Most Powerful DTV Signal Claimed

Acrodyne Industries announced Monday that WLNY television had gone on the air with “what is believed to be the world's most powerful Digital Television signal.”

According to the FCC TV Engineering Database in CDBS, WLNY is using a Jampro JSM-16/47-TCCP circularly polarized antenna with 1,000 kW effective radiated power on Channel 47. The use of circular polarization means that a linear receive antenna, regardless of its orientation, will receive the full 1,000 kW signal. If a circularly polarized receive antenna is used, the signal will be 3 dB higher, the same as if the station were transmitting 2,000 kW in the horizontal plane only.

“We designed this system specifically to enhance our ability to reach both fixed and mobile audiences,” said Robert Mulliner, director of engineering and IT for WLNY. “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 market.”

The Jampro JSM-16/47-TCCP antenna that the station is using has a very narrow azimuth pattern, with a 3 dB beamwidth of about 45 degrees. The high azimuth gain allows WLNY to generate a 1,000 kW circularly polarized signal with a two-IOT transmitter. The Acrodyne Industries Quantum transmitter uses the Rohde and Schwarz SX-800 exciter and two e2v ESC energy efficient multi-stage depressed collector IOTs to generate a 36.26 kW transmitter output.

The high azimuth gain of the station’s antenna makes it easy to achieve maximum power with circularly polarization. It will be interesting to see if other stations with lower gain azimuth patterns will make the investment in additional amplifiers needed to achieve circular polarization at 1,000 kW effective radiated power.