(!!!!!) (Best Overall Pair) 6F6G Marconi Spain NOS 1940's (33.2ma and 34.2ma)
(!!!!) (Recommended Pair) 6F6G Marconi Spain NOS 1940's (37.5ma and 39ma)
(!!!) (Best Single) 6F6G Marconi Spain NOS 1940's (35.8ma)
(!!!) (Best Single) 6F6G Marconi Spain NOS 1940's (44ma)
(!!!) (Best Single) 6F6G Tungsol NOS 1950 (37.2ma)
(!!!) (Recommended Pair) 6F6 RCA metal can NOS 1963-1968 (35.6ma and 38.8ma)
(!!!) (Single) 6F6G Marconi Spain NOS 1940's (35.2ma)
(!!) 6F6GT Tungsol NOS 1953 (37.2ma)
(!) (Best Single) 6F6 RCA metal can NOS 1961 (46.5ma)
(!) 6F6G Sylvania Philco NOS 1949 (36.5ma)
(!) 6F6G=VT-66A Sylvania used/tests like new 1940's (45ma)
1613=VT-175=6F6 RCA NOS 1963 (42ma)
1621=6F6 selected for long life RCA NOS
6F6 GE metal can NOS 1952 (38ma)
6F6 Ken Rad metal can NOS 1950 (33ma)
6F6 Ken Rad metal can NOS early 1940's (42ma)
6F6=VT-66 RCA metal can NOS 1940's (40.5ma)
6F6G National Union black plate NOS 1951 (40.5ma)
6F6G National Union used/good mid-1940's (47ma)
6F6G RCA Cunningham used/good 1947 (31ma)
