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
December 1997. 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.
NOTICE: RF
Current was
not published December 1st. Items up to the U.S. Thanksgiving
Holiday appeared in the November 26th Extended Edition.
Items after that appear in the December 8th edition.
NOTICE: RF
Current was
not published on December 29th due to the Christmas and New Years
holidays. The December 22 edition was kept open through December
24th. The January 5 edition will contain stories from December 25
through January 5. Enjoy the Holiday season with your family and
friends. Don't forget the real reason this time of year is
special. Thanks again for your comments and support. Please
accept my wishes for a happy and enlightening 1998!
December 24 - Issue 99 Extended
Edition
- SATELLITE - Hughes Communications Outlines SPACEWAYTM System Plans(Dec.
23)
- Hughes Communications announced it had filed two
applications with the FCC today to increase system
capacity and add higher data rate transport services to
its SPACEWAYTM global
broadband communiations system. A Hughes Release said
"The SPACEWAY EXPTM
filing outlines an eight-satellite system operating at
geostationary Earth orbit (GEO), providing high data rate
transport services. The SPACEWAY NGSOTM
filing describes a 20-satellite system operating in
nongeostationary Earth orbit (NGSO). These additions will
increase overall SPACEWAY capacity, especially in
high-demand areas. Both systems will operate in the
Ka-band frequency range (17.7 GHz to 30.0 GHz)."
The proposed system will cover four regions: North
America, Asia Pacific, Latin America and
Europe-Africa-Middle East. Hughes said the system will
provide "businesses and consumers with fast access
to terrestrial networks, such as the Internet..."
The system will work with antennas as small as 26 inches
(66 cm) in diameter and provide data rates up to 6 Mbps.
SPACEWAY EXP will use geostationary satellites and focus
on high data rate markets. Hughes has requested locations
at 117°, 69°, and 26.2° West longitude and 99° East
longitude. SPACEWAY NGSO will "consist of four
planes with five satellites in each plane, inclined at 55
degrees with respect to the equator and in circular
orbits at an altitude of 10,352 km. Hughes said the
satellites with incorporate multiple-beam antennas,
digital processors for switching traffic among beams, and
intersatellite links to interconnect the satellites.
More information is available in the Hughes
Press Release.
- DTV - Samsung Tests HDTV Receiver Compatibility with
ATTC and CBS (Dec. 22)
- In a Press
Release issued today, Samsung electronics said it had
successfully competed HDTV receiver compatibility tests
at the Advanced Television Test Center (ATTC) in
Washington DC and at CBS Engineering laboratories in New
York. Sumsung's Release claimed its 1920x1080 HDTV format
will be the highest resolution at the Consumer
Electronics Show, starting January 8 in Las Vegas, NV.
CBS affiliate KLAS-TV will provide off-air signals for
Samsung's demonstration in Room N107 of the Las Vegas
Convention Center from January 8 to 11.
- SATELLITE - INTELSAT 804 Launched (Dec. 21)
- INTELSAT announced it has successfully launched INTELSAT
804 using an Ariane 42L launch vehicle. The satellite has
38 C-band transponders and 6 Ku-Band transponders. It
will be positioned at 64 degrees East and provide service
to markets in Europe, Asia and Africa. INTELSAT 804 is
expected to be available for commercial service beginning
in February 1998, after orbital maneuvers and in-orbit
testing is completed. More details are available in the INTELSAT
Press Release.
- CHIPS - Panasonic Claims First Single-Chip DTV Decoder
(Dec. 18)
- With the first DTV sets due in the stores in less than a
year, Panasonic joined the growing number of companies
offering semiconductor solutions for consumer DTV sets.
Panasonic said "The chip--technically termed a
"Digital Television MPEG2 Main Profile at High Level
Video Decoder" -- functions in both a 'full- spec'
mode and a 'down-conversion' mode. In the full-spec mode,
it decodes the compressed video signal from the broadcast
and outputs the original format, that is, either HDTV
(1080-lines interlaced or 720-lines progressive) or SDTV
(480-lines interlaced or 480-lines progressive). The
'down-conversion' mode converts all compressed video
signals to 480-interlaced and 480-progressive formats.
