I remember watching a UK television series episode or a film about a group of people wandering around (Britain). The group seem to suffer collectively from a technology phobia, for example they reacted badly to electicity cables and pylons and sought to avoid them. Also when entering a barn full of farm machinery they were shocked and closed the door. I believe it may have been a children's film or series as I was a child at the time of watching it in the mid to late 1970s. I know it is not a lot to go on, but the imagery was so powerful that it stayed in my memory all this time and I would love to exhume the rest of the story.
It sounds like 1975 series, The Changes. Britain goes back to the stone age as all technology is abandoned. It was a children's sci-fi series on BBC. Full details on Wikipedia.
The Changes posits a Britain where a sudden enveloping noise emanating from all machinery and technology causes the population to destroy them. The resulting upheaval displaces many people and reverts society to a pre-industrial age where there is a deep suspicion of anyone who may be harbouring machinery. Even the words for technology are taboo. The remnants of modern technology that escape destruction (such as electricity pylons) produce a physical and sometimes violent repulsion among those left in Britain.
As I said in the comment, it's The Tripods, though that was '80s rather than '70s.