. The Bell System technical journal . lay of one circuit at any frequency from about600 cycles to 20,000 cycles or more with respect to the delay on theother circuit at a fixed frequency. The functioning of the apparatus may be briefly described asfollows: Simultaneously into each line there was transmitted acarrier current, each carrier being modulated by 250-cycle currentfrom the same oscillator. The modulation was accomplished in push-pull vacuum tube circuits so that the undesired products of modulationwere ehminated by balance. The carrier on the line under measure-ment was adjusted to th
. The Bell System technical journal . lay of one circuit at any frequency from about600 cycles to 20,000 cycles or more with respect to the delay on theother circuit at a fixed frequency. The functioning of the apparatus may be briefly described asfollows: Simultaneously into each line there was transmitted acarrier current, each carrier being modulated by 250-cycle currentfrom the same oscillator. The modulation was accomplished in push-pull vacuum tube circuits so that the undesired products of modulationwere ehminated by balance. The carrier on the line under measure-ment was adjusted to the frequency at which a measurement wasdesired, and the carrier on the other circuit, used for reference, waskept at a fixed frequency of 5100 cycles. At the receiving point identical circuits were provided for amplifying ^Voice-Frequency Carrier Telegraph System for Cables, B. P. Hamilton,H. Nyquist, M. B. Long and W. A. Phelps, Journal A. I. E. E., Vol. XLIV, pages213-218, March, 1925. 630 BELL SYSTEM TECHNICAL JOURNAL 0)> u 01 c.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
