Communication and Power Industries / Eimac media collection, circa 1944-1990

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Summary

Title:
Communication & Power Industries, Eimac Division media collection
Dates:
circa 1944-1990
Creators:
Eimac (firm), Varian Associates. Eimac Division, and Communication & Power Industries. Eimac Products
Abstract:
The Communication Products Industry (CPI), Eimac Division media collection includes photographic media, film, and sound recordings produced from the mid-1940s to late 1980s by Eitel-McCullough Incorporated (Eimac), an early innovator in the development and application of high frequency vacuum tubes and radar technology founded in San Bruno, California in 1934. The company's in-house produced media were used for operational and administrative purposes including product development and testing; employee training and staff recognition; conference presentations; and publicity and marketing needs. The collection is augmented by a limited amount of business-related records, including Eimac-Varian company annual reports; indexes for equipment inventory and quality check reference; and planning materials for employee appreciation and award events.
Extent:
71.5 Linear Feet ; 126 containers (32 record cartons; 69 manuscript boxes; 21 flat boxes; 4 card boxes; and 1 non-standard size box);
Language:
English .
Preferred citation:

[identification of item], Communication & Power Industries, Eimac Division (CPI/Eimac) media collection and files (M0917). Dept. of Special Collections and University Archives, Stanford Libraries, Stanford, California.

Background

Scope and content:

The Communication Products Industry (CPI), Eimac Division media collection includes motion films, photographic media, and sound recordings produced from the mid-1940s to late 1980s by Eitel-McCullough Incorporated (Eimac), an early innovator in the development and application of high frequency vacuum tubes and radar technology that was founded in San Bruno, California in 1934. The company produced media for their operational and administrative needs, including product development and testing, employee training, and publicity and marketing.

Eimac's media-produced content was featured in internal communications, marketing materials, annual reports, supply catalogs, technical bulletins, product sheets; and in professional papers and conference presentations given by their engineers.

Photographs and negatives comprise the bulk of the collection. Major subject areas covered include company facilities and operations; products and applications; and employees. Photographs of the latter group include identification badge portraits; production and assembly line workers, engineers and scientists; and engagement in social activities. Audio recordings from the 1960s to 1970s are of employee interviews and company award events.

Supplementing the collection's media is a limited amount of related historical business files and several artifacts. These include a limited run of Eimac-Varian company annual reports; indexes for equipment inventory and quality check reference; planning materials for employee appreciation and award events; and miscellany about the founders of Eimac and the company's achievements.

Biographical / historical:

Eitel-McCullough Inc. was founded in 1934 by radio engineers and business partners, Bill Eitel and Jack McCullough in San Bruno, California. The company started out developing innovative radio vacuum tubes that provided higher frequency transmission for radio communication and eventually transitioned into components used in klystron-powered machines used for manufacturing. The innovative microtube technology that was developed by the Eitel-McCullough (Eimac) company led it to be a leading manufacturer of transmitter tubes for radar and other radio equipment and making it a pioneer of radio frequency-based applications. From 1947 to 1959, Eitel-McCullough owned and operated KSBR FM radio station in San Bruno, California. The factory engineers built the transmitter to use for testing tubes in "real-world" performance and with its location atop Mount Diablo, it an exceedingly broad coverage area.

The company began working in klystron technology pioneered by Russell and Sigurd Varian and Edward Ginzton, founders of Varian Associates invented the klystron tube in 1937. In 1957, Eimac revealed the X626, a more efficiently powered electron tube that was used in radar and linear accelerator operation. Klystrons are used in satellite systems, television broadcast, and radar, as well as particle accelerators and medicine, and Eimac's klystron tubes were extensively used for Distant Early Warning systems by the U.S. military and for commercial television and communication services. The model X626 was a landmark pioneering invention of Eimac, and their electron tubes were used in klystron systems devised for industrial manufacturing of products such as tan oak bats.

Eimac moved to San Carlos, California in 1959, and in 1965, merged with Varian Associates. In 2007, the last remaining Eimac plant at San Carlos was closed and consolidated into CPI's Microwave Power Tube operation in Palo Alto. [Source: Engineering and Technology History Wiki https://ethw.org/Eimac]

Acquisition information:
This collection was given in two parts by H. Frederick Koehle, representative of Communication Power Industries and Marshall Loring to Stanford University, Special Collections in 1997.
Arrangement:

The collection is arranged in the following series: Series 1: Historical Files; Series 2: Audio-visual Media; Series 3: Slides; Series 4: Photographs; and Series 5: Negatives. Detailed summaries of each series are provided for each in this finding aid.

Physical location:
Special Collections and University Archives materials are stored offsite and must be paged three business days in advance. For more information on paging collections, see the department's website: https://library.stanford.edu/libraries/special-collections.
Physical facet:
Documents; print matter; photographs; film negatives and slides; 8mm and 16mm film; magnetic audio and video tape recordings; glass-plate negatives and slides; and artifacts.
Rules or conventions:
Describing Archives: A Content Standard

About this collection guide

Collection Guide Author:
Chris Doan
Date Encoded:
This finding aid was produced using ArchivesSpace on 2025-09-29 14:50:28 -0700 .

Access and use

Restrictions:

Open for research, with the exception of born-digital materials, which are closed until processed. Note that material must be requested at least 36 hours in advance of intended use. Audiovisual materials are not available in original format, and must be reformatted to a digital use copy. Digital files are closed until processed.

Terms of access:

While Special Collections is the owner of the physical and digital items, permission to examine collection materials is not an authorization to publish. These materials are made available for use in research, teaching, and private study. Any transmission or reproduction beyond that allowed by fair use requires permission from the owners of rights, heir(s) or assigns.

Preferred citation:

[identification of item], Communication & Power Industries, Eimac Division (CPI/Eimac) media collection and files (M0917). Dept. of Special Collections and University Archives, Stanford Libraries, Stanford, California.

Location of this collection:
Department of Special Collections, Green Library
557 Escondido Mall
Stanford, CA 94305-6004, US
Contact:
(650) 725-1022
specialcollections@stanford.edu
Website