[Antennas] Elevated Vertical

Mon Mar 21 21:30:21 EST 2005

Hi Gary:
 The general belief is that as few as two elevated radials can work as well as 50+ ground mounted radials if they are high enough. The band you intend to operate on will have an impact on the overall discussion that follows.
 As you get further away from the ground in wavelengths [based on the band you are operating on], the less important the ground conductivity becomes and the greater efficiency you will acheive with elevated radials. Of course, antennas are effected by the ground as far away as 1/2 wavelength or, in the case of 40 meters, 64 feet. In your case, you are getting pretty close to that magic height for 40 meters, but the ground will still have its effect on 80 meter operation. 
 If you can get the radials high enough, the vertical becomes a ground plane antenna which, in theory, is independent of the ground. One other problem is that on the ground, the length of each radial isn't all that critical as long as you are at least 1/8 a wavelength on the lowest frequency you want to operate on and you have many many radials (50+). Generally, longer and more wire is best. In the air, you will need radials cut to 1/4 wavelength on each band. Just the same, as few as two radials on each band may be a lot better than 50+ on or in the ground if they are high enough.
 My advise would be to try the vertical in the air with two radials on the bands you want to operate. At the height you have indicated, I think you will be pleased with the results.
Ron W7MRR
 --- On Mon 03/21, Gary Smith < wa1tjb at yahoo.com > wrote:
From: Gary Smith [mailto: wa1tjb at yahoo.com]
To: antennas at mailman.qth.net
Date: 2005年3月21日 18:09:08 -0800 (PST)
Subject: [Antennas] Elevated Vertical
I am considering putting up a Butternut HB9 vertical. <br>I am thinking about mounting it atop a 40 or 50 foot<br>mast with the radials fanned out around it. Is there<br>any advantage to getting this kind of height or am I<br>better off to mount it closer to the ground?<br><br>73 de Gary<br>WA1TJB<br><br><br>		<br>__________________________________ <br>Do you Yahoo!? <br>Yahoo! Small Business - Try our new resources site!<br>http://smallbusiness.yahoo.com/resources/ <br>______________________________________________________________<br>Antennas mailing list<br>Home: http://mailman.qth.net/mailman/listinfo/antennas<br>Help: http://mailman.qth.net/mmfaq.html<br>Post: mailto:Antennas at mailman.qth.net<br>
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