Press TV
January 17, 2012

Jamming signals transmitted from unidentified locations on the transponder belonging to Islamic Republic of Iran have interrupted the broadcast of IRIB channels.
The waves have been transmitted on frequency 12437 MHz, symbol rate: 27500, FEC ¾ since Tuesday afternoon.

The Eutelsat telecommunication giant has declined to comment on the problem.

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Al Jazeera TV jammed from Iran (Dec 2011)