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.

This page contains stories from RF Current issues published in September 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.

September 28, 1998 - Issue 135 Final Edition

FCC Report and Order Authorizes Fixed 2-Way Transmissions For MDS and ITFS Licensees (Sept. 25)
As reported in last week's RF Current, the FCC has amended Parts 21 and 74 of the FCC Rules to enable Multipoint Distribution Service (MDS) and Instructional Television Fixed Service (ITFS) licensees to engage in fixed two-way transmissions. The full text of the Report and Order (FCC 98-231) was released this week. See the September 21 RF Current for an overview of this report and order.

Some of the technical details not covered in the news release issued last week include modulation methods, the spectral mask for emissions, frequency tolerances, and interference. The Report and Order also includes an comprehensive propagation model for calculating signal strength and analyzing interference, listing "Four Major Steps for Response Station Interference Analysis". Key points: Licensees and system will be permitted to any digital emssion in circumstances where interference is unlikely or where all parties potentially affected by interference have consented to such use. In addition to QAM and VSB, QPSK and CDMA modulation will be permitted on a regular basis at all MDS and ITFS stations.

The FCC adopted the spectral mask parameters specified in the Notice of Proposed Rulemaking in this proceeding, but amended them to take into account issues raised by General Instruments concerning the area 250 kHz above and below the channel. GI proposed 25 dB of attenuation at the edges, increasing linearly to 40 dB of attenuation at 250 kHz above and below the edges. The existing +/- 1 kHz frequency tolerance requirement was retained for all main station digital and analog transmitters and for all digital and analog booster transmitters with EIRP exceeding -9 dBW. No frequency tolerance was imposed on booster transmitters below -9 dBW EIRP and all response transmitters.

Response station power levels up to 33 dBW EIRP will be permitted, provided interference criteria are met. A new methodology was adopted for calcuating coverage and interference. A data format for submitting analyses to the Commission was also specified. Additional data is to be submitted on diskettes accompanying the application forms. However, the Report and Order specifically states that It should be understood clearly that the Commission is prepared to, and will, order the immediate de-activation of part, or all, of a system if that system is causing interference and the licensee has not cooperated fully and in a timely manner to eliminate the interference.

Refer to the Report and Order - In the Matter of Amendment of Parts 21 and 74 to Enable Multipoint Distribution Service and Instructional Television Fixed Service Licensees to Engage in Fixed Two-Way Tranmissions MM Docket No. 97-217 for additional information. The 180 page Report and Order is available on the FCC web site as an ASCII text file, a compressed zip file containing attachments and as an Adobe Acrobat PDF file.

FCC Order Responds to Petitions for Reconsideration of TV/MMDS Receive Antenna Rules (Sept. 25)
The FCC has released an Order on Reconsideration in the rulemaking on CS Docket 96-83, Implementation of Section 207 of the Telecommunications Act of 1996 - Restrictions on Over-the-Air Reception Devices - Television Broadcast Service and Multichannel Multipoint Distribution Service. The rules adopted in the Report and Order in this proceeding, released August 6, 1998, "generally prohibit bot governmental and nongovernmental restrictions that impair the installation, maintenance or use of over-the-air reception devices covered by Section 207, unless the restriction is necessary for safety or historic preservation reasons and is no more burdensome than necessary to achieve those objectives."

Some of the actions the FCC took in this Reconsideration included:
Additional actions and a more complete discussion of these issues are contained in Order on Reconsideration - FCC 98-214.

SPACE - Very Large Array Radio Telescope Finds Evidence of Most Powerful Magnetic Field Ever Seen (Sept 25)
Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope have discovered a magnetar -- "a neutron star with a magnetic field billions of times stronger than any on Earth and 100 times stronger than any other previously known in the Universe." On August 27, an intense wave of gamma rays from the 1900+14 soft gamma-ray repeater struck the Earth's atmosphere. On September 3, the VLA found a new source of radio emission where one had not previously existed. A National Science Foundation (NSF) article Cosmic Flasher Reveals All, explained "The immediate importance of this finding is that it provides a new and independent confirmation of the magnetar model. These impulsive particle 'winds,' predicted by theory, carry as much energy as the flashes of hard X-ray emission and are important in slowing down the spinning magneta.". Refer to the NSF article for more information and links to additional magnetar web resources.

