RationalKeith wrote:Interesting practice of different radio "stations" on the same frequency in early days of radio in Vancouver BC.
They really were different stations in those days, in every way you would define a station.
I was just writing a short piece on CKUA. And realized that I had never thought about it before. But each station sharing 580 KHz in Edmonton had its own studios AND transmitter. I believe there were 4 stations sharing the frequency at one point. There is a fairly famous story from the late 1920s of a play-by-play going long on one Edmonton station, with everyone on the edge of their radio "seat", to see how it would end. And they ended up being very frustrated as another station signed on at its assigned time, creating a huge mess.
There were a few cases of frequency sharing still in existence in the 1960s. KTW and KWSC (later KWSU) shared 1250 KHz after dark, but both were on during the day. Seattle and Pullman, Washington, respectively.
WBAP and WFAA shared two frequencies in Fort Worth and Dallas, Texas. And it was a really odd arrangement that varied by day of the week. And even saw the network affiliation stay with the frequency, not the station. They might have shared the same pair of transmitters. 570 and 820 KHz.
The weirdest was KGBS Los Angeles and KDKA Pittsburgh. Both on 1020 KHz with 50,000 watts. KGBS was licensed daytime only, with one exception. Midnight to 5 a.m. Eastern time on Monday mornings, when KDKA was off the air for transmitter maintenance and KGBS was on the air in its place. KGBS also had a simulcast full-time FM which only helped things a bit, as there weren't a lot of FM receivers in the 1960s.
Back to the early 1930s. There was another kind of frequency sharing. With phantom stations. The CNR (railway) bought large blocks of radio time on stations across Canada, and aired their own programming under their legally-assigned call letters. The CPR did, too, at one point. And I believe that the predecessor of the CBC (the CRBC, which Allan McFee would often ID the CBC as) did for a time, too, until they got their own dedicated radio stations.