2N2526 semiconductor manufactured by Sylvania, listed as 2N2526 (circa 1979).

2N2524 semiconductor manufactured by Sylvania, listed as 2N2524 (circa 1979).

2N2523 semiconductor manufactured by Sylvania, listed as 2N2523 (circa 1979).

2N2522 semiconductor manufactured by Sylvania, listed as 2N2522 (circa 1979).

2N2521 semiconductor manufactured by Sylvania, listed as 2N2521 (circa 1979).

2N2520 semiconductor manufactured by Sylvania, listed as 2N2520 (circa 1979).

2N2512 semiconductor manufactured by Sylvania, listed as 2N2512 (circa 1979).

2N2511 semiconductor manufactured by Sylvania, listed as 2N2511 (circa 1979).

2N2510 semiconductor manufactured by Sylvania, listed as 2N2510 (circa 1979).

2N2509 semiconductor manufactured by Sylvania, listed as 2N2509 (circa 1979).

2N2501 semiconductor manufactured by Sylvania, listed as 2N2501 (circa 1979).

2N2498 semiconductor manufactured by Sylvania, listed as 2N2498 (circa 1979).

2N2496 semiconductor manufactured by Sylvania, listed as 2N2496 (circa 1979).

2N2495 semiconductor manufactured by Sylvania, listed as 2N2495 (circa 1979).

2N2494 semiconductor manufactured by Sylvania, listed as 2N2494 (circa 1979).

2N2493 semiconductor manufactured by Sylvania, listed as 2N2493 (circa 1979).

2N2492 semiconductor manufactured by Sylvania, listed as 2N2492 (circa 1979).

2N2491 semiconductor manufactured by Sylvania, listed as 2N2491 (circa 1979).

2N2490 semiconductor manufactured by Sylvania, listed as 2N2490 (circa 1979).

2N2489 semiconductor manufactured by Sylvania, listed as 2N2489 (circa 1979).