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.

This page contains stories from RF Current issues published in April 1998. Links referenced in the articles were current when published but by this time may have changed. If you find a bad link, try connecting to the home page of the publication or company and look for an archive of past articles. If you find a changed link, I'd appreciate it if you'd let me know by dropping me a note indicating the new location at dlung@transmitter.com.

April 27, 1998 - Issue 115 Final Edition

FCC - NAB Asks FCC to Deny Petitions Calling for "Microradio" Service (Apr. 27)
The National Association of Broadcasters, in comments filed at the FCC, asked the FCC to deny petitions calling for establishment of a low power radio service called "microradio". The comments said Microradio "would create small islands of usable coverage in an ocean of interference." The filing also indicated that any change in the FCC's allocation rules would be detrimental to the evolution of in-band, on-channel digital radio. NAB is concerned about the interference such a service could provide. NAB President and CEO Edward O. Fritts said, "We think it would be folly for the FCC to add hundreds of micropower stations that would only increase the problem."

See the full text of the NAB Press Release for more information. Also visit the FCC's Audio Services Division Engineering Subjects Page for links to Acrobat copies of the two proposals for low power radio service and actions relating to unlicensed radio operations.

DTV - Microsoft and Compaq Push 720P HDTV Formats (Apr. 22)
Microsoft and Compaq said they were extending their PC support for DTV transmission formats to include all frame rates of the 720 line progressive HDTV format. Craig Mundie, senior vice president, consumer platforms division at Microsoft, said "Since progressive transmission formats help keep the cost of the receivers low and allow for interactive services and programming, we believe this step brings the PC and TV industries into alignment." The Microsoft Press Release referred to the support the progressive formats had received from ABC and Fox. The release also said "consumers will likely be able to purchase PC add-in cards from third-party companies that support all 480 and 720 progressive formats as early as late 1998." No mention was made of the 1080 interlaced format, which has gathered support (along with the 720P formats) from most chip manufacturers, including Intel, Philips, and Thomson SGS.

TECHNOLOGY - Programmable Digital Camera Takes Shape at Stanford (Apr. 22)
Stanford and many industry leaders, including Canon, Kodak, HP, Intel and Interval Research, have embarked on a project to develop innovative designs for the digital imaging sensors used in cameras, camcorders, and scanners. The Stanford team is using pixel-level processing, optics and image science to design the new advanced imaging chips. Abbas El Gamal, associate professor of electrical engineering at Stanford, observed that "Pixel-level processing provides a number of potential advantages. Those advantages include a dynamic range large enough to capture details of objects in bright sunlight and deep shade at the same time; reduction in noise; and pixel-level programmability, which could aid in processes like automatic image recognition."

El Gamal's group,with the assistance of Brian Wendell, professor of psychology and Joseph Goodman, Professor of Electrical Engineering, has finished and begun testing of the second version of a third-generation chip. It contains 1.2 million transistors and includes pixel-level digitization that came be programmed to improve its performance in different environments.

If you are interested in learning more about this interesting technology, its history and its potential, see the Stanford News Release. It has more information as well as links to various Stanford and industry web sites on digital imaging.

FCC Releases Public Notice on "Class A" TV Petition For Rulemaking(Apr. 21)
The FCC released a Public Notice outlining a Petition for Rulemaking filed by the Community Broadcasters Association ("CBA"). Interested persons may file statements on the petition (opposing or supporting) by May 22, 1998. Replies are due by June 8, 1998.

The Petition for Rulemaking, RM-9260, requested amendment of the TV Rules in Part 73 to create a "Class A" TV Service. Class A TV stations, as proposed in the Petition, would have to provide similar protection to other TV stations (analog TV, DTV, LPTV and TV translator stations) as the existing LPTV service. However, unlike LPTV, Class A TV stations would be given primary user status and would have to comply with "all requirements applicable to TV broadcast stations", with some exceptions due to the power level and the "manner in which the channel was assigned to the station under the LPTV rules in Part 74." Maximum effective radiated power levels of 10 kW for low VHF channels, 31.6 kW for high VHF channels and 500 kW for UHF channels were proposed.

"Qualified" LPTV stations would be allowed to apply for Class A status. The qualifications are similar to those discussed in Congress -- three hours per week of locally produced programming. More details on these qualifications, DTV transition for Class A stations and additional steps for protecting existing TV stations from interference are discussed in the Public Notice (pnmm8061), a web page on RM9260 and the Petition for Rulemaking itself (in Adobe Acrobat format).

