Ultimate 160m NVIS sensitivity using Circular Polarization

Triple End Fed Three Phase Circularly Polarized Antenna for 160m. Installation in a clay valley, No other local QRM other than three or four electric fences on nearby farms. This is easily dealt with by the FT-101Z Noise Blanker. AGC disabled to ensure linear receiver behavior and polarization flipped between RHCP and LHCP, starting at 25s. You can clearly hear the difference in noise level. This experiment was made with a strong E layer at an estimated altitude of 117km (vertical ionosonde measurement at 55° latitude). It remains to be seen whether this is some kind of atmospheric/íonospheric noise (ITU-R P.372-14 measurements were made mostly with omnidirectional antennas) or omnipresent man-made noise refracted from the zenithal ionosphere. Receive sensitivity is however rather ultimate with this installation.