26-05-2016, 08:42 PM
(This post was last modified: 26-05-2016, 08:44 PM by Geordie McBoyne.)
The Rediffusion cable 405 line TV system differed in many respects from the British Relay CATV system. In the two channel Rediffusion TDUK2 system the vision carriers were distributed in the tete-beche method.
One channel had a vision carrier frequency of 4.95Mhz operating on the upper sideband.
The other channel had a carrier frequency of 8.45Mhz operating on the lower sideband.
Sound was sent at loudspeaker level.
I believe in the British Relay system one the vision carriers was as low as 3.5Mhz.
Because of the very low carrier frequencies full wave vision demodulators were employed. Channel section on British Relay TV sets was accomplished by a control on the TV receiver just like an aerial set. With Rediffusion wired TV channel selection was by means of a wall mounted switch unit.
Were similar cable TV systems operated by other firms?
Geordie McBoyne.
One channel had a vision carrier frequency of 4.95Mhz operating on the upper sideband.
The other channel had a carrier frequency of 8.45Mhz operating on the lower sideband.
Sound was sent at loudspeaker level.
I believe in the British Relay system one the vision carriers was as low as 3.5Mhz.
Because of the very low carrier frequencies full wave vision demodulators were employed. Channel section on British Relay TV sets was accomplished by a control on the TV receiver just like an aerial set. With Rediffusion wired TV channel selection was by means of a wall mounted switch unit.
Were similar cable TV systems operated by other firms?
Geordie McBoyne.
