The cables needed to transmit electrical power may seem simple but are actually complex technological artifacts. Modern cables inherit the lessons learned during more than a century of research and experience. This power cable was described by GE engineer William Clark in 1898 as follows: “1,000,000 [circular mil] cable composed of 59 wires, each .1305" in diameter, containing two insulated pressure wires each 2500 C.M. area, the whole insulated with saturated paper 5/32" thick and finished with lead 1/8" thick. This is a feeder cable for circuits not exceeding 2000 volts working pressure on Edison three wire circuits."
Invention rarely stops when the inventor introduces a new device. Thomas A. Edison and his team worked to improve his electric lighting system for some years after the initial introduction in 1880. This lamp shows changes made after about ten years of labor aimed at lowering costs and increasing production. The simplified base required little material; the diameter and thread-pitch are still used today. The filament was changed from bamboo to a treated cellulose, based on an invention by English chemist Joseph Swan. The bulb was probably free blown by Corning Glass Works, but would soon be replaced by a bulb made by semi-skilled laborers blowing glass into iron molds. The cost had dropped from about $1.00 per lamp to less than 30¢.
The cables needed to transmit electrical power may seem simple but are actually complex technological artifacts. Cables are designed for many different applications, for example, indoor or outdoor use. This power cable was described by GE engineer William Clark in 1898 as follows: “500,000 [circular mil] cable, 3/32" rubber insulation, braided. [This cable is] for general use in interior wiring."
This model 55 Shure microphone was used at the KCOR-AM radio building in San Antonio, Texas during the 1950s. First introduced in 1939, the microphone became iconic due to its adoption by radio personalities and musical acts. The microphone uses Shure’s “Unidyne” element, a pick-up element that only accepts sounds from one direction and forms a cardioid sensitivity pattern. KCOR was licensed and operated by Raoul A. Cortez (1905-1971), a pioneer of Spanish-language media in the United States. Cortez later established the KCOR-TV station in 1955, and programmed his stations to serve the Spanish-speaking community in Texas.
The Global Positioning System (GPS) consists of a network of orbiting satellites that transmit special time signals. GPS receivers detect the signals from several satellites and calculate the user’s position with high precision. While many civilian uses have been developed, the system originated as a tool for the U.S. military. Other nations also adopted GPS for military use as seen on this 1992 model 1000M5 receiver. The buttons are labeled in Arabic for use by the Egyptian Army.
Cameraman and reporter, Andreas Morin used this handheld Sony Trinitron color camera when he worked for the Spanish-language KWEX-TV in San Antonio, Texas. The camera recorded to ¾-inch tape, allowed reporters to leave the studio and easily capture news on location. The camera connected to a portable recorder ( object 2015.0002.04) which was worn via on over-the-shoulder strap.
KWEX-TV Channel 41 broadcast various news and local interest programming from locations around the city, including Mass from the San Fernando Cathedral. KWEX traces its roots to KCOR-TV, launched by Raoul A. Cortez in 1954-1955 as the first Latino-owened, Spanish-language station in the continental United States. Cortez sold the station to his son-in-law, Emilio Nicolas and a group of investors in 1961. It would become the hub of operations for the Spanish International Network, the forerunner to Univision.
Before 1954, so-called portable radio receivers used vacuum tubes to receive and amplify signals. The large batteries needed to power most tubes made radios large and heavy. Receivers built with subminiature tubes existed but were expensive. The invention of transistors in 1947 allowed engineers to design radios that could fit in a large pocket and such radios were first sold in late 1954. This RCA receiver from 1956 used 8 transistors and ordinary flashlight batteries. Though too large for a pocket, this radio was much easier to carry and more reliable than tube-based radios.
This Sony "Walkman" portable tape player dates from the early 1980s. Originally introduced in 1979 as the “Soundabout,” two people could listen simultaneously while a small microphone permitted them to converse without removing their headsets. Powered by a 9-volt battery, the recorder sold well until the decline of the cassette format in the mid 2000s.
Until the middle of the twentieth century portable recording equipment could be quite heavy. The introduction of small transistor radios in 1954 marked a new era in portable entertainment. Philips’ invention of a compact recording cassette in 1962 provided a convenient medium for music distribution.
Motorola produced this BPR 2000 model pager around 1982. Prior to the widespread availability of inexpensive cell phones many people carried telephone pagers to stay in contact with work or home. A miniature radio receiver, a pager alerted the user that someone needed to talk to them and provided the call-back number. The BPR 2000 featured a dual address and numerical display to also show the user the source of an incoming call. Later alphanumeric pagers could communicate messages to the user. Pager use declined as cell phone coverage expanded across the U.S.
