Note
QST, Jan 1937, back cover.
Radio Craft, Jan 1937, p. 395.
Radio, Mar 1938, back cover, (now only $4.00)
The RCA 913 was a one-inch cathode ray tube introduced by RCA in 1936, designed to be an affordable option for hobbyists and experimenters. Unlike larger, more expensive CRTs, the 913 had a small, metal-jacketed envelope with a spherical screen. It featured electrostatic deflection and produced a green trace on a medium-persistence phosphor. The tube was specifically marketed for use in low-cost test and measurement instruments, and it became a popular choice for building amateur-built oscilloscopes and modulation monitors. Its low price and compact size made CRT technology accessible to a wider audience, paving the way for further innovation.
The 913 was immensely popular, appearing in several small commercially available oscilloscopes, and in more than a dozen construction projects published in popular magazines.
The tube was probably made until the United States entry into WWII, when wartime production shifted to larger tubes for military use. Nevertheless, it was probably available from existing stock during the war, and for a number of years following war. The last construction project involving the 913 appeared in 1957.
References
Technical description. Radio Craft, Jan 1937, p. 395.
A Low Cost Scope for the Phone Man. Radio, Jan 1937, p. 94.
A Cathode Ray Scope you can Afford. Radio News, Feb 1837, p. 464.
Make this Midget Oscilloscope. Radio Craft, Feb 1937, p. 470.
Brief description. Radio News, Mar 1937, p. 521.
Build this 913 Cathode Ray Oscilloscope. Radio News, Mar 1937, p. 530.
Radio Craft Midget Oscilloscope, part 1. Radio Craft, Apr 1937, p. 595.
Radio Craft Midget Oscilloscope, part 2. Radio Craft, Apr 1937, p. 666.
Clough Brengle 105, Radio News, May 1937, p. 657.
Make a Junior Oscilloscope. Radio Craft, Mar 1937, p. 527.
A Practical Low Cost Oscilloscope. Radio, Feb 1937, p. 19.
Short Review of Midget Scopes. Radio News, Aug 1937, p. 139.
A One Inch Oscilloscope. Radio. Apr 1938, p. 52.
Modulation Indicator. Radio, May 1938, p. 42.
A Cathode Ray Oscilloscope for $1.37. Radio, Jun 1938, p. 45.
A 913 Frequency Meter Modulation Monitor. Radio, May 1940, p. 38.
A Miniature Scope for the Ham Shack. Radio News. Feb 1957, p. 68.
CRT
