Chennai, Nov 23: Regional channels of DD in Tamil Nadu including 'Podhigai' and all AIR channels including Chennai A, Chennai B, FM and commercial channels went off air since morning, sources said. As part of their nation-wide strike, Employees of Prasar Bharati affilated to National Federation of Akashvani and Doordarshan Employees (NFADE) here commenced a 48-hour "duty boycott" from today to press for various demands, including repeal of the Prasar Bharati Act. More than 200 employees especially from programming, technical and engineering sections, who began their protest from 9 am, alleged that the "12 years of Prasar Bharati experiment" had "dented" the reputation of All India Radio and Doordarshan, NFADE sources said. Regional channels of DD in Tamil Nadu including 'Podhigai' and all AIR channels including Chennai A, Chennai B, FM and commercial channels went off air since morning, sources said. AIR with 336 broadcasting centres and DD with a network of 60 production centres and 1,404 transmitters served 99.13 and 94 per cent of the country's population,they said. NFADE is an umbrella organisation of 21 service associations of around 40,000 employees working in AIR and DD. (Arunkumar, Deccan Chronicle)