2N439 semiconductor manufactured by Sylvania, listed as 2N439 (circa 1979).

2N350A semiconductor manufactured by Sylvania, listed as 2N350A (circa 1979).

2N255 semiconductor manufactured by Sylvania, listed as 2N255 (circa 1979).

2N521A semiconductor manufactured by Sylvania, listed as 2N521A (circa 1979).

2N438A semiconductor manufactured by Sylvania, listed as 2N438A (circa 1979).

2N350 semiconductor manufactured by Sylvania, listed as 2N350 (circa 1979).

2N254 semiconductor manufactured by Sylvania, listed as 2N254 (circa 1979).

2N521 semiconductor manufactured by Sylvania, listed as 2N521 (circa 1979).

2N438 semiconductor manufactured by Sylvania, listed as 2N438 (circa 1979).

2N346 semiconductor manufactured by Sylvania, listed as 2N346 (circa 1979).

2N253 semiconductor manufactured by Sylvania, listed as 2N253 (circa 1979).

2N520A semiconductor manufactured by Sylvania, listed as 2N520A (circa 1979).

2N433 semiconductor manufactured by Sylvania, listed as 2N433 (circa 1979).

2N345 semiconductor manufactured by Sylvania, listed as 2N345 (circa 1979).

2N252 semiconductor manufactured by Sylvania, listed as 2N252 (circa 1979).

2N520 semiconductor manufactured by Sylvania, listed as 2N520 (circa 1979).

2N432 semiconductor manufactured by Sylvania, listed as 2N432 (circa 1979).

2N344 semiconductor manufactured by Sylvania, listed as 2N344 (circa 1979).

2N251A semiconductor manufactured by Sylvania, listed as 2N251A (circa 1979).

2N519A semiconductor manufactured by Sylvania, listed as 2N519A (circa 1979).