stg44 wrote:Air war:
If German night fighters had received the FuG 240 radar sets from March 1943 (OTL: March 1945), then Windows could not have blinded German defenses as it did in OTL from July 1943, and losses of Lancasters and Halifaxes from mid-1943 onwards could well have been so high that some targets deep inside Germany would have escaped destruction - at least at night.
The Mosquito could still have operated with relative impunity.
The USAAF could still have attacked during that day as it did in OTL.
Flak directed by 9cm devices like FuMG Egerland would have been more effective both day and night, but I am doubtful if this would have been enough to be a game changer against high flying Mosquitoes or B-17s.
Germany still gets smashed from the air, but with less urban destruction.
IMO it's really important to quantify the likely effect on shoot-downs/shell to judge outcomes. As you say upthread, German Flak efficiency varied by a factor up to 8 during different periods of the war. If the Flak is suddenly 4-8x more effective that's a potential game-changer. Westermann's Flak
notes that a late-war radar set decreased shells/kill to 300 IIRC. That system included a more advanced gun-laying computer but if the Germans have better radar resolution on aerial targets perhaps they develop better gun-laying directors earlier and build more of them.
We also have to consider adaptation in response to more-effective Flak. In economic speak, when an input (Flak) becomes more efficient at creating output (downed bombers), the rational response is to invest more in it. Radically more effective Flak would have drawn more investment (steel allocations at the expense of, say, concrete bunkers for factories) and therefore would have meant greater quantity of Flak barrels in addition to greater effective quality. At a certain point, the LW/Speer could make strategic decisions to make certain targets effective "dead zones" for bomber streams - points over which 20% losses would be expected. Production could then be concentrated under those Flak umbrellas rather than dispersed with attendant efficiency cost. If Germany "dead zoned" the Ruhr and Hamburg, for instance, that would have big knock-on effects in terms of transport capacity saved, damage avoided, agglomeration economies, etc.
Even if it doesn't stop the CBO, it would reduce the amount of bombs dropped - and therefore damage - massively: a plane that has been destroyed in March obviously can't bomb in April.
I agree there's no way this wins the war for Germany, but something like, say, a 30% increase in German output in 1943 due to less bomb damage could impact the course of the war.