Captain Zee wroteColonAnd what's the story with radar in this game? I've heard the actors in the PC version yelling about "enemies sighted on radar, captain!" Wasn't radar not invented until the middle of WWII?
The RAF had an operational radar early warning system in place by the start of the Battle of Britain, but the technology was being experimented with in the 1930s.
I think it is conceivable that some of the developed nations might have functioning prototypes in the alternate '37, but the thing to consider is that early radar was used to spot incoming squadrons of aircraft, in an otherwise clear sky. In the CS universe you'd have a lot more air traffic, so while you could see incoming air craft you'd have no way of identifying them (beyond size) without visual confirmation.
The other thing to remember is that originally you didn't have the circular screen with the line sweeping around and dots for each aircraft.