The roundies were long gone by the 70's at CBS NY.At that time they were
using Conrac RHA series transistor color monitors.These monitors had a
separate HV power supply and two flybacks,one for horiz. sweep and the
other for HV.If the horiz. or vert. sweep failed the HV supply would
shut down to prevent the crt from being burned.CBS NY still had quite a few
of the Conrac CYA (hybrid) rectangular color monitors still in use up untill
the early 80's.
Regards,
Swanson