Using a sensor and procedure discussed in my article, I made the following plot comparing the magnetic field strength along a 30m-band half-wave dipole fed at center and one end.
Key points include:
- No feed lines (just a small transmitter WiFi controlled)
- No wires to magnetic sensor (WiFi controlled)
- Center-fed has direct connection while the two end-fed variations have a transformer
- VSWR presented to transmitter is 1.5 or less
- Just a dipole hanging in free space (or as close as I could get for this test)
Have I proven one can feed a dipole from its end without need for something to electrically "push against" such as a strategic counterpoise wire or the usual feedline? Or, as quite a few reviewers suggest, is the capacitive coupling to ground still a large player in making the end-fed case work?
I ask because I plan on repeating the experiment with the antenna much further away from ground to confirm what I think I'm seeing in the data and to ascertain the role of capacitive coupling to ground. Tips for the next test are welcome and appreciated.