Topband: Asymmetric radials for GP antennas; Just in case others seek what I've just found...

[Charles Moizeau]

A careful reading of Rudy's piece does show that in a situation where you are, and must remain,  totally compromised throughout a 180-degree sector, i.e., with zero radials, you can at least pick up from the deficient direction 0.52 dB (-1.39 dB vs. -1.91 dB, in his cases C7 vs. C3) just by intensifying the radial density--increasing the number of radials in the favored 180-degree sector.

Admittedly, the improvement is "small beer", but at least a psychological recompense.

73,

Charles, W2SH

> Date: Mon, 16 May 2011 18:20:14 +0100
> From: ei4hq.mail at gmail.com
> To: topband at contesting.com
> Subject: Topband: Asymmetric radials for GP antennas; Just in case others seek what I've just found...
> 
> All,
> 
> I've been searching for clarity and hard data on the effects of asymmetric
> radials on radiation patterns and efficiency of a vertical as I'm installing
> a 21m vertical for 80/160 and will have to live with a radial system that is
> significantly compromised over a 180 degree sector.
> 
> I was a bit surprised to "not find" this subject dealt with in any clear
> decisive way in e.g. the ARRL Antenna Book or ON4UN's otherwise excellent
> Low Band DXing book (Did I miss it in either publication? If so, just send
> me a "your an idiot" email and I'll crawl back under my cabbage leaf
> suitably chastened).
> 
> I was surprised as I had always assumed it is something many hams have to
> deal with unless they are prepared to go on "stealth missions" in the dead
> of night to lay radials on or under neighbours property (I don't recommend
> this course of action by the way; I attempted just such a thing once and got
> caught. As a mental exercise to occupy you during those quite times when
> calling CQ on a dead 160m, try explaining your way out of that one).
> 
> On the basis that there might be one/some/many out there, who, like myself,
> are installing verticals with radial systems that are compromised
> directionally as well as "length-ways", I just thought I'd share what I
> found; N6LF's excellent (if not exactly encouraging) summary of the
> consequences of asymmetrical radials at
> http://rudys.typepad.com/files/qex-ground-systems-part-7.pdf . It's well
> worth the read.
> 
> I hope to hear you all on the far side of the Summer...
> 
> -- 
> Regards
> Cormac (EI4HQ)
> [Cork/UTC+1] NNNN++++
> http://86.43.106.118/ei4hq/
> http://www.corkharbourweather.ie
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