ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Tuesday, December 17, 1996 TAG: 9612170091
SECTION: EXTRA PAGE: 3 EDITION: METRO
COLUMN: At home with technology
SOURCE: DAVID BUTLER
Q: I was intrigued by a new product I heard about that would allow me to watch videos or listen to music from any room in the house without having to string wires everywhere. What can you tell me about this?
A: Whether you own a satellite receiver, laser disk player, mega-CD changer or VCR, a wireless audio/video network can add a new dimension to your family's entertainment experience. No longer are you limited to a single room while enjoying your A/V gear.
The best thing about wireless: It's easy to install. Simply connect the transmitter to your audio or video component, connect the receiver to a remote television or audio system, and you're in business! Some models do video, some do audio and some do both. All make provisions for transporting signals from your remote control back to the source equipment.
If you have a cable converter, you can use a video transmitter to dispatch your favorite cable channel to any TV in the house, saving you the monthly fee for an extra converter. Or you could set up a camcorder in the nursery to monitor an infant. Since there aren't any wires, it only takes a minute to move the system from room to room.
If the need arises, you can expand a wireless network simply by purchasing additional receiver units. And since most systems have selectable frequencies or channels, it's possible to operate more than one transmitter at the same time.
Apart from hard-wired methods, there are three ways to distribute A/V signals around the house. An RF (radio frequency) system works like a cordless phone - the transmitter and receiver each have antennas. One RF system achieves superior signal quality by relying on directional antennas. However, additional receivers may prove difficult to accommodate.
Secondly, a power line carrier system is available that transmits audio and video over ordinary household electrical wiring. According to an official whose company produces the system, it will not interfere with other PLC products such as X-10, CEBus or intercoms, nor the converse.
Finally, one company will soon introduce a system that operates over existing telephone wiring. Since it transmits at a much higher frequency than voice or data, it will not interfere with normal telephone traffic. This is referred to as out-of-band signaling.
The relative performance of the various approaches may depend more on the environment than anything else. If possible, buy from a source that will allow you the benefit of a no-risk trial.
If you're mostly interested in audio distribution, you can opt for a set of wireless speakers. Several companies sell 900-Mhz (RF) models with individually powered left and right speakers. Each speaker has its own receiver. For added convenience, the latest versions will run on batteries as well as an AC adapter.
Wireless headphones offer yet another alternative for enjoying tunes throughout the house. Some models are designed to work with the same transmitters that drive wireless speakers. With a range of 100 feet or more, you can wear your headset while doing chores in and around the house. Infrared headsets are less expensive, but must remain within line-of-sight of the transmitter.
To receive a list of companies that manufacture wireless audio/video networks, please send $2 and a self-addressed envelope to David Butler F-628 Department TWN, P.O. Box 36352, Cincinnati, Ohio 45236-0352. The list includes toll-free phone numbers and a summary of each company's products. You'll also receive information on wireless headsets.
TechTalk: Connection methods vary among audio/video networks. The video signal is either composite (RCA connector) or modulated channel 3/4 (coaxial connector). The former carries no audio while the later usually carries mono audio. Transmitters with stereo audio usually connect to left and right speaker (amplified) or line-level outputs (RCA connector). The receiver can connect to another audio system or a set of powered speakers. One company's receiver has a built-in amp so it can drive conventional speakers.
LENGTH: Medium: 76 lines ILLUSTRATION: GRAPHIC: This audio/video network uses the phone line to sendby CNBhigh-quality audio and video signals throughout the home.