This is accomplished by a memory-efficient MPEG
down-conversion algorithm developed by PAVCAL [Panasonic
AVC American Laboratories, Inc.] ."
The chip will decode any of the 18 ATSC formats and was
designed for use in standard and high definition digital
TV sets, digital set-top boxes, computers and other
digital products. It will be in products demonstrated at
the Consumer Electronics Show in Las Vegas January 8-11.
More information is available in the Panasonic
Press Release.
- FCC Requests Comments on Fee Alternatives for
Ancillary or Supplementary DTV Services (Dec. 18)
- The FCC is requesting comments on "various fee
alternatives for broadcasters' use of excess digital
capacity to offer certain services that would be
'ancillary or supplementary' to their over-the-air
digital broadcast (DTV) signals." No fees would be
accessed for advertiser supported services
A News
Release (nrmm7021) summarizes the request. More
details are available in the complete text of the Notice
of Proposed Rule Making. (also available as a WordPerfect
document.)
FCC
Chairman Kennard's Statement said the proceeding
would "provide guidance to broadcasters as they
continue to build-out their DTV stations."
Commissioner Susan Ness, in her statement,
said "Congress has made it abundantly clear that it
fully expects broadcasters to focus their digital
capacity on providing their local communities with a
wealth of free broadcast programming, including
programming transmitted in high definition. While the
opportunity to provide many new and exciting services is
available through the flexibility of the digital
standard, I do not anticipate broadcasters will abandon
their birthright of top quality free video
broadcasting."
- FCC Experimental Actions In November (Dec. 17)
- The FCC has released its monthly list of experimental
actions. Most are for licenses to use IMMARSAT terminals,
however one may be of interest to readers - WA2XOT,
Motorola, Inc. to use 2450-2500 and 2162- 2180 MHz. for
test and development of equipment for wireless cable data
networks in Schaumburg, Illinois. See the Public
Notice (pnet7028) for the entire listing.
- CHIPS - NDS, Motorola and Alps Deliver DTTV Chip Set
Solution (Dec. 17)
- While most of the focus on terrestrial digital TV has
been with the U.S. ATSC DTV system, the European
community is also beginning a DTV build-out. The European
system is based on the MPEG-2, DVB-compliant data and a
COFDM transmission system. Motorola and Alps said their
"front-end solution" is "achieved with
three chips which provide Coded Orthogonal Frequency
Division Multiplex (COFDM) demodulation, 2K-mode Fast
Fourier Transform (2K-FFT) processing, and forward Error
Correction (FEC)." A Motorola
Press Release said: "The new DTTV front-end
solution takes signals from existing roof top aerials and
demodulates them using the DVB-T specification, and
outputs an MPEG-2 stream for use in digital TV sets or
digital set-top boxes. The front-end has been designed to
receive 2K carrier DVB compliant signals, the profile for
DTTV broadcasting in the U.K. as specified by the d-MUX
organization."
Samples of the three chip set are available now.
Production release is scheduled for first quarter 1998.
- SATELLITE - INTELSAT and Columbia Communications
Resolve Orbital Slot Issue (Dec. 16)
- Both INTELSAT and Columbia Communications had claimed the
319/319.5 degree East orbital slot position. In a Press
Release issued today, INTELSAT said they had reached
an agreement on the slot. It said "Under the terms
of the agreement, Columbia will cease operation of the
TDRS-4 spacecraft at the 319ºE/41ºW location by 15 May
1998. In its place, Columbia will take title to the
INTELSAT 515 spacecraft, to be renamed Columbia 515, and
begin operating that satellite by 1 April 1998 at
322.5ºE/37.5ºW. Columbia will lease back to INTELSAT at
no charge a number of transponders on the Columbia 515
satellite."
More information on Columbia Communications is available
at http://www.tdrss.com.
- DTV - ATSC Group to Tackle Data Broadcasting Over ATSC
Broadcast Systems (Dec. 16)
- A new ad hoc group on Data Broadcasting Implementation
will meet January 8, 1998 in Washington D.C. "to
create a list of requirements and recommended practices
that will allow a preferred implementation/recommended
practice to be created for data sources to be connected
to ATSC broadcast systems in a known and implementable
way."
The meeting will focus on these issues:
- How to connect a data source into the transport
multiplex
- How is flow control to be handled?
