The RAF had 150 mile radar coverage from the English coast into France.
Their radar did not cover over Britain itself. For that the RAF relied on reports grom ground observers.
Radar was able to be killed in the 1st AH BoB but it wasnt a victory condition (IIRC) and was repaired between frames. I had jabo 110s punch holes in the radar screen to allow room for ju88s to slip in. Base warning range was long so their were only temporary narrow gaps.
Dont get off track, the lw objective in the BoB was to destroy the RAF, not just get bombers to and fro....
Channel shipping attacks, raids on the radar, airfield raids and and the general bombing campaign were all set to draw the RAF up where they could be killed.