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 July 10 - Issue 222

July 17, 2000 - Issue 223 Final Edition

SATELLITE - Geomagnetic Storm Threatens Earth, Satellites Survive (July 17)
The morning of July 14th NOAA satellites and SOHO, the Solar and Heliospheric Observatory, observed a huge solar flare. A NASA web page warned Space Radiation Storm and said this was "one of the most powerful solar flares of the current solar cycle." The first effects soon hit earth. Gary Heckman, a space weather forecaster at the NOAA Space Environment Center said, "Energetic protons from the flare arrived at Earth about 15 minutes after the eruption. This triggered a category S3 radiation storm."

A large coronal mass ejection (CME) followed the flare. The CME was predicted to cause a geomagnetic storm reaching G3 (strong) to G4 (severe) levels. This level of geomagnetic storm should produce aurora visible into the mid-latitudes. (Note from DL: I was in northern Idaho Saturday night, normally an ideal location to view the aurora. Unfortunately, if any aurora was visible a full moon hid it from view.) A NASA Space Weather Bulletin said the flare resulted in an R3 (strong) radio blackout.

Fortunately, this strong storm did not appear to cause any problems with satellite communications or power grids. GE Americom, in a Statement Concerning Solar Max 2000 released last month, said "Some reports have exaggerated the potential consequences of this increased solar activity on satellites. However, these exaggerated reports should not be interpreted as an issue of major concern for users of GE Americom's in-orbit spacecraft."

There are numerous web sites with scientific data on solar activity and geomagnetic storms. Recommended sites include:


SATELLITE - Galaxy IVR Begins Transmissions (July 17)
A news release titled PanAmSat Flips the Switch as Galaxy IVR Satellite Begins Transmissiosn Across North America for Premier TV, Radio and Internet Customers announced the completion of process that started in May 1998 with the failure of PanAmSat's Galaxy IV satellite at 99 degrees West Longitude. Galaxy IVR is a Hughes-built HS-601 HP spacecraft with 24 C-band and 24 Ku-band transponders.

Some of the customers using Galaxy IVR include National Public Radio and Hughes Network Systems (HNS). HNS is using the satellite to transmit its AOL Plus service to consumer homes via DirecPC. AT&T Broadband is using the satellite for its digital cable programming service. PanAmSat also plans to use Galaxy IVR for its Galaxy 3D(tm) digital delivery service. Now that Galaxy IVR is operational at 99 degrees, Galaxy XI will move to 91 degrees, where it will replace the Galaxy VI and Galaxy VII satellites. Galaxy VI will move to 74 degrees West Longitude. The PanAmSat news release did not indicate where Galaxy VII would be located.

SATELLITE - EchoStar VI Successfully Launched (July 17)
Space Systems Loral (SS/L) said EchoStar VI, the second in a series of four direct broadcast satellites it was building for EchoStar Communciations, was successfully launched Friday morning on a Lockheed Martin Atlass II AS launch vehicle.

The satellite will be tested at 148 degrees West Longitude before being moved to 119 degrees West Longitude, pending FCC approval. The satellite has 32 transponders operating at 125 watts. The satellite can also be configured as 16 transponders operating at 250 watts each. SS/L said total satellite power will be 10,000 watts DC in autumnal equinox.

More information is available in the Loral Space Systems News Release.

FCC Denies Petition to Reconsider Ultra-wideband Waivers (July 14)
The U.S. GPS Industry Council, American Airlines and United Airlines filed a consolidated petition for reconsideration of three waivers granted to U.S. Radar, Time Domain Corporation and Zircon Corporation to allow limited marketing of ultra-wideband (UWB) services. Because of the wideband nature of UWB services, an FCC waiver was required because emissions would fall into the TV broadcast bands and other restricted frequency bands, including the GPS spectrum. In addition, Part 15 emission measurement procedures would have required application of a pulse desensitization correction factor to measured results when determining total output power. The FCC said this factor, if applied to UWB signals, "ould severely limit emissions such that the devices would be unusable."

According to the FCC Order denying reconsideration, the petitioners said the FCC Office of Engineering and Technology, in granting the waiver, "did not consider the GPS spectrum, or, in particular, that it did not adequately investigate the potential for harmful interference could be caused to GPS operations." The FCC answered, "Transmitters being manufactured under these waivers are required to comply with limits on radiated emissions that are similar to those currently applied to millions of other unlicensed devices, such as personal computers. Those limits have already been proven successful in controlling harmful interference. Also, the emission levels produced by equipment authorized under the UWB waivers are considerably lower than those produced by present land mobile transmitters and broadcast television stations."

In the Order - Consolidated Petition for Reconsideration of Waivers Issued under Delegated Authority by the Chief, Office of Engineering and Technology (FCC 00-029), the FCC found "that no new information has been submitted by thePetitioners that would cause it to reconsider the waivers issued to U.S. Radar, Time Domain or Zircon. The Commission concludes that the standards and operating conditions specified by OET and by NTIA areappropriate to reduce the probability that UWB equipment operated under the waivers will cause harmfulinterference to GPS operations. The Commission also concludes that granting these waivers will not prejudice the outcome of the rule making proceeding in ET Docket No. 98-153. The Commission will continue to address the standards necessary to protect GPS and other radio operations from UWB devices in this latter rule making proceeding."

