2N4208 semiconductor manufactured by Sylvania, listed as 2N4208 (circa 1979).

2N4207 semiconductor manufactured by Sylvania, listed as 2N4207 (circa 1979).

2N4182 semiconductor manufactured by Sylvania, listed as 2N4182 (circa 1979).

2N4181 semiconductor manufactured by Sylvania, listed as 2N4181 (circa 1979).

2N4180 semiconductor manufactured by Sylvania, listed as 2N4180 (circa 1979).

2N4179 semiconductor manufactured by Sylvania, listed as 2N4179 (circa 1979).

2N4178 semiconductor manufactured by Sylvania, listed as 2N4178 (circa 1979).

2N4177 semiconductor manufactured by Sylvania, listed as 2N4177 (circa 1979).

2N4176 semiconductor manufactured by Sylvania, listed as 2N4176 (circa 1979).

2N4175 semiconductor manufactured by Sylvania, listed as 2N4175 (circa 1979).

2N4174 semiconductor manufactured by Sylvania, listed as 2N4174 (circa 1979).

2N4173 semiconductor manufactured by Sylvania, listed as 2N4173 (circa 1979).

2N4172 semiconductor manufactured by Sylvania, listed as 2N4172 (circa 1979).

2N4171 semiconductor manufactured by Sylvania, listed as 2N4171 (circa 1979).

2N4170 semiconductor manufactured by Sylvania, listed as 2N4170 (circa 1979).

2N4169 semiconductor manufactured by Sylvania, listed as 2N4169 (circa 1979).

2N4168 semiconductor manufactured by Sylvania, listed as 2N4168 (circa 1979).

2N4167 semiconductor manufactured by Sylvania, listed as 2N4167 (circa 1979).

2N4149 semiconductor manufactured by Sylvania, listed as 2N4149 (circa 1979).

2N4148 semiconductor manufactured by Sylvania, listed as 2N4148 (circa 1979).