Axcera's DT2B ATSC exciter-modulator operates using 100 percent digital signal processing. The unit uses a VSB modulation technique, which makes it possible to generate a virtually perfect 8-VSB IF signal. The DT2B is a reprogrammable digital television exciter. It can be upgraded in the field with new software versions. Critical parameters can be set and queried directly on the color LCD screen or through an interface to a personal computer.
The DSP circuitry also handles frequency offsets, allowing an unlimited number of user selectable offsets. In addition, the frequency offsetter is used to compensate for errors in the SMPTE-310M input sample rate.
The companion upconverter accepts the output of the digital VSB modulator and produces on-carrier RF for any TV channel. The upconverter is based on dual-conversion technology using low noise PLL sources. Both the upconverter and the 8-VSB modulator can be locked to an external 10 MHz reference for synchronization or precise frequency offset control.
Non-volatile operation is achieved through flash-RAM (random access memory) which instantly stores all digital settings for the entire exciter-modulator system.
For more information visit www.axcera.com.
