RF CURRENT

Welcome to RF Current, a weekly electronic newsletter focusing on Broadcast technical and F.C.C. related issues. This newsletter is part of The RF Page @ www.transmitter.com, a web site devoted to TV Broadcast RF engineering. For more information see the What is... guide to the R.F. Page site.

Issues are dated each Monday, although recently I've needed an extra day or two to complete each issue. Articles may be posted earlier if time permits or if there is a major, breaking story.

<<< Back to April 17 - Issue 210

April 24, 2000 - Issue 211 Final Edition

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Norfolk, Virginia (Apr. 21)
WTKR-TV, Inc. (WTKR), licensee of station WTKR, NTSC Channel 3 in Norfolk, Virginia, has requested the substitution of DTV Channel 40 for its assigned DTV Channel 58. WTKR asserted that because its allocated DTV channel is outside the core spectrum, it would be required to either switch its DTV operation to channel 3 or shift to a totally new channel inside the core at the end of the transition period. Operation on DTV channel 40 would allow it to continue broadcasting on the same channel.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 40 would specify an effective radiated power of 1,000 kW at a height above average terrain of 313 meters.

Interested parties may file comments on or before June 12, 2000. Reply comments are due on or before June 27, 2000. Refer to the Notice of Proposed Rule Making (MM Docket 00-68) for details on the request and information on filing comments.

DTV - Strategy Analytics Report Says ATSC Close to Collapse (Apr. 20)
Strategy Analytics released a report titled "ATSC Close to Collapse". The title is somewhat misleading, as the report deals with the 8-VSB standrd developed by ACATS, not the ATSC itself. A snapshot of the report is available on the Strategy Analytics web site. It states "The ATSC system is on the brink of collapse. Developments at last week's NAB are leading to a rapid re-evaluation of the ATSC system and growing pressure from broadcasters to find an alternative technology. Some insiders suggest that we have now entered a '30-day meltdown' period. The end result could open up the US digital TV market to new competitors from Europe and elsewhere."

Additional details were made public on the OpenDTV mailing list. The posting said there were two possible outcomes. One was the ATSC would recommend a rapid implementation of a DVB-T solution based on COFDM and it is accepted by the FCC. Strategy Analytics said in this case a DVB service could be in place within a year. The second outcome the Strategy Analytics research mentioned was that the ATSC would recommend adoption of a new system, but leave the details open to further discussion. The report said scenario 2 was the most likely and it could take several years before the situation is resolved.

Information on how to purchase the complete report may be found on the Strategy Analytics web site.

FCC Experimental License Grants for February 2000 (Mar. 30)
Many of the experiment licenses granted in February were for wind profiler radar on 915 MHz. One interesting license was granted to Space Data Corporation for the use of 12.5 KHz of spectrum at 901.8375 MHz and 50 KHz of spectrum at 930.750 MHz for test and development of paging systems. The grant is for mobile operation, nationwide, at an altitude of 30.5 km (100,000 feet). AT&T was granted a licenese to operate on 20-30 GHz in the state of New Jersey for testing of a CDMA satellite system. Refer to the FCC Public Notice (pnet0007) for a complete listing.

DTV - ATTC Begins Project to Capture Real World RF DTV Signals (Mar. 27)
ATTC, the Advanced Television Technology Center, has started digitally capturing real world RF DTV signals. ATTC will capture RF data from at 30 different locations in Washington, DC, its first target area, from the six DTV stations on-air. Both indoor and outdoor antennas will be used. Additional data captures are planned for Philadelphia, New York and Los Angeles.

The received RF is captured using a Celerity high-speed digitizer, 1 gigabyte of RAM and a 50 gigabyte hard drive. Each capture, about 24 seconds in duration, contains approximately 1 gigabyte of data.

ATTC Executive Director Paul DeGonia stated, "This is one of the most important projects that the ATTC has undertaken, and it parallels our development of a controlled environment RF Test Bed. This project has the potential to make a very positive and direct contribution to the implementation of DTV. Our industry, and DTV receiver manufacturers in particular, has been hampered by a lack of reliable real world material with which they can test their receivers. Our target is to assemble a large variety of various interference conditions that will provide an excellent measurement tool for the evaluation of DTV receiver performance."

MSTV is supplying a field test truck and personnel to assist in the data collection effort. Senior Vice President of MSTV, Victor Tawil, commented, "In contributing to this effort, MSTV continues to underscore the urgency of improving DTV reception and its commitment to support manufacturers in developing and testing new designs. Providing samples of real-world signals to manufacturers will expedite their development work and serve as a benchmark for assessing improvements."

ATTC said the "data files will be made available to all DTV equipment manufacturers that wish to acquire them for a nominal fee that will be used to partially recoup the cost of the project." This information was obtained from the ATTC release ATTC Announces An Innovative Project to Assist DTV Receiver Manufacturers. The document is a PDF file. Adobe Acrobat is required to read it.

OTHER Items of Interest

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