(!!!!!) (Best Value Single) 5U4G RCA Emerson like new 1953 (57/40 and 56/40)
(!!!!!) (Best Value) 5U4G RCA used/good "D" getter 1951 (48/40 and 52/40)
(!!!!!) (Best Value) 5U4G Zenith by Tungsol low hours/tests like new "D" getter 1950 (53/40 and 57/40)
(!!!!) (Best Value Single) 5U4G CBS used/tests like new "D" getter 1950 era (55/40 and 60/40)
(!!!!) (Best Value Single) 5U4GB RCA Super Airline NOS 1960 era (58/40 and 60/40)
5U4G Crosley Sylvania used/good 1950 (55/40 and 56/40) stains at top from usage
5U4G RCA used/good 1953 a few oxide flakes inside tube (50/40 and 52/40)
5Z3P Chinese (substitute is 5U4G or 5U4GB)