of almost −180°. This would cause poor transient response in the control loop due to low phase margin. The output might exhibit squegging. Bernard M. Oliver showed that slight compression of the gain by the amplifier mitigates the envelope transfer function so that most oscillators show good transient response, except in the rare case where non-linearity in the vacuum tubes canceled each other producing an unusually linear amplifier. References Other references ; Speaks of Terman's inspiration by Black and his late 1930s graduate seminar about negative feedback and fixed-frequency audio oscillators; Hewlett finishing masters and looking for engineers thesis; hiring San Francisco patent attorney in 1939. . Frequency and amplitude stabilization of an oscillator with no tube overloading. Uses tungsten lamp to balance bridge. . Shows that amplifier non-linearity is needed for fast amplitude settling of the Wien bridge oscillator. ; Wien, briged-T, twin-T oscillators ; Hewlett graduated from Stanford and spent a year doing research; then he goes to MIT to get his masters. Hewlett joins the army, but is discharged in 1936. (diode limiting) External links Model 200A Audio Oscillator, 1939, HP Virtual Museum. Wien Bridge Oscillator, including SPICE simulation. The "Wien bridge oscillator" in the simulation is not a low distortion design with amplitude stabilization; it is a more conventional oscillator with a diode limiter. Online Simulator of Wien Bridge Oscillator – Gives online simulation of Wien bridge oscillator. Bill Hewlett and his Magic Lamp, Clifton Laboratories (Acks Edward L. Ginzton at end of paper.) (Presented 16 June 1938 at 13th Annual Convention, Manuscript received 22 November 1938, abridged 1 August 1939); Meacham presented at 13th Annual Convention on 16 June 1938, too. See BSTJ. Also presented at Pacific Coast Convention, Portland, OR, 11 August 1938. , §Resistance-stabilized Oscillators Employing Negative Feedback, state "For a discussion of ordinary resistance-stabilized oscillators see pages 283–289 of F. E. Terman, 'Measurements in Radio Engineering,' McGraw-Hill Book Company, New York, N.Y., (1935)." (diode limiting) state, "This oscillator [Hewlett's] somewhat resembles that described by H. H. Scott, in the paper 'A new type of selective circuit and some applications,' Proc. I.R.E., vol 26, pp. 226–236; February, (1938), although differing in a number of respects, such as being provided with amplitude control and having the frequency adjusted by variable condensers rather than variable resistors. The latter feature makes the impedance from a to ground constant as the capacitance is varied to change the