. The Bell System technical journal . ROR PRODUCTION BY EXTRANEOUS INTERFERENCE A knowledge of the performance of a regenerative repeater withvarious types and amounts of interference added to the input signal isimportant. Consequently a study of such errors produced in one ofthese repeaters was undertaken. Two general types of extraneous inter-ference was used in this study. The first is impulse noise, the type whichis produced by telephone dials, switches, lightning surges and crosstalkfrom other pulse systems. The second is sinusoidal noise, the type whichcome from power line or carrier cro
. The Bell System technical journal . ROR PRODUCTION BY EXTRANEOUS INTERFERENCE A knowledge of the performance of a regenerative repeater withvarious types and amounts of interference added to the input signal isimportant. Consequently a study of such errors produced in one ofthese repeaters was undertaken. Two general types of extraneous inter-ference was used in this study. The first is impulse noise, the type whichis produced by telephone dials, switches, lightning surges and crosstalkfrom other pulse systems. The second is sinusoidal noise, the type whichcome from power line or carrier crosstalk. This interference may affectthe regenerated output in a number of ways. It may produce a phaseshift or jitter in the output; cause a pulse to be omitted; or cause aspurious pulse to be inserted in the signal code. The phase jitter will belargely removed by timing regeneration in subsequent repeaters, butomission and most insertion errors will be carried through the remainingrepeaters, causing distortion in the decoded Plate IV — Superimposed picture of the outputs of and miles of 19 gaugecable with identical injjuts. TRANSISTOR BINARY PULSE REGENERATOR 1075 605550454035302520151050 , y / EQUALIZED MILES / 1/ — _!L. ^_ .» V > 1 EQUALIZER = LUS -y ^ MILES CABLE A ^^ \ MILES CNB19 GAUGE CABLE .^ ^ 1 1 1 1 1 1 1 1 1 1 1 8 10 20 40 60 80 100 200 FREQUENCY IN KILOCYCLES PER SECOND 400 600 1000 Fig. 6 — Effect of changing the length of 19 gauge line with fixed equalization. Description of Error Detecting and Counting Circuit An error detecting and counting circuit was built to count insertionand omission errors. This circuit (block diagram, Fig. 7) is a coincidencedetector in which each pulse or space of the repeater input signal iscompared to its corresponding regenerated output. As long as the twosources are the same, , having corresponding pulses or spaces, thereis no output from the detector. If the two differ the detector p
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