OTHER Items of Interest

April 20, 1998 - Issue 114 Final Edition

FCC Postpones Initial Date for Filing TV Translator and LPTV Displacement Apps. (Apr. 16)
As TV consulting engineers across the country scrambled to meet the April 20th filing date for TV translator and LPTV replacement channels, the FCC took another look at the "Ex Parte Request for Stay of Effective Date of Eligibility for Filing DTV Related Displacement Applications" filed March 24, 1998 by the National Translator Association (NTA) and decided to extend the initial date until June 1. Dr. Byron St. Clair, on behalf of the NTA, pointed out that large number of potentially displaced stations needed more time to prepare applications. The NTA request said the engineering community is undergoing a "steep learning curve" with regard to DTV coverage and interference analysis. Indeed, the FCC's posted version of the FLR program used to create the DTV Table of Allotments was not updated to include the changes in the Memorandum Opinion and Order on the Sixth Report and Order on Advanced TV until mid-March. Since this software forms the basis of the FCC's method for determining coverage and interference, most engineers had to modify the parameters used in their software for DTV analysis to match what the FCC was using.

The FCC recognized the difficulty engineers faced in preparing displacement applications and agreed that more time was needed. There was concern "applicants may be inclined to submit hastily prepared deficient applications in order to reserve their place in line, intending to later correct deficiencies identified by the Commission staff." The Commission also recognized the delay could disadvantage some stations, but was persuaded that far more stations would benefit from a postponement. Applications received before June 1 will be held at the Commission and given a filing date of June 1, 1998. There is no advantage to filing applications prior to June 1 and while indications were the FCC did not plan to make these applications public, there was no guarantee that they would be exempt from release under a Freedom of Information Act request. More details are available in the FCC Public Notice (pnmm8057).

WIRELESS - Hughes Network Systems Introduces Wireless Access System (Apr. 14)
Hughes Network Systems, building on its experience with Direct PC and earlier wireless access systems, today introduced AIReach(TM) Broadband. The system includes a range of products operating from 800 MHz to 42 GHz. providing fractional T1/E1 data rates up to 45 Mbps per radio link. More information in available in the Hughes Network System Press Release.

SATELLITE - INTELSAT 502 De-Orbited After 17 Years of Service (Apr. 14)
INTELSAT said today that it had completed the last burn needed to de-orbit INTELSAT 502. The satellite had been in service for a record 17 years. When the satellite was launched in late 1980, it was predicted to reach the end of its operational life in 1987. However, in 1988 INTELSAT reduced station keeping to simple East-West manuevers, resulting in enough fuel savings to extend its life to 17 years. Conny Kullman, INTELSAT's VP of Operations and Engineering, said "The outstanding accomplishment of the INTELSAT 502 is clear evidence of INTELSAT's commitment to offering superior spacecraft performance that surpasses the predicted design life." INTELSAT 502 was initially located at 338.5 degrees East. In 1994 it was moved to 319.5 degrees East. It was built by Ford Aerospace, now known as Space Systems/Loral. See the INTELSAT Press Release for more information.

OTHER Items of Interest

April 13, 1998 - Issue 113 Final Edition

FCC Allows LPTV Displacement Filings Starting April 20 (Apr. 8)
Keith Larsen, Assistant Chief for Engineering at the Mass Media Bureau of the FCC, reminded LPTV broadcasters at NAB that all LPTV stations within certain distances from stations allocated DTV facilities on the same channel (162 miles for UHF stations) may file for a displacement channel starting Monday, April 20. Applications will be handled on a "first come - first serve" basis, so LPTV broadcasters and consulting engineers were struggling to complete studies prior to the Monday deadline. The National Translator Association requested an extension of the initial filing date and, at Wednesday's FCC Regulatory session at NAB, Keith Larsen indicated the FCC was considering it. [The FCC has postponed the initial date for filing of LPTV and translator DTV displacement applications to June 1. See the FCC Public Notice for details.]

DTV Transmitter Options at NAB '98 (Apr. 9)
Most transmitter manufacturers showed DTV transmitters at this year's NAB convention in Las Vegas. I'll have a full report on DTV developments at NAB in my TV Technology RF Technology column in late May 1998. Acrodyne, EMCEE and ITS Corporation, companies usually associated with LPTV transmitters and translators, showed innovative products for UHF DTV. EMCEE Broadcast Products, Inc. was showing the 2.5 kW average power "Transition Transmitter" introduced last year. New this year was an 8-VSB modulator from Harris Corporation. EMCEE said it would be testing the transmitter at PBS station WITF in Harrisburg, PA. More information on this product is available in an EMCEE Press Release.

