2N6509 semiconductor manufactured by Sylvania, listed as 2N6509 (circa 1979).

2N6508 semiconductor manufactured by Sylvania, listed as 2N6508 (circa 1979).

2N6507 semiconductor manufactured by Sylvania, listed as 2N6507 (circa 1979).

2N6506 semiconductor manufactured by Sylvania, listed as 2N6506 (circa 1979).

2N6505 semiconductor manufactured by Sylvania, listed as 2N6505 (circa 1979).

2N6504 semiconductor manufactured by Sylvania, listed as 2N6504 (circa 1979).

2N6500 semiconductor manufactured by Sylvania, listed as 2N6500 (circa 1979).

2N6499 semiconductor manufactured by Sylvania, listed as 2N6499 (circa 1979).

2N6498 semiconductor manufactured by Sylvania, listed as 2N6498 (circa 1979).

2N6497 semiconductor manufactured by Sylvania, listed as 2N6497 (circa 1979).

2N6496 semiconductor manufactured by Sylvania, listed as 2N6496 (circa 1979).

2N6494 semiconductor manufactured by Sylvania, listed as 2N6494 (circa 1979).

2N6493 semiconductor manufactured by Sylvania, listed as 2N6493 (circa 1979).

2N6492 semiconductor manufactured by Sylvania, listed as 2N6492 (circa 1979).

2N6478 semiconductor manufactured by Sylvania, listed as 2N6478 (circa 1979).

2N6477 semiconductor manufactured by Sylvania, listed as 2N6477 (circa 1979).

2N6476 semiconductor manufactured by Sylvania, listed as 2N6476 (circa 1979).

2N6475 semiconductor manufactured by Sylvania, listed as 2N6475 (circa 1979).

2N6474 semiconductor manufactured by Sylvania, listed as 2N6474 (circa 1979).

2N6473 semiconductor manufactured by Sylvania, listed as 2N6473 (circa 1979).