06.18.2009 01:43 PM
Originally featured on BroadcastEngineering.com
WLNY puts 1Mw CP signal on air in New York
WLNY TV-10/55, serving the boroughs of New York City, most of Long Island and southern Connecticut, has gone on the air with what is being described as one of the world’s most powerful digital television signals.
WLNY TV-10/55 is now transmitting a circular polarized signal at power levels of 1MW in both the vertical and horizontal planes from its antenna located in Riverhead, NY.
Achieving the maximum effective radiated power level allowed by the FCC, the circular polarized signal is intended to provide saturated coverage for both fixed and mobile receivers to an area that includes more than 4.5 million viewers.
The WLNY TV-10/55 transmitter is a QDC2 Quantum system, manufactured and installed by (Ai) Acrodyne Industries in Oaks, PA. It uses a pair of e2v ESCIOT depressed collector IOT tubes to achieve the required transmitted power level in an efficient manner. The transmitter includes the SX800 exciter from Rohde & Schwarz of Columbia, MD, upgraded to provide a signal compliant with the ATSC Mobile DTV proposed A/153 standard. Rohde & Schwarz also provided its AVE264 encoder and AEM100 ATSC Mobile DTV emission multiplexer, to create and add the mobile signal to the existing DTV signal, integrated into a version of Ai’s Mobile360 system. The system gives the station flexibility to transmit multiple channels of programming to mobile and handheld receivers as well as to meet its obligation to provide DTV to fixed home receivers.
The new WLNY TV-10/55 RF system was specifically designed to enhance the station’s ability to reach fixed and mobile audiences, said Richard Mulliner, director of engineering and IT for WLNY TV-10/55.
WLNY used a Sikorsky heavy-lift helicopter to remove its transitional antenna from its 600ft tower and install the new 16-bay Jampro JSM DTV-ready medium power UHF slot. Before ordering the antenna, Mulliner traveled to Jampro’s test range in California where he and the company optimized the circularly polarized pattern. The JSM is the medium power version in Jampro’s Prostar Series of UHF slot antennas and is compatible with DTV, NTSC and PAL broadcasting.
“We believe that the use of circular polarization for digital transmission at the maximum FCC allowed power level provides the necessary foundation to achieve easy, robust reception by all devices in the WLNY TV-10/55 market,” he said.