ITU Q.29:1988
ITU Q.29:1988 Causes Of Noise And Ways Of Reducing Noise In Telephone Exchanges
Table of Contents
1Powersupplynoise1.1Powersources
1.2Supplyleads
1.3Earthreturns
2Noisegeneratedinthespeechcircuit
2.1Contactnoisecausedbyvibration
2.2Fryingnoise
2.3Contactnoisecausedbywettingcurrents
2.4Chargeanddischargeclicks
2.5Unsoundcontacts
2.6Tappinglosses
2.7Reductionofthenumberofswitchingcontacts
3Noiseinducedinthespeechcircuit
3.1Noiseinducedinthespeechcircuit
3.2Noisesduetounbalancedtransmissionbridge
circuits
3.3Low-levelspeechcircuits
3.4Longitudinalinterference