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: [email protected] > To: [email protected] > 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 > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
