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 March 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.

The Preview Edition of the April 6th RF Current is now available.

March 30 - Issue 111 Final Edition

DTV - Tiernan to Introduce HDTV Encoders at NAB '98 (Mar. 30)
Tiernan Communications, Inc. announced today it will be showing a line of products for HDTV broadcasting at NAB '98. Among the products announced were the full featured THE 1, a DTV encoder supporting SDTV and HDTV formats. The flexible unit will work with either the ATSC standard or the MPEG-2 Main Profile at High Level (4:2:2) at rates from 10 Mbps to 160 Mbps. A lower cost alternative is the THE 10 for ATSC HDTV broadcasting in either 720P or 1080I formats. This unit includes a multiplexer meeting the ATSC standard. Other products include a modular Integrated Receiver Decoder (IRD), the TDR6H, which can be configured for various HDTV applications. Tiernan also has digital video equipment for satellite distribution. No information was available on the Tiernan web site concerning the new products.

DTV - Harris/PBS DTV Express Attracts Attention from FCC - See it at NAB (Mar. 27)
The FCC is showing its support for DTV Express, a joint effort of Harris Corporation and PBS. The 66 foot, 18-wheel vehicle is designed as an educational display to help broadcasters prepare for the DTV transition. It includes digital programming demonstrations and simulations in a "Living Room of Tomorrow", "Classroom of the Future" and a DTV station. The curriculum has two tracks - one focusing on business operatiosn and the other on technical management.

FCC Commissioner Susan Ness congratulated PBS and Harris for their work on DTV Express at its launch Monday, noting that "As one who has labored in the regulatory vineyards, I am particularly excited to witness digital television being transformed from concept to reality." (Commissioner Susan Ness - remarks as prepared for delivery) Harris Corporation said Friday that FCC Chairman Kennard would discuss DTV at NAB Monday morning (April 6) at 10:30 AM in front of the Harris/PBS DTV Express at the Harris booth.

DTV - Circuit City Claims Spot as First Retailer to Demo Consumer HDTVs with Live Broadcasts
Circuit City says it will be the first retailer in the U.S. to demonstrate a live HDTV broadcast using actual HDTVs expected to be available for consumers. The demonstration will take place at the Galleria Circuit City store at 13838 Dallas Parkway, Dallas and the North Richland store at 8701 Airport Freeway in Fort Worth, Texas. The demonstration will use the KXAS-DT broadcast of the Texas Rangers Major League Baseball home opener. (See the March 23 RF Current for more information on this broadcast.)

Sets for the HDTV display will be provided by Panasonic and Zenith. The Panasonic set is a 56-inch widescreen rear projection model with a DTV set-top converter box. The Zenith set is a 64-inch widescreen rear projection unit. Alan McCollough, Circuit City president, said "This broadcast marks the first time a U.S. retailer has given consumers the opportunity to view a live digital high definition broadcast on televisions they can purchase later this year." He commented that "Since we began advertising this event, customers have been calling our stores for information regarding products and the broadcast. We expect a significant turnout for this historic occasion."

DTV - Texas Instruments to demo DLP technology at Texas Rangers HDTV broadcast (Mar. 25)
Texas Instruments (TI) joins other companies using KXAS's HDTV broadcast of the Texas Rangers Opening game to demonstrate their HDTV products and technology. Texas Instruments will have a receiver at the Ballpark "to create a digital signal for display" using TI's Digital Light Processing technology (DLP). Jerry Setliff, TI's Manager for the project, said "It is important to understand that what we will be showing at The Ballpark is not a television product. Rather, we'll be showing a technology that has significant potential for the future: it's a technology. which is the only truly digital projection/display technology currently in widescale production." More information on DLP is available at http://www.ti.com/dlp/main.html.

DTV - Mitsubishi Unveils Second Generation HDTV Encoders and Decoders at NAB 98 (Mar. 25)
Mitsubishi will be demonstrating its new 1100 series of DTV encoders. The series includes the MH line of HDTV encoders and decoders, the BC line of SDTV encoders and decoders and the TM line of multiplexers and demultiplexers. Encoder features include automatic detection of film-based material, internal conversion of 60 field interlaced materials and a dedicated RS-232 port for EIA-708 standard advanced caption data. The units can accept 4:2:2 or 4:2:0 component signals.