SCIENCE - Hurricane Georges Puts on A Light Show (Sept. 23)
Researchers participating in the third Convection and Moisture Experiment (CAMEX-3), were treated to a display of rarely seen lightning fields and purple sprites detected in the eye of Hurricane Georges by the ER-2 pilot flying more than 19.8 km (65,000 feet) above the Atlantic. The sprites may be part of a global electrical circuit. The NASA report on the sprites stated:
The sprites appear high above the thunderstorm while the jets shoot out from the top of the thunderstorm. Sprites appear to cascade as high as 96 km (60 mi) above the Earth. Sprites can look like giant red blobs, picket fences, upward branching carrots, or tentacled octopi, and can occur singly or in clusters. The jets appear to be ejected from the storm top with velocities as high as 100 km per sec and move up as high as 32 kilometers.

Stratospheric lightning events could generate strong electric fields and electromagnetic pulses which may interact with the Earth's ionosphere and magnetosphere. Strong fields at high altitudes may generate runaway electrons which could then produce high energy x-rays and even gamma rays. Thus, it is possible that lightning may generate a broad spectrum of electromagnetic radiation, ranging from extremely low energy to extremely high-energy gamma radiation. This theory is supported by the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma Ray Observatory which has detected gamma rays coming up from the Earth - not deep space - when the spacecraft was over thunderstorms.
Scientists are studying upward lightning to determine what effect it might have on future commercial aviation operations. For more information on this interesting phenomenom, including pictures, refer to the NASA article Hurricane Georges puts on a light show.

FCC Experimental Actions for August 1998 (Sept. 23)
The FCC has released its Experimental Actions list for August 1998. Interesting actions include a new experimental license WA2XLC issued to EMS Technologies, Inc., to operate in 806-960, 1429-1513, 1710-1990 and 2400-2499 MHz to test antennas in Norcross, GA and WA2XRU, issued to Globalstar L.P., to operate in 1606-1630 to test satellite system performance for a big LEO system at Clifton, TX.

CHIPS - LSI Logic L64780 Single-chip COFDM Demodulator Exceeds Performance Specifications in BBC Tests (Sept. 22)
LSI Logic announced yesterday that its L64780 single-chip COFDM demodulator was shown to be 100 percent interoperable with DVB-T modulators in all tested modes in tests conducted by the DVB-T VALIDATE project. LSI Logic said its chip "was the only demodulator with a perfect score, maintaining clear reception for the maximum time specified for all modes tested, which included both 2K and 8K, single frequency network operation, and hierarchical and non-hierarchical tranmsission." The BBC tests found the L64780 chip performed 4 dB better than the frequency plannign assumptions for co-channel PAL interference. LSI Logic said its chip is designed to handle a single echo with Doppler, which would occur during reception from moving objects, such as a train or car. More information is available in the LSI Logic Press Release.

DIGITAL TELEVISION STATION ACTIONS - See ac980928.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WESH 11 WESH Television Daytona Beach FL 45 476 Dielectric THV-6A11


OTHER Items of Interest

September 21, 1998 - Issue 134 Final Edition

SPACE - Engineers Succesfully Regain Control of SOHO Spacecraft (Sept. 19)
RF Current has been following the attempts to regain control of the Solar and Heliosperic Observatory (SOHO) spacecraft since it spun out of control in late June. While not directly related to commercial wireless applications, the descriptions of the actions taken to restore the spacecraft provided an excellent introduction to spacecraft system design.

On September 16th spacecraft controllers successfully regained control of the SOHO spacecraft. A series of commands directed the spacecraft to fire thrusters and turn its face and solar panels fully towards the sun. Dr. John Credland, European Space Agency head of scientific projects, stated "It's a big step forward in our recovery plan to SOHO. We were never quite sure that we would manage to make the spacecraft point back towards the Sun, which is essential for its proper operation." Dr. George Withbroe, Director of the Sun Earth Connection science theme at NASA Headquarters remarked "...we always stayed hopeful that the resourceful people on the team could save the day. We're not there yet -- we still have to see if the scientific instruments survived. But this gives us reason to hope." Dr. Bernhard Fleck, ESA's project scientist for SOHO noted that "In some cases, the instruments have been through an ordel of heat or cold, with temperatures approaching plus or minus 100 degrees Celsius. But I'm cautiously optimistic that SOHO can win back much of its scientific capacity for observing the Sun."

More details are available in the NASA/ESA Press Release. For a complete history of the SOHO recovery effort, see the Diary of a Drama web page. This page is quite technical and very informative.