DTV - ADC Bandwidth Enhancement Technology(TM) To be Tested In Texas (July 13)
ADC is working with North Texas Public Broadcasting, Inc., in Dallas, Texas to its Bandwidth Enhancement Technology (tm) or "BET" at KERA-DT, channel 14. KERA-DT is hoping BET will help it solve interference problems with two-way radio services operating just below channel 14. Analog Channel 14 TV transmitters typically deal with the problem of out of band emissions by using sharp filters. If the same filters were used in a Channel 14 DTV installation, the linear distortions (including large changes in group delay and frequency response) at the lower edge of the channel near the pilot would cause the transmitted signal to have a high error vector magnitude (or reduced SNR).

ADC's BET circumvents the problem by narrowing the total bandwidth of the 8-VSB signal. Rich Dell, product manager for ADC's Broadcast Systems Division, explained, "Bandwidth Enhancement Technology is designed to be completely compatible with the standard 8-VSB transmission system, currently used by all DTV channels in the United States. By narrowing the total bandwidth of the signal by only 200 to 400 kHz, you can fit much more aggressive channel filters to the transmitter system, thereby greatly reducing any chance of out-of-band interference." ADC said BET "is designed to 'move' information from one part of the channel to another, allowing bandwidth reduction without reducing the useable data rate."

Rick Own, chief engineer for KERA, is hoping the BET is a winner. "ADC's technology may be the only solution to this problem. By working with ADC to prove this new technology, we intent to ensure that we are protecting these services which are very important to our city."

This information was obtained from the ADC News Release ADC Forms Alliance With Dallas Public Television Station To Test New DTV Technology.

RADIO - Lucent Digital Radio and USA Digital Radio Merge to Form iBiquity (July 12)
Lucent Digital Radio, USA Digital Radio have agreed to merge operations to form a new combined company, iBiquity. The new company is backed by an investor coalition that includes 15 of the nation's largest radio broadcasters aas well as other technology, media and investment companies.

The new company will develop AM and FM In-Band On-Channel (IBOC) digital radio in the United States. It will use Lucent Digital Radio's PAC(tm) audio compression technology to allow both AM and FM radio broadcasters to transmit high quality digital audio and data on the same frequency and together with their traditional analog programming. Robert Stuble, current president and chief executive officer of USA Digital Radio and future president and CEO of iBiquity, stated, "Today, digital radio takes a major step towards becoming a reality. Our proposed merger will establish a clear path for AM and FM radio to not only join the digital revolution, but also to propel it well into the next generation. This merger of equals creates a new, world class company whose focus and industry transforming technologies will be directed toward making AM and FM digital radio broadcasting a reality for listeners, broadcasters and manufacturers. Together our organizations represent the best of the best in technical skills and marketplace understanding. iBiquity Digital will change how the public uses, thinks of and benefits from radio."

Suren Pai, president and CEO of Lucent Digital Radio will join Robert Struble as co-chairmen of the Board of iBiquity. He added, quot;Combining the complementary strengths of our organizations under Bob's executive leadership positions iBiquity Digital as a global digital broadcast technology powerhouse. We will be able to expedite the standard setting process by offering the Federal Communications Commission (FCC) and consumer electronics and broadcast equipment manufacturers the best technology available as the US standard for digital radio broadcasting."

Gary Shapiro, CEO of the Consumer Electronics Association, promised his organization would support digital radio. He commented, "This is terrific news for all of the players, especially the consumer electronics manufacturers and consumers. I applaud the decision of both companies, and pledge to work together to bring digital broadcast services to the United States. This is a powerful combination of resources and now we can continue the revolutionary transition from an analog world to a digital world. Historians will mark this decade as the most technologically momentous time."

More information can be found in a Lucent Digital Radio and USA Digital Radio Press Release andon the iBiquity web site at www.ibiquitydigital.com.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Bryan, Texas (July 13)
KWTX/KBTX License Corporation, licensee of station KBTX, NTSC Channel 3 in Bryan, Texas, has requested the substitution of DTV Channel 33 for its assigned DTV Channel 59. KWTX/KBTX said changing its DTV allotment to an in-core channel would eliminate the need to design and construct two digital facilities.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 33 would specify an effective radiated power of 1000 kW at a height above average terrain of 477 meters.

Interested parties may file comments on or before September 5, 2000. Reply comments are due on or before September 20, 2000. Refer to the Notice of Proposed Rule Making (MM Docket 00-124) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Miami, Florida (July 13)
NBC Stations Mangement, Inc., licensee of station WTVJ, NTSC Channel 6 in Miami, Florida, has requested the substitution of DTV Channel 31 for its assigned DTV Channel 30. NBC contended the channel change will reduce interference to stations WFLX, channel 29 in West Plam Beach and WGCU, channel 30, in Fort Myers. The change would also allow WTVJ-DT to move the station into the main antenna farm and reduce its dependency on translator stations, improving spectrum efficiency.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 33 would specify an effective radiated power of 1000 kW at a height above average terrain of 318 meters.

Interested parties may file comments on or before September 5, 2000. Reply comments are due on or before September 20, 2000. Refer to the Notice of Proposed Rule Making (MM Docket 00-125) for details on the request and information on filing comments.

OTHER Items of Interest

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