- What are the communications protocols between the
data source and the \par \par broadcasting
system?
- How are the SI and PSIP information formulated
and injected?
- Where are the protocols and transport created?
For details on how to participate or to obtain more
information see http://www.atsc.org/Data_Implementation.html.
- DIGITAL TELEVISION STATION APPLICATIONS
- WFAA-DT Channel 9 - Dallas, TX -
18.6 kW - Dielectric TW-789-R antenna - see ap971224.txt
- WFLX-DT Channel 28 - West Palm
Beach, FL - 21601 kW (must be a typo in FCC
listing!) - Harris 18C-VSM-28 antenna - see ap971223.txt
- WOIO-DT Channel 10 - Shaker
Heights, OH - 3.5 kW - Harris TAC-2FMA antenna -
see ap971223.txt
- WOIO Ch. 19 - EXPERIMENTAL -
Shaker Heights, OH - 3720 kW - No antenna
description - see ap971223.txt
- OTHER Items of Interest
-
December 15 - Issue 98 Edition
- FCC To Consider Fees for Ancillary or Supplementary
Use of DTV Spectrum (Dec. 15)
- The Agenda
for the FCC Open Meeting on December 18th lists an item
where "The Commission will consider action
concerning implementing the transition to digital
television (DTV) for existing television broadcasters in
accordance with the provisions of the Telecommunications
Act of 1996 regarding fees for ancillary or supplementary
use of DTV spectrum."
Also being considered are "substantive amendment and
modifications to the Commisson's general competitive
bidding rules for all auctionable services that are
intended to simplify the Commission's regulations,
eliminate unncessary rules wherever possible and increase
the efficiency of the competitive bidding process."
The audio portion of the meeting will be broadcast live
on the Internet. See the FCC's Internet audio broadcast
page at http://www.fcc.gov/realaudio/.
Following the open meeting the Commission will hear a
presentation on the status of competition in the
multichannel video industry. Details on this are
available in the Public
Notice (pnmc7025)
- Satellite - INTELSAT Finds Spot for Recovered 605
Satellite, Plans New Launches (Dec. 11)
- As reported in the September
and October
issues of RF Current, INTELSAT engineers developed a
method for working around the telemetry anomaly detected
in the 605 satellite in September. The INTELSAT Board of
Governors was satisfied with the performance of this fix
and, at their December 6-11 meeting, decided to deploy
605 at 332.5 degrees east. An
INTELSAT Press Release noted that "The new
decision to assign this spacecraft to the 332.5ºE
location...represents the conclusion of extensive
analyses and tests which began on 11 September, and
INTELSAT's succsss in devising a ground-based solution to
compensate for the loss of the telemetry information.
At the same meeting mentioned above, the INTELSAT Board
of Governors also authorized procurement of two
additional INTELSAT spacecraft, and procurement of three
launches on Ariane 5 launch vehicles for INTELSAT 902,.
903 and 904. The INTELSAT IX series satellites are built
by Space Systems / Loral. More information is available
in a Press
Release.
- TECHNOLOGY - ParkerVision Claims First Universal
Direct Conversion Receiver IC's (Dec. 10)
- If you've experimented building radio receivers, you've
probably build one of the simple "direct
conversion" receivers for reception of shortwave
signals. I used a direct conversion receiver as the basis
for my frequency calibrator described in my March
and May
1994 RF Columns in TV Technology (also see the drawing).
It appears ParkerVision has taken this simple receiver
approach and refined it into a commercial product.
According to the company's news release, "The
'Eddie' chip receives and processes any frequency from 1
MHz. to 1 GHz., consumes less than 10 mA of power, passes
signal bandwidths up to 3 MHz, provides excellent signal
to noise allowing for high gain/high sensitivity, and
costs a fraction of the current RF electronics that Eddie
replaces."
ParkerVision CEO Jeffrey Parker said "We are certain
that there are also many new wireless architectures that
our technology now makes possible. For example, with our
Universal Direct Conversion Receiver technology we
created a very low cost FM data link that can move
megabits of digital data and has over 100 times (20db)
more interference rejection than a traditional FM link,
yet costs much less. This kind of reliability and low
cost is lacking in today's RF electronics. In addition to
the benefits that can be derived from applying our
technology to traditional wireless products, our goal is
to help create new and unique products and systems in
concert with those visionaries who have been waiting for
the breakthroughs that our technology represents, and
together raise the standards by which RF products are
judged.
