i saw a transistor history page on the web, and the story is that Raytheon was making transistors for the military, and if it fell outside the military specs, but still worked, they marked it as a CK722 and sold it on the hobby markets... they also marketed some commercial versions with better defined specs than the hobby devices. this allowed them to recover some of the cost of making transistors that were originally classified as rejects. when i was a kid i had a bunch of CK722 devices but they were really leaky... i'll have to look for that history page again... i think i have it bookmarked on my pc at home.