Editing Zenith Electronics (section)

==Notable products==

===Shortwave radio===
[[File:Zenith cube radio.jpg|thumb|upright|A Zenith Model 5-S-220 "cube" radio {{Circa|1937}}]]
Among Zenith's early famous products were the "Royal" series of transistor radios and the "[[Trans-Oceanic]]" series of shortwave portable radios, which were produced from 1942 to 1981.

===Subscription television===
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]]). Their experiment involved a descrambler box mounted on the television set, and plugged into the telephone lead. 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.<ref name="time001">[https://web.archive.org/web/20090727053712/http://www.time.com/time/magazine/article/0,9171,805681,00.html "Phonevision" ''Time'' January 8, 1951]</ref>

While the [[National Association of Theatre Owners|Theatre Owners of America]] claimed the concept was unsuccessful, Zenith itself claimed the experiment was a success.<ref name="time002">[https://web.archive.org/web/20070930101325/http://www.time.com/time/magazine/article/0,9171,858097,00.html "Report on Phonevision" ''Time'' June 4, 1951]</ref> As Phonevision broadcast films, it was seen as a potential competitor for traditional theatres. In spite of the fact that the three films initially available to the first 300 test households were more than two years old, about 18 percent of Phonevision viewers had seen them at the movies, and 92 percent of Phonevision households reported that they would prefer to see films at home.<ref name="time002" />

===Remote controls===
{{Unreferenced section|date=September 2012}}

Zenith is, perhaps, best known for the first practical wireless television [[remote control]], the Space Command, developed in 1956.

[[File:Zenith Space Command.jpg|thumb|A Zenith Space Command 600 remote control]]
[[File:Zenith space.jpg|thumb|A box advertising a remote control system often referred to as "Space Command Tuning"]]

The original television remote control was a wired version, released in 1950, that soon attracted complaints about an unsightly length of cable from the viewer's chair to the television receiver. [[Eugene F. McDonald]], Zenith President and founder, ordered his engineers to develop a wireless version, but the use of radio waves was soon discounted due to poor interference rejection inherent in 1950s radio receivers. 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. However, bright sunlight falling on the television was found to activate the controls. These remote controls would activate a motor, causing the tuning dial on the television to switch by itself, and this could be used for mischief if someone else was attempting to tune the television.

Lead engineer [[Robert Adler]] then suggested that ultrasonic sound be used as a trigger mechanism. This was produced in the hand held unit by mechanically struck aluminum rods of carefully constructed dimensions—a receiver in the television responded to the different frequencies this action produced. Enough audible noise was produced by pressing the buttons that consumers began calling remote controls "clickers". The miniaturization of electronics meant that, eventually, the sounds were produced in the remote unit electronically; however, the operating principle remained in use until the 1980s, when it was superseded by the infrared light system.

Zenith said that Space Command increased television sales by 40%. The company licensed the technology to RCA and others, and twice successfully sued Admiral for violating its patent.{{r|perry198808}} The photograph is of a Space Command 600, which was the remote control designed for use with their color television receivers. The Space Command 600 was introduced in 1965 and this particular design was in use until the end of the 1972 model year. The Space Command 600 remote control had an additional, distinctive feature—this remote control could also adjust color hues. By pressing the mute button on the remote, a relay would be activated at the television in which to transfer the VHF motor drive tuner circuit to the motorized hue control. This would allow the user to adjust the hue in increments by depressing the channel up or down buttons on the remote control, and restore the television to normal tuning operation when the mute button was pressed again (mute off).

===Space phone===
Some models of Zenith's ''[[Zenith System 3|System 3]]'' line of televisions made from the late 1970s to the early 1990s had a feature called the Space Phone by Zenith. It was basically a hands-free [[speakerphone]] built into the television set. It used the set's speaker and remote control, in addition to a built-in microphone. A Space Phone-enabled television would connect to a telephone jack (using a built-in phone cord), and making a call was performed by pressing a button on the remote to activate the Space Phone (which would mute and begin controlling the program audio going to the speaker). The telephone number is dialed using the numeric keys on the remote, which then displays the digits being dialed on-screen (using the on-screen display features of the System 3 line). The user could then converse with another caller hands-free, much like a regular speakerphone.{{Citation needed|date=December 2022}}

===The porthole television===
In the late 1940s, Zenith entered the television market. These sets were all-round tube sets. The main feature was that the entire round screen was exposed. They were available in 12-inch, 16-inch and 19-inch sizes. Later round-tube models had a switch that would show the picture in the 4:3 ratio, or have the entire round screen exposed. These sets are very desirable among television collectors. Many porthole sets used metal-cone CRTs, which are now scarce. It is not uncommon for collectors to replace a bad metal-cone tube with an all-glass tube. Zenith porthole sets came in tabletop models, stand-alone consoles and television/radio/phono combos.

===Hand-wired chassis===
[[File:Zenith Tube Box.jpg|thumb|upright|Zenith vacuum tube carton]]

In the late 1950s, many electronic manufacturers, such as [[RCA]], [[General Electric]] and [[Admiral (electrical appliances)|Admiral]], were changing from hand-wired metal chassis in their radios and televisions to [[printed circuit board]]s. While circuit boards save time and errors in assembly, they are not well suited for use with [[vacuum tube]] equipment, in which high temperatures are generated that can break down boards, eventually causing the boards to crumble if one attempts to remove a tube. Zenith, and to a lesser extent [[Motorola]], avoided this problem by continuing to use hand wired chassis in all their vacuum tube equipment. Zenith kept circuit boards out of their televisions until the Chromacolor line of the early 1970s, and even then used them only with solid state components, mounting the four tubes used in the Chromacolor "4 tube hybrid" on the steel chassis. Zenith began using circuit boards in radios when they converted to solid-state in the late 1960s, but even Zenith's early transistor radios were completely hand wired with socketed transistors. Due to the use of this chassis construction (and the high quality components), Zenith televisions and radios of the 1950s to 1970s found today are often still working well, needing little work to restore them to like-new operating condition.