Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, April 4, 1995 TAG: 9504050025
SECTION: EXTRA PAGE: 3 EDITION: METRO
SOURCE: DAVID BUTLER
DATELINE: LENGTH: Medium
Each additional video source adds more than its share of difficulty to the hook-up and operation of an entertainment center. An audio-video receiver with enough inputs would solve your switching problem, though it wouldn't do anything to get the satellite signal to other TVs.
A video modulator can solve both problems. It provides a smooth way to select and view a source component from any television. For example, you could be watching a satellite channel in the den. When it's time to start dinner, you can turn on the same channel on the kitchen TV. Meanwhile, someone else could watch a video disc or video tape in the den.
Here's how it works: The modulator takes the video signal from the satellite receiver and broadcasts it on an unused UHF or cable channel. The modulator's output is then combined with off-air (or cable) channels and distributed around the house over a coaxial cable. This means that any TV can receive satellite channels by simply tuning to the designated channel. Since most TVs can tune over 100 channels, finding an unused channel is seldom a problem.
Video modulators will work with any source that has "A/V" outputs (e.g., video, audio left and audio right). For the ultimate whole-house video system, you could assign additional modulators to your VCR and video-disc player. Other likely sources for in-house channels include security cameras and cable converters.
All but the least expensive modulators are frequency-agile, that is, their output channel is user-selectable. However, analog modulators must be re-tuned from time to time (similar to fine-tuning an older television). Digital modulators are now available that lock onto the output channel electronically. Video modulator prices vary dramatically, so it pays to do your homework.
Only the most expensive models are capable of encoding MTS audio, required for stereo television. However, you can get around this limitation with a separate audio modulator. It converts stereo audio signals from your source gear to a frequency that a standard FM radio can pick up.
One accessory you'll definitely want to consider is an infrared repeater. It allows you to use your existing remote to operate source components from wherever you happen to be watching TV. You can also use the same repeater with audio gear. Wired and wireless versions are available at prices starting around $50.
Another distribution technique relies on a special switch called a video matrix. One model can connect each of three sources to any of its five outputs. Small set-top boxes at each TV accept commands from a hand-held remote. This allows you to switch sources at the push of a button. You can use the same remote to operate your source components, eliminating the need for a separate infrared repeater.
In most cases, whole-house video requires professional installation. A qualified installer can balance the system so that each outlet provides a consistent signal, regardless of the source or distance. An improperly installed system can easily exceed limits set by the FCC for radio emissions.
To receive a list of companies that manufacture whole-house video systems, please send $1.50 and a self-addressed envelope to David Butler F-504, Department TWN, 14713 Pleasant Hill Road, Charlotte, NC 28278-7927. The list includes toll-free phone numbers and a summary of each company's products. You'll also receive information on wireless video transmitters and infrared repeaters.
Tech Talk: Cable television channels are divided into four bands: midband (channels 14-22), superband (23-36), hyperband (37-64) and ultraband (65-120). UHF channels 14-69 are located in the same spectrum as ultraband. That's why cable-ready TVs must have a cable/antenna switch.
by CNB