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Flex 6400M NB Settings

Hi All -

Just got myself a 6400M and been experimenting with the noise blanker settings. Does anyone have some recommendations for settings to remove power line noise? I've experimented with both NB and WNB settings but was not able to remove the power line noise present on 80 meters. Just wondering if anyone had any preferred settings?


Best Answer

  • John KB4DU
    John KB4DU Member ✭✭✭✭
    Answer ✓

    The history of the WNB is that there was a noisy pole transformer near the Austin facility, so wnb was developed to work on it. It never helped my situation. Steve Hicks said I probably didnt have the right kind of noise. Working with the local power company reduced the noise a lot.


  • Ha Gei
    Ha Gei Member ✭✭✭
    edited December 2021

    All my NB and WNB does :

    Distort signals and heavily decrease IP3 , so big signals makle more trouble.

    It worked nearly perfect with SSDR 2.X but after 3.x went to unusable.

    6400 with latest 3.x

    But...my FTD101D is just a little bit better , takes away all noise..but chops that out of the audio of the signal

    The last good NB was in the KW 830

    So.. get the antenna away as much as possible and fight the powerline noise.


  • Mike N9NTC
    Mike N9NTC Member ✭✭
    edited December 2021
    The NR works on 80 Meter noise at my QTH\N9NTC
  • Lionel
    Lionel Member ✭✭✭

    NR works fairly well, though it does seem to reduce the audio level of the intended signal. At high I find a need to increase the audio gain, which seems a bit counterproductive.

    NB works on some types of noise, though it can distort the signal if turned up too high. It seems to be affected by preamp setting and AGC-T. It feels like a conventional NB that you would find on older analog rigs, but the digital version's code needs to be optimized. At high settings, distortion and interference occur.

    WNB has done some amazing things on certain types of noise. I have used it to take out powerline noise and other unknown WB noise. At high settings, the rig is more susceptible to interference from nearby strong signals. However, it does not always work. In my experience, it fails to function as expected more often than not. The setting of AGC-T is important, or so it seems. Setting AGC-T at the knee or below seems to work best, when it works at all. The code for the WNB is now legacy and seriously needs an update and optimization.

    These are three distinctly different functions that do not seem to interact.

    With respect to all three, your results may vary. Fiddling is required. Nearly everyone seems to have a different experience.

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi Chad, Generally, powerline noise is wide-band in nature so the WNB is most likely to work - but as Lionel points out, every experience is different...

    If you try WNB, you need to know that it takes several seconds to gather enough information across the band to calculate and apply the noise mitigation. You can't quickly switch it in and out to see if it is working. You should turn it on and wait to see what effect it has. In my case keeping it at around 30 seems to take most of the junk out. Without the WNB, I almost can't operate from my location on some days.

    You know the WNB is doing something when the WNB indicator in the upper right hand corner of SmartSDR goes from grayed-out to bright. For me, some days it kind of pulses on and off, keeping up with something in the neighborhood. Other days it comes on and stays lit all day (this is very band-dependent).

    The NB functions well on impulse noise. I have almost none at home, so I don't tend to use it much here. When I am camping, people run quad-runners and dirt bikes with noisy ignitions, and the NB works great for that.

  • Trucker
    Trucker Member ✭✭✭

    I agree the WNB is a good option in many cases. We have an LG washer and dryer set. The dryer produces no noticeable RFI. But, the washer is a different story. It makes 80 and 40 meters almost unusable. But, with the WNB it brings the noise down to the point both bands are usable. It take a few minutes for it to do its magic. But, once it does, it's very noticeable. In the past wd had a neighbor who had something they ran off and on and there was nothing that eliminated the noise. Thankfully, they moved!



  • n0yk
    n0yk Member ✭✭
    Thanks everyone for the great feedback! I'll keep experimenting.

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