For many years, their famous slogan (borrowed from Crown Piano maker George Bent of Chicago, used through the 1890s) was "The quality goes in before the name goes on".

[3] Zenith-branded products were sold in North America, Germany, Thailand (to 1983), Cambodia, Laos, Vietnam, India, and Myanmar.

Zenith was one of the first companies to introduce a digital HDTV system implementation, parts of which were included in the ATSC standard, starting with the 1993 model Grand Alliance.

[5] The 1962 Illinois Manufacturers Directory (50th Anniversary edition) lists Zenith Radio Corporation as having 11,000 employees, of which at least 6,460 were employed in seven Chicago plants.

The corporate office was in plant number 1, located at 6001 West Dickens Avenue (north of the Chicago, Milwaukee, St. Paul and Pacific railroad tracks), where 2,500 workers made radio and television sets and Hi-Fi stereophonic phonographs.

Plant number 2 was located at 1500 North Kostner Ave., where 2,100 employees made government electronics, radio and television components, transistors and hearing aids.

Plant number 3 was located at 5801 West Dickens Ave. (also north of the Milwaukee Road tracks), where 300 employees made electronics and did servicing.

A subsidiary of Zenith, the Rauland Corporation, located at 4245 North Knox Avenue, employed 850 workers who produced television picture tubes.

The other Zenith subsidiary in Chicago was Central Electronics, Incorporated, located at 1247 West Belmont Ave., where 100 employees made amateur radio equipment and performed auditory training.

[8] During the pendency of that suit, Zenith Radio Corporation encountered increasing financial difficulty as their market share progressively went to Japanese companies.

[14] The case was appealed, and in March 1986 the Supreme Court of the United States ruled in favor of the defendants on Zenith's antitrust claims.

[17] The company changed its name to Zenith Electronics Corporation in 1984 to reflect its interests in computers and CATV, having left the radio business two years earlier.

[citation needed] By the late 1980s, ZDS's profits were sustaining its parent, while from 1987 Zenith's consumer business lost money.

[5] To raise money for HDTV research efforts and reduce debt, Zenith instead sold ZDS to Groupe Bull in October 1989 for $635 million.

To avoid this, Zenith sold a five-percent stake to the Korean company GoldStar (now LG Electronics) as part of a technology-sharing agreement.

Zenith was too small to compete in the consumer electronics industry, which had become global in nature, and its high-quality products made it attractive for acquisition.

[21] The Zenith headquarters building was occupied by Aon and subsequently demolished in 2018 to create room for nearby Abt Electronics to expand.

Zenith was the first company to experiment with subscription television, launching their Phonevision system with experimental Chicago station KS2XBS (originally broadcasting on Channel 2 before the Federal Communications Commission forced them to relinquish it to WBBM-TV).

When a preannounced broadcast was ready to begin, viewers would call an operator at Zenith who would send a signal with the telephone leads to unscramble the video.

The 1955 Flash-Matic remote system, invented by Eugene Polley, used a highly directional photo flash tube in the hand held unit that was aimed at sensitive photoreceivers in the four front corners of the television cabinet.

In the late 1950s, many electronic manufacturers, such as RCA, General Electric and Admiral, were changing from hand-wired metal chassis in their radios and televisions to printed circuit boards.

Zenith, and to a lesser extent Motorola, avoided this problem by continuing to use hand wired chassis in all their vacuum tube equipment.