For more information, contact Nat Ostroff, Vice President of New Technology, 410 568-1500.
Sinclair Calls Zenith Demonstration Misleading And Possibly Flawed
Sinclair Broadcast Group, Inc. (NASDAQ: SBGI) criticized the recent 8VSB/COFDM comparative demonstrations carried out by Zenith Corporation at the Consumer Electronics Show in Las Vegas and in Washington, DC recently. In an attempt to defend their patented 8VSB modulation system for over the air Digital Television, Zenith engineers compared the performance of their latest 8VSB receivers using the ATSC standard to that of receivers using COFDM designs from several European manufacturers using the DVB -T standard. The demonstration attempted to show the recent improvements made in 8VSB technology and the superior performance of these receivers over that of the DVB -T COFDM receivers in various simulated multi-path and noise environments. Sinclair engineers were invited to the demonstration as part of a delegation from MSTV, the organization for Maximum Service Television. The Sinclair engineers concluded that Zenith was making a fundamental mistake in how they were conducting the demonstration. The use of simulated, rather than live, multi-path test signals did not allow for full evaluation of the two systems, as had been found previously by Motorola. In this respect, the demonstration was misleading. However, a potentially major flaw in the demonstration was the use of signal levels sent into the COFDM receivers that may have exceeded their operational design limits. This potential overload of the COFDM receivers may have distorted their capabilities and made all of the measurements erroneous at best. Nat Ostroff, Vice President of New Technology for Sinclair said, ""It would be a gross technical error to overload the COFDM receivers and then compare their resulting diminished performance to that of the non-overloaded 8VSB receivers."" During the demonstration Zenith disclosed that the input signals to the 8VSB receivers were set at a power level of minus 30dbm or about one (1) milliwatt. The maximum input specification to at least one of the COFDM receivers used in the demonstration is also minus 30bdm and the second demonstration receiver is minus 35dbm or about one third (1/3) of a milliwatt. Unfortunately, the signal levels into the COFDM receivers were raised above the minus 30dbm level to compensate for the wider 8Mhz bandwidth use for CODFM in the demonstration. When the multi-path, bandwidth compensation power and noise simulation signals are added, the total overdrive condition to the COFDM receivers could easily have exceeded both COFDM receivers' capabilities. Mark Aitken, a senior Sinclair engineer, said, ""This demonstration would have been much fairer if there was no possibility of distorting the results by overdriving the test COFDM receivers."" About Sinclair Broadcast Group Sinclair Broadcast Group, Inc. is a diversified broadcasting company that currently owns or programs 58 television stations in 38 markets and 6 radio stations in one market. Sinclair's television group reaches approximately 24.4 percent of all U.S. television households and includes ABC, CBS, FOX, NBC, WB, and UPN affiliates. Sinclair, through its wholly owned subsidiary, Sinclair Ventures, owns equity interests in Internet-related companies including BeautyBuys.com, Inc., an on-line e-tailor of brand name health and beauty products; NetFanatics, Inc., a web developer offering e-business solutions and applications; and Synergy Brands, Inc., a developer of on-line consumer product companies. Other strategic investments of Sinclair Broadcast Group include Acrodyne Communications, Inc., a leading manufacturer of transmitters and other television broadcast equipment.