[TowerTalk] elevated verticals....radial config.

[Gedas]

Very interesting discussion. Over the years I have had a R7 and R8 at various heights from 10' to 90'.  With them above 40' I always had them DC grounded to the mast which was grounded to the tower which was grounded to earth at the base.  These antennas are different than a 1/4 wave vertical with drooping radials which I think is what the original question was about.  Assuming one is talking about the 1/4 wave antenna what was the consensus about grounding the radials to the top of the tower?  I must have missed it somewhere, sri.

Gedas, W8BYA

e-mail  w8bya at mchsi.com
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----- Original Message ----- 
From: Rod Elliott 
To: towertalk at contesting.com 
Sent: Monday, June 13, 2005 2:46 PM
Subject: Re: [TowerTalk] elevated verticals....radial config.


<This is a slightly revised version of a response I sent to Tom W8JI rather 
than the list, in error>  :)

In support of current baluns on the feedline....

I've had success with a Butternut HF6V vertical mounted on top of a 25-foot 
tall wooden pole. There were a total of twelve resonant wire radials, 2 for 
10m, 2 for 20m, 2 for 30m and 2 for 40m. The wires in each band-pair were 
mounted 180 degrees apart. The twelve radials were fanned out symmetrically 
around the base, with the wires sloping downward at about 20 degrees. The 
40m radials provided a useable match on 15m.

The coax feedline ran straight down the pole, then ran underground about 60 
feet to the shack. Nicely symmetrical with respect to the radials (at least 
above the ground)

After running SWR curves for each band, I installed a current balun 
(several dozen ferrite beads) at the midpoint of the vertical section of 
the feedline. I then re-ran the SWRs and saw that the minimum SWR 
frequencies had changed a bit on several bands. I concluded that, despite 
lots of radials and good symmetry, line currents were indeed flowing 
initially, so I left the beads on.

This contraption worked quite well, giving me over 300 DXCC entities 
barefoot over an 8-year time span.

73
Rod Elliott VE3UW



At 18:26 06/13/05, you wrote:
>You also have to watch the feedline and mounting very
>carefully. When you use less than 10 radials feedline
>currents start to be an issue. When you use two radials it
>is a big problem.
>73, Tom W8JI
>
>----- Original Message -----
>From: "Terry Conboy" <n6ry at arrl.net>
>To: <jimjarvis at ieee.org>; <towertalk at contesting.com>
>
> > According to modeling in EZNEC, as long as the two radials
>are symmetrical
> > (180 degrees apart, same slope), the azimuth and elevation
>patterns are
> > very uniform, and the horizontal radiation cancels quite
>well in the far field.
>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>
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_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

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