Nautel said FM station KDKB in Phoenix is one of the first to implement the company’s HD PowerBoost system.
The technology is intended to increase digital power output while increasing efficiency, and is aimed at stations that want to run HD Radio at injection levels greater than 20 dB below carrier. Nautel says it uses an intelligent peak to average power ratio (PAPR) technique to squeeze more hybrid power from a transmitter and increase hybrid-mode efficiency.
Nautel released a summary of the KDKB project, which involved a new transmitter site on Phoenix’s South Mountain, in a city park. The job included a new Nautel NV40 transmitter, with a Nautel NV7.5 as backup. The station is feeding 25.5 kW analog output power into the antenna system; HD operation is adjusted for –10 dBc, or 2.55 kilowatts.
Nautel said the station received a replacement exciter with PowerBoost firmware. After installing the exciter and verifying proper operation, a preset was created for the NV40 that would incorporate PowerBoost. The transmitter was tested into a dummy load before placing it back in service.
Jim Stanley of Stanley Broadcast Engineering was on site for the facility construction and handled FCC licensing for Sandusky. “To optimize PowerBoost, adjustments were made to the PA voltage while carefully monitoring PA dissipation and PA efficiency,” Stanley said in the Nautel summary. “The optimum PA voltage setting was determined by spectral compliance with the iBiquity emission mask and minimum spectral regrowth outside the emission mask. Once operating on the antenna system, spectral compliance was again verified.”
Clayton Creekmore is chief engineer of the Sandusky station, which airs at 93.3 MHz. The GM is Chuck Artigue. The dealer was Broadcast Connection, which helped with the pattern analysis, structural studies and system design as well as providing equipment.