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This page contains stories from RF Current issues published in August 1997. Links referenced in the articles
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August 25 - Issue 83 Final
- FCC Releases OET-65 Bulletin on Evaluating RF Exposure
Compliance (Aug. 25)
- The FCC Office of Engineering Technology has released its
long awaited OET Bulletin 65 on "Evaluating
Compliance With FCC Guidelines for Human Exposure to
Radiofrequency Electromagnetic Fields". OET-65 is
considerably more detailed than OST-65, which it
supersedes. OET-65 contains information on evaluating
compliance near more complex structures such as parabolic
antennas. One handy feature is the addition of tables
showing the minimum distance where RF exposure levels are
not predicted to be exceeded for various combinations of
frequency and power level.
OET-65 was released in two parts. The core document,
OET-65, outlines the general procedures for determining
compliance, while OET-65A, a supplement, includes tables
and formulas specifically for use by broadcasters. OET-65
is available in WordPerfect and Adobe Acrobat formats. It
appears some of the figures may be missing in the Adobe
Acrobat version. For links to all OET-65 documents, use
the FCC web page http://www.fcc.gov/oet/info/documents/bulletins/#65
or visit the ET93-62
- FCC Amends Parts 73 and 74 of Rules to Permit Certain
Minor Changes without a CP (Aug. 25)
- The FCC released its Report
and Orderin Mass Media Docket 96-58 "In the
Matter of Amendments of Parts 73 and 74 of the
Commission's Rules to Permit Certain Minor Changes in
Broadcast Facilities Without a Construction Permit".
Most of the rule changes dealt with FM broadcast
stations, however, some of the changes will be of
interest to TV licensees. Some of the changes now
permitted without first obtaining a construction permit
include (with certain restrictions) replacement of one TV
directional antenna with another, changes to the
vertically polarized ERP up to the authorized
horizontally polarized ERP, and use of formerly licensed
main TV facilities as auxiliary facilities.
These new rules are not reflected in current FCC
applications. Stations wishing to take advantage of these
rule changes should use the forms included in the Report
- DTV - Update - KITV Files for DTV facilites on
Haleakala, Hawaii (Aug. 25)
- Today's list of FCC
Broadcast Applications included an application from
Argyle Television, Inc. in Wailuku Hawaii for a new
digital TV facility for KMAU-TV on digital channel 29.
The ERP was specified as 51.2 KW at an HAAT of 1,770
meters, near the summit of Mt. Haleakala. The antenna
specified was an RFS PHP4.
- FCC Releases NPRM on Preemption of Local Restrictions
on Broadcast Facilities (Aug. 21)
- Responding to a "Petition for Further Notice of
Proposed Rule Making" filed by the National
Association of Broadcasters and the Association for
Maximum Service Television, the FCC released a Notice
of Proposed Rule Making In the Matter of the Preemption
of State and Local Zoning and Land Use Restrictions on
the Siting, Placement and Construction of Broadcast
Station Transmission Facilities. The petitioners
proposed a rule which would set specific time limits for
state and local government action in response to requests
for approval of broadcast transmission facilities. The
time limits requested varied depending on the nature of
the request, but in all cases were 45 days or less. If
the local government did not act in this time frame the
requested would be deemed granted.The petitioners also
requested categorical preemption of other local laws
restricting transmission facility construction due to
environmental or health effects due to RF emissions.
The Commission asked for comments on how far it should go
in preempting local regulations. Comments are due October
30, 1997 with reply comments due December 1, 1997. Full
text of the Notice of Proposed Rulemaking is available
on-line from the FCC in plain
text (fcc97296.txt) or Adobe
Acrobat (fcc97296.pdf) formats.
- TECHNOLOGY - Univ. of Florida Engineers Use Lightning
to Test Electrical Systems (Aug. 20)
- University of Florida engineers in Gainesville have built
their own runway, complete with lighting systems and now
plan to launch rockets with wires attached into likely
lightning generating clouds. The purpose is to test ways
to reduce the expensive damage caused by lightning and
also reduce the potential danger to pilots.
Two different runway surfaces will be tested along with
two different lighting systems -- one using direct buried
cables and stake mounted lights and the other with the
light mounted on a metal can with the transformer inside.
More information on this interesting experiment is
available in the University of Florida
- OTHER Items of Interest
August 18 - Issue 82 Final
- DTV - KITV-TV Honolulu to Start DTV In 1997 (Aug. 18)
- Argyle Television announced today that KITV-TV, its ABC
affiliate in Honolulu, will begin broadcasting DTV in
December of this year. pending receipt of all necessary
permits. Bob Marbut, chairman and CEO of Argyle, said
"Channel 4, along with its satellite stations
KMAU-TV and KHVO-TV, will be the first to achieve digital
transmission in Hawaii and will be among the first to do
so in the United States."
