Think of a dipole close to the ground, it will not be efficient with all that coupling to earth and resulting losses.
73 Peter -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of David Cutter Sent: Mittwoch, 9. November 2016 17:37 To: Mike Waters; Rob Atkinson; topband Subject: Re: Topband: 160 m inverted L I recall reading from Ralph Holland that 0.015 wavelength was a good height. David G3UNA ----- Original Message ----- From: "Mike Waters" <[email protected]> To: "Rob Atkinson" <[email protected]>; "topband" <[email protected]> Sent: Wednesday, November 09, 2016 4:11 PM Subject: Re: Topband: 160 m inverted L > Fifty feet?! That means the feedpoint --the bottom of the antenna-- would > be 50 feet up! Do you know how high the top would have to be? I don't > agree > with that at all. And I've never heard of anyone who ever did that. > > The four elevated radials in these tests were just 16 feet high! And what > is more, the frequencies were 1490, 1450, 1240, and (maybe) 625 KHz. > Almost > as effective as 120 buried radials. > lists.contesting.com/_topband/2007-11/msg00248.html > > I forget the radial height in Rudy Severns' (N6LF) tests, but IIRC they > weren't anywhere near 50' high. > > My two elevated radials were 10' high. I know that a little higher (and a > few more of them) would have been better, but I can tell you that that > 160m > inverted-L WORKED! And I'm by no means the only one. :-) > > 73, Mike > www.w0btu.com > > On Wed, Nov 9, 2016 at 6:10 AM, Rob Atkinson <[email protected]> > wrote: > >> The rule of thumb for effective elevated radial height is 1/10 >> wavelength, >> so on 160, around 50 feet up. >> >> 73 >> >> Rob >> K5UJ >> > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
