This is just a place where I store random links to things I'm interested in or want to share with others.
Information for the Amateur Designer of Transformers for 25- to 60-Cycle Circuits (PDF 2.1 MB). This is circular C408 of the National Bureau of Standards published in 1935. The object of this circular according to its introduction is "to assist the amateur in the design of small and medium-sized single-phase transformers for operation in the usual power frequencies. It is assumed that one transformer, or at most a few transformers are to be built, and that successful operation with good-efficiency and reasonable cost is the goal...."
Special Purpose Oscillators and Amplifiers TM-11-680 (PDF 7.8 MB, 130 pages). This is a Department of the Army Technical Manual published in 1952. It outlines design principles for wide and narrow-band amplifiers and various sorts of oscillators.
Bates, R. H. "A Direct-Coupled Amplifier with Cathode Follower." Radio & Television News (November, 1949), pp. 62-63.
Hust, L. B. “Extended Class A Amplifier,” Radio & Television News (1953 September), pp. 40-42, 146-148.
Terman, Frederick E., "Regeneration in Multistage Audio- and Video-frequency Amplifiers," Electronic and Radio Engineering. New York: McGraw-Hill Book Company, 1955, pp. 360-363.
Magnatone Model 109 schematic. This is an example of once commercially available self-split 6V6 amplifier. It uses the screen-fed self-split arrangement.
milliAmp, a 12DW7 single-tube amplifier. This is a simple little project that got kick started awhile back on the AX84 bulletin board. I've got a prototype started but it languishes waiting for me to make more time for it (sigh).
Ampex A692 schematic. This an interesting studio recording amplifier that has the entire tone compensation network embedded into the global feedback loop.
Webcor Model 2010 tape recorder schematic (PDF 78K).
