

Clifford Heath.



 
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
Polarization Questions Robert11 Antenna 18 April 8th 08 03:23 AM
Rotation of the polarization question Jerry Martes Antenna 9 March 30th 07 04:06 PM
ISP WAP Polarization RST Engineering Antenna 3 April 25th 05 03:34 AM
Polarization conversion Reg Edwards Antenna 12 July 1st 04 12:06 AM
45 degree polarization?? Robert Lyons Antenna 27 November 13th 03 03:20 PM


All times are GMT +1. The time now is 01:09 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