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Re: Topband: Newbie Antenna Question (long)

To: topband@contesting.com
Subject: Re: Topband: Newbie Antenna Question (long)
From: Rik van Riel <riel@surriel.com>
Date: Tue, 06 Sep 2011 12:06:27 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>
On 09/05/2011 11:03 PM, Jim Bennett wrote:
> I accept the fact that a vertical antenna is the best bet (for transmitting, 
> anyway) 160 meters, AND that the Inverted L is basically a vertical antenna. 
> If that is the case, does this mean that it radiates just like any other 
> vertical, primarily omnidirectional? If it is omnidirectional, does it matter 
> in which direction the horizontal portion of an Inverted L is aimed? I can 
> run mine in either of two different directions; one higher, but not too 
> stealthy, the other direction a tad lower, but more hidden from the HOA Nazis.
>
> Oh, and yes, I am planning on installing several looooong radials. It would 
> be great if I could plop down 50-100 of 'em, but that isn't realistic, 
> either! I've already got two strung out along the fence perimeter, and I 
> might be able to get one or two more put down, providing the XYL doesn't go 
> ballistic with all the wire strung out around the house. At least she's also 
> a ham, so she "might" cut me some slack on that part of the project!

The double L antenna could be a stealthy alternative too, which does
not require radials.  It outperforms an inverted L with a smaller
number of radials and comes pretty close to the performance of an
inverted L with a reasonable number of radials.

Depending on how much copper you want to sink into the ground (60+
radials could be a lot of work and I don't know how much time/energy
you have), it could go either way.

Here is some info on the double L antenna:

http://www.yccc.org/Articles/double_l.htm

http://surriel.com/radio/160-meter-double-l-antenna

As you can see from the photos, it's barely visible.  The
performance is 6dB (1 S point) below a vertical over perfect
ground.  That corresponds to maybe 2-3dB below that of an
inverted L with 30-70 1/4 wave radials over poor ground.

Given that I do not have the space for that many 1/4 wave
radials on 160m, I'll take the low effort antenna any day
over 2dB more performance for 10x as much work :)

You can add radials over time to get some more performance,
but the double L does not require them to get started...

-- 
All rights reversed.
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UR RST IS ... ... ..9 QSB QSB - hw? BK

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