(!!!!) (Best Pair) 5R4GB GE black base NOS 1981 (50-52/40 and 50-53/40 x 2 tubes)
(!!!!) (Best Pair) 5R4GB GE black base NOS 1981 (51-53/40 and 51-54/40 x 2 tubes)
(!!!!) (Best Pair) 5R4GB GE black base NOS 1981 (51-54/40 and 52-55/40 x 2 tubes)
(!!!!) (Pair) 0D3 Hytron NOS and like new 1948 (argon)
(!!!) (Best Pair) 0C3 Hytron NOS 1954 (argon)
(!!) (BEST PAIR 1950's) 0C3 CBS NOS 1955 (argon)
(!!) 0C3 Sylvania branded GE NOS 1972-1976 (1 Pair)
(!!) 5R4GYB RCA branded Westinghouse NOS 1970 large getter (50/40 and 52/40)
(!!) 5R4GYB RCA like new 1963 a few oxide filament flakes inside tube slightly tilted glass (50/40 and 52/40)
(!!) 5R4GYB RCA NOS 1962 large getter (54/40 and 50/40)
(!!) 5R4GYB RCA rebranded Raytheon NOS 1960's (50/40 and 53/40)
(!) (1 PAIR) 0C3 GE branded 0C3A NOS 1976 (argon)
(!) (1 PAIR) 0D3 Tungsol used/test like new 1950's (argon)
(!) (BEST PAIR) 0C3 RCA NOS - 1 tube branded GE 1959 and 1962 (1 pair) (argon)
(!) (Recommended Pair) 0D3 RCA NOS 1963-1966
(!) 0C3 RCA like new 1952 reboxed (argon)
(!) 0C3 RCA used/test like new 1951 (1 pair)
(!) 0D3 Hytron NOS 1951 (argon)
0A3 RCA branded Marshall Electronics used/good 1950's (neon)
0A3 US Brands used/good (4 in stock)