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

Cormac Gebruers ei4hq.mail at gmail.com
Mon May 16 10:20:14 PDT 2011


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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