Ummm, more misinformation from you. The only miniatures to get a VT designation were a couple of battery tubes and the 9000 series. Geez, you really dont know your subjects but post anyway. You still are sadly mistaken. See Post 111 and 115 The 6AG7 was developed in early 1939 as a video amp tube for USN use in 1939 as the US was ramping up to eventually enter the looming war in Europe. and received the VT 247 designation. The USN already had some radars in 1938 and they needed a better video tube. It also saw limited use in the commercial TV experiments but volume was low until after the war. I never made a claim WHEN the 6AG7Y was released BUT it was after the RMA VT designations were replaced by the JAN system in 1942. If it had been earlier it would have received a VT-247A designation. Try to stop making up things as you go along with your versions of history just to save face. I might even tell you why the J-310 was a poor choice if you behave.