http://www.belden.com

KDTV-Channel 14
Robert Wyatt
408/538-8064

Brill Electronics
Marci Mearns
510/834-5888

Energy Transformation Systems
Jack Andresen
Michael LaPorte
800/752-8208

When Univision, the parent company of KDTV-Channel 14, decided to commission the building of a new television broadcast facility, chances are the company had no idea that its cabling infrastructure would make broadcasting history -- but, in fact, it has. KDTV-14 is the first television studio to use Belden's revolutionary new MediaTwist UTP cable for virtually the entire cable plant. Incredible as it may sound, one cable -- MediaTwist -- has been successfully installed here for a multitude of applications, including analog audio, digital AES/EBU audio, analog video, digital video, RGB video and RS-422 machine control.

Univision's KDTV-Channel 14, a Spanish-language broadcasting station, serves the Hispanic community in San Francisco's Bay Area and is the fourth largest such station in the nation. According to Robert Wyatt, KDTV's chief engineer, the time was right to update the technology as the move was made to a new location.

"As KDTV-14 has grown over the years, our cabling infrastructure had accumulated many layers," he says. "With the move to digital technology almost upon us, we wanted to be able to continue our delivery of high-quality broadcasting and, at the same time, be well-positioned to provide the interactive services our market will want and expect in the future. The decision to design and build an all-new, state-of-the-art facility made good business sense."

Partnering for Success

KDTV-Channel 14 chief engineer, Robert Wyatt, was the cable and equipment systems integrator for the new broadcast facility, and led the team responsible for this innovative cable plant design and installation.

As chief engineer, Wyatt is responsible for the technical performance of KDTV-14. He was also responsible for the design and implementation of the new broadcasting infrastructure. Early in the project, Wyatt determined that his consulting and technical partners would include Steve Lampen, Technology Development Manager for Belden and Marci Mearns, Field Sales Engineer for Oakland, California-based Brill Electronics. Brill is a distributor of audio/video parts and equipment for the broadcast industries.

Mearns, a broadcast engineer herself, details the role played by Brill Electronics. "A project as large-scale and complex as this involves a great deal of advance planning and engineering work, including product specification."

"As sales engineer, I coordinated communications and activities among key team members. The Brill team selected and brought in product samples at an early stage to help Bob Wyatt and KDTV-14 uncover unique solutions for achieving their goals."

One of the solutions introduced by Brill and Belden was MediaTwist UTP cable -- a new product from Belden which captured Wyatt's attention and sparked his creativity. According to Lampen, the new cable had been suggested for certain limited applications within the facility. "However," Lampen notes, "after studying Belden's and Underwriters Laboratories' test results and seeing product demonstrations, Wyatt came up with an extraordinary proposal. He wanted KDTV-14 to be the first broadcast facility to use twisted pair technology throughout and specified MediaTwist as the primary multimedia cable."

Open Architecture, Award Winning Performance

The first cable on the market built on totally open architecture, MediaTwist is an unshielded twisted pair (UTP) cable uniquely designed and constructed to support multiple applications such as audio, video, data, machine control and telephone -- simultaneously -- using the four-pairs to carry any of these signals.

In the audio/video community, a key concern is cable leakage. Since MediaTwist is unshielded, Belden sought to allay this concern by testing the product with Sony 270 Mbps/135 MHz serial digital equipment at the Underwriters Laboratories (UL) facility in Northbrook, Illinois. Not only did MediaTwist pass stringent tests intended for coaxial cable, but was awarded a Class A Certification for Digital Devices.

MediaTwist's performance, versatility and reliability stem from a number of cable design improvements, many of which are patented or patent pending. These include bonding of the conductors in each pair for unmatched impedance tolerance, and a crescent-shaped jacket which resists crushing, maintains pair-to-pair spacing, and makes the cable virtually installer-proof.

The Balun Challenge

Once Wyatt made the decision for MediaTwist, the project's main challenge was finding a way to match the signal format to the cable. Since most video signals are formatted for coaxial cable, a solution had to be devised to make MediaTwist work in KDTV-14's environment. At this point, the team turned to Energy Transformation Systems, Inc. (ETS), a Menlo Park, California firm known for its innovations in balun design.

A balun is a device that matches balanced to unbalanced signals. In this case, ETS was asked to create a balun that would both impedance match and transform unbalanced coaxial video to MediaTwist's balanced twisted pair system. The quality of the balun is a significant part of the whole system. And, although ETS had designed state-of-the-art digital audio baluns for Belden and its customers, the company had never been called upon to make the quantum leap in balun quality required for on-the-air TV transmission.

According to Jack Andresen, ETS president and CEO, "Designing an economically feasible balun to balance the signal so it would not radiate or transmit noise was quite a challenge for us. To stay within standard broadcast specifications, the design parameters are much tighter than with data. Baluns for video had been tried before with less than optimal results. We worked closely with the KDTV project team and tried several experimental versions before coming up with the right combination of product price and performance."

Mike LaPorte, ETS sales and marketing vice president, adds that ETS' efforts paid off. "We were able to deliver a broadcast quality video balun on time and within budget," he says. "We are confident that the baluns we designed for MediaTwist provide a level of quality and performance that will serve KDTV well for years to come."

Marci Mearns concurs: "Of the many challenges inherent in a project of this size and scope, the biggest was the development of the media converters used to interface the 75 ohm unbalanced equipment with the balanced MediaTwist cabling. ETS did a remarkable job in developing these baluns to our specifications, on a very tight schedule."

A Unique Broadcast Cable Plant

In addition to video applications, Belden MediaTwist is used for KDTV-14's analog and digital video. MediaTwist UTP cable can be punched down easily on this ADC punchdown panel, and with no ground wire, the problem of ground loops is completely eliminated.

