Rayer began his science writing after suffering a heart attack at a young age.
When Michael Moorcock became editor of New Worlds Rayer largely switched to non-fiction writing.
Rayer also wrote for county magazines and daily newspapers in Worcestershire, and Reader's Digest.
In the 1950s Rayer was able to buy a cottage with the proceeds from his writing, known as The Reddings, at Longdon Heath, Worcestershire which he renovated.
In the 1960s he became interested in DX work and gathered a large collection of amateur QSL cards.
Rayer wrote more than thirty technical books, covering the topics of electronics, computing and radio.
Rayer wrote many short stories for SF magazines such as New Worlds, Fantastic Adventures and Nebula.