FCC Approves Two-way Digital ITFS and MDS Communications (Sept. 17)
In an Order announced today, the FCC said it was adopting new rules that would permit MDS and ITFS licensees " to use all or part of any of their 6 MHz channels for two-way service." Furthermore, "Licensees will be able to use 'response station hubs,' which will serve as collection points to response station signals and for which the operators will be issued blanket licenses, and will not have to apply for each license individually."

The technical rules for two-way operation are flexible. Multiple 6 MHz channels may be combined for wider bandwidth or "subchannelizing" of a 6 MHz may be used when less bandwidth is needed. ITFS licensees may swap channels to create contiguous spectrum. The Order retained the existing 2-hour per-channel per-week requirement for educational usuage of the ITFS channels, but the requirement may be fulfilled using data, voice, or video transmissions. ITFS licensees operating digital systems must retain at least five percent of the capacity of the licensed spectrum for educational use. Permissible lease term limits were extended to 15 years.

Interference protection will now be provided on the basis of a 35 mile radius protected service area, in addition to the current registered receive site protection. Prior notification is required before activating response station transmitters located within 1960 of a registeristed ITFS receive site. See Mass Media Report 98-52 for additional information.

FCC Proposes Changes for Terrestrial and Satellite Services in the 18 GHz Band (Sept. 17)
Currently the entire 17.7 to 19.7 GHz band is shared between terrestrial fixed service and satellite services. In the present proceeding on allocations in that band, the FCC received petitions and comments that outlined the need for blanket licensing of proposed satellite systems, noting "the difficulty in sharing between ubiquitous satellite systems and terrestrial fixed services even without blanket licensing." As a result, the FCC said "we tentatively conclude that the public interest is best served by redesigning the 17.7-19.7 GHz band to separate terrestrial fixed services from most satellite earth station operations.

The proposed plan would provide primary allocations for terrestrial fixed services in the 17.7-18.3 GHz band, for Geostationary Orbit Fixed Satellite Service (GSO/FSS) in the 18.3-18.55 GHz band and for Non-Geostationary Orbit Fixed Satellite Service (NGOS/FSS) in the 18.8-19.3 GHz band. The 18.55-18.8 GHz band would be shared on a co-primary basis by terrestrial fixed service and GSO/FSS. The 19.3-19.7 GHz would be shared by terrestrial fixed service and Mobile Satellite Service Feeder Link systems, again on a co-primary basis. Terrestrial fixed service stations operating in the 18.3-18.55 and 18.8-19.3 GHz band would be grandfathered. The Notice of Proposed Rulemaking also includes a proposal to allocate additional spectrum in the 17.3-17.8 GHz for Broadcast Satellite Service (BSS) use and 24.75-25.25 GHz for BSS feeder link use.

Several other frequencies in the 17.3 to 30 GHz range are affected by the proposals in this NPRM. The FCC requested comments on these proposals. For more information, see the full Notice of Proposed Rulemaking - FCC 98-235 or the International Bureau News Release.

FCC Adopts Rules to Implement Universal Licensing System for Wireless Services (Sept. 17)
The FCC moving forward in the implementation of the Universal Licensing System, or ULS. ULS is an intergrated database and automated processing system for electronic filing of wireless applications, license applications. The system allows public access to related information for all wireless radio services. The FCC's Wireless Bureau developed the system.

Some of the actions the FCC took in the Report and Order adopted today include consolidation of 40 existing wireless services application form into four forms. One, Form 605, is a Quick-Form application use by the Ship, Aircraft, Amateur, Restricted and Commercial Operator, and General Mobile Radio Services. Existing forms may be used until six months after the effective date of the new rules. The FCC said ":electronic filing in ULS will be mandatory for applicants and licensees in services that are licensed by auction, but not for applications and licensees in other wireless services. Public safety, private land mobile services on shared spectrum, Amateur Radio, GMRS, Ship and Aircraft, and Commercial Radio Operators may file forms either manually or electronically. However, electronic filing in ULS will be mandatory for frequency coordinators in all services, including volunter examiner-coordinators (VECs) in the Amateur service.

While this Report and Order focused on the ULS system, other items were adopted, including a proposal to authorize reciprocal operation for foreign amateur radio licensees by rule, pursuant to recent international reciprocal operating agreements. More information is available in the Wireless Bureau news release or on the FCC's ULS webpage at http://www.fcc.gov/wtb/uls/.

