[NowhereMan 1966]

I know back in 1948/49, WDTV of the Dumont TV network went on the air on channel 3. They were later shunted down to channel 2 in the early 1950's because Cleveland, OH had WEWS in channel 3 and there was concern that in the middle of the two cities, you would have co-channel interference. Later on, WDTV became KDKA-TV when Dumont went under and Westinghouse bought the station. There was a channel 6 in Beckley, WV that ran at halff maximum power because there was WJAC in Johnstown, PA on channel 6 also. Maybe not exactly co-channel interference, but when WTAE-TV, channel 4 in Pittsburgh signed off at night, there were times WRC-TV from Washington DC came in.