- SCIENCE - Scientist Find Magnetosphere May be Filled
by Energized Gas From Earth's Pole (Dec. 9)
- Scientists have generally believes the Earth's magnetic
field captured a lot of the solar wind and formed the
giant cloud of electrified gas that surrounds our planet.
Now Dr. Rick Chappel and Dr. Barbara Giles will present
papers showing that this magnetosphere may actually be
filled by a fountain of energized gas blowing from the
north and south poles.
NASA's Marshall Space Flight Center has posted an outline
of the findings on a very interested and well illustrated
web page. If this subject interests you, check out Earth
Weaves Its Own Invisible Cloak.
- OTHER Items of Interest
-
December 8 - Issue 97 Final
Edition
- DTV - ATSC Issues RFI on Standard for Satellite
Transmission of DTV Signals (Dec. 8)
- The ATSC Specialist group on Satellite Transmission has
issued a Request for Information "with the goal of
defining the paramters of importance for a voluntary ATSC
standard for satellite transmission of DTV signals."
It said such a voluntary standard and recommend
practicies for satellite distribution of DTV would allow
manufacturers to build equipment that which will be
interoperable with equipment from other manufacturers,
allow TV networks to share signals feeds (at their
discretion) and make it possible for satellite owners and
users to "understand the operating objectives for
DTV satellite transmission."
The RFI defines three types of satellite transmission:
contribution - such as program source material in its
original or very early form, distribution - program
material nearly in its final form except for processing
at local broadcast facilities, and Direct-to-home (DTH) -
programs packages and processed for reception by end
users.
The deadline for responding to the RFI is December 15,
1997. The complete RFI is available in HTML, see T3/S14 Request
For Information. Also see http://www.atsc.org/T3S14_RFI_information.html.
- FCC Seeks Comment on DTV Channel Allotment Filings
(Dec. 3)
- Yesterday the FCC issued a Public
Notice (pnmm7238) requesting comment on filings by
the Association for Maximum Service Broadcasters, Inc.
(MSTV) and others requesting changes to the FCC's DTV
Table of Allotments. The MSTV filing suggested making 357
changes to the table to reduce interference to both
analog and DTV stations in the most congested areas of
the U.S. and cure "a large number" of the case
of DTV-DTV adjacent channel short spacings.
The Public Notice also asked for comment on the proposal
from the Association of Local Television Stations, Inc.
(ALTV) to address the disparity in authorized power
between UHF DTV facilities of VHF NTSC stations and UHF
DTV facilities of UHF NTSC stations. The ALTV proposal
would permit DTV stations to increase power to 1000 kW,
provided they used antenna beam-tilt and/or other
technologies to prevent "any incremental visibile
interference." This proposal does not seek changes
in channel assignments.
The FCC said it would provide a single, brief 15 day
period for response to these filings. Specifically, the
FCC said "We request comment on whether the
proposals set forth in these filings by MSTV and ALTV
represent full industry agreements." "With
regard to MSTV's filing, we seek comment on whether the
issues raised by MSTV are more appropriately handled on
an individual case-by-case basis or through a new
Table." "With regard to the ALTV filing, we
request comment on how such an antenna beam tilt approach
would relate to other solutions for resolving the UHF
power problem." Comments must be submitted on or
before December 17th.
- DTV - SRI Consulting Study Says Most Viewers Will
Watch DTV Using Converter Boxes (Dec. 3)
- SRI-Consulting
said a new study it conducted found most of the the 12
million consumers worldwide who will watch terrestrial
DTV in the next ten years will use a digital converter
box rather than a digital TV set. The high cost of
digital HDTV and digital SDTV TV sets was listed as the
reason most consumers will go with converter boxes.
Paul Di Senso, senior consultant and lead researcher for
the "Digital Broadcast Television" report
issued by SRI Consulting, said "The high cost of
digital-TV sets means that most consumers who want to
watch digital terrestrial broadcasts will choose to buy
or rent a converter box."
