CSS203 affords the control of the audio modulation presence. Inserted on a stereo audio link, it allows the monitoring of two unsimultaneous balanced stereo sources to one balanced stereo output. It includes two sections: the first one controls the modulation presence, and the second controls the phase between the left channel and the right channel.

If there is a problem, the CSS203 automatically swings on an external save source according to an adjustable delay. The swing back delay is also adjustable.

In alarm mode, the CSS203 sends several signals to display the started up alarm type (blank modulation or phase error), and to start save broadcast machines up. 

• Each alarm mode can be indepently activated, with its own alarm type led and alarm delay parameters (dip-switch).
• Blank detection threshold is setted by dip-switches. Detection method: modulation blank on left or right channels or on both.
• Phase detection allows real-time phase monitoring (phasemeter) and activates phase alarm mode when L and R channels are out of phase.
• Alarm reset delay set by dip-switches regardless of activated alarm type. Alarm mode can be substained by a switch, while a technician is looking for troubles in the audiophonic chain. This switch can be useful to test the start of the save machines.
• Alarm mode indicated by a front panel led: flashing when  automatic alarm or fixing when test mode.
• Output modulation can be controlled by the monitoring section (headphones and peakmeter).
• External remote commands define the input to control (A or B) and can disable the alarm mode activation.
• Possibility to insert a 19 KHz filter on the audio analysis in order to use it on a FM MPX signal.
• Option for testing the presence of the modulation on safe input before switching.

Besides, thanks to its design (relay commutations), the CSS203 is entirely transparent about the modulation (any noise, any distortion signal, and allows the input flow during the power off.

APPLICATION:

CSS203 would be used in radio broadcasting stations, for example, as a backup to the broadcast in case of the main modulation disconnection. It would preferably be situated at the end of a broacasting installation or just after the satellite receiver for the regional disconnections in local stations.