SATELLITE - PanAmSat Successfully Launches PAS-7 (Sept. 16)
An Ariane 44LP rocket launched from French Guiana successfully carried PAS-7 into space. The FS 1300 satellite, built by Space Systems/Loral will be co-locatedd with PanAmSats's PAS-4 Indian Ocean Region satellite at 68.5 degrees East Longitude. It has 44 transponders. PAS-7 increases PanAmSat's global fleet to 17 satellites. More information is available in the PanAmSat Press Release.

DIGITAL TELEVISION STATION ACTIONS - See ac980921.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
KFMD 55 Midwest Television San Diego CA 703 208 Dielectric TFU-30DSCC170
WBAL 59 WBAL Hearst-Argyle Baltimore MD 537 312 Dielectric TFU-20GTH-R 04
KATU 43 Fisher B'casting Portland OR 0.4246 355 Shively Labs 2010 8-Bay
KGTV 25 McGraw-Hill B'casting San Diego CA 316 205
KLRU 22 Cap. of TX Public Tele. Austin TX 59.9 345
KCET 59 Comm. TV of So. CA Los Angeles CA 190 913


OTHER Items of Interest

September 14, 1998 - Issue 133 Final Edition

CHIPS - Wavelet Technology Used in New Real-Time Video Compression Chips (Sept. 14)
Analog Devices today announced its ADV611 and ADV612 real-time video compression chips optimized for remote surveillance and closed-circuit television applications. The chips are based on wavelet video compression algorithms instead of the more common MPEG and JPEG compression methods. The chips can take an uncompressed 216 Mbits/sec. video signal and compress it through the range from 4:1 (virtually lossless) to 7500:1. The higher compression ratios make it possible to send the video over 56 Kbits/sec analog modems. Although this technology is not aimed at broadcast applications, wavelets have been used in the past for broadcast quality video. Information on the chips is available in the Analog Devices Press Release. Technical Documentation and Application Notes and FAQs are also available on the Analog Devices Web Site.

DTV - CEMA Publishes New DTV Interface Standards (Sept. 11)
One issue that has attracted the attention of the Federal Communications Commission and others is the interface between cable boxes, VCRs and the new DTV sets. The Consumer Electronic Manufacturers' Association (CEMA) and its associated Electronic Industries Association (EIA) has published four interface standards for connection of digital TV equipment. One standard is the IEEE-1394 interface. EIA document EIA-770 covers a component video interace to link a cable set-top box to a TV receiver, EIA-679 describes the National Renewable Security Standard (NRSS) Interface, and EIA-762 outlines an RF Remodulator Interface. The RF Remodulator standard specifies a baseband input and a VSB RF output on channel 3 or 4. Since it is likely that a TV station's program system information protocol (PSIP) will not be correct when it is coming from a secondary source such as a digital VCR, the TV set should be able to allow for this. CEMA adopted a recommended practice, CEBS, that details a mode that is accessed like the auxiliary input on analog TV receivers.

CEMA has released several papers outlining these new standards. For more information, see CEMA Press Releases New Choices for Linking Cable and TV Sets, CEMA Committee to Develop Versatile 1394 Internace for Cable, A/V applications, CEMA VSB Digital TV Interace Standard, CEMA Component Video Standard to Link Cable Boxes and TV Receivers and New CEMA/NCTA Standard Helps Consumers Access Cable, Satellite, Telephony and E-Commmerce Services via Smart Cards. Not everyone agrees with these new standards. See EE Times news article Industry at Odds Over DTV Interface.

SATELLITE - INTELSAT Announces Next Round of MPEG-2/DVB Interoperability Testing (Sept. 11)
INTELSAT announced it was releasing a Statement of Work (SOW) to the manufacturers of MPEG-2/DVB equipment that participated in any of the three previous rounds of INTELSAT interoperability tests in Washington DC. Other manufacturers interested in participating in the next round of tests, scheduled for early 1999, may obtain a copy of the SOW. This round of tests will "focus strictly on ensuring the interoperability of news pool feeds (i.e., transmission of 8 Mbps, FEC=3/4, Reed-Solomon outcider coding)." Manufacturers which successfully complete the interoperability testing will be certified as "ISOG Mode Compliant," and will be listed in a catalog published by INTELSAT for broadcasters. The Inter-Union Satellite Operations Group (ISOG) and INTELSAT have developed the "ISOG Reference System". It is a set of technical paramaters to provide interoperability between different manufacturers' encoders and decoders. Manufacturers wishing to participate in the tests must submit a notice of compliance with the ISOG Reference System specifications to INTELSAT by December 15, 1998. Deutsche Telekom will coordinate the testing, using global beam transponders on INTELSAT satellites in all three ocean regions.

