Kenwood TS-590S manual 4.6.5 NR1 Based on a Line Enhancer AF Processing, 4 DSP

4 DSP

4.6.5 NR1 (Based on a Line Enhancer) (AF Processing)

As a noise suppression process, the line enhancer method based on a DSP has been adopted by many amateur radio transceivers in recent years. This method automatically adjusts the filter characteristics according to the characteristics of a RX signal to obtain filter characteristics suitable for passing periodic signals such as a CW signal. Because the process automatically passes and emphasizes periodic signals, it is called a line enhancer (line spectrum enhancer). Since the degradation of receive audio is small, a line enhancer is an easy-to-use, engineer-friendly technique. For the TS-590S, we have reviewed part of the NR1 process and succeeded in drastically improving the noise reduction capability compared with previous models. Below you can see the result of frequency analysis conducted on the receive audio containing a sine wave while NR1 (based on a line enhancer) is inactive in Figure 4-16 and the result while NR1 is active in Figure 4-17.

Target signal

Figure 4-16 NR1 (Line Enhancer Method) (Inactive)

Target signal

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Figure 4-17 NR1 (Line Enhancer Method) (Active)

CONTENTS TS-590S