[QuadList] TV Stereo

[rabruner at aol.com]

The first TV stereo broadcast in the United States was by WTTW in Chicago.  Here is a fairly accurate summary of the development of TV stereo directly lifted from Wikipedia:

Multichannel Television Sound was adopted by the Federal Communications Commission as the U.S. standard for stereo television transmission in 1984. Initial work on design and testing of a stereophonic audio system began in 1975 when Telesonics approached Chicago public television station WTTW. WTTW was producing a music show titled Soundstage at that time, and was simulcasting the stereo audio mix on local FM stations. Telesonics and WTTW formed a working relationship and began developing the system which was similar to FM stereo modulation. Twelve WTTW studio and transmitter engineers added the needed broadcast experience to the relationship. The Telesonics system was tested and refined using the WTTW transmitter facilities on the Sears Tower. In 1979, WTTW had installed a stereo Grass Valley master control switcher, and had added a second audio channel to the microwave STL (Studio Transmitter Link). By that time, WTTW engineers had further developed stereo audio on videotape recorders in their plant, using split audio track heads manufactured to their specifications, outboard record electronics, and Dolby noise reduction that allowed Soundstage to be recorded and electronically edited. In addition, an Ampex MM1100, 24-track audio recorder was also used for music production and mixing. PBS member stations who wished to deliver Soundstage in stereo were provided with a four-track (left, right, vertical drive, and time code) audio tape that could be synced with the video machines in those cities.
During the FCC approval process, several manufacturers applied to the FCC for consideration. Most notably the Electronic Industries Alliance (EIA) and Japanese EIA asked to be included in order to represent their members in the testing and specification phases of the approval process. WTTW engineers helped set standards for frequency response, separation, and other uses of the spectrum. They also provided program source material used for the testing and maintained the broadcast chain. A 3M 24-track audio recorder was used to allow the selection of 12 different stereo programs for testing. The Matsushita Quasar TV manufacturing plant and laboratory, just west of Chicago, was used as the source for all testing of the competing systems. Following the testing, several questions were raised about the validity of some of the tests, and a second round of testing began.
WTTW installed a Broadcast Electronics prototype stereo modulator in October 1983, and began full-time broadcasting in stereo at that time using the Telesonics system prior to FCC rule-making on the BTSC system. Following EIA and FCC recommendations, the BE modulator was modified to meet BTSC specifications, and by August 1984 was in full-time use on WTTW.
Sporadic network transmission of stereo audio began on NBC on July 26, 1984, with The Tonight Show Starring Johnny Carson, although at the time only the network's New York City flagship station, WNBC, had stereo broadcast capability;[1] regular stereo transmission of NBC programs began in 1985. ABC and CBS followed suit in 1986 and 1987, respectively. One of the first television receiving systems to include BTSC capability was the RCA Dimensia, released in 1984. [2]

It should be pointed out that WTTW had to invent the whole chain, as mentioned in the article above, modifying VR-1200s and VR 2000s for stereo audio, providing stereo switching in the plant, stereo audio paths, stereo STL, etc., all this besides having to create and produce the source material to broadcast.  They even had to create stereo TV audio receivers to pick up the broadcasts off the air.  They used Marantz 10B receivers modified to tune to Ch 11 and decode the 15,750 subcarrier.  It would be a few years before the commercial operators caught up. 

Bob Bruner
Engineer In Charge
Maintenance and Design
WTTW/Chicago







From:
Dennis Degan <DennyD1 at verizon.net>

To:
Quad List <quadlist at quadvideotapegroup.com>

Subject:
Re: [QuadList] Jan. 21, 1959 Kraft Music Hall--In Color on N-B-C

Date:
Thu, 24 Mar 2011 16:59:59 -0400


>>I say: 
 
I don't know how you figure the US was behind at the time. Stereo TV broadcasting was not standardized until 1984. Even so, the multiplex audio system was equipped for stereo from the start, in 1977. By 1980, it was common though broadcasting stereo was not yet allowed. Some TV stations and specific programs got around this by simulcasting stereo audio on local FM radio. 
 
Dennis Degan, Video Editor-Consultant-Knowledge Bank 
NBC Today Show, New York 
 
 





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