This article describes an easy retrofit for multi-source, multi-zone audio/video and control on existing coaxial cables. A lot of homes in North America were wired with coaxial cables for the Sony DST system that was abandoned by Sony shortly after its introduction in the mid 1990s. This article will show a simple method to utilize these existing wires and provide DVD quality audio/video signals and controls over them. Even though this article shows a specific case study, it can be extended to a variety of structured wiring that has been installed in the last decade. The simplicity of the system architecture and power of the technology is visible in performance and ease of the installation.

During the mid 1990s, Sony had introduced a coaxial cable based multi-room audio/video distribution system called DST. It was discontinued a very short time after its introduction to the market. Unfortunately many homes around the country, wired for Sony?s DST system were left in a lurch due to this abandonment. Figure 1 shows the wiring required for Sony?s DST system. It shows coaxial cables (RG-6 or RG-59) home-run from the central location to various rooms. The coaxial cables terminate in a wall-plate location near the TV set that would have housed an amplifier and demodulator. A 3-pair shielded cable ran from the wall-plate to the keypad location. The local zone amplifier would have resided in the wall-plate location as well and the speaker wires were run up to the in-wall or in-ceiling speakers.

In the past few years, most homeowners settled for channel modulated video signals on the coaxial cables to all the rooms, only to be demodulated by a standard TV set or a VCR. The high resolution and high fidelity DVD or DSS audio/video signals were reduced to TV or VHS quality for distribution around the house.

One such home that had the wiring for Sony DST installed has been enabled to distribute DVD and DSS quality audio/video and control signals on the existing RG-6 coaxial cables with plug-and-play simplicity. In the following section the system is described in more details.

System Description

The task was to distribute a satellite receiver, a cable box, an AM/FM tuner and a CD/DVD jukebox to 7 rooms in the home. There were four rooms with audio/video outputs and three locations with audio output only. Full IR remote control for all the source equipment was required from all the rooms and an interface keypad controller in the wall was needed. The problem was very easy to solve using Pragmatics? proprietary and patent pending CATS? products. Normally it operates on standard cat5 or cat3 twisted-pair cables, but is very easily adaptable to other transmission medium such as coaxial cables and fiber optic cables. Custom interface converters were built to connect the RJ-45 cat5 cables to the RG-6 cables F- connectors. All the CATS? signals that were carried on cat5 now are carried on the coaxial cables. Figure 2 shows the interface converter.

Figure 2

This custom interface converter enables the coexistence of all the CATS? signaling, keypad controls and IR data on the same coaxial cable. Figure 3 shows the details of the source components, CATS? transmitter, CATS? router, interface converter, CATS? receivers with amplifiers, and CATS? keypads.

Figure 3

The CATS? keypads were also custom modified to adapt to the transport over RG-6 cables. Figure 4 show the keypads used in this installation. Since the old cavities in the wall for the Sony DST keypads was 3-gang wide, a special plate was fabricated. The keypad features an automatic brightness adjustment based on the ambient light.

Figure 4

The keypad is very intuitive and menu driven. It allows for source control of the A/V equipment, source selection from the router and local controls of volume and mute.

Utilizing the CATS? with the special coaxial to RJ45 interface adapters, true DVD quality audio/video signal distribution and control is achieved on the old abandoned coaxial wiring for Sony DST.

Finally there is a solution for the homes that were abandoned by the Sony DST years ago. There is a simple plug-and-play solution for multi-zone, multi-source Audio/Video signal distribution and control over RG6 or RG59 cables also. The advanced keypad controller also enhances the aesthetics of the system. Any standard structured wired home with home-run coaxial cables can also benefit from this solution.
About the Company

Pragmatic Communications Systems, Inc., is a Silicon valley company established in 1994 to design, develop, and produce a variety of innovative products for wireless audio, video, and data communications. The majority of company?s products until 1997 were primarily designed for industrial and commercial applications. The success of these products has led to a strong and dynamic technology base, which has been applied to new generation of products such as CATSTM and others like the DMSTM, TrueMusicTM wireless hi-fi system and TrueViewTM wireless video system. The company?s philosophy is to use its technologies to solve problems that have gone unresolved for decades.

CATSTM, TrueViewTM, TrueMusicTM and DMSTM are trademarks of Pragmatic Communications Systems, Inc. Products and technologies described in this article have patents pending are also available for licensing to qualified manufacturers of consumer electronics products.
Author?s biography

Prasanna M. Shah is the Chief Pragmatist and Thinker at Pragmatic Communications Systems, Inc. He earned his M.S. degree in Electrical Engineering from Stanford University and B.S. degree in Electrical Engineering from Santa Clara University, Santa Clara, CA. He is a member of Tau Beta Pi and Eta Kappa Nu Electrical Engineering Honor Societies. He has more than two decades of experience working on semiconductors for analog and digital audio, video, cellular telephones, wireless communications, fiber optic communications, data communications, data acquisition and industrial controls in the Silicon Valley. He holds one patent on power line communications and several patents pending on audio, video and wireless multimedia systems. An avid audiophile and music lover, in his free time, he likes to apply his pragmatic thinking to solve complex problems.