In the spring of 1940, CBS staff engineer Peter Goldmark devised a system for color television that CBS management hoped would leapfrog the network over NBC and its existing black-and-white RCA system.[85][86] The CBS system "gave brilliant and stable colors", while NBC's was "crude and unstable but 'compatible'".[87] Ultimately, the FCC rejected the CBS system because it was incompatible with RCA's, along with the fact that CBS had moved to secure many ultra high frequency (UHF), not very high frequency (VHF), television licenses, leaving them flatfooted in the early television age.[88] In 1946, only 6,000 television sets were in operation, most in greater New York City where there were already three stations; by 1949, the number had increased to 3 million sets, and by 1951, had risen to 12 million.[89] There were 64 American cities with television stations, though most of them only had one.[90]