(Best Single #1) 6F5 GE Amperex metal can NOS (1.6ma Gm=1800)

6F5 GE Amperex metal can NOS 1970 era (1.6ma Gm=1800)

(strong single)

(6F5 octal base is similar spec-wise to 7B4 loktal, Mu=100)

Zenith 10S669 radio 1941
Zenith 9S369 radio