Constant-Resistance Modulators with Built-in Frequency Selectivity

Zobel O. J. Distortion correction in electrical circuits with constant resistance recurrent networks. Bell Syst. tech. J. 7, p. 438, (1928)

Tucker D. G. Constant-resistance modulators. J. Br. Instn. Radio Engrs. 21, p. 491 (1961); also Chapter 9 of Circuits with Periodically-varying Parameters. Macdonald, London (1964)

Tucker D. G. , and Terreault G. The performance of practical constant-resistance modulators in relation to their use in FDM systems. J. Instn. Elect. and Rad. Engrs. 31, p. 310 (1966)

Caruthers R. S. Copper oxide modulators in carrier telephone systems. Bell Syst. tech. J. 18, p. 315 (1939)

Tucker D. G. The generation of a.c., or a specified harmonic using d.c. power and switches with idealized frequency-selective circuits. Int. J. elect. Engng. Educ. 3, p.583 (1965)