I have been making a few types of J-Pole half wave verticals, mostly from twin lead and 450 ohm open wire which seemed to work the best for me and was easier to work with due to the wide spacing.
Has anyone ever actually compared the standard J-Pole design to the Slim Jim version of the J? I know that theoretically some (e.g., W4RNL), have suggested that the Slim Jim might actually have slightly lower gain based upon modeling.
Considering that it is usually more work to build and tune a Slim Jim is there anyone who has found a true benefit?
Also, N0IMW's Arrow Antenna Company has a J design which appears exceptionally well made and avoids the issue of finding the 50 ohm point on the matching section. He uses both matching rods for both 2 meters and 440.
Has anyone physically compared this design to a conventional J and found any difference?
Has anyone ever physically compared the 5/4 wave J that was designed to directly connect to coax? This antenna is likely to have high angle radiation. http://www.rason.org/Projects/ant54/ant54.htm