(!!!!) (Recommended Single) Z729=EF86 GEC UK mesh-plate NOS "D" getter halo 1950's (3.1ma)
(!!!!) (Recommended Single) Z729=EF86 GEC UK NOS "D" getter halo 1950's (2.9ma Gm=2000)
(!!!) (Best Single) KT88 Genalex England NOS 1967 rebranded SC1000 Stromberg-Carlson (147ma)
(!!!) (Single) KT66 Osram UK black base used 1950's (57ma) (Gm=60%)
(!!!) (Single) KT66 Osram UK brown base used 1950's (62ma) (Gm=65%)
KT66 GEC UK brown base used/70% 1966 (64ma)