Many broadcasters with adjacent channels are looking for technology that will allow them to use the same antenna and transmission line for DTV and NTSC. Acrodyne its ACT - Adjacent Channel Technology - on display with a transmitter designed for KBLR in Las Vegas. The original plan was to have the transmitter on the air from KBLR with DTV on channel 38 and NTSC on channel 39. Unfortunately for KBLR and Acrodyne, after the antenna and filter was ordered the FCC, in the Memorandum Opinion and Order, changed KBLR's DTV channel to channel 40. Acrodyne was unable to have the antenna and filter changed in time for an on air demonstration. The results from the booth setup, which showed the output from the IPA, were encouraging. It was difficult to see any degradation of the NTSC signal from the DTV signal, since the off air signal from KBLR was always visible in the NTSC RF signal generated in the booth. However, there was no obvious change when the DTV signal was switched off and a quick glance at the HP8441A vector modulation analyzer showed a clean, combination signal.

Those broadcasters that want to take full dvantage of the recent FCC rules allowing increased power for UHF DTV stations may need more than the 2.5 kW average DTV power level these transmitters offer. (The Acrodyne unit can generate more DTV power if the NTSC power is reduced below 25 kW.) ITS Corporation announced an innovative way of combining high power NTSC and upper adjacent channel DTV signals into one antenna. The adjacent channel combiner combines the station's visual and DTV transmitters first and then diplexes the aural carrier onto the combination later, the same way the aural carrier is added to the visual single in most existing TV transmitters. This approach reduces the need for steep filters at the lower NTSC upper DTV channel junction. The slope of both filters can now extend into the portion of the NTSC channel previously used for the aural carrier. ITS said they had used this approach sucessfully when combining adjacent channel MMDS transmitters. More information is available in the ITS Press Release.

FCC Chairman Kennard and Commissioner Ness Discuss DTV at NAB '98 (Apr. 8)
FCC Chairman William Kennard, in his address to the NAB Convention in Las Vegas April 7th, said "Now, no one has figured out what the digital future will look like --- exactly." "...every person you talk to has a slightly different vision of that future. About the only certainty is that the future will be vastly different from today. And that change will come quickly." He said the FCC will hold to the deadlines for the DTV rollout it set in the 6th Report And Order. He offered some words of assistance from the FCC. He said "I stand ready to work with those of you who face unique tower siting problems or other obstacles." He also promised to reduce the time it takes to get applications through the FCC, saying "Service delayed is service denied." Regarding enforcement of the rules, the approach will be "Trust, but verify."

For those concerned about cable must-carry of DTV signals, Chairman Kennard commented that the Commission "needs to guard against any gatekeeper who might hinder or distort the growth of the digitalmarketplace." He also warned that the isssue goes beyond must carry, saying "It's also about equipment -- equipment compatibility and the availability of equipment for consumers. No consumer wants to buy five set top boxes, six remotes and a six thousand dollar television set that doesn't work with cable."

Commissioner Susan Ness also addressed the cable TV issue in her address Wednesday morning. Worrying that consumers will be confused as to what constitutes a cable-ready DTV set, she asked "Will the true high definition set that they just bought display the true high definition signal that the broadcaster has just transmitted if the set is hooked up to cable?" She continued, "The answer had better be yes. I do not wish to see a bottleneck provider, such as cable, be able to defeat the choices that broadcasters and consumers have made -- whatever those choices may be -- by failing to pass through to a digital set the full resolution in the signal." With regards to the equipment, she expected we will begin to see set-top devices that support both cable and DBS appearing in commercial retails outlets soon after the conclusion of the FCC's rulemaking on navigation devices.

Commissioner Ness advised broadcasting contemplating a change in their tower to get in touch with their municipal authorities early - even a year or two before the DTV launch is planned. She also offered the help of an FCC "strike force" to help local governments sort through their questions.

See the full text of FCC Chairman William Kennard's An Era of Opportunity remarks and Commissioner Susan Ness's remarks before The Road to DTV Panel at NAB '98 for more information.

SCIENCE - New Mitigation Strategy Minimizes Asteroid Collision Risk (Apr. 10)
Remember the images of Comet Shoemaker-Lvey 9 crashing into Jupiter four years ago? Were you concerned about the projected "near miss" of Asteroid 1997 XF11 with Earth in October 2028? The April Astronautics News Release from the University of Illinois at Urbana-Champaign may help you sleep a bit better. Researchers there are working on mitigation strategy to minimize the risks of large objects in space colliding with earth. Blasting the objects to bits isn't a good idea, since it would create "a multitude of smaller -- but equally lethal -- objects coming at us" according to Professor Bruce Conway. He suggested a better alternative would be to deflect the object. Conway has developed an analytical method to determine the proper direction in which to push the object to maximmize the deflection. Admitting that such calculations may never be needed, they are nice to have just in case. Conway said "While the probability of a large asteroid or comet colliding with the Earth is low, the potential for destruction is immense. It's probably not something we should lose sleep over; but, on the other hand, it would be really silly not to do anything."