Dick Tauber, ISOG Chairman and CNN VP of Satellites and Circuits, said, "We are looking forward to this next round of interoperability testing, as we perceive it will have very practical uses in the field. The ISOG, (the group of major international broadcasters, signatories, satellite operators and service providers) now understands where the greatest benefits from interoperability can be achieved, and we believe that this new round of testing will get us there." More information is available in the INTELSAT Press Release.

DTV - U.S. Companies Show DVB DTV Encoder Solutions At IBC '98 (Sept. 11)
U.S. manufacturers used the IBC '98 conference in Amsterdam, the Netherlands, to demonstrate their technology was not limited to the U.S. 8VSB/ATSC DTV market. Lucent Digital Video and Harris Broadcast demonstrated the Harris FlexiCoderTM MPEG-2 encoder used with a Harris COFDM modulator. The Lucent Press Release noted that the FlexiCoder can be upgraded from standard definition (SDTV) to high definition (HDTV) with the addition of a single module. Encoder modules can be "hot-swapped" while on the air. Jay Adrick, VP of Harris Broadcast Division, said "Today's global broadcaster wants a 'one-size-fits-all' MPEG-2 encoder that will play as reliably in their network operation center in New York as it does in their Paris affiliate, with interfaces for all modes of DTV transmission. The DVB interface is another clear demonstration of the Flexicoder's versatility."

Lucent Technologies used the IBC '98 show to announce the initial commercial shipments of its MPEG-2 dual encoder for SDTV, the EVA-200. Lucent also announced the HDC-100, a modular HDTV encoder and the HDEC-100, an HDTV decoder. Lucent's MPEG-2 Digital Video System is shipped with the SMPTE 310M interface. The HDC-100 controls three EVA-200 modules and can handle 1080i or 720p HD formats. More information is available in the Lucent Digital Video Annoucement.

Scientific Atlanta showed a 4:2:2 profile encoder, third party conditional access support, an electronic programming guide, data broadcast, and HDTV at IBC '98. The electronic programming guide and data broadcast services are provided through support of the DVB-T standard. Third-party conditional access support is through a marketing agreement with SkyStream Corporation, which "will support conditional access and subscriber authorization systems available from multiple third party providers." HDTV products include the PowerVu HDTM family and PowerVu PlusTM statistical multiplexing. For more information see the Scientific Atlanta Press Release.

DTV - WBTV-DT 1,000 kW DTV Station On-The-Air with COMARK Transmitter (Sept. 10)
COMARK claimed that its transmitter powered the first digital station in the country "on-the-air" at the FCC maximum power of 1,000 kW. COMARK said the system is fully compliant with the FCC emission mask and provided a final system SNR of better than 31 dB into the antenna. The AdvantageTM transmitter consists of four IOT amplifiers, generating a total of 100 kW and COMARK's digital 8VSB modulator with digital adaptive precorrection - DAPTM. COMARK said it was "the first transmitter supplier to commercially demonstrate specification compliant performance at the 25kW (per tube) power level."

WBTV-DT is licensed to Charlotte NC and owned by Jefferson-Pilot Communications. Other system compoents include a Mitsubishi MH1100E HDTV encoder and a Dolby DP569 AC-3 encoder. More information is available in the COMARK Press Release.

TECHNOLOGY - Bell Labs Breakthrough May Boost Wireless Data Rates 10-20 Times (Sept. 9)
When it is necessary to transmit more data in the same bandwidth, one option is to use a more complex modulation method. However, as modulation efficiency is increased, performance in difficult environments decreases. Scientists at Lucent Technologies' Bell Labs have developed another option, which they call BLAST, short for Bell Labs Layered Space-Time. BLAST has the potential to increase the capacity of certain wireless links by ten to twenty times. The technology depends on transmitting multiple signals on the same frequency from multiple antennas, then using advanced digital signal processing and multiple receive antennas to extract the spatial dimension of the transmitted signals. According to Lucent, "the capacity of a given frequency band increases proportionally to the number of antennas." For more information on this breakthrough technology, its limitations and its background, refer to the Lucent Technologies' Press Release. The Press Release contains links to articles on the subject and additional technical background information.

