Topband: Newbie Antenna Question (long)

[Rik van Riel]

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...

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