Mitsubishi is currently involved in several DTV projects, including Comark Digital Services work with TV Globo in Brazil for World Cup Soccer HDTV broadcasts, LIN Television and Comark's Texas Rangers broadcast on KXAS and WHD-TV, and WFAA's first DTV broadcast on VHF earlier this year.

FCC Reacts to DTV Interference to Medical Devices (Mar. 25)
The case of WFAA's DTV station interfering with unlicensed medical monitoring equipment (see the March 9th RF Current) has attracted the attention of the FCC and Food and Drug Administration (FDA). In a Joint Statement, the FCC said it "will ensure that TV broadcasters communicate with area hospital and other health care facilities to avoid interference to medical telemetry devices." The FCC also agreed to provide a Fact Sheet on the problem and a listing of the channels that will be used for DTV in each area. The FDA said it is sending a Public Health Advisory to all U.S. hospitals and nursing homes alerting them to the potential problems with DTV interference. The FDA will also "work with medical device manufacturers to ensure the devices are adequately labeled to alert users about the need to take steps to avoid interference."

With vacant TV channels destined to become more scarce, the FCC and FDA said they will "explore the long term spectrum needs of medicla devices so as to avoid future interference problems.". See the FCC Digital TV and Medical Telemetry Devices web page for more information.

FCC Experimental Actions (Mar. 25)
The FCC released its monthly Experimental Actions Public Notice on the FCC web site one day before the release date on the Notice. No applications were granted that impact broadcast or broadcast auxiliary spectrum during February. Two grants were interesting. Johns Hopkins University Applied Physics Lab was authorized to operate WA2XPM on frequencies from 8 to 20 MHz. "to measure global-scale magnetospheric convection by observing plasma motion in the atmosphere." The station will be in Chiniak (Kodiak Island) Alaska. Millitech Corporation was granted WA2XPY "to test broadband interactive media transmission" in various bands between 24.25 and 31.3 GHz throughout the continental U.S., Alaska and Hawaii. See the FCC Office of Engineering and Technology Public Notice, Report 309, for the complete list.

DTV - TV Manufacturers Showcase HDTVs At NAB (Mar. 24)
The Consumer Electronic Manufacturers Association (CEMA) is sponsoring a demonstration at NAB 1998 in Las Vegas showing HDTVs by Panasonic, Sharp and Zenith. The sets will be displayed in "family room enviroments similar to those consumers will enjoy", in the TV Broadcast Sales Exhibit Hall in the Las Vegas Hilton Pavilion April 6-9. Other set manufacturers including Sony, Philips and Matsushita will be displaying sets elsewere in the Las Vegas Convention Center. The sets will be receiving a "live" over-the-air broadcast from KLAS-TV (CBS) in Las Vegas.

Panasonic will show a 56 inch widescreen DTV-compatible rearview projection TV and a "full spec" set-top box. Zenith will have a 64-inch rear projection set designed for 1920 x 1080 HDTV resolution and is designed to receive all 18 formats in the ATSC DTV standard. Sharp's 34-inch DirectView DTV will also be on display. It too is capable of displaying all ATSC video formats. In addition, Sharp will preview a prototype DTV set-top box converter that, according to the CEMA Press Release, will convet all 18 ATSC digital broadcasts to a 1080I output.

More information is available in the CEMA Press Release.

FCC Cracks Down on Unlicensed Radio Operations After Air Safety Threatened (Mar. 24)
An FCC News Release, Report CI-98-3 (Acrobat or WordPerfect files only) posted today reported on the FCC's efforts in closing down an unlicensed radio operation that was threatening air safety at Sacramento Airport. The interference was traced to an unlicensed transmitter operating on 107.2 from the office of Dollar and Sense Productions in Sacramento California. The FAA said interference was being received on 119.5, 122.2, 125.0 and 126.8 MHz. Once the unlicensed station was located the operator voluntarily shut down the transmissions.

This is not the first time unlicensed radio transmitters have interfered with aircraft communications. In October 1997 the FCC found two separate unlicensed operations interfering with air traffic control frequencies at Miami International Airport and West Palm Beach International Airport. In February, 1998, the FCC obtained a court order to confiscate equipment from an unlicensed station interfering with San Juan International Airport after the operator refused to shut down voluntarily.

