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 October 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.

October 27 - Issue 92 Final Edition

SATELLITE - Innovative Solution For INTELSAT 605 Anomaly (Oct. 23)
In the September 15th RF Current we reported on a telemetry anomaly with INTELSAT 605. In a Press Release issued today, INTELSAT announced it had come up with a way to obtain the spacecraft orbital attitude information it couldn't get from the telemetry. Steve Stott, INTELSAT Director of Satellite Engineering Support and Processes, said "INTELSAT has devised a series of ground-based software monitoring promgrams which can determine the attitude of the spacecraft by measuring the RF signal strength. INTELSAT is presently using this methodology, and this technique will provide the required information with accuracy levels that result in no impact on services carried on the spacecraft.

See the Press Release for more information on this interesting technique.

SCIENCE - Spectacular Photos from Hubble Space Telescope Show Colliding Galaxies (Oct. 21)
NASA reported its Hubble Space Telescope "has uncovered over 1,000 bright, young star clusters bursting to life in a brief, intense, brilliant 'fireworks show' at the heart of a pair of colliding galaxies." Dr. Francois Schweizer, Carnegie Institution, said "These spectacular images are helping use understand how globular star clusters formed from giant hydrogen clouds in space."

More details on this discovery are available in the NASA Press Release. The Space Telescope Science Institute Hubble Reveals Stellar Fireworks Accompanying Galaxy Collisions page has links to related images.

FCC Permits Biomedical Telemetry on TV Channels (Oct.21)
Yesterday the FCC released its Report and Order on ET Docket 95-177 Amendment of Part 15 of the Commission's Rules to Permit Operation of Biomedical Telemetry Devices on VHF TV channels 7-13 and on UHF TV channels 14-46. These devices may be used "solely on the premises of health care facilities" but not in mobile vehicles, even if they are associated with a health care facility. The new rules state "The field strength of the fundamental emissions shall not exceed 200 mV/m, as measured at a distance of 3 meters using a quasi-peak detector."
Biomedical devices operating on TV channels must be at least 10.3 km outside the Grade B contour for VHF stations, 5.5 km outside a UHF TV station's Grade B contour, at least 5.1 km outside the Grade A contour of a VHF low power TV or TV translator station and at least 3.1 km outside the Grade B contour of a UHF LPTV or TV translator station. Plus, "Whatever distance is necessary to protect other authorized users within these bands."

Reading between the lines, it appears the FCC decided to keep these operations within channels included in both "core spectrum" DTV channel plans. Also, UHF LPTV and translator stations received little protection from interference through the space rules. The FCC rules clearly state, however, that these biomedical telemetry devices must not cause harmful interfererence to broadcast TV stations, LPTV and translator stations (Part 74 Subpart G) and low power auxiliary (wireless microphones and similar uses under Part 74 Subpart H).

More information is available on the FCC OET Docket ET 95-177 page, which includes links to all relevant FCC documents available on the 'net. Also see articles in the December 1995 and March 1996 RF Current.
OTHER Items of Interest

October 20 - Issue 91 Final Edition

FCC Sets Rules for Radio Astronomy Coordination Zone in Puerto Rico (Oct. 17)
On October 15 the FCC released its Report and Order in ET Docket 96-2 regarding Amendment of the Commission's Rules to Establish a Radio Astronomy Coordination Zone in Puerto Rico. The new rules require most operators of transmitters to notify the Arecibo Observatory at least 45 days prior to commencing operations of a new transmitter. The rules vary slightly depending on the service. STA (Special Temporary Authorization) applicants will need to provide technical information to the Observatory at the same time they file the STA request with the Commission. Amateur radio operations are mostly excluded from the Coordination Zone, but the FCC encourages informal coordination for new amateur beacon and repeater stations within 10 miles of the Observatory.

Transmitters above 15 GHz. are excluded, as are "mobile stations in the land mobile raido services, temporary base or temporary fixed stations (other than shor-term broadcast auxiliary operations), the Civil Air Patrol, new amateur stations (other than amateur beacon and repeater stations within 10 miles of the Observatory), mobile earth terminals licensed under Part 25, or stations aboard ships or aircraft."

