Tube Journals
Tech's Filing Cabinet Miscellaneous General Electric RCA Tube Tech Semi Tech Audio Radio

Scanned articles covering tube technology. Unless otherwise noted, these scans were done by John Atwood. Articles marked "*" were extracted from scans. Listed chronologically.

Warner 1923 Recent Developments in High Vacuum Receiving Tubes - Radiotrons Model UV-199 and Model UV-201-A * - The introduction of General Electric's "X-L tungsten filament" tubes, i.e. thoriated-tungsten filaments. The UV-201A replaced the pure tungsten UV-201, with 1/4 the filament current. The UV-199 was a new tube with low enough filament current to be run from dry cells. Both these these tubes made consumer broadcast receivers much more practical.

Muhleman 1926 Vacuum Tubes and Their Uses - An article from the Aug. 1926 issue of Radio News describing all the varieties of American receiving tubes. Note that these are all triodes.

Radio News 1926 A New Rectifier Tube for A-B-C Power Units - Radio News from Oct. 1926 describes Raytheon's BH rectifier - a gaseous rectifier that could supply 350 volts at 85 mA. This is the predecessor of the 0Z4. The article claims it can supply A, B, and C power, but this is stretching things - the C (bias) voltage is derived from a back-bias resistor and the A (filament) voltage can only supply type 199 tubes in series.

Harris 1927 A New Electron Tube - Sylvan Harris describes Hull's "shielded grid" tetrode (originally devised by Schottky in Germany). This evolved into the type 24 tetrode, which revolutionized RF and IF amplifier design - eliminating the need for neutralization. From Radio News, July 1927.

Millen 1927 The Raytheon A Rectifier - James Millen describes the Raytheon "A" rectfier, an electrolytic rectifier designed to be used in an "A eliminator", i.e. to supply the 6 volts needed to run the 01A-based radios of the day. Note that a small storage battery was still required for hum filtering. From Radio News, Aug. 1927.

Radio News 1928 The Shielded-Grid Tube at Last Arrives - Radio News from Oct. 1926 describes the first American shield-grid tetrode in some detail. Oddly, the type number of the tube (UX-222) is not mentioned.

Weaver 1929 A High-Power Output Tube-The 250 - The factors that went into the design of the 250 - the first American high-power audio triode. It got limited use, due to the need for 450 volts for maximum power. It was quickly overshadowed by the 250 volt UX-245.

Engel 1929 Engineering Features of the UX-245 - An audio triode that put out 1.6 watts at 250 volts. This was the dominant radio output tube until the advent of the 47 pentode and, later, the 2A3 triode.

Van Der Mel 1933 The 2B6 - A Duplex Triode - An alternative to the power pentode: a cathode-follower directly driving a high mu triode in class A2 mode. Not appreciably better than a pentode - this was likely done to get around the pentode patents.

Salzberg & Burnside 1935 Recent Developments in Miniature Tubes - Describes the need for, and the development of the VHF "acorn" tubes. Originally published in the Proceedings of the I.R.E. in Oct. 1935.

Germeshausen & Edgerton 1937 The Strobotron * and White et al 1937 The Strobotron II * - The Strobotron was a cold-cathode neon-based strobe light that could also be used as a fast high-current trigger tube. It was used in the first generation of the General Radio "Strobotac".

Schade 1938 Beam Power Tubes - classic 1938 article by O.H. Schade of RCA on the requirements of audio amplifier tubes and how the beam power tube (6L6) is the best solution. Even if you are only into triodes, this is worth a read, since it combines a good "requirements document" for audio amplifiers along with the electron physics of how beam power tubes operate. Originally published in Proc. of the I.R.E., Feb. 1938, this was scanned from the RCA Electron Tubes Vol. I (1935-1941), published by RCA Review in 1949. 45 pages.

