2N2587 semiconductor manufactured by Sylvania, listed as 2N2587 (circa 1979).

2N2586 semiconductor manufactured by Sylvania, listed as 2N2586 (circa 1979).

2N2572 semiconductor manufactured by Sylvania, listed as 2N2572 (circa 1979).

2N2571 semiconductor manufactured by Sylvania, listed as 2N2571 (circa 1979).

2N2570 semiconductor manufactured by Sylvania, listed as 2N2570 (circa 1979).

2N2569 semiconductor manufactured by Sylvania, listed as 2N2569 (circa 1979).

2N2565 semiconductor manufactured by Sylvania, listed as 2N2565 (circa 1979).

2N2564 semiconductor manufactured by Sylvania, listed as 2N2564 (circa 1979).

2N2541 semiconductor manufactured by Sylvania, listed as 2N2541 (circa 1979).

2N2540A semiconductor manufactured by Sylvania, listed as 2N2540A (circa 1979).

2N2540 semiconductor manufactured by Sylvania, listed as 2N2540 (circa 1979).

2N2539 semiconductor manufactured by Sylvania, listed as 2N2539 (circa 1979).

2N2534 semiconductor manufactured by Sylvania, listed as 2N2534 (circa 1979).

2N2533 semiconductor manufactured by Sylvania, listed as 2N2533 (circa 1979).

2N2532 semiconductor manufactured by Sylvania, listed as 2N2532 (circa 1979).

2N4231 semiconductor manufactured by Sylvania, listed as 2N4231 (circa 1979).

2N2531 semiconductor manufactured by Sylvania, listed as 2N2531 (circa 1979).

2N2529 semiconductor manufactured by Sylvania, listed as 2N2529 (circa 1979).

2N2528 semiconductor manufactured by Sylvania, listed as 2N2528 (circa 1979).

2N2527 semiconductor manufactured by Sylvania, listed as 2N2527 (circa 1979).