DATA TRANSMISSION BY MEANS OF RAILWAY TELEPHONE CIRCUITS AT SPEEDS EXCEEDING 600 BAUDS. INTERFERENCE IN ADJACENT AUDIO-FREQUENCY AND CARRIER-FREQUENCY TELEPHONE CIRCUITS DUE TO THE METHODS OF TRANSMITTING LOW-FREQUENCY SELECTION PULSES, AND MEASURES TO BE ADOPTED FOR REDUCING THEM
This report principally deals with the results of tests carried out on various Administrations for the purpose of determining the interference produced by inductive dialling methods (pulse generator, type DB Ed 5) in adjacent audio-frequency and carrier-frequency circuits. The cross- talk attenuation between circuits has been artifically reduced to 8 nepers with 800 Hz by means of capacitances. The noise was tape-recorded with a view to the subsequent simulation of actual transmissions on the ORE measuring installation at Vienna. Corrective measures: modification of contacts of relays, filtering, smoothing circuits for inductive pulses, reduction of transmission voltage, synchronisation of a.c. dialling pulses. The mode application of these measures is also given.
- Restriction on the use of this document are contained in the explanatory material.
International Union of RailwaysOffice of Research and Experiments
- Publication Date: 1969-10
- Pagination: 32 p.
- TRT Terms: Communications; Data communications; Inductive interference; Interference; Telephone equipment; Track circuits
- Old TRIS Terms: Audio frequency track circuits; Question a76
- Subject Areas: Operations and Traffic Management; Railroads;
- Accession Number: 00052706
- Record Type: Publication
- Source Agency: International Union of Railways
- Report/Paper Numbers: A76/RP 7/E
- Files: TRIS
- Created Date: Apr 21 1976 12:00AM