Just finished reading this 1959 vintage book about the events of June-December1940 and the threat to the UK of invasion by Hitler's forces.
It provides a thoughtful (and thought-provoking) assessment of the German threat and British response. I found it to be pretty well balanced, the author pointing out obvious logical/capability flaws on BOTH sides, often with humour thrown in. My only gripe is his final "what if" analysis which is rather binary and would benefit from a "third way" scenario of the Luftwaffe maintaining focus on radar stations and sector airfields, and the potential of toppling the Churchill government if that persistence paid off. I think this book best captures the rapidly evolving situation in Britain during the crucial months from the Fall of France to the winter of 1940. Definitely one to add to your collection if you're interested in this period.
Out of interest, the author is the brother of Ian, of James Bond fame.
Capt Vick turned me onto the signal books IIRC, I have found I much prefer the Walk Around series as opposed to the In Action series, at least as a source of good reference photos.