In article , Frank Johnson wrote:
For all the national services, the programme chain at the transmitter
site is:
Energis fibre or Microwave link feed, 8.448Mb/sec
Demultiplers down to 4x 2048 kbit/sec
"RE" electronics NICAM decoder, each national service has a bitrate of
676Kbit/sec for the stereo pair.

I presume that's 640 kbit/s for two channels of 10 bit samples at 32
ksample/s plus some overhead. (IIRC, NICAM encodes the original 14 bit
samples at 32 kbit/s down to 10 bits.)

If so, as has been pointed out, it's interesting to note just how good
FM stereo broadcasts of live events can sound.

The overall coding seems different from the 728 kbit/s stream that I
think is used for the rather versatile TV NICAM streams (according to
EN 300 163). I guess it's different to get three stereo channels into
2048 kbit/s.

Nicam decoders provide L+R analogue output.
Several metres of balanced lines from the NICAM bay to the "Transmitter
Input Equipment bay"
SBS Electronics "MPX5" stereo coder. RDS data is added at this point.
TM4 series RF drive where the Frequency Modulation is applied.
High power amplifier.

--
John Phillips