DIGITAL TELEVISION STATION APPLICATIONS - See ap980910.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WPME 28 New England Television Lewiston ME 200 251 Andrew ATW30H3H
WCAU 67 NBC Stations Mgmt. Philadelphia PA 112 262 Dielectric TLP-16A(C)
WPVI 64 ABC Philadelphia PA 500 390


DIGITAL TELEVISION STATION APPLICATIONS - See ap980909.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
KBIN 33 Iowa Public B'casting Council Bluffs IA 200 98 Dielectric TFU-24-GTH-R04
WGBX 43 WGBH Educ. Foundation Boston MA 200 391 Harris TAD-24UAD-5/60
WGBH 19 WGBH Educ. Foundation Boston MA 900 370 Harris TAD-24UDA-5/60


DIGITAL TELEVISION STATION APPLICATIONS - See ap980908.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WPXT 4 HMW Portland ME 5.5 265 Dielectric THP-O
WDBD 41 WDBD License Jackson MS 200 353 Andrew ATW30HS3H
WWLF 9 WOLF License Hazleton PA 6.3 488 Dielectric THP-0-2-1
WILF 29 Pegasus B'cast Assoc. Williamsport PA 200 223 Andrew ATW30HS3H
WOLF 31 WOLF License Scranton PA 200 360 Andrew ATW30HS3H
WDSI 40 WDSI License Chattanooga TN 75 350 Andrew ATW30HS6H
KSIN 28 Iowa Public B'casting Sioux City IA 200 611


DIGITAL TELEVISION STATION ACTIONS - See ac980908.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WUSA 34 The Detroit News Washington DC 646 254
WJLA 39 Allbritton Comm. Washington DC 646 254


OTHER Items of Interest

September 7, 1998 - Issue 132 Final Edition

SATELLITE - GE American Files Application to Move GE-3 Satellite (Sept. 4)
The FCC has found GE American Communications application to move its GE-3 satellite from 81 degrees West Longitude to 72 degrees W.L. acceptable for filing. PanAmSat Corporation filed a motion to withdraw its Application for Review and the Comision de Nacional de Comunicaciones has withdrawn its Petition for Reconsideration of the GE Americom satellite move. GE negotiated the move with Argentina.

FCC Releases Notice of Inquiry on Ultra Wideband Radio Systems (Sept. 2)
The FCC initiated an inquiry in Engineering and Technology Docket 98-153 to investigate the possibility of permitting operation of ultra-wideband (UWB) radio systems on an unlicensed basis under Part 15 of its Rules. Such systems are used for radar applications, including high resolution imaging of objects behind or under other surfaces. The Notice of Inquiry observed that current Part 15 rules limit implementation of UWB technology because the fundamental emissions may fall into restricted frequency bands such as the TV broadcast band. However, the FCC questions whether these limitations, which were developed for narrow band systems, should apply to UWB technology. U.S. Radar, Inc., Time Domain Corp. and Zircon Corporation have filed Requests for Waiver to permit operation of UWB systems. The FCC said these would be considered separately from the Docket 98-153 proceeding.

More technical information on the Rules being considered for UWB devices is available in the FCC's Notice of Inquiry. Comments are due 75 days after publication of the Notice in the Federal Register.

FCC Releases First List of Mutually Exclusive LPTV Displacement Applications (Sept. 2)
In a Public Notice released today, the FCC released its first list of mutually exclusive television translator and low power TV (LPTV) DTV displacement applications. LPTV and TV translator licensees and permittees who faced channel displacement by DTV stations were able to file applications for new channels beginning on June 1, 1998. Applications appearing on the list will have ninety days to attempt to resolve their mutual exclusivities and file minor amendments. If no resolution is possible, "the Commission reserves the right to subject these competing applications to competitive bidding." Refer to the Public Notice Report MX98-1 for more information and a list of the applications involved.

CHIPS - Philips Introduces New LDMOS devices for UHF TV Transmitters (Sept. 1)
Philips Semiconductors announced the introduction of a series of LDMOSFETs for use in frequency ranges up to 2 GHz. One member of series, the BLF861, is designed for use in 470 MHz to 860 MHz UHF broadcast transmitters. It is a 120 watt device with a gain of over 14 dB. The series also includes four BLF10xx series devices for use up to 1 GHz at power levels between 10 and 90 watts and the BLF20xx series for use up to and beyond 2 GHz. More information is available in the Philips News Release.

OTHER Items of Interest

Other Issues Available:

1998

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Last modified September 29, 1998 by Doug Lung dlung@transmitter.com
Copyright © 1998 H. Douglas Lung