The FCC did not grant the Observatory the right to insist on a blank check for interference avoidance. The Report and Order states "To the extent that the Commission determines that reasonable efforts have been made by the applicant to protect the Observatory from interference, there will be no further obligation for the applicant to modify its proposed operations or to upgrade the Observatory's facilities. Consequently, if under those circumstances the Observatory believes that the applicant's proposed operations must be modified or its own facilities upgraded to protect the Observatory from interference, the Observatory will be required to pay for any such modification or upgrade."

Broadcasters requesting new permanent installations in Puerto Rico or modifications to existing authorizations in Puerto Rico involving changes in frequency, power, antenna height, directivity or location have to notify the Interference Office at Arecibo Observatory, in writing or electronically, of the technical parameters of the proposal. The FCC will allow Arecibo a period of 20 days for comments or objections to the proposed operation. Similar rules apply to many TV auxiliary operations within a 4 mile radius of the Observatory.

More information is available in the Report and Order.

FCC Posts Erratum for FCC 97-303 on RF Exposure Guidelines (Oct. 16)
Today the FCC posted on the its web site an ERRATUM to FCC 97-303, the Second Memorandym Opinion and Order in ET Docket 93-62 on Guidelines for Evaluating the Environmental Effects of Radiofrequency Radiation. Refer to the ERRATUM for the text of the change. The correction applies to Section 1.1307(b)(4) of the final rules and affects the transition provisions of the rule. The engineering data did not change.

SCIENCE Weizmann Institute Finds Evidence of Radio-Like Mechanism in the Brain (Oct. 14)
Scientists at the Weizmann Institute of Science in Rehovot, Israel, have found evidence the brain uses a mechanism "remarkably similar to that of an FM radio" when interpreting sensory input. In the study, researcher Dr. Ehud Ahissar and his colleagues show that "neural signals generated by touch modulate the oscillation frequency" of certain cells in the cortical areas of the brain. The timing of incoming signals is compared with the regular and persistent oscillations of the cortex cells.

More information is available in a Press Release from the Weizmann Institute of Science.

OTHER Items of Interest

October 13 - Issue 90 Final Edition

FCC Proposes Allowing Two-way Transmission by MDS and ITFS Licenses (Oct. 10)
Friday the FCC said it had issued a Notice of Proposed Rule Making (NPRM) "seeking comment on proposed amendments to Parts 21 and 74 of its rules to enable Multipoint Distribution Service (MDS) and Instructional Television Fixed Service (ITFS) licensees to engage in fixed two way transmissions." The NPRM proposes to allow MDS and ITFS licenses to "utilize all or part of a 6 MHz. channel for return path transmissions from subscriber premises, to cellularize their transmission systems to take advantage of spectrally efficient frequency reuse techniques, and to emply configurations involving bandwidths either larger or smaller than 6 MHz., all while providing incumbent MDS and ITFS licensees interference protection equivalent to what they currently receive."

Other changes proposed include amending the definition of a "response station" and proposing response station hubs, which would service as collection points for upstream signals from response stations. More information on proposed changes to this and other technical rules is available in the News Report (NRMM7014). The NPRM is now available as an Adobe Acrobat file - fcc97360.pdf or a WordPerfect file - fcc97360.wp..

FCC Adopts NPRM on New Public Safety Band on Upper TV channels (Oct. 9)
In a News Release (NRWL7043), the FCC's Wireless Telecommunications Bureau today announced it was issuing a Notice of Proposed Rule Making (NPRM) on its plans to allocate 24 MHz. of spectrum between TV channels 60 and 69 for Public Safety use. The NPRM seeks comments on service rules for the spectrum, including rules to "advance the goals of developing interoperability and efficient public safety networks, and to enable public safety agencies to develop the advanced capabilities, such as data and video communications, that will allow them to fulfill their missions more effectively."

The FCC also proposed technical requirements to protect incumbent analog broadcast licensees and planned digital television operations from interference during the DTV transition period.

Full text of the NPRM had not released on the FCC web when this was written. It will be added to this story when it becomes available. Check back later in the week.

