(!) 6189=12AU7A GE NOS 1975 (9.6/10ma) 1-2% section balance
6189W GE JAN NOS 1973 mica flake inside tube (9.0/9.2ma) 1-2% section balance
6189W GE JAN NOS 1981 (8.4/9.0ma)
6189W GE JAN NOS 1985-1986 (9/11.2ma)
JG-6189=12AU7WA GE double mica NOS 1963-1964 (10.2/12ma)
JG-6189=12AU7WA GE NOS 1964 (10.2/11ma)
JG-6189=12AU7WA GE triple mica NOS 1963 (8.6/10.4ma)