06.18.2010 04:48 PM
Originally featured on BroadcastEngineering.com
Rohde & Schwarz introduces two new VHF transmitters
Rohde & Schwarz is extending its R&S SCx8000 family of transmitters with two models for the VHF band, the R&S SCA8000 and the R&S SCW8000. This family now includes models in the 200W to 600W power range for DTV and DAB and in the 350W to 1100W power range for analog TV. The R&S SCW8000 supports both analog and DTV standards such as ATSC Mobile DTV, DVB-T, DVB-H and MediaFLO, and is DVB-T2-ready. The R&S SCA8000 supports the DAB, DAB+ and T-DMB audio broadcasting standards.
The R&S SCx8000 broadcasts DTV and DAB with an output power of up to 600W and is only 4RU high. Its compact size is due in large part to its LSI design and innovative exciter and amplifier redundancy concept. Up to six 600W transmitters can be installed in a single rack, enabling network operators to significantly lower their infrastructure, site lease and installation costs. With its high efficiency of up to 24 percent in the VHF band, the R&S SCx8000 also reduces power consumption and electricity costs.
The transmitter's power output stages have a set-and-go feature that provides broadband precorrection for each digital standard. This eliminates the need for manual, on-site precorrection and enables the transmitter to be deployed quickly. In addition, the transmitter can be switched from analog to DTV with the push of a button and without the need for hardware changes.
The amplifiers, with an output power of up to 400W for DTV and DAB and 700W for analog, come with two power supplies as standard. Optionally, a third power supply can be added to provide 2+1 redundancy. In the event that one of the two power supplies fails, transmission continues uninterrupted. Using only two exciters, the space-saving exciter redundancy concept guards against broadcast outages, and a CCU is not required. The control exciter acts as the transmitter control unit, and the program exciter acts as the RF source. If the program exciter fails, the control exciter takes over RF signal generation. If the control exciter fails, the program exciter continues transmitting using the known parameters.