Westinghouse made stopper lamps to avoid infringing Edison's patents. The lamp is based on Sawyer-Man patents and includes a removable adapter to allow use of the lamp in both the special sockets made for stopper lamps and standard Westinghouse sockets.
Although wired communications systems can be more secure, wireless systems have the advantage of flexibility. For example, if one or two towers fail in a cellular telephone system the phone simply locates a working tower and the call goes through. This reliability proved critically important to New York mayor Rudy Giuliani on September 11, 2001 when he used this cell phone to help coordinate recovery efforts. Wired telephone service was disrupted in much of the city but the cellular system remained operational.
In 1998 Qualcomm introduced their model PDQ-800 cellular phone. An early so-called “smart phone,” the PDQ-800 combined a cell phone with a personal digital assistant (or PDA) based on the interface used by Palm Pilots. The user simply flipped down the number pad and wrote Palm “Graffiti” characters with a stylus to interface with the unit.
U. S. Robotics' subsidiary company Palm, Inc. produced this Pilot 5000 personal digital assistant (PDA) in 1996. With a purchase price of $369, the Pilot 5000 had a Motorola processor that operated at 16 megahertz and 512 kilobytes of memory. A touch screen accepted input via a stylus pen. Unlike the Apple Newton released a few years earlier, the Pilot’s system of “graffiti” shorthand provided users with an effective text input system. The back of this Pilot shows the characters that can be “drawn” by the “graffiti” system. Default applications for the Pilot included an address book, calculator, date book, memo pad, and to-do lists that could be synchronized with a personal computer via a special cradle connected to a serial port.
The high cost of building and maintaining prisons motivated a search for alternatives. One approach adopted by state and local governments for certain offenders entailed home confinement monitored by an electronic device. This ankle bracelet communicates with the control box. Should the wearer move out of range of the box without authorization a message is dispatched to local law enforcement authorities.
This hand puppet of the character “Reddy Kilowatt” has lightning bolts for limbs and a light bulb for a nose. First created in 1926 by Ashton B. Collins of the Alabama Power Company, Reddy Kilowatt served as a licensed spokes-character for privately-owned electric utilities. Designed to put a friendly face on electricity, Reddy was used to advance a variety of electrical messages, first encouraging electricity adoption, then electrical safety and efficiency. Collins also used the character to promote his conservative political views. Reddy appeared in print advertisements, animated shorts, films, TV ads, and a variety of licensed merchandise.
Western Electric manufactured the pink “Princess” telephone beginning in 1959. The original Princess phone was model 701 that needed an external ringer; this phone is model 702B that was manufactured in September of 1969 with the ringer moved inside the base. Henry Dreyfuss, already popular for his design of the Western Electric 302 tabletop phone, designed the Princess telephone. As telephones became mainstream instruments of teen communication, phone manufacturers began designing specifically for the growing teenage market. Available in white, beige, pink, blue, and turquoise the Princess was designed to be a bedside phone for teenagers—specifically teenage girls. To facilitate bedside use, the phone took up only a third of the space of the standard desk phone, while containing a night light under the dial. These features were brought to the fore with the advertising slogan “It’s little, it’s lovely, it lights.”
Intel introduced its 8080A 8-bit central processing unit (CPU) microprocessor in April 1974. Generally considered as the first truly usable microprocessor, the chip ran at 2 megahertz and powered the Altair 8800 and the IMSAI 8080, two of the first Personal Computers. Housed in a 40-pin DIP package that contained 6,000 transistors, the integrated circuit could receive 8-bit instructions and perform 16-bit operations. This particular example is marked "8321"indicating it was made in the 21st week of 1983. The "D8080A" means the unit has a housing of black ceramic.
A transformer was one of the critical components needed to make an electrical power system based on alternating current. Transformers raise and lower the electrical voltage (or potential) or the current, depending on the design. Electrical inventors Lucien Gaulard and John Gibbs introduced a practical design in Europe in 1882. George Westinghouse licensed their design and William Stanley, an engineer working in his company, added refinements that improved the device. This potential transformer has two coils of wire–one coil with a few turns of thick wire, the other with many turns of thin wire. A current passing through one (the primary coil) induces a current in the other (the secondary coil). The voltage can be raised or lowered depending on which coil serves as primary.