SATELLITE - INTELSAT Board of Governors Approves Satellite Shuffle (Mar. 24)
As outlined in an INTELSAT Press Release, the INTELSAT Broad of Governors, meeting in Salvador, Brazil, approved several changes to its satellite deployment plan "to better meet customer and system requirements." Among the changes:

OTHER Items of Interest

March 23 - Issue 110 Final Edition

FCC Releases NPRM for Universal Licensing System (Mar. 20)
The FCC released its Notice of Proposed Rule Making (NPRM) amending the FCC Rules to &quoteFacilitate the Development and Use of the Universal Licensing System in the Wireless Telecommunications Services.". The Universal Licensing System (ULS) was described in the February 23 RF Current. Among the proposed rules changes are initiatives to require electronic filing of applications and other documents as well as consolidating, and in some cases revising, rules that determine whether a change is considered "major" or "minor". The NPRM was released March 18th and comments will be due 30 days after publication in the Federal Register. Reply comments are due 15 additional days after that. See the NPRM, FCC98-025, for more informaiton.

DTV - LIN Television and Comark Plan Opening Day HDTV Broadcast (Mar. 19)
LIN Television Corporation and Comark Digital Services (CDS) announced plans to broadcast the Texas Rangers Opening Day baseball game over KXAS-DT in the Dallas-Fort Worth area. The game between the Texas Rangers and the Chicago White Sox will also be sent by MCI to Washington DC where it will be broadcast on WHD-TV. Six HDTV cameras The Ballpark at Arlington Texas will cover the event, including pre-game ceremonies. It is scheduled to begin at 2:35 Eastern Time on March 31, 1998. See the Comark News Story for more information. [Corrects earlier article which said the signal would be sent to WHD-TV by satellite.]

Harris Corporation made news last year with the first live digital high definition television broadcast of a Major League Baseball game on September 16, 1997. See Harris Corporation Transmits First Live Digital Television Major League Baseball Broadcast for information.

NASA TRACE Mission to Study Sun's Atmosphere (Mar. 19)
Any engineer working with wireless communications has an interest in what's going on around the sun. Solar flares can disrupt MF and HF communications and disable communications satellites. NASA hopes to discover more about what is going on in the Sun's corona and ":transition region" through its Transition Region and Coronal Explorer (TRACE) mission scheduled for launch March 30, 1998. A NASA Press Release described the mission: "Using instruments sensitive to extreme-ultraviolet and ultraviolet wavelengths of light, TRACE will study the detailed connections between the fine-scale surface features and the overlying, changing atmospheric structures of hot, ionized gas, called plasma. The surface features and atmospheric structures are linked by fine-scale solar magnetic fields."

More information is available on the TRACE home page, including a brief outline of the mission and a description of its most important scientific goals. NASA said that "TRACE will be the first space science mission with an open data policy. All data obtained by TRACE will be available to other scientists, students and the general public shortly after the information becomes available to the primary science team."

DTV - CableLabs® Chooses IEEE 1394 Links for Digital Set-Top Boxes (Mar. 17)
CableLabs® has specified the IEEE Standard 1394 interface for use on OpenCableTM advanced digital set-top boxes. A CableLabs Press Release explained that "OpenCableTM is a CableLabs-managed initiative aimed at developing key interface specifications to foster interoperability among advanced digital set-top boxes built by multiple vendors and used in broadband two-way cable networks." The IEEE 1394 interface can pass data at rates up to 400 Mbps using twisted pair shielded cable. Some digital equipment, including pro-sumer DV camcorders and computer interface cards already include IEEE 1394 connections. The interface should also be present on new DTV products such as the HDTV sets anticipated later this year. Security concerns had previously complicated efforts to use IEEE 1394 in digital set-top boxes. The CableLabs release noted that "A joint effort by the cable and computer industries and the Hollywood studios recently achieved preliminary consensus around key security issues."