FCC Adopts Policies and Rules for Little LEO Sat Services (Oct. 9)
In a News Release (NRIN7034) issued today the FCC said it had adopted a Report and Order setting rules and policies for low earth orbiting, non-geostationary mobile satellite systems commonly called "Little LEO" satellite systems. These systems operate below 1 GHz. and provide various two way data services.

The "Little LEO" systems share spectrum currently assigned to the Department of the Air Force and NOAA. The FCC was able to create a spectrum sharing plan that allows allow second processing round applicants to be licensed, avoid the need for auctions. The FCC news release said "The newly licensed systems will increase competition in the Little LEO service markts, which will likely result in lower prices and increased service options for customers."

The full text of the Report and Order is now available in file ASCII text file fcc97370.txt.

DIGITAL - WaveTop VBI Decoder Included in Windows 98 (Oct. 8)
Microsoft Corporation and WavePhore Inc. today announced an agreement to include the WaveTopTM vertical blanking interval (VBI) software and service in the Microsoft® Windows® 98 operating system. WavePhore uses the PBS National Datacast system to reach more than 99 percent of the TV households in the U.S. WaveTop joins the animated Barney dolls, another Microsoft effort, using the PBS network's VBI.

WavePhore has lined up several content providers for the new service, including CBS Sportsline, PBS ONLINE, Quote.com, The Weather Channel, N2K's Music Boulevard, BarnesandNoble.com, NECX, People, TIME, Entertainment Weekly, Money, FORTUNE and Sport Illustrated for Kids.

While this announcement focused on the WaveTop product, it appears stations could take advantage of the capability built into Windows 98 to add their own web based content on their signals. The maximum data rate for VBI signals is equivalent to ISDN. WaveTop, however, will not have full use of the PBS VBI, due to other data included in the PBS National Datacast system.

For more information check the web sites for WavePhore, WaveTop and NewsCast. More details are available in the Microsoft Press Release.

INDUSTRY - Kline Iron & Steel Sells Third of the Company to OmniAmerica Wireless (Oct. 8)
Jerry Kline, chairman and CEO of Kline Iron and Steel, a name known to most broadcasters for their tall tower experience and construction of such landmarks as the Sutro Tower in San Francisco announced today he was selling one third of the company to OmniAmerica Wireless, L.P. OmniAmerica Wireless, based in West Palm Beach Florida, was recently formed by Carl E. Hirsch and Anthony S. Ocepek in conjunction with Hicks, Muse, Tate & Furst, Inc., a Dallas investment firm, to "construct, aquire and manage broadcast and telecommunications towers."

The deal is expected to close this month. It includes Kline Towers, Kline Structural and Kline Coatings. Mr. Kline will retain controlling interest in the company. The announcement said the company will continue to "employ some 300 associates at both its Columbia and West Columbia facilities:"

Jerry Kline said "This partnership will open new doors to incredible opportunities for Kline and our employees, and is key to the success of our long-range strategic plan for growth." Mr. Hirsch said "The alliance with Kline fits neatly with OmniAmerica's strategy to create a vertically-integrated company that not only designs, fabricates and erects towers, but also owns two which lease tenant space to broadcasters and telecommunications companys." He observed that "Outstanding opportunities exist in what is currently a fragmented industry with very few qualified players."

It remains to be seen what the impact of the sale of one third of Kline to OmniAmerica Wireless will be on other Kline customers.

TV - Zenith Earns Emmy Award for Pioneering TV Remote Control (Oct. 8)
Most people take the remote control for granted. However, like so many technologies that are now commonplace, the TV remote control had an awkward beginning. TV remote controls began as wired devices, attempted to transition to wirelesss using visible light (which didn't work), had success with ultrasonic audio tones and finally evolved to the advanced infrared transmitters we use today.

Last night the National Academy of Television Arts and Sciences recognized Zenith Electronics Corporation's role in inventing the first TV remote control forty years ago by presenting the company with an Emmy Award for "Pioneering Development of Wireless Remote Controls for Consumer Television."

A copy of the Press Release announcing this award references an interesting Fact Sheet on "Four Decades of Channel Surfing: History of the TV Remote Control." It presents an interesting view of remote control development by describing the work of Zenith engineers on the project. Interesting reading!

