>From your description and your measured data, Larry, I don't see how you could improve the antenna noticeably! Why do you feel a need to improve it? I appears to be resonant, well-matched and it appears to have an excellent ground image system! I think you might be kidding yourself if you change anything! As the old adage says n "If it ain't broke -don't fix it"!
73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry K4AB Sent: Wednesday, December 10, 2014 2:41 PM To: topband@contesting.com Subject: Topband: 160 Shunt-Fed Tower Readings The antenna is a 94' Rohn 25, with a Force 12 24'boom Delta 6BA on top. Note that the elements are insulated from the boom. The base of the tower is grounded. 73 radials are attached to the base ranging in length from 130'-250'. 15,000 feet of radials, average length of ~200'. It is fed through a series 1000pF 10KV Jennings vacuum variable. The shunt is a 4 wire cage about 3" in diameter and attached at ~45' level. It is spaced about 3' from the tower. Here are the readings I get from a RigExpert AA-30 at the feedpoint: 1.830 kHz Series model: lZI: 59.7 Ohms R:59.5 Ohms SWR: 1.23 X:5.6 Ohms C: 15893 pF What are these reading telling me,and how can I improve the antenna? Thanks, in advance! 73, Larry K4AB _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband