Doug Lung's

DTV Reference Page

April 21, 1997

Watch this page for more information and links.
New FCC DTV Allocation Tables are Now Available

What is the DTV Reference Page?

The change from NTSC to Digital TV has been compared with the transition from radio to television. Just as TV started with video versions of popular radio shows, digital TV will likely duplicate what we see on TV today. What will be interesting will be to see how it evolves as programming starts to take advantage of the 20 Mbs data stream the Grand Alliance / ATSC standard offers.

This page was created to provide a starting point for researching Digital TV (DTV), including High Definition Television (HDTV) on the web. I also offer it to broadcasters, manufacturers and related organizations as a reference point to list their web offerings on DTV. If you are interested in providing technical papers, FCC comments or related information on DTV and your company does not have its own web site, I will consider adding them to the site. Please email me at for more information.

Notice! Many of the links here contain documents in word processor format that are not directly viewable on most web browsers. The documents can be viewed if loaded into a compatible word processor. To do that, use the "right" mouse or trackball button (the secondary one) and choose the "Save" or "Save As" option. Enter or select an appropriate file name, save the document, and view it later with the word processor. Documents in Microsoft Word format can be viewed using a free viewer available from Microsoft at Information on this viewer is available in the file at The most universal way of sending formated text documents over the web is the Adobe PDF format. Readers are available for almost all current computer platforms. More information, download and installation instructions are available at the Adobe Acrobat Download Page. I now have the capability to convert most desktop formats into PDF documents and will be happy to do so for anyone wishing to post relevant documents on either this web site or their own. Email for more information.

You haven't seen Under Construction signs on before. I don't usually show pages until they are finished. This page will be an exception. I'm making the information available here in a very plain format, as I collect it, to get it to you quickly. I hope, over the next several weeks, to pretty it up a bit. Please bear with me. I haven't had much spare time lately.

DTV Resources On the 'Net

Advanced Television Standards Committee

At this site you can download copies of the ATSC standards and the ACATS report. Member companies and organizations are listed, along with links to their web sites where appropriate, making it a good starting point for tracking down DTV information.

HDTV Newsletter Online

Dale Cripp's excellent source of information on HDTV, including tutorials. Navigation aids are sparse, but its worth the time to work your way through the site.

Public TV and the Transition to Digital HDTV from PBS' Current

A hypertext summary of HDTV, including technical material and links to other sites with relevant data.

Technical Papers on DTV

Coverage Extension with Digital VSB Transmission by Richard Citta and Wayne Bretl

Abstract: The need for coverage extension and possible means of attaining it is discussed, with lessons learned from the Charlotte NC tests of the Grand Alliance 8-VSB transmission system conducted by the FCC Advisory Committee on Advanced Television Service.

Implications of the FCC DTV Allotments - Dielectric Communications

Abstract: "Replicated Coverage", the basis for the high ERP's is discussed. Additionally, the transmitter power issue is examined by considering the "peak" vs. "average" power requirements. Finally, we address the importance of DTV system design studies to assist the broadcaster in evaluating the implications of the "Table".

Stacked Antenna Considerations For HDTV Conversion by Ernst Mayberry, Dielectric Communications

Abstract: Broadcasters facing the addition of HDTV transmission facilities must choose an antenna system configuration that provides good signal coverage, minimizes tower wind loading, and maximizes the available tower space. Tower top, stacked antenna systems provide an approach for achieving these desirable characteristics. Issues examined include: existing antenna replacement by stacked HDTV/NTSC antenna systems, stack height impact on gain and effective radiated power (ERP), tower loading considerations, and implications of the proposed DTV allotments. Several examples of stacked antenna combinations are presented. Alternative antenna configurations are reviewed comparing relative advantages and disadvantages.

Digital Video Transmission Standard for Cable Television from CableLabs

The QAM modulation and Forward Error Correction (FEC) technology which, after modification, has been adopted as a standard by the ITU and the Society of Cable Telecommunications Engineers (SCTE) is available in Adobe PDF format from CableLabs. You will need Adobe's Acrobat reader to view it.

DTV Broadcast Pioneers

DTV Stations On the Air or Under Construction

WRAL Raleigh NC
WHD-TV Model HDTV Station - Washington D.C.
KOMO TV-HD Seattle, WA (from HDTV Newsletter Online
WETA - Planned Technology Projects

DTV Program Production

HD Vision Inc.

DTV Manufacturers


Au-DTV15 Diacrode DTV Transmitter (Jan. 21, 1997)


Comark and NBC Sign Strategic Agreement (Dec. 1996)
Paxson Communications and Comark Sign Strategic Agreement (Nov. 12, 1996)
Comark IOX Series Transmitter Supplied for Model HDTV Station Project
Advantage ATV Transmitter
Comark's Digital TV History


Adjacent Channel Antenna Goes to WETA (Dec. 16, 1996)
Dielectric and Cox Sign Agreement (Nov. 6, 1996)
ABC and Dielectric Sign Agreement (Nov. 6, 1996)
Dielectric and Hearst Sign Agreement (Oct. 29, 1996)
Tribune and Dielectric Sign Agreement (Oct.9, 1996)


Cox Selects Harris For HDTV Transmitters (Aug. 15, 1996)
WRAL-HD Uses Harris Transmitter (June 21, 1996)
Harris and Capital Cities/ABC Sign ATV Transmitter Purchase Agreement (June 12, 1996)
Harris SigmaCD Series UHF Digital ATV Transmitters
Harris Introduces Antennas for High Power Multiple Channel Operation


DTV Standards - Convergence Issues

FCC Adopts DTV Standard (MM Docket No. 870268)

FCC News Release on DTV Standard (Dec. 26)
FCC Fourth Report and Order Adopting Digital TV (DTV) Standard - text or WordPerfect version
The Agreement Between the Broadcasters Caucus, CEMA and CICATS

Industry Comments

Acrodyne Comments on FCC Ruling on DTV Standard
ATSC Applauds FCC Advanced Television Decision
ATSC Welcomes Industry Accord on Advanced Television
Consumer Electronics Manufacturers Association - Victory in Digital TV Battle
Zenith Electronics Comments

Papers on DTV / Computer Convergence

Computer Industry Consortium for Advanced Television Service (Alvy page)
Response of Charles Pantuso to CICATS position
High Definition Technology, Today and Tomorrow by Charles A. Pantuso, HD VISION, Inc.
Computer-Television Convergence: Why? by Charles A. Pantuso
Other sources: RF Current October 1996

FCC DTV Information

Sixth Further Notice of Proposed Rule Making on Advanced TV -- Office of Engineering And Technology

A page on the FCC web site containing links to the 6th NPRM and the proposed DTV Table of Allotments in various formats. Also see the Erratum to the 6th NPRM.

Mass Media Bureau DTV Page

Comments Filed in Response to the FCC 6TH NPRM on Advanced TV

Final Joint Broadcasters Comments to the Sixth Notice of Proposed Rule Making in MM Docket 87-268

This is actually a link to a web page the Broadcasters Caucus has at the NAB Science and Technology web site. The page contains links to the Broadcasters' very comprehensive comments, in both Word and WordPerfect format, along with many of the Appendices attached to the filing. The proposed DTV Channel Allotment Table and stations' requests for studies and changes are among those available now. More will be added in the future. The Broadcasters' comments reject the FCC's Core Spectrum approach to channel allocations and encourages flexibility in allowing DTV modifications. It also outlines a new set of planning factors for DTV which affects the DTV power and signal level necessary to replicate NTSC service. One of the changes results in a 3 dB reduction in the signal level at the UHF DTV contour. (40.8 dBu versus 43.8 dBu in the FCC plan.)

Comments of the Association of Federal Communications Consulting Engineers

A detailed technical proposal for a practical DTV transmission implementation. The comments propose new planning factors to better match real-world conditions and the use of low noise amplifiers at distant receive sites instead of extremely high transmitter powers to replicate over the horizon VHF coverage. The associated Technical Exhibit is also available. Both are in HTML format. For more details see the AFCCE web site.

Comments of KYES

Word 7.0 format, should be viewable on older versions of Word as well. (I will supply a content summary later.)

Comments of Telemundo Group Incorporated

Comments on potential DTV interference to adjacent channel operations, concerns about co-channel assignments in Southern California, Puerto Rico DTV allotments and methodology, LPTV displacement and possible solutions, and ERP calculations for antennas with large amounts of beam tilt. This file is in Microsoft Word 6.0 format. If you are using Internet Explorer and Microsoft Word, click on "open" to view it, otherwise, save it to disk and view it using Microsoft Word or other compatible word processor. I hope to have an HTML translation (sans footnotes) available soon.

Press Release detailing PBS and APTS Comments

This is an HTML version of a press release issued November 22nd outlining the comments of the Public Broadcasting System and the Association of America's Public Television Stations. Public TV endorsed, in principle, the Broadcasters Caucus comments but did not endorse its modified table of DTV allotments. The comments addressed the need for the full broadcast TV band during the transition: "Public Television does not believe that the public interest would be well served by packing as many NTSC and DTV channels as possible into the spectrum below Channel 60 during the digital transition period. Public Television's position is in concert with the broadcasters' comments in supporting use of the full spectrum during the transition period. After the transition, channels outside of a core region can be cleared of broadcast licensees and can be reallocated for other purposes." Public TV includes a list of the advantages of this approach. The Press Release also noted that Public TV urged adoption of measures to prevent displacement of TV translators.

Reply Comments Filed in Response to the FCC 6TH NPRM on Advanced TV

Reply Comments of the Association of Federal Communications Consulting Engineers
This document is in HTML and can be viewed directly on any web browser. The reply comment reiterate AFCCE's assertion that the ACATS, FCC and MSTV planning factors "may not employ optimal parameter values", with one result being a wide variation in DTV power levels in the same market. The reply comments also respond to issues raised by the National Radio Astronomy Observatory concerning potential interference to their operations. The AFCCE agrees with some of the comments of Motorola, but also addresses "apparent discrepancies" in the comments regarding potential interference to land mobile radio facilities. The reply comments noted that, based on an analysis of an antenna 300m high, "it appears that there is little to be gained from antenna elevation pattern or beam tilt adjustments in overcoming the effects of low ERP." New interference to TV service caused by intermodulation is also addressed, With regards to indoor reception, AFCCE notes "Signal level certainly is an issue when considering indoor reception but further work needs to be done to determine minimum requirements in "typical" indoor reception scenarios."

In summary, AFCCE comments that:

"The challenge for the Commission is to preserve the spectrum through the adoption of specific channel allotments while leaving in-place a mechanism to modify the allotments based on the results of the activities of a TASO-like organization. AFCCE envisions these as parallel activities, with the Commission taking the lead in establishing the scope of activities (task assignments) and setting hard timetables; the industry must respond by providing talent and financial resources to permit the studies to be completed on a timely but technically sound basis."

Reply Comments of the Community Broadcasters Association (CBA)

The above link is to an Adobe Acrobat PDF document. See the link at the top of this page for information on obtaining a free viewer for PDF files. A WordPerfect 5.x version is also available. The CBA's reply comments note that "Much progress has been made, but more remains to be done before a smooth transition can be made to digital TV. Allotting digital channels without regard to LPTV and translators will cause more loss of service than initially anticipated." With regards to the additional work, CBA mentions the need to gather information about LPTV station operations and the need to take another look at the engineering used to generate the FCC's Table of Allotments. The Reply supports the AFCCE's maximum power level of 500 kW for UHF DTV stations. The last paragragh in the summary aptly illustrates CBA's concern about early auctioning of TV spectrum:

"It is well-established that the loss of free broadcasting service is prima facie not in the public interest. Preserving service is the Commission's primary mission, even today when "competition" is almost the only watchword. Auction prices are already falling. Deferring TV spectrum auctions will reduce the chance of error in an uncertain digital transition process and will also increase the revenue obtained as spectrum value increases. A quick 1997 auction will dissipate a valuable asset forever. The temporary revenue bulge will soon be forgotten, but the public will not forget when its TV sets go dark."

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Last modified April 21, 1997 by Doug Lung
Copyright © 1996 H. Douglas Lung