I posted this about 2 years ago in the general history thread. I was a bit puzzled about this, but I think I’ve found what this “CTV-1” channel is.
Apparently it consisted of a VCR and an RF modulator + a BBC Micro computer (to generate Teletext in vision) which was hooked up to the community TV antenna on the roof of public housing units in Waterloo and Redfern. 2000 people would have been able to view it. See this vid below: