Aerth Group Mission

The Aerth Group exists to study and to improve the old system of 'Earth Current Telegraphy'. This system was utilised in the last century to communicate without wires, before the invention of radio. In essence it is the sending of alternating currents into the ground via two widely spaced electrodes and the detection of that current at a distance by a similar pair of electrodes. It saw service in the First World War but was superseded by radio. Modern methods incorporate the use of digital modes such as PSK31 and very slow CW (using QRS software invented by Rik ON7YD), high powered amplifiers, VLF receivers. DSP techniques and specialist software such as Spectrogram that analyses the audio spectrum. Frequencies used vary from baseband (audio) to the 73 and 136 kHz amateur bands.

Booklet on earth current systems (Adobe Acrobat 471k) The ground as antenna at 73 and 136kHz - possible explanation Report on summer 1998 ground tests - 73kHz and 136kHz Report on winter 1998 ground tests - 73kHz and 136kHz Report on summer 1999 ground tests - 73kHz, 136kHz and 1kHz G0AKN's present earth current system PSK31 WAV files Latest test results on 1kHz and 6kHz distance record Download Aerth Group membership certificate Mail G0AKN to add your name to membership list Useful links