I found this on G3YYD's QRZ.com profile, interesting...(was looking him up regarding WSPR activity)
"During the late 70s worked with G3PLX in developing various error correcting communication systems, which culminated in the first use of AMTOR in September 1979 on 2m between myself based at that time in Watford, England and Peter G3PLX based in Chandlers Ford. Little did we realise at the time it was going to have such a large impact. It was known at the time that the AMTOR code was not ideal but as it was so close to CCIR (now ITU-R) 476 recommendation, it was thought that the UK authorities at least would OK it's use. In the UK at that time the license allowed the use of 'data' on the 2M band without having a definition of what 'data' meant. So for our purposes we defined data as AMTOR and the various other ARQ and FEC systems we tried out. " -- Andy K3UK
