daphne du maurier

The main character is in the military, I think, and is asked by his CO to transfer to a project on the Suffolk (UK) coast run by the CO's friend, after someone else dropped out (went mad?). It turns out the project, which only has a few people, has developed a machine that can do something...

I read the first book somewhere between 1983-1986. The only part of the book that I remember clearly is the main character was taught Aikido. It seems it was possibly set in a future dystopian society. Not much to go on, but maybe someone knows. The second book was read probably in the late...