2N2931 semiconductor manufactured by Sylvania, listed as 2N2931 (circa 1979).

2N2930 semiconductor manufactured by Sylvania, listed as 2N2930 (circa 1979).

2N2929 semiconductor manufactured by Sylvania, listed as 2N2929 (circa 1979).

2N2928 semiconductor manufactured by Sylvania, listed as 2N2928 (circa 1979).

2N2927 semiconductor manufactured by Sylvania, listed as 2N2927 (circa 1979).

2N2926G semiconductor manufactured by Sylvania, listed as 2N2926G (circa 1979).

2N2926 semiconductor manufactured by Sylvania, listed as 2N2926 (circa 1979).

2N2925 semiconductor manufactured by Sylvania, listed as 2N2925 (circa 1979).

2N2924 semiconductor manufactured by Sylvania, listed as 2N2924 (circa 1979).

2N2923 semiconductor manufactured by Sylvania, listed as 2N2923 (circa 1979).

2N2921 semiconductor manufactured by Sylvania, listed as 2N2921 (circa 1979).

2N2907A semiconductor manufactured by Sylvania, listed as 2N2907A (circa 1979).

2N2907 semiconductor manufactured by Sylvania, listed as 2N2907 (circa 1979).

2N2906A semiconductor manufactured by Sylvania, listed as 2N2906A (circa 1979).

2N2906 semiconductor manufactured by Sylvania, listed as 2N2906 (circa 1979).

2N2905A semiconductor manufactured by Sylvania, listed as 2N2905A (circa 1979).

2N2905 semiconductor manufactured by Sylvania, listed as 2N2905 (circa 1979).

2N2904A semiconductor manufactured by Sylvania, listed as 2N2904A (circa 1979).

2N2904 semiconductor manufactured by Sylvania, listed as 2N2904 (circa 1979).

2N2897 semiconductor manufactured by Sylvania, listed as 2N2897 (circa 1979).