The RCA Selectron -- Charactron Tube Development

These excerpts and documents are reproductions of material not readily available from libraries in electronic form, and span the history from the origins at Consoldated Vultee Aircraft Corporation through the final commercial products from Datagraphix Corporation.

Although the character stencil beam tubes had been explored at other organizations for purposes other than human readable displays Joseph McNaney Working for Convair was the first to reduce to practice both the CRT and supporting electronics. Like devices from Bell Telephone Laboratories, McNaney's first work was for converting alphanumeric data encoded as holes on punched paper tape in a digitally encoded format to human readable characters printed on photographic film. The first disclosure was in June 1940 as a US patent application which was granted in 1942 as US2275017. This patent teaches a way to transform a sequence of data punched onto a paper tape into a sequence of single characters appearing in the center of a CRT face which then exposed photographic film. This device anticipated the single character Indicoder of sixteen years later.

US Patent 2275017 Signalling System

US Patent 2275017 Signalling System














By 1952 McNaney's designs had progressed to where multiple characters forming a message could be displayed on a CRT face as shown in US2735956.pdf. At this early stage the character selection was performed with conventional electrostatic deflection places while the deflection of the character to the desired location on the screen was performed by a rather unconventional set of deflection coils:

US Patent 2275017 Cathode Ray Apparatus

US Patent US2735956 Cathode Ray Apparatus















Prototype per US Patent 2275017
Photo courtesy Glenn Robbins
Note that the actual cathode ray tube was produced by Vacuum Tube Products Company of Carlsbad, California, with the assistance and expertise of VTP founder and chief engineer Harold W. Ulmer. Convair did not yet have the facilities nor expertise for electron tube design and realization. Before founding VTP Ulmer worked for Raytheon Mfg. Company and ITT Corporation.

Earliest trade magazine mention of the Charactron

Earliest trade magazine mention of the Charactron








Copyright 1949 Caldwell-Clements, Inc
All Rights Reserved
Archived copy courtesy AmericanRadioHistory.com



Earliest trade magazine photograph of Joseph McNaney.

Earliest trade magazine photograph of Joseph McNaney











Copyright 1949 Caldwell-Clements, Inc
All Rights Reserved
Archived copy courtesy AmericanRadioHistory.com



Additional coverage of Charactron introductory press release

Additional coverage of Charactron introductory press release







Copyright 1949 McGraw-Hill Publishing Company
All Rights Reserved



Photo of Convair's McNaney with VTP's Ulmer

Photo of Convair's McNaney with VTP's Ulmer
This link takes you to John Atwood's One-Electron pages which include many documents and history about Harold Ulmer and Vacuum Tube Products Co.
This link takes you away from rcaselectron.com







Photo copyright 1952 VTP Co.
All Rights Reserved



In March of 1952 McNaney presented a paper on the Charactron at the annual convention of the Institute of Radio Engineers in New York City.

The below photograph may be of the Convair exhibit which would have been at the convention.

Convair Charactron exhibit

Convair Charactron exhibit







Photograph courtesy of and used with permission of Glenn Robbins.



In July of 1952 Convair, as Consolidated Vultee now called itself, advertized for engineers on the project.

Convair employment ad

Convair employment ad







Copyright 1952 McGraw-Hill Publishing Company
All Rights Reserved



1953 group photos at Convair site at Lindbergh Field in San Diego, California

Convair group photo with a 19

Convair group photo with a 19" and 5" Charactron







Photograph courtesy of and used with permission of Glenn Robbins.



Convair group photo

Convair group photo



Photograph courtesy of and used with permission of Glenn Robbins.





Convair house organ

Convair employee newspaper



Copyright General Dynamics Corporation. Convair Division. Used by permission.
Convairiety, Volume 7, Number 16, Wednesday, August 11, 1954, periodical, August 11, 1954; Fort Worth, Texas.
(https://texashistory.unt.edu/ark:/67531/metapth777361/: accessed July 3, 2020)
University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu;
crediting Lockheed Martin Aeronautics Company, Fort Worth.
(Whew!)





By this time the contract with IBM for the AN/FSQ-7 (SAGE) displays was in full force.
Convair worked with IBM, MIT, and several other firms -- and competitors -- to deliver
military project quality Charactron tubes in production quantities.

Project Whirlwind logo of arithmetic symbols and an electron tube being drawn up into a sketch of a stylized  cyclone

Massachusetts Institute of Technology -- Project Whirlwind

Development of the Charactron and Typotron











Front page of QST magazine article on Charactron Morse code convertor

Article on Charactron based Morse Code convertor/display by McNaney and Jackson








Courtesy March 1954 QST
Copyright American Radio Relay League / used by permission
All Rights Reserved



Photograph used in QST magazine article on Charactron Morse code convertor

Photograph used in article on Charactron based Morse Code convertor/display by McNaney and Jackson








Photograph courtesy of and used with permission of Glenn Robbins.



Front page of Aviation Week magazine article on Charactron display

Article on Charactron and its effect on air defense








Copyright 1954 Aviation Week
All Rights Reserved



1956 advertisement

1956 advertisement











Stromberg-Carlson Indicoder documents circa 1957

Stromberg-Carlson Indicoder articles circa 1957








Stromberg-Carlson Charactron

Stromberg-Carlson Charactron 1957 Catalog




Copyright 1957 Stromberg-Carlson / General Dynamics
All Rights Reserved



Charactron tube with multiple phosphors on one screen

Don Pugh observing Charactron tube with multiple phosphors on one screen



Photograph courtesy of Pea Hicks



Vade Mecum listing of Charactron types in 1962

Vade Mecum listing of Charactron types in 1962







DatagraphiX S-C 1100 Charactron based terminal, circa 1965

DatagraphiX S-C 1100 Charactron based terminal, circa 1965




Copyright 1965 Stromberg-Carlson
All Rights Reserved
Archived copy courtesy ADSAUSAGE



DatagraphiX S-C 1100 Charactron based terminal, brochure circa 1965

DatagraphiX S-C 1100 Charactron based terminal, brochure circa 1965




Copyright 1965 Stromberg-Carlson / General Dynamics
All Rights Reserved
Archived copy courtesy Internet Archive



DatagraphiX 1110 Charactron based terminal, circa 1969

DatagraphiX 1110 Charactron based terminal, circa 1969




Copyright 1969 Stromberg-Carlson
All Rights Reserved
Archived copy courtesy ADSAUSAGE



DatagraphiX 1072 Charactron based terminal, circa 1970

DatagraphiX 1072 Charactron based terminal, circa 1970




Copyright 1970 General Dynamics
All Rights Reserved
Archived copy courtesy Internet Archive



DatagraphiX 2220 Charactron based projection display, circa 1970

DatagraphiX 2220 Charactron based projection display, circa 1970




Copyright 1970 General Dynamics
All Rights Reserved
Archived copy courtesy Internet Archive



DatagraphiX Charactron based terminal, circa 1977

DatagraphiX Charactron based terminal, circa 1977




Copyright 1977 DatagraphiX / General Dynamics
All Rights Reserved