Working well but I killed twice the 3 elt 40 m KLM rotator (T2X) with power. Legal US power !
73’ Jean-Paul F6FYA depuis son iPhone > Le 28 juil. 2024 à 06:04, Jim Brown <[email protected]> a écrit : > > On 7/27/2024 6:59 PM, jim.thom [email protected] wrote: >> Quarter wave sloper ? >> Just to be xtal clear, when I said 1/4 wave sloper, > > Yes, and that's been a popular way to do it. I chose another, and described > it. It is, indeed, a quarter wave, and it slopes. > > BTW -- those rods under the tower are an effective earth connection for > lightning. But they are NOT a low-impedance path for RF, simply because the > earth is a big resistor. > > The only function of an earth connection for transmitting antennas is > lightning protection. The earth is a big resistor. The functions of radials > are 1) to SCREEN (shield) the field produced by the antenna from lossy earth; > and 2) to provide a low resistance path for the antenna's return current. A > counterpoise provides only the second function. > > N6LF has been publishing some excellent work on radial systems, describing an > interactive research process wherein he models various conditions, then built > and measured them extensively, revising his model or modeling different > variables, depending what he learned in the measurements, and so on. It is > excellent engineering, and has given me many new understandings/insights of > why radial systems behave the way they do. Many of us consider it the most > important work on LF antennas in fifty years. > > https://www.antennasbyn6lf.com/ > > The 2009 series on ground systems and the 2012 series on elevated radial > systems are the material I find so worthwhile. Grab them and settle in with a > nice Scotch. > > 73, Jim K9YC > > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
