I'll just leave this here. It's a schiz for a "VT" fuze, named variable timing because the fact that it was actually a proximity fuze was super secret.
As far as I can tell, it was in use for quite awhile before being acknowledged at all, even by the deliberate misnaming. But for example,
Drachinifel mentions in his latest about how the anti-air fire "suddenly become a lot more effective" but then quotes an officer saying it's going to get better once some new shells arrive. Pretty much all other sources say...no one was told of these until they arrived and put in use. such is the nature of secrets and national security limitations. If you did something "cool" in that context, it's even more of a secret. Bragging about it generates a lot of motivation for countermeasures - better to let "them" think there's not a problem, then when they make a noise, misrepresent what it actually was in some relatively believeable way. War's a dirty game.
Here's one historian's take, but the schiz came from one I can't find again just now - which was a LOT More detailed and informative about the thing, as well as the dates involved.

- Looks more like a thermin than a radar to me...or just something that notices the bounceback interfering with the goes-outa.
You can type in that URL if you want. Good luck with that. Kinda hard to cut-paste from a picture.
Or maybe it just went out of oscillation when it go close to something?
At any rate, historians not in the secrecy/tradecraft game loop argue about this stuff....endlessly. And governments (remember history is written by the winners) brag about their successes, but omit things like the fact that "the desert fox" was in part foxy because unlike the Brits claiming total intelligence superiority,
the code named "black" was broken and info was being fed to him in the desert, helping him make those lucky guesses....you can read a heck of a lot about Rommel without ever hearing about that one, because, well, it was kind of embarrassing to the governments who control what we know when they can.
There's quite a lot of that.
All those guy who died on long rang bombing in WWII because the US bomber mafia was
more than a little disingenuous about the existence and availability of drop tanks for P47s...because they didn't want any resources diverted to other than their bombers until it was undeniable and there were P51's whether they liked it or not. Like I said, war is dirty...
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.