My K3 SR # 4636 with MCU 4.60 FPF 1.15 DSP 2.80 I was on 20 meters CW and touched the NR button to engage the noise reduction but the display said N/A…. What? Is that right? It seems to me that it has always worked... OR am I just confused??? The NB works just fine BTW Phil K5SSR Santa Fe