Rohde&Schwarz has been selected to provide a pair of 78 kW solid state UHF transmitters for NBCUniversal-owned NBC 5 / KXAS and Telemundo 39 / KXTX in Dallas-Fort Worth, TX as part of their plan to prepare for the repack and ATSC 3.0. The company's task was to supply twice the output power of the old IOT transmitters in order to support the variable polarization technology the customer chose for the stations’ new antenna. But the greatest advantage of the R&S THU9 is that it continues to deliver 100 percent output power when switching to the ATSC 3.0 TV standard.
When the Dallas-Fort Worth broadcaster decided to switch to an antenna featuring Variable Polarization Technology (VPT), the required transmitter power doubled to feed adequate power in both planes. Needing power in the range of 75kW per station, NBC 5 and Telemundo 39 Vice President of Technology Matt Varney opted for liquid-cooled solid state from Rohde & Schwarz instead of IOT technology. “With our new design, we expect the efficiency of the entire transmitter plant to be greater than that of our current IOT plant. The liquid-cooled solid state design requires a fraction of the air conditioning required for IOT operation due to its extremely low heat dissipation in the building. This is a big factor for us in Texas during the summer months.” The R&S THU9-72 was also supplied with liquid-cooled test loads and combiner reject loads to keep heat dissipation down and AC requirements to a minimum.
Installing a new transmitter before the repack and the introduction of ATSC 3.0 means the transmitter must be frequency agile and easy to convert to the new broadcast standard. The R&S THU9 can be rechanneled with no need to replace amplifier components or go off air to make the change. With the tunable RFS mask filter, the system is ready for the repack. The R&S THU9 will be capable of running the new ATSC 3.0 standard once the final standard is approved, plus the transmitter is capable of making the same power in ATSC 3.0 as it does in ATSC 1.0, so the station will suffer no reduction in power upon converting.
Rohde&Schwarz has already installed more than 2000 R&S THU9 transmitters worldwide.
