Star-Ko was also a brand name for tubes but Tyne did not mention this brand in his "Saga of the Vacuum Tube". He only mentioned "Star" with the note: "Made by Star Radio Laboratories, New York". It could well be that later this company changed at least the brand name.

In any case: Star-Ko made adds for tubes like Y-224 "AC Screen Grid Amplifier" (for $ 1.39) and X-245 "Power Amplifier" (for $ 1.69) and claimed: "They are produced in tremendous quantities and sold on a quantity basis which accounts for their low price." This indicates clearly that Star-Ko did not produce themselves. But one can consider Star-Ko as a tube brand and a brand for power supply models for home use.