- DTV - First Commercial DTV Television Stations On-Air
(Dec. 2)
- KITV-DT begain transmitting ATSC digital television at
3:34 PM HST, November 28th, in Honolulu, Hawaii. It was
joined by satellite station KHVO-DT, Hilo, Hawaii on
December 2nd at 8:59 PM. An Itelco
Press Release noted these two stations are the first
commercially licensed digital television stations in the
United States. Itelco supplied the liquid-cooled solid
state transmitters used at these stations.
KITV-DT transmits from an antenna atop the Ala Moana
Hotel in Honolulu. The KHVO-DT antenna is mounted below
the KHVO NTSC antenna on top the Naniloa Hotel in Hilo.
(Editor's note - when I drove by the Naniloa Hotel in
Hilo December 7th I noticed two RFS panel antennas
mounted side by side, for a narrow beam, on the short
tower supporting KHVO's main VHF antenna. Unfortunately,
I didn't have a portable Sony Digital Watchman with me so
I couldn't verify what the station was actually
transmitting!)
Studio and transmitter facilities were designed by and
constructed under the supervision of Thomas L. Mann,
Garrison C. Cavell and Joseph Davis, principals in
Cavell, Mertz and Perryman, Inc., Consulting Engineers,
Fairfax, Virginia and Los Angeles, California. Antenna
installatin was done by LDL Communications, Inc. Philips
BTS provided the Grand Alliance digital encoders and
interface.
- DTV - Canada and South Korea Adopt ATSC Standard (Dec.
1)
- ATSC said that the Department of Industry of the Canadian
government formally adopted the ATSC DTV Standard on
November 8th. The Korean Ministry of Information and
Communication selected the ATSC standard on November 21.
Robert Graves, Chairman of the ATSC, said:
"We believe these
countries are the first of many throughout North and
South America, Australia, and Asia that will adopt our
standard." Canada and Mexico participated
extensively in the U.S. process during the past ten years
to help develop what was always intended to be a North
American standard. Consequently, Mexico is considered
certain to adopt the Standard along with all of Central
America. Moreover, Brazil and Argentina are carefully
evaluating the ATSC Standard, and the chances are
excellent that it will be adopted throughout all of South
America. In Australia, laboratory and field tests have
recently been completed as part of an extensive
evaluation of the ATSC Standard and the competing
European standard, and here again the prospects for
adoption of the ATSC Standard are excellent. In Asia, in
addition to the recent Korean decision, Taiwan has made a
tentative decision to adopt the ATSC Standard, and China
is conducting a careful evaluation where once again the
prospects for the ATSC Standard are excellent."
More details are available in
the ATSC
Press Release.
- DTV - Intel Files for Experiment TV License (Dec. 1)
- The November
28, 1997 Broadcast Applications listed in today's FCC
Daily Business included an application from Intel
Corporation in Santa Clara, California, requesting a
construction permit for a new experimental television
station on channels 6, 12, 28 and 62. The ERP listed was
18 kW (vis.) and the transmitter location was given as
2200 Mission College Blvd., Santa Clara, CA. The antenna
proposed is an Antenna Research Associates, Inc. VBC-31J
at 38.7 meters.
- OTHER Items of Interest
-
- DIGITAL TELEVISION STATION GRANTS
- WSB-DT Channel 59 - Atlanta, GA
- 1000 kW - Dielectric TRU 30DSC-R 04 antenna -
see ac971128.txt
- DIGITAL TELEVISION STATION APPLICATIONS
- WXIX-DT Channel 29 - Newport, KY
- 247.6 kW - Harris 18C-VSM-29 antenna - see ap971202.txt
- WBOC-DT Channel 21 - Salisbury.
MD - 173.8 kW - Dielectric TVP-P4-16-1 antenna -
see ap971202.txt
- WKOW-DT Channel 26 - Madison, WI
- 218.5 kW - Dielectric TFU-30GTHR(S) antenna -
see ap971202.txt
- WNWO-DT Channel 49 - Toledo, OH
- 302.3 kW - Harris 18C-VSM-49 antenna - see ap971205.txt
Other Issues Available:
1998
1998
1997
1995 and 1996
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Last modified January 4, 1998 by Doug Lung dlung@transmitter.com
Copyright © 1998 H. Douglas Lung