Mike Rosenberg, general manager of KITV, added that
KITV's DTV transmitters will be capable of delivering
four or more digital pictures simultaneous and
"...will also offer high-speed Internet and sother
data services during most of the broadcast day and a
superb, theater-quality picture during prime time."
Rosenberg said KITV has invested "$15 million and
more than two years of research and planning to enhance
Argyle's effort in Hawaii should offer a good test of the
technical soundness of the 8-VSB U.S. DTV modulation
scheme. KITV is located in Honolulu, but KMAU is on Maui
and KHVO is located in Hilo on the east side of the big
island of Hawaii. All the NTSC facilities are VHF: KITV
is channel 4, KMAU channel 12 and KHVO channel 13. The
last two have CP's to improve facilities. For DTV, all
are on UHF: KITV is on channel 40 at 1,000 kW, KMAU on 29
at 50.1 kW and KHVO on 18 at 50.1 kW.
The topography of the Hawaiian Islands allows reception
over great distances. In the early 80's I showed it was
possible to receive channel 26 from Wiliwilinui Ridge on
Oahu on the Kona side of the Big Island of Hawaii. The
propagation path over water was quite variable. KITV has
the advantage of an intermediate station in Maui.
Haleakala on Maui, at an elevation over 10,000 feet,
provides an excellent relay point. It will be
interesting, however, to see how the long over water
paths affect the 8-VSB digital signals.
- FCC Issues Order and NPRM on Use of Frequencies Above
40 GHz. (Aug.15)
- Thursday the FCC's Office of Engineering and Technology
released FCC 97-267, Memorandum Opinion and Order and
Fourth Notice of Proposed Rulemaking in ET Docket 94-124,
Amendment of Parts 2, 15, and 97 of the Commission's
Rules to Permit Use of Radio Frequencies Above 40 GHz.
for New Radio Applications. FCC 97-267 makes available th
59-64 GHz. band for fixed field disturbance sensors and
reaffirms an earlier decision limiting spurious emissions
from vehicle radar systems operating in the 46.7-46.9
GHz. band. The NPRM portion of FCC 97-267 addresses the
proposed spectrum etiquette filed by the Millimeter Wave
Communications Working Group.
While manufacturers of systems operating in these bands
will be interested in the details of the document, many
RF engineers will find the descriptions of new millimeter
wave technology interesting. "Synthetic vision"
systems for use in airport environments during poor
visibility conditions are mentioned as one use of the
frequencies above 90 GHz. The full text of FCC
97-267 is available from the FCC web site.
- SCIENCE - Notre Dame Researchers Demo Transistorless
Approach To Computing (Aug. 15)
- University of Notre Dame researchers reported in the
August 15 issue of Science on their "first
experimental demonstration of a transistorless approach
to computing, calling quantum-dot cellular automata
(QCA)". In the experiment a single electron was used
to control the position of another electron. If a
practical implementation of QCA is successful, the
researchers said a 4-inch square QCA chip could contain
as many as 40 trillion devices.
More details on this revolutionary technology are
available in the Notre
Dame Press Release and at the QCA Home Page.
- INDUSTRY - P-Com, Inc. to Install 40 GHz. Broadcast
Video System (Aug. 13)
- P-Com, Inc. announced that its Technosystem unit in Italy
was award a contract to build a 40 GHz. broadcast video
system to serve local TV sets. It will have a
"potential transmission capacity of up to 24
channels and will be utilized by RAI in Rome",
according to the P-Com
The service is part of a "project financed by the
European community for the development of a cellular
radio system to provide broadband digital TV and
multimedia services to subscribers."
More information on P-Com is available at www.p-com.com.
- DTV - Lucent Technology to join Microsoft in DTV Team
- Lucent Technology said Tuesday it would join the Compaq
Computer, Intel Corporation and Microsoft Corporation
"DTV Team" in their effort to bring new,
affordably priced digital broadcast services to market.
In its Press
Release, Lucent said its Microelectronics Group is
"developing a DTV receiver reference design
architecture that will be compatible with the DTV Team's
HDO proposal for adding new capabilities as the
technology develops." Lucent is also involved in the
design and implementation of encoder / decoder circuits
for ":higher resolution signals." Last year
Lucent said it was working with Mitsubishi to jointly
develop HDTV chip sets.
Lucent received commendations from other members the DTV
Team, including Craig Mundie, senior VP of Microsoft's
consumer platform division, who said: "Their core
competencies in the area of microelectronics will be of
great value to our partners as they move forward in
implementing convergence products in 1998 and 1999. Of
paramount importance to the broadcasters is Lucent's
CODEC and telecommunication product families.
- OTHER Items of Interest
August 11 - Issue 81 Final
- SATELLITE - PanAmSat Announces Successful Launch of
PAS-6 (Aug. 8)
- PanAmSat announced that "PAS-6, the first of three
high-powered broadcast satellites built by Space
Systems/Loral (SS/L) for PanAmSat Corporation of
Greenwich, Conn., was successfully launched in orbit at
2:46 a.m. Eastern Time from Kourou, French Guiana."
