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SmartSDR 3.5.9 - Is ANF working?

N5NHJ Member ✭✭✭
edited September 23 in SmartSDR for Windows

I was listening to a DX station on 10 meters on my remote 6400. There were two carriers right in the passband of the filter. Perfect scenario for the ANF.

I heard no difference at all turning the ANF on or off. Cursor at 0 or 100, no difference.

Is it working for you?

TNF works fine.


  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Just tried mine, and it seems to be working fine. I think it might even be better than before. I notice that it is taking out most of a CW signal, when before it wasn't fast enough to keep up with it. Anyone else seeing this?

  • Trucker
    Trucker Member ✭✭✭

    I have found that if the carrier/tone, occurs near either edge of the passband, then the ANF is effective in notching it out without any problems. ( popping in and out of the audio)

    But, if it is at or near the center of the passband, it will allow the tone to pop through the audio ( qso) you are trying to listen to. No matter what setting you use in the ANF Slider. The problem was acknowledged by the head of Flex Radio's engineering department several years ago at a presentation he gave at a hamfest I attended. He told me that the problem was going to be fixed in the next release of SmartSDR. That was version 2.49. It has yet to be fixed. I asked one of Flex Radio's developers about it some time ago and he told me that it was to be fixed in the release that I mentioned. But, for some reason it was dropped at the last minute and has