Annunciators were call systems that alerted servants to the needs of the household in which they worked. Each room contained a button to trigger the annunciator housed in servant's quarters. Primitive 18th-century bell systems evolved with the rise of battery power, telegraphy, and home electrification. This device was from the Charles F. Brush mansion, inventor of the arc lamp.

This device was part of a system used to amplify the time signal from U.S. Navy station NAA at Arlington, Virginia. Station NAA received a time signal from the Naval Observatory clock via telegraph wire, rebroadcasting it via a powerful transmitter to receivers all over the nation. Americans utilized radio technology to set their clocks to this standardized signal.

This spark coil operated as part of a spark gap transmitter, an early design of transmitter that used sparks to create radio waves. The spark coil creates these electric sparks. German Telefunken equipment was used in commercial radio installations in the US, including Tuckerton Station, NJ. These stations, and the equipment contained within, were seized by the US military during WWI.

John Hays Hammond, Jr., was largely responsible for launching the field of radio control. In 1926, he built a medieval-inspired castle in Gloucester, Massachusetts. This site served as his home and research laboratory. With over 400 patents to his name, Hammond developed ideas for radio control, autopilot function, and targeted missile detonation. This device was used in Hammond's laboratory.

This radio was used on USS George Washington when President Woodrow Wilson made his first voyage to the Paris Peace Conference in 1919. Its donor, Fred Schnell, belonged to an elite group of radio operators working for the US Navy. Using this radio, Schnell transcribed several messages instrumental to the peace talks that ended WWI, including the peace acceptance from Germany.

The Universal Transoceanic Phantom is a long-range radio receiver produced in 1927. Each set was tested and calibrated at the Leutz factory to receive stations 2,000 or more miles away. The high price of the set was offset through advertisements touting its exceptional materials and technology. As further testament, the Phantom was advertised as being used onboard the battleship USS Utah.

Charles Francis Jenkins, pioneer of mechanical scanning television, also developed one of the first marine facsimile systems, depicted here. In 1926, Jenkins created an experimental device similar to a modern fax machine, capable of transmitting weather maps to ships at sea. In September, it became a lifeline, guiding the USS Kittery to safety against the blows of the Great Miami Hurricane.

The SE950 was produced commercially during WWI as a rugged field radio; its versatile nature allowed it to remain useful in Charles Francis Jenkins' laboratory. The radio was used in a curious 1924 experiment as Mars drew near Earth's orbit. The SE950 was connected to a device capable of photographically recording any "alien communication" broadcast during military-imposed radio silence.

Lee de Forest was a telecommunications inventor, responsible for the Audion vacuum tube. In 1907, his "radiophone" allowed phonograph music and human voice to broadcast wirelessly. The device used a "singing arc" to generate radio carrier signals. The US Navy purchased six radiotelephones for installation on the Great White Fleet. This is one of the earliest radiotelephones made by de Forest.

A transmitter is an electronic device that, coupled with an antenna, generates radio waves. Transmitters remain essential to devices that we use every day: cell phones, wireless computer networks, navigational tools. During WWII, experiments to use weather balloons as long-range missiles were conducted. It is uncertain at this time if this artifact is connected to this research.

Thomas Edison received a patent in 1876 for "Autographic Printing," covering the electric pen and flatbed press; a patent for "Autographic Stencils" followed in 1880. The mimeograph was invented by Albert Blake Dick in 1887, who licensed and refined Edison's patents. This low-cost, stencil-based printing technology was popular until displaced by photocopying machines and offset printing in the 1960s.

This is a demonstration device to promote the helium-neon gaseous optical maser. "Maser" was an early term used by Bell Laboratories, who were interested in the device's communication potential; "laser" predominated in the end. Presented to the museum at the Institute of Electrical and Electronics Engineers' meeting of 1963, this is one of the few maser demonstration versions ever made.

Edwin H. Armstrong was a pioneer of radio engineering, credited as the inventor of FM radio. In 1918 he filed a patent for the superheterodyne radio circuit. This technology increased the sensitivity and selectivity of radio receivers. The radio depicted is the first portable superheterodyne radio receiver ever made. Armstrong gave it to his wife, Marion, on their 1923 honeymoon.

The IMSAI 8080 was a clone of the Altair 8800, the first mass marketed personal computer. It was a popular "kit computer," requiring assembly and programming. With no keyboard, toggle switches allowed input and LED lights signaled output. This could be modified using an IBM I/O typewriter. The donor, O.S. Narayanaswami, was a mechanical engineer interested in the educative power of computers.

Western Electric produced the first commercially available condenser microphone. It was widely used in broadcast, cinema, and studio applications until the mid-1930s, when ribbon microphones were introduced. WXYZ-Radio (whose call letters were WGHP until 1930) was a charter member of the CBS Radio Network, producing popular programs like The Lone Ranger and Green Hornet.