This was the first ITV series I ever saw and I had to go round to a friend's house in Broomfield Road to watch it as the early TV we had could only receive BBC programmes! They had a 'remote control' unit on their's which consisted of a rotary switch in a huge metal box connected by a 21-core cable which was only a few feet long in any case. They never used it as it was just as easy to change channels (all two of them) manually.