See the University of Illinois at Urbana-Champaign News Release for more details. For an interesting (although California-centric) view of what would happen if a comet were to impact earth, I recommend Lucifer's Hammer by Larry Niven and Jerry Pournelle. It is available on the Net from Amazon.

OTHER Items of Interest

April 6, 1998 - Issue 112 Final Edition

FCC Moves to Electronic Filing, Streamlines Other Processes (Apr. 2)
In three separate actions today the FCC moved towards electronic filing and streamlined the broadcast application and licensing process and the equipment authorization process. In Report and Order FCC 98-56, the FCC amended its rules to allow the public to file comments and other pleadings electronically in many proceedings. These include most notice and comment rulemaking proceedings, most proceedings involving petitions for rulemaking, Notice of Inquiry proceedings, and petitions for reconsideration in these proceedings. The Electronic Comment Filing System (ECFS) will replace the existing FCC Record Image Processing System (RIPS) once all data and images are transferred to the new system. The public can access ECFS through the Internet and file, review and print documents on-line. This system complements systems individual Bureaus have set up, such as the Wireless Bureau's planned Uniform Licensing System (ULS). See Report GN 98-4 or the full Report And Order for more information

The FCC also announced a Notice of Proposed Rulemaking (FCC 98-57) to streamline the broadcast application process. Much of the streamlining would come from substituting applicant certifications for certain narrative exhibits. Random audits would be conducted to ensure compliance and applicants not complying would be severely sanctioned. The FCC requested comment on whether to mandate electronic filing for broadcast application and reporting forms. The Commission also proposed eliminating the payment restructions on the sale of unbuilt stations. The NPRM also proposes extending the initial time period for constructing or modifying stations to three years, although the grounds for construction permit extensions would be substantially narrowed. See Report MM 98-5 or the full text of the Notice of Proposed Rulemaking FCC 98-57 in Acrobat or WordPerfect formats for more details.

The FCC, in its Report and Order on ET Docket 97-94 (FCC 98-58), streamlined the equipment authorization process by simplifying the existing application process, moving to a system of electronic filing of equipment authorization applications and deregulating and relaxing equipment authorization requirements for types of equipment that have demonstrated a good record of compliance. Authorization for Part 15 interface devices, radio receivers (except for scanners) and Cable Service Terminal devices was relaxed from Certification to the Declaration of Conformity self-approval procedure. Equipment used in several services, including Part 74 Auxiliary Broadcast aural relays and boosters, Part 78 Cable Television Relay fixed transmitters and Part 101 point-to-point microwave transmitters had approval procedures changed from Notification to Verification. The Notification program was eliminated and the Type Acceptance program was combined in the Certification program. More details are available in Report ET 98-3.

SATELLITE - INTELSAT Transfers Satellites to Independent Spin-Off Company (Mar. 31)
INTELSAT's Assembly of Parties, meeting in Salvador, Brazil, unanimously approved the creation of New Skies Satellites N.V.and transferred six satellites to the independent, spin-off company. An INTELSAT Press Release said "There will be a complete and clear structural separation between New Skies and INTELSAT. New Skies will be subject to the regulatory bodies of every country in which it may operate and will have no privileges or immunities." INTELSAT Director General and CEO Irv Goldstein stated, "Today's historic decision proves that the 142 member-nations of INTELSAT can accomplish fundamental change in a positive way and in a manner which creates a new satellite communications company in a fair competitive framework." He added, "...it is important to remember that the creation of New Skies is the first step in the ultimate and full commercialization of INTELSAT."

The following satellites are to be tranferred to New Skies:

INTELSAT 513 at 183 deg. E
INTELSAT 703 at 57 deg. E
INTELSAT 803 at 338.5 deg. E
INTELSAT 806 at 319.5 deg. E
INTELSAT K at 338.5 deg. E
K-TV at 95 deg. E
Ka-band frequency registrations at 95 deg. E and 319.5 deg. E

OTHER Items of Interest

Other Issues Available:



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Last modified April 27, 1998 by Doug Lung dlung@transmitter.com
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