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6600M and WNB after update

It appears my WNB doesn't seem to make a difference on or off since the update on 80M. Anyone experiencing this?


  • Ha Gei
    Ha Gei Member ✭✭✭

    Did not yet try, but it was unusable since the first 3.x update and never came back to usable. 2.x it worked perfect.

    I will try later and hopefully WNB and NB can be used again. NB also was unusable in 3.x due to distorting all signals when some strong signals are nearby.

  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator

    For my power line arcing WNB works 3xcellent at level of 93.

    Depending on what kind of noise you have your mileage may vary.

    Dave wo2x

  • Brian  K0BUS
    Brian K0BUS Member ✭✭

    As I said, my WNB worked fairly good until the update. Now is doesn't appear to do anything.

  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Mine still behaves exactly the same. Depending on the band, time of day and to some extent, the time of year, I get anywhere from 2 dB up to almost 10 dB of relief from whatever junk is in the air in my neighborhood.

  • Lionel
    Lionel Member ✭✭✭

    I find very little use for the WNB even though on upper HF and 6 meters I have between 3 and 5 or 6 S units of frying noise at times that looks and sounds like line noise. Six meters on a dipole has a -103dbm noise floor regardless preamp settings. No WNB help here. The WNB will give me between 2 dB and zero dB, generally zero, on 20-10 meters regardless of the settings between about 20 and 90s and is not very useful.

    Oh, in most cases, the WNB symbol shows engaged and working, though my questions about its effectiveness are now very common.

    I, too, thought it worked better in earlier versions, but I cannot say when this was first noticed and remember some amazing results in the 10dB range in prior versions.

    The target noise(s) for the WNB has become a confusing topic for me, given the high number of comments and anecdotal stories about its effectiveness.

    The WNB now gets little use because it has little effect on my ambient noise.

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    The WNB is a noise subtraction filter of sorts and it works on rhythmic noise patterns, not random noise patterns. I doubt it will work on ambient noise to improve any SNR values. It monitors a large chunk of the radio spectrum.

    Page 52 SmartSDR User Guide


    The Wideband Noise Blanker (WNB) is used to combat fast rise time pulse-type noise such as power line hash and car ignitions. To enable the Wideband Noise Blanker, click the WNB button, then adjust the threshold control for the best noise suppression. In general, the default setting is adequate, but depending on the noise characteristics, some adjustment can help. The WNB Threshold control adjusts the level at which a sample is considered to be impulse noise. The general rule of thumb for this adjustment is to use the lowest level that is effective. For large impulse noise (meaning the noise floor jumps are large) a lower level should be used. If the impulse noise is causing only small jumps in the noise floor, a higher level can be used.

    Large signals, both in the passband and around it, can result in distorted audio if the WNB threshold control is set too high.

    Since the Wideband Noise Blanker operates at the SCU level rather than at the Slice level easy detection of wideband correlated noise pulses is possible. The algorithm employs an automatic slider normalization function to make the WNB work consistently on different bandwidths and signal levels. This unique architecture allows pulse removal with far less distortion than many traditional noise blankers.

    Given the wideband nature of this feature, the threshold slider in the GUI controls an entire SCU, which may have several Panadapters and/or slice receivers attached to it. For convenience, the slider control is available in each slice and each Panadapter. Adjusting any one of them adjusts for an entire SCU, and all related slider controls are updated. Enabling and disabling the WNB function is available separately for each Panadapter. All Slices present on a Panadapter inherit the same value for the WNB enable and level.

    When the WNB detects a significant change in signal level or bandwidth, it attempts to normalize the slider value. During this time, blanking will be momentarily bypassed, and the WNB indicator in the Panadapter will start to flash (blink). Once a suitable normalized slider range has been re-established, the noise blanking action will resume, and the WNB indicator will return to a solid color.

    It is possible for certain WNB level settings to cause distortion with certain types of signals. For example, in the proximity of very large signals, noise may become worse with aggressive settings of WNB. If this is the case, either lower the WNB level setting, or disable WNB on that Panadapter.

    Here is a great example of it working.

  • Brian  K0BUS
    Brian K0BUS Member ✭✭

    Thanks Mike, I've read that many times. However, as I said it appeared to work in my conditions and on 80m and now after the update it doesn't matter if it's on or off. So, either the condition disappeared after 2 years or........ ? Just curious if anyone else has experienced my issue.

  • WX7Y
    WX7Y Member ✭✭✭

    Mine works fine here on the 6600M using SmartSDR 3.3.29.

    Did you do a HARD reset after the update?

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    I downgraded to 3.2.39 and then back up to 3.3.39 and I didn't hear any difference.

  • Brian  K0BUS
    Brian K0BUS Member ✭✭

    Of course

  • John KB4DU
    John KB4DU Member ✭✭✭✭

    The pan will help determine the type of noise The 60/120 hz generated by arcing ac insulators, transformers, etc. is noticeable by its regularity, which is the only type that WNB addresses, since the noise is the same across a wide range of frequencies. It was developed by Flex because of the arcing on a power pole near their site in Austin. I live next to an army base that generates a variety of RFI and the WNB is no help.

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