HEALTH - SFSU Study Links Mouse Position to Muscle Tension (Oct. 7)
If you use a computer today, you probably use a mouse. A San Francisco State University found that people who use a mouse ":suffer more than twice as much muscle tension in their arms, necks and shoulders as those who don't use a mouse..." How can you avoid this? One suggestion is to switch to a centrally located trackball or trackpad pointer instead of a mouse. Another suggestion is to place the mouse where you don't have to extend your arm as much to use it and take quick "microbreaks" every minute during computer use. More details are available in the SFSU Press Release.

OTHER Items of Interest

October 6 - Issue 89 Final Edition

DTV - KOMO Seattle Files for Digital Television Station (Oct. 2)
The October 2nd FCC Public Notice of Broadcast Applications Accepted For Filing included an application from Fisher Broadcasting for a new digital television station KOMO-DT on channel 38 in Seattle, Washington. The application requested an average ERP of 810 kW using a Dielectric TFU-32DSC antenna. The antenna location at 157 Galer Street is the same as that currently used by the NTSC KOMO on channel 4. The center of radiation for the DTV antenna will be 24 meters below the NTSC antenna's center of radiation, according to the FCC filing.

TV - FCC Releases NPRM on Video Blocking Technology (Oct. 1)
Today the FCC posted its Notice of Proposed Rulemaking (NPRM) in the Matter of Technical Requirements to Enable Blocking of Video Programming based on Program Ratings. It is available in plain text, Adobe Acrobat and WordPerfect file formats. The September 29th RF Current had a summary of this NPRM.

The FCC requested comment on whether date/time/channel blocking should be required as well as the proposed line 21 based blocking technology. The Commission also sought comment on "whether ratings are likely to be distributed via a means other than line 21." The NPRM said the FCC tentatively concluded that while the system should be user friendly, it should be secure enough that children cannot easily override it. Refer to the NPRM for more detailed information.

TV - CEMA Announces V-Chip Engineering Standards Now Available (Oct. 1)
The Consumer Electronics Manufacturers Association (CEMA) issued a Press Release today applauding Vice President Gore's endorsement of the proposed TV ratings proposal submitted by the NAB, MPAA and others.

CEMA also said that "On September 23, during an R4.3 engineering meeting in Phoenix of broadcasters, TV set manufacturers and programmers, industry engineers approved two V-chip technical proposals." Standard EIA-744 describes a new extended data packet transmitted in the vertical blanking interval (VBI). A "Recommended Practices for the Content Advisory XDS Packet" stated that channel blocking should include muting program audio, render video blank or "otherwise indecipherable" and elimate captions. The practices also set the default state of the TV set to a not block the signal until the ratings packet is received. To avoid confusion, the TV set should display a message on screen to "indicate to the viewer that content advisory blocking occurred."

Although this data was sent to the FCC on September 24th, it did not arrive in time to be incorporated into the latest Notice of Proposed Rulemaking on the V-chip. (See article above.)

DTV - ATSC Conducts First Digital HDTV Broadcasts In Australia (Oct. 1)
The Advanced Television Systems Committee (ATSC) continued its world tour promoting the U.S. ATSC standard as an international model for HDTV, multiple SDTV and data delivery services. After demonstrating the ATSC HDTV standard in China (see the September 1 RF Current for details), on October 1st the ATSC conducted what is claimed were the first digital HDTV broadcasts in the southern hemisphere. The transmission originated from the TCN Channel 9 tower in Willoughby and was received at the Observatory Hotel in Sydney, Australia. The Federation of Australian Commercial Television Stations (FACTS) helped organized the demonstrations, laboratory tests and field tests.

Several member ATSC member organizations supported the tests. The trransmitter was provided by Harris Corporation. Mitsubishi Electronics American provided the video decoding equipment. CBS, Snell & Wilcox, Sony, Dolby Laboratories and Zenith also provided equipment and/or technical support.

More information is available in the ATSC Press Release and the Zenith Electronics Press Release.

OTHER Items of Interest

Other Issues Available:



1995 and 1996

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Last modified October 20, 1997 by Doug Lung dlung@transmitter.com
Copyright © 1997 H. Douglas Lung