All of the "no radial verticals" that I've seen are electrically 1/2 wavelength long and so behave as an end-fed dipole. Since the feed point impedance is very high, there is very little current flowing and so a ground connection has relatively little impact on the efficiency.
Another great reference for vertical antennas is "Vertical Antenna Classics" published by the ARRL (ARRL Order No. 5218, ISBN 0-87259-521-8) 73, Ron AC7AC -----Original Message----- ...If elevated radials are not tuned and not quarter wave, the efficiency may be even higher than with quarter wave radials but the feed point is likely to be at a very high voltage. This requires either very high impedance chokes or transformers. No radial verticals are case in point. There is a 160m vertical with innovative elevated radial (http://www.w0uce.net/K2AVantennas.html). It is equivalent to two elevated radials and coil. There is an anecdotal information that this vertical works much better than a vertical with many short ground radials. Ignacy, NO9E -- View this message in context: http://elecraft.365791.n2.nabble.com/OT-Radials-for-Vertical-Antenna-tp75760 89p7576111.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
