SOUND PROCESSOR
Document (PDF):
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Improving Audio Reception of Weak Analog Satellite Signals
With DIGITEX we have offered a tool for picture improvement. But what is about the audio performance ?
If the picture quality is good audio would be no problem. Developments like the WEGENER/ PANDA system are providing higher audio signal-to-noise ratios for an exciting stereo sound.
But what happens if the satellite signal is too weak?
Several different techniques for improvement of the picture are known. But if the picture is restored in many cases audio remains a big problem.
That`s why we have developed this module.
As described in certain examples improvement of the sensitivity of a receiving system is possible by narrowing it`s bandwidth. Therefore many satellite receivers have switchable audio bandwidth filters which allow a static decreasing of the audio channel bandwidth.
Instead of static filters the Sound Processor uses a dynamic tracking filter with an bandwidth of about 20KHz. This gives a C/N-improvement of about 8dB compared to a conventional 150KHz filter.
The practical effect is that even on poor and weak transponders (no colour/distorted syncs) understandable audio reception is still possible, but naturally not in HIFI quality standard.The audio subcarrier range from 5.50 to 9.50MHz is PLL controlled tunable in 10KHz-steps .
The demodulating principle is also PLL-type which is an optimum choice for weak signal reception. Also a special noise reduction circuit is implemented.
TECHNICAL DATA
Subcarrier Frequency Range: 5.50 - 9.50MHz
Stepping: 10KHz
Baseband Input (Cinch): 1Vss / 75W (adjustable)
IF Bandwidth Range: 20 - 280KHz
Audio Output (Cinch): 600mV / 1KW
Deemphasize: 60us / J17 (switchable)
Power Supply: 12 - 15V DC / max. 150mA
Dimensions: 31 x 113 x 165mm
Weight: ca. 250gSpecifications are subject to change without notice.
All trademarks accepted.