VHFcontesting
[Top] [All Lists]

Re: [VHFcontesting] [VHF] Rovers-Halo's Vs. Loops

To: "Les Rayburn" <les@highnoonfilm.com>
Subject: Re: [VHFcontesting] [VHF] Rovers-Halo's Vs. Loops
From: James Duffey <jamesduffey@comcast.net>
Date: Fri, 3 Jul 2009 09:41:21 -0600
List-post: <vhfcontesting@contesting.com">mailto:vhfcontesting@contesting.com>
There have been several good points made here. I run horizontal  
polarization in the rover, including a horizontal loop while roving.  
Here are some observations I have.

With my horizontally polarized antennas, I typically work guys with  
verticals OK out to 40 or 50 miles. At this distance the guys with  
simple loops are louder than the verticals, but both are blown away by  
guys with even simple Yagis. At 75 to 100 miles most of the guys with  
omnidirectional antennas are not heard.

Around here, polarization is probably not too well preserved as there  
are mountains and valleys for the signals to reflect from, and I with  
each reflection can come some change in polarization.

Also, as someone pointed out there can be some horizontal radiation  
from vertical antennas, particularly in motion, and there can be some  
vertical radiation from horizontal antennas. One thing that  
contributes to this mixed polarization is feedline radiation and I  
suspect that with rigorous attention to decoupling the outside of the  
feedline from the antenna, the difference in polarization will become  
more evident.

Lastly, the human ear/brain and modern AGC really do make the  
differences in modest signals hard to tell without some sort of  
reproducible measurements being done. If you have access to a 6M  
beacon, try doing the vertical/horizontal loop comparison again. -  
Duffey
--
KK6MC
James Duffey
Cedar Crest NM





_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting

<Prev in Thread] Current Thread [Next in Thread>