In addition to assisting in the balun specification process, Brill Electronics was responsible for supplying the MediaTwist and other cables, as well as interconnect products, patch panels and more. The installation required 26,000 feet of MediaTwist cable (Part No. 1872A) for diverse applications that include analog and digital (AES/EBU) audio, analog and digital video, RGB video (which splits the video signal into its component parts), broadband cable TV and 10baseT and 100baseT data networking.

Lampen notes, "The shared-sheath possibilities of MediaTwist allowed KDTV to run RS-422 machine control on two pairs and 100baseT data on the other two pairs. Workstations edit their news with the picture on distal 100baseT but the control on RS-422 like old tape-based systems."

In addition to MediaTwist, the KDTV-14 installation also utilized 56,000 feet of Belden DataTwist® 350 (Part No. 1700A) for its voice and data infrastructure, and 12,000 feet of Serial Digital Coax (Part No. 1694A) for critical video within the Master Control Racks.

KDTV-14: Poised for the Future

KDTV-14's new broadcasting facility held its Open House in December, 1997. Wyatt is well satisfied that the station will be able to handle the coming transformation to digital technology, quickly and easily. "Currently, we are using a combination of analog and digital signals," he says. "With MediaTwist's open architecture, KDTV-14 will not have to change cabling as the industry moves to full digital transmission."

Open Architecture, Award Winning Performance

The first cable on the market built on totally open architecture, MediaTwist is an unshielded twisted pair (UTP) cable uniquely designed and constructed to support multiple applications such as audio, video, data, machine control and telephone -- simultaneously -- using the four-pairs to carry any of these signals.

In the audio/video community, a key concern is cable leakage. Since MediaTwist is unshielded, Belden sought to allay this concern by testing the product with Sony 270 Mbps/135 MHz serial digital equipment at the Underwriters Laboratories (UL) facility in Northbrook, Illinois. Not only did MediaTwist pass stringent tests intended for coaxial cable, but was awarded a Class A Certification for Digital Devices.

MediaTwist's performance, versatility and reliability stem from a number of cable design improvements, many of which are patented or patent pending. These include bonding of the conductors in each pair for unmatched impedance tolerance, and a crescent-shaped jacket which resists crushing, maintains pair-to-pair spacing, and makes the cable virtually installer-proof.

The Balun Challenge

Once Wyatt made the decision for MediaTwist, the project's main challenge was finding a way to match the signal format to the cable. Since most video signals are formatted for coaxial cable, a solution had to be devised to make MediaTwist work in KDTV-14's environment. At this point, the team turned to Energy Transformation Systems, Inc. (ETS), a Menlo Park, California firm known for its innovations in balun design.

A balun is a device that matches balanced to unbalanced signals. In this case, ETS was asked to create a balun that would both impedance match and transform unbalanced coaxial video to MediaTwist's balanced twisted pair system. The quality of the balun is a significant part of the whole system. And, although ETS had designed state-of-the-art digital audio baluns for Belden and its customers, the company had never been called upon to make the quantum leap in balun quality required for on-the-air TV transmission.

According to Jack Andresen, ETS president and CEO, "Designing an economically feasible balun to balance the signal so it would not radiate or transmit noise was quite a challenge for us. To stay within standard broadcast specifications, the design parameters are much tighter than with data. Baluns for video had been tried before with less than optimal results. We worked closely with the KDTV project team and tried several experimental versions before coming up with the right combination of product price and performance."

Mike LaPorte, ETS sales and marketing vice president, adds that ETS' efforts paid off. "We were able to deliver a broadcast quality video balun on time and within budget," he says. "We are confident that the baluns we designed for MediaTwist provide a level of quality and performance that will serve KDTV well for years to come."

Marci Mearns concurs: "Of the many challenges inherent in a project of this size and scope, the biggest was the development of the media converters used to interface the 75 ohm unbalanced equipment with the balanced MediaTwist cabling. ETS did a remarkable job in developing these baluns to our specifications, on a very tight schedule."

A Unique Broadcast Cable Plant

In addition to video applications, Belden MediaTwist is used for KDTV-14's analog and digital video. MediaTwist UTP cable can be punched down easily on this ADC punchdown panel, and with no ground wire, the problem of ground loops is completely eliminated.

In addition to assisting in the balun specification process, Brill Electronics was responsible for supplying the MediaTwist and other cables, as well as interconnect products, patch panels and more. The installation required 26,000 feet of MediaTwist cable (Part No. 1872A) for diverse applications that include analog and digital (AES/EBU) audio, analog and digital video, RGB video (which splits the video signal into its component parts), broadband cable TV and 10baseT and 100baseT data networking.

Lampen notes, "The shared-sheath possibilities of MediaTwist allowed KDTV to run RS-422 machine control on two pairs and 100baseT data on the other two pairs. Workstations edit their news with the picture on distal 100baseT but the control on RS-422 like old tape-based systems."

In addition to MediaTwist, the KDTV-14 installation also utilized 56,000 feet of Belden DataTwist® 350 (Part No. 1700A) for its voice and data infrastructure, and 12,000 feet of Serial Digital Coax (Part No. 1694A) for critical video within the Master Control Racks.

KDTV-14: Poised for the Future

KDTV-14's new broadcasting facility held its Open House in December, 1997. Wyatt is well satisfied that the station will be able to handle the coming transformation to digital technology, quickly and easily. "Currently, we are using a combination of analog and digital signals," he says. "With MediaTwist's open architecture, KDTV-14 will not have to change cabling as the industry moves to full digital transmission."