NQ5T:
>The results are as follows (LCW, 1000Hz spot tone, NR=9)
>BW=3000Hz: SNNR improves by approx 1dB with NR=9.
Implies a noise bandwidth of ~2400 Hz.
Simply setting DSP BW = 1800 would improve S/N
by 2.2 dB, and going to 1500 Hz would improve
it by 3.0 dB. These DSP BW settings require
PBT be set to ~200 Hz for best intelligibility.
>BW=500Hz: SNNR degrades by approx 2dB with NR=9.
Degrades?...strange result! This
implies a noise bandwidth of ~800 Hz. Simply
turning DSP BW to 100 (which has an actual BW
of 150 Hz) should **improve** S/N by 5.2 dB.
The 500 Hz result definitely means
something is not working correctly.
73, Bill W4ZV
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