No Nazi radar
The Nazi didn’t have radar, at least until later in the war, maybe.
When they went in to take the radar tube from the base of the radar tower, it couldn't be there yet.
The first practical radar system was produced in 1935 by the British physicist Sir Robert Watson-Watt, and by 1939 England had established a chain of radar stations along its south and east coasts to detect aggressors in the air or on the sea.
The UK was at war with Germany, I doubt they'd give them plans to build one.