"The answer to Pile's problems of directing the guns was the American S.C.R. 584 radar, the one used on the American 90mm anti aircraft gun, which had power elevation and traverse and an automatic fuse setter. The S.C.R. 584 was a gun-laying radar and "the most successful single application of the micro-wave ten-centimeter technique to ground fighting in World War IL It could automatically track an unseen target at night or in cloud or fog, supplying range,
azimuth and elevation data to a gun director." The S.C.R. 684 had a range of 90,000 yards for early warning, and as a target got within 32,000 yards the set acted as a gun layer. It had no blind spots and could detect low-flying targets like the Fi 103. Unlike the British radar sets, it was also immune to Window. However, it was a complex piece of electronic equipment and required a number of scarce materials like tantalum, molybdenum and tungsten, as well as 140 vacuum tubes
which were then in short supply in the United States. The fielded version weighed several tons and cost $100,000."
Impact, pg 174-175
"Aside from the redeployment, one of the reasons for the gunners' success was that new equipment had arrived. Anti-Aircraft Command received 135 of the long-awaited S.C.R. 584 radar sets and Pile was able to "borrow" an additional 165. Adapting these to the static British 3.7-inch gun required 200 modifications to the gun. Along with the radar sets came proximity fuses and 20 American batteries armed with the radar-controlled 90mm gun."
Impact, pg 207
"When controlled by the S.C.R. 584 radar set, the U.S. 90mm Ml Antiaircraft Gun was the finest antiaircraft gun of World War II. During the campaign they were operated 22 hours a day with two hours a day for maintenance."
Near the end of the blitz, the Brits claimed they were getting one kill per 100 rounds fired. That's an insane number, possible only with VT (proximity) fuses and radar directed gunnery.
The numbers from before those two advancements were closer to 100k rounds per kill
I've read opinions that radar was the single most effective innovation in WW2. It essentially doubled the effectiveness of anti-aircraft gunnery.
For example, the Bismarck battleship was loaded up with anti-aircraft guns. But it was unable to stop a handful of slow moving stringbags that attacked it, and one torpedo from one of them crippled the ship, leading to its destruction.
In contrast, radar directed anti-aircraft guns proved extremely effective against Kamikaze attacks.
The proximity fuse also used radar. Me, I would never have developed such a shell because I couldn't believe such a mechanism could survive being fired out of a cannon.
"The answer to Pile's problems of directing the guns was the American S.C.R. 584 radar, the one used on the American 90mm anti aircraft gun, which had power elevation and traverse and an automatic fuse setter. The S.C.R. 584 was a gun-laying radar and "the most successful single application of the micro-wave ten-centimeter technique to ground fighting in World War IL It could automatically track an unseen target at night or in cloud or fog, supplying range, azimuth and elevation data to a gun director." The S.C.R. 684 had a range of 90,000 yards for early warning, and as a target got within 32,000 yards the set acted as a gun layer. It had no blind spots and could detect low-flying targets like the Fi 103. Unlike the British radar sets, it was also immune to Window. However, it was a complex piece of electronic equipment and required a number of scarce materials like tantalum, molybdenum and tungsten, as well as 140 vacuum tubes which were then in short supply in the United States. The fielded version weighed several tons and cost $100,000."
Impact, pg 174-175
"Aside from the redeployment, one of the reasons for the gunners' success was that new equipment had arrived. Anti-Aircraft Command received 135 of the long-awaited S.C.R. 584 radar sets and Pile was able to "borrow" an additional 165. Adapting these to the static British 3.7-inch gun required 200 modifications to the gun. Along with the radar sets came proximity fuses and 20 American batteries armed with the radar-controlled 90mm gun."
Impact, pg 207
"When controlled by the S.C.R. 584 radar set, the U.S. 90mm Ml Antiaircraft Gun was the finest antiaircraft gun of World War II. During the campaign they were operated 22 hours a day with two hours a day for maintenance."
Impact, pg 271