The satellite's on-board power is is over 10 kilowatts,
with a total satellite transmitter RF power greater than
3600 watts, divided among 36 Ku-band transponders.
PanAmSat claims this makes it "one of the most
powerful communications satellites ever launched."
The satellite will be stationed at 43 degrees West
More technical details are available in the Loral
News Release. Earlier this week Loral announced it
received an order to build a third digital audio radio
service (DARS) satellite for CD Radio. Information on
this satellite is also available in a Press
- DTV - Comark Announces Agreement with MRC for DTV STL
Microwave Products (Aug. 7)
- Comark Digital Services said it had reached an agreement
with MRC, a division of California Microwave, "to
offer integrated systems for digital television.".
Broadcasters will, in most cases, have to transmit their
digitized conventional NTSC TV signal along with the
compressed DTV signal using the same spectrum they are
now using for one analog TV STL (Studio Transmitter
Link). California Microwave has posted an application
note on Converting
from Analog to Digital Video STLs, along with other
digital microwave information on their web site at http://www.cm-mrc.com.
- TECHNOLOGY - Robot "LawnNibbler" Cuts Grass,
Not Kids (Aug. 6)
- Kevin Hakala, a graduate student at the University of
Florida's Machine Intelligence Laboratory has developed a
robot lawnmower that uses a combination of an RF
activated perimeter wire, sonar and infrared sensors and
emitters to know where its been what what obstacles are
in its way. Hakala said ":It will trim the grass in
a defined area while avoiding obstacles such as trees,
children, toys or pets. It uses two smart systems: one to
tell it where it is and another to tell it what to
More information is available in a News
Release from the University
- OTHER Items of Interest
August 04 - Issue 80 Final
- TECHNOLOGY - Acrodyne Introduces Single Tube Dual
Channel Transmitter Line (July 31)
- Acrodyne announced it has developed a method of combining
an NTSC analog UHF TV signal with an adjacent channel DTV
signal, all in the same transmitter. Acrodyne calls it
"ACT (for Adjacent Channel Technology)".
Acrodyne's press release used a transmitter equipped with
a Diacrode with a peak envelope power rating of 104kW as
one example. It could transmit a 25kW NTSC visual signal,
a 2.5kW NTSC aural signal and a 2.5 kW DTV signal
simultaneously. Additional amplifiers can be added for
more power capability and the ratios between the various
signals adjusted, so long as the peak power does not
exceed the tube's rating.
One advantage of this technology is that a station could
change the ratios to favor the DTV signal when digital
sets become more widespread. The transmission of three
signals through one amplifier will require excellent
linearity to prevent intermodulation products from
creating interference among the signals.
More information on this technology is available in the Acrodyne
Press Release and on Acrodyne's Engineering Forum,
accessible through a marketing
survey form. You can bypass the form by clicking on
the link at the top of the form to indicate you've
already filled it out.
- SATELLITE - Motorola Announces First Iridium Space to
Ground Mobile Tests (July 31)
- In a Press
Release issued today, Motorola said it had
established IRIDIUM(R) system satellite-to-ground mobile
paging and radio communications links. Motorola claims
these are the first such transmissions through a
low-earth orbit mobile satellite communications system.
The Motorola release said "On July 3, an IRIDIUM
satellite transmitted hundreds of messages to IRIDIUM
prototype pagers during a South-to-North orbital pass
over Motorola's Satellite Communications Group (SCG)
Chandler facility. The first links between the satellite
and IRIDIUM prototype phone handsets were made July
According to the release, the phone handsets weren't
talking to each other. Instead, they transmitted ring
channel burst signals. These signals enable the handset
to locate and acquire the satellite. They will be able to
handle voice, fax and data messages. The system is
expected to be activated commercially late in 1998.
Amateur Radio licensees have experimented with
communications through low earth orbiting satellites for
over a decade. More information on this side of the LEO
story is available from AMSAT.
- DTV - CEMA President Predicts Rapid DTV Acceptance
- Gary Shapiro, President of the Consumer Electronics
Manufacturers Association (CEMA) told attendees of the
Marketing Society of the Cable and Telecommunications
Industry National Marketing Conference that
"American consumers always wanted the best
entertainment products the market could provide."
He predicted that HDTV will become the preferred medium
for TV advertisers, with Superbowl ads in HDTV by 1999.
He also saw most prime time network programming shot in
HDTV by 2000 and one million HDTV sets sold by 2000. He
suggested HDTV sets will be in short supply, saying 30
million Americans are early adopters of new technology
and noting 18 million Americans have spent over $2,000 on
large screen TV sets, which will be ready for replacement
in the next few years. Additional predictions are
contained in the CEMA
- OTHER Items of Interest
Other Issues Available:
1995 and 1996
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Last modified August 25, 1997 by Doug Lung email@example.com
Copyright © 1997 H. Douglas Lung