This Report describes a series of experiments carried out during March 1979 in which 60 Mbit/s digital television signals were transmitted via the OTS from Goonhilly Downs Satellite Earth Station. In these experiments, the error rate in the digital television signal was measured over a range of system operating conditions which include simulations of co-channel and adjacent-channel interference from other satellite channels. Particular reference is made to those operating conditions which are specified for large earth stations in the future European Communications Satellite (ECS) system.