OTHER Items of Interest

March 16 - Issue 109 Final Edition

DTV - Simultaneous HDTV and SDTV Microwave STL Demoed At WHD-TV (Mar. 16)
WHD-TV, the Model HDTV station in Washington DC, has installed a digital microwave link demonstrating simultaneous transmission of "legacy NTSC programs streams and new digital TV program streams on the same microwave STL system". The link consists of a Microwave Radio Communications MRC DAR45 (DS3 - 44.736 Mbps) digital video microwave system, a 16QAM modulator and World Access multiplexer. The multiplexer combines the 9 Mbps NTSC signal and the 19.4 Mbs ATSC signal into a ITU G.703 compliant DS3 signal. Randy Pruitt, supervisor of the engineering laboratory at PBS, said "The established transmission characteristics of the standardized DS3 signal format translates into simpler interface requirements for broadcasters. It allows us to interface with different media: terrestrial, fiber, data networks as well as satellite."

The link operates on 7.0125 GHz. over a path of 8.77 miles. More information is available in the California Microwave Press Release.

FCC Releases Revised DTV Table of Allotments (Mar. 12)
The FCC quietly released a revised version of the DTV Table of Allotments included with the FCC's Memorandum Opinion and Order. Only three allocations were changed in the new version. The DTV power on channel 9 for NTSC channel 8 in Houston dropped from 21.9 to 8.4 kW, based on an interference agreement. NTSC Channel 7 in Lake Charles, Louisiana swapped DTV channel 53 for 8 and dropped power accordingly. NTSC channel 8 in Jonesboro, Arkansas changed from DTV channel 58 to 9. While only three stations had their power and/or channel changed, the "new interference levels" for many NTSC stations changed. Under the new rules the FCC allows a de minimis amount of interference, up to two percent of the population the DTV Table shows in the service area, not to exceed ten percent total. This requires the table have accurate interference numbers. The March 12th DTV Table of Allotments is available on-line from the FCC in text, Adobe Acrobat and WordPerfect formats. Download fc9824r1.xls from the RF Page for an EXCEL 3.0 worksheet version of the new table. A state by state listing will be posted here soon.

DTV - CEMA Standard Helps TV Sets Relate Digital And Analog Signals (Mar. 10)
The Consumer Electronics Manufacturers Association (CEMA) announced it has published Standard EIA-752 specifying the method for transmitting a 16-bit transmission signal identifier in the NTSC TV line 21 extended data packet. According to the CEMA Press Release, "By comparing a MPEG transport stream identifier contained in the digital broadcast signal with a new NTSC transmission signal identifier carried on line 21 of the vertical blanking interval, a digital TV receiver can determine that the digital signal and the NTSC signal are coming from the same broadcaster."

CEMA said that it is expected the FCC will assign a unique 16-bit MPEG transport stream identifier to each DTV station. CEMA recommended the FCC use only odd numbers for DTV, leaving related even numbers for identifying the associated analog TV station with EIA-752 data. More information and sources for purchasing EIA-752 are listed in the CEMA Press Release.

FCC Public Notice Solicits Comments on Environmental Impact of Zoning Preemption (Mar. 10)
The National Audubon Society filed a petition on December 1, 1997, requesting the FCC prepare an Environmental Impact Statement (EIS) and solicit public comment on the Statement as part of the proceeding on the Commission's Notice of Proposed Rule Making In the Matter of Preemption of State and Local Zoning and Land Use Restrictions on the Siting, Placement and Construction of Broadcast Station Transmission Facilities (FCC No. 97-296, MM Docket No. 97-182)(NPRM).

The FCC, through a Public Notice, is seeking comment "as to first, whether the proposal contained in the NPRM would have a significant environmental effect such that an EIA should be prepared; and second, what would be the environmental effect of the proposal." Comments on this Public Notice must be filed on or before April 14, 1998 and reply comments must be filed by April 29, 1998. See the Public Notice (DA980458) for more information.

OTHER Items of Interest

March 9 - Issue 108 Final Edition

SCIENCE - DOE's Lawrence Berkley National Laboratory Reveals Electron Dynamics (Mar. 9)
The motion of electrons is the most basic element in today's electronic systems. Scientists at the Department of Energy's Lawrence Berkley National Laboratory conducted an experiment recently that recorded the movements of electrons between a conductor and an insulator with femtosecond time resolution. The experiment showed it was possible to "observe the dynamics of electrons as they move across the boundaries where metals and non-metals meet." Charles Harris, a senior scientist in the Laboratory's Chemical Sciences Division, said "Our findings for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes."

The results of this work were published in the journal Science (January 9, 1998). More technical details about the experiment and the results can be found in the Lawrence Berkley National Laboratory article Electron Experiment Holds Promise For Electronics Industry.

WIRELESS - Companies Unite to Establish Wireless Comm Standard for the Home (Mar. 4)
The Home Radio Frequency Working Group (HRFWG) plans to publish open specifications for home wireless communications, called the "Shared Wireless Access Protocol" or SWAP. The system will use the 2.4 GHZ. ISM band with a transmitter power of 100mW. Data rate is up to 2 Mbps with a range large enough to cover a typical home and yard. Use of the Blowfish encryption algorithim for data security should alliviate concerns about eavesdropping. Applications of the system range from cordless telephones to portable terminal Internet access around the house. The system is also envisioned for use in advanced remote control devices for other home electronic systems.

More information on this new industry initiative is available in the Microsoft RFWG Press Release.or the Motorola RFWG Press Release. A Technical Summary of the SWAP Specification is also available. Also see the EE Times Article.

DTV - WFAA-DT On the Air - Signals Received at Baylor Medical Center! (Mar. 3)
WFAA won the race to transmit the first digital high definition television signal in Texas when it placed WFAA-DT on the air on channel 9 with 18.3 kW ERP. The Dallas-Fort Worth market has seen a lot of interest in HDTV. KXAS-DT was granted this week (see below) and the application for KDFW-DT, channel 35, was granted January 6th. Details about the WFAA-DT installation, including photos of the antenna being installed on the tower and Wayne Kube switching on the DTV transmitter are available in the story WFAA Makes HDTV History on the WFAA web site. WFAA has also posted a useful FAQ on HDTV.

While WFAA-DT was enjoying its success, "Murphy" had other plans. At Baylor Medical Center, technicians noticed some older heart monitors weren't working properly. The reason? They operated on TV channel 9. WFAA turned off its DTV transmitter until Baylor can change frequencies on the equipment. This was mentioned at the end of The HDTV Revolution is Here on WFAA's web site.

Will other stations experience the same problems? It's possible. As we reported in October 27, 1997 RF Current, the FCC amended its rules to allow biomedical telemetry devices to operate without a license on TV channels 7 through 46. Did WFAA-DT have to go off the air? No, but shutting down heart monitors at a nearby hospital isn't good publicity! The FCC Report ET 97-9 on the Order allowing use of these channels said "...that, like other Part 15 unlicensed devices, such devices must accept any interference that may be received from other radio operations. The operators also are responsible for resolving any interference problems caused by the operation of their devices, even if resolving that interference requires that the biomedical telemetry device cease operation." More information on the Report and Order is available on the FCC's Office of Engineering Technology ET95-177 Web Page.

CHIPS - ParkerVision Says Tests Confirm Single Chip RF Receiver Specifications (Mar. 3)
Parkervision reported that the Boeing Company completed a series of test measurements on ParkerVision's single-chip direct-conversion high-performance receiver chip. The test found tests performed by Boeing and those performed by ParkerVision on the "Eddie" chip "are in accord." ParkerVision said the test results "show that the performance of the technology is appropriate for use in commercial grade wireless communications and is compatible with many broadly deployed communications protocols."

More information on ParkerVision's "Eddie" chip is available in the December 15, 1997 RF Current and in the ParkerVision Press Release on the Boeing tests.

OTHER Items of Interest

March 2 - Issue 107 Final Edition

DTV - Sinclair Broadcast Claims First Multi-Station Multi-Channel DTV Broadcast (Mar. 2)
Sinclair Broadcast Group, Inc. said it "has begun broadcasting the nation's first-ever multi-station, multi-channel digital television (DTV) signals in Baltimore." WBFF-TV and WNUV-TV began broadcasting the digital signals on channels 46 and 40 (respectively) on February 27, 1998. The stations are currently broadcasting several programs in standard definition. Sinclair CEO David Smith said "We are very pleased with this first phase of our digital TV demo in which we are transmitting a variety of programs simultaneously." TV transmitter pioneer Nat Ostroff, now Vice President of New Technology at Sinclair, added "We want to show the flexibility of digital television by demonstrating some of the many options that are available to broadcasters and the consumer in the DTV world," One of the purposes of the demonstration is to "illustrate the options created when two or more television stations work together to deliver a wide variety of programming and services to the public."

More ivnformation is available in the Sinclair Broadcast Group Press Release.

FCC Plans Beta Testing of an Electronic Form 731 for Equipment Authorization (Mar. 2)
The FCC's Office of Engineering and Technology and Dyncorp, Information and Engineering Technology will be testing a prototype electronic Form 731, Application for Equipment Authorization, from March 2 until March 13, 1998. Interested parties are encouraged to file test applications using the system during the test period. Note that these applications will not be officially filed with the FCC. The FCC expects to have the real system in place in May.

More information is available in Office of Engineering and Technology Public Notice PNET8006. Instructions and the electronic form can be found on the secure server at https://dettifoss.fcc.gov/beta/oet/index.html.

SATELLITE - INTELSAT 806 Satellite Sucessfully Launched (Feb. 27)
INTELSAT said it successfully launched INTELSAT 806 at 7:21 AM EST this morning. The satellite will be positioned at 319.5 degrees east. It is expected to begin service in May this year. The INTELSAT Press Release said
"The INTELSAT 806 satellite special hemi beam has been specifically designed to offer simultaneous connectivity to Latin America, the US and Europe, and accommodates distribution and contribution applications on both sides of the Atlantic. For example, services uplinked in Europe are also downlinked in South and North America at the same time and with no extra charge. In addition, with an e.i.r.p. of up to 40 dBW over most cities, the INTELSAT 806 is the only satellite with coverage of the Americas and Europe via earth stations as small as 1.8 meters, which makes the use of the satellite really attractive and more affordable to broadcasters."
See the Press Release for a list of the video channels on the new satellite and additiona information. A Map of INTELSAT 806 Coverage is also available.

SATELLITE - First Teledesic Ka-Band Satellite Launched (Feb. 24)
Orbital Sciences Corporation said it successfully lauched Teledesic LLC's T1 satellite and NASA's Student Nitric Oxide Explorer (SNOE) satellite. A modified L-1011 carried the Pegasus rocket 39,000 feet above the Pacific ocean. At a special site off the California coast, the rocket was dropped. allowed to free-fall for five sections, then ignited to take the two satellites to an orbit approximately 565 kilometers above the earth.

A Press Release from Orbital Services Corporation said the Teledesic T1 satellite was "the world's first commercial "Ka" frequency band LEO spacecraft." T1 is an experimental satellite that will be used to develop the technology needed for Teledesic's "Internet-in-the-Sky" network. When completed, it will consist of a constellation of 288 low-Earth-orbit satellites and provide "affordable, worldwide, 'fiber-like' access to telecommunications services, such as linking enterprise computing networks, broadband Internet access, videoconferencing and other digital data needs."

For more technical details on the Teledesic project, visit http://www.teledesic.com/.

FCC Experimental License Grant List Released - Some Broadcast Frequencies Shared (Feb. 24)
Yesterday the FCC's Office of Engineering and Technology released its list of Experimental Actions. Broadcasters may be interested in the license KO2XDO granted to BST, Inc. The experimental license allows mobile operation of equipment in the 450-451 MHz. and 455-456 MHz. broadcast auxiliary bands, all UHF TV channels except for channel 37, 944-952 MHz., 1850-1910 MHz., 1930-1990 MHz. and 2390-2450 MHz. The purpose of the license is to "develop and test video equipment used for remote transmissions." The area of operation is the continental United States, Alaska and Hawaii. VHF TV broadcasters in the Great River, NY area should be aware of a license granted to Northrup Grumman Corporation for mobile operation on frequencies including TV channels 2-6.

The complete list of Experimental Actions in January was published in FCC Report 308.

OTHER Items of Interest

Other Issues Available:



1995 and 1996

Return to The RF Page @ www.transmitter.com

Last modified March 30, 1998 by Doug Lung dlung@transmitter.com
Copyright © 1998 H. Douglas Lung