Smith & Schooley 1940 Development and Production of the New Miniature Battery Tubes - Describes the first set of 7-pin miniature tubes, intended for portable AM radios: the 1R5, 1T4, 1S5, and 1S4. These battery types were used extensively in World-War II portable radios. Originally published in the April 1940 issue of RCA Review.

Jervis 194- Amplification Chart - From a collection of articles from Electronics. No date, but likely from the 1940s. Equations and a nomograph for determining amplification factor ("mu") from a tube's geometry.

Harries 1944 Secondary Electron Radiation - Very detailed summary of the physics of secondary emission. On the second-to-last page is the little-known history of the "critical-distance" tetrode (called a beam-power tube by RCA) and some issues on how it works. Originally published in the Sept. 1944 issue of Electronics, this scan is from a compilation of article from Electronics.

Mouromtseff et al 1944 Review of Demountable vs Sealed-off Power Tubes - Demountable tubes are ones that can be easily taken apart to be repaired. Generally these are only of the very high power types. From the Nov. 1944 issue of the Proceedings of the I.R.E..

Swedlund 1945 Improved Electron Gun for C-R Tubes * - The evolution of CRT electron gun design at RCA.

Heins 1946 Hydrogen Thyratrons * - Describes the development of the 4C35 and 5C22 hydrogen thyratrons. The bulk of the article is actually on radar line modulator design.

Dailey 1948 Designing Thoriated Tungsten Filaments * - Complete equations for designing thoriated tungsten filaments.

Adler & Haase 1949 The 6BN6 Gated Beam Tube - A two-part article on the concept and design of the 6BN6 gated-beam tube. Adler prototyped the tube at Zenith Radio, and Haase reduced it to practice at General Electric. From the Proceedings of the National Electronics Conference, Vol. V, Sept. 1949.

Espe, Knoll & Wilder 1950 Getter Material for Electron Tubes - An article from Oct. 1950 Electronics. Everything you wanted to know about getters. Extensive bibliography.

Espe & Steinberg 1951 Aluminum-Clad Iron for Electron Tubes - Description of the development of aluminum-clad iron, called "P2 Iron" by its German inventors. This is the grey-colored plate, which replaced the black plates of carbonized nickel. This was crucial for the Axis tube manufacturing during World War II: (from the article): "It has been estimated that the Middle-European Electron Tube industry, during the years 1936 to 1944, saved about 500 tons of nickel by the use of P2-Iron". An important article.

Jones 1954 Voltage Regulator Tubes - A brief summary of the gaseous voltage regulator tube. A list of American types are given. This came attached to RCA Application Note AN-161.

Jones 1954 Tube Envelope Temperature - The bulb temeperatures vs power for various miniature and subminiature tube envelopes, and reasons for keeping the temperature low. This came attached to RCA Application Note AN-161.

Rowe & Welch 1954 Developments in Trustworthy-Valve Techniques - This article comes from S.T.C. in England and describes their efforts to make what Americans would call ruggedized or high-reliability tubes. Details on reducing noise, both random and microphonic, in tubes. From the Sept. 1954 issue of Electrical Communication.

AE of AGOET 1956 Heater-Cathode Leakage - Author: "The Application Engineers of the Advisory Group on Electron Tubes". The causes and mitigation of heater-cathode leakage. Article reprinted and distributed by RCA, Tube Division.

Espersen & Rogers 1956 Studies on Grid Emission - A paper from the IRE Transactions on Electron Devices on grid emission due to vaporized barium oxide and other contaminants. Extensive details on the experimental methods used. Key results: gold plating helps a lot but titanium grids are by far the best.

Bowe 1959 What Cathode is Best for the Job - Factors for selecting the type and material for vacuum tube and CRT cathodes. From the April 1959 issue of Electronic Industries.

Hasset 1961 The Materials and Shapes of Vacuum Tube Heaters - The configurations and manufacturing techniques for vacuum tube heaters. From the Dec. 1961 issue of Electronic Industries.