Very low frequency (VLF) enthusiast Joe Craig, VO1NA, reports that Stefan Schaefer, DK7FC, copied his 50-character message transmitted from Newfoundland on 8.271 kHz, with a radiated power of 10 mW.
“This is a new record for amateur transatlantic VLF,” Craig told ARRL. “The mode used was EbNaut by Paul Nicholson. EbNaut is a synchronous coherent BPSK mode for use at VLF and low LF. Craig’s tower supports a VLF RL (rotated L) 10-meter (33 feet) average height and 100 meters (328 feet) long. VLF is the ITU designation for radio spectrum in the range of 3 – 30 kHz, corresponding to wavelengths from 100 to 10 kilometers, respectively.
“Since VLF waves can penetrate at least 40 meters (131 feet) into saltwater, they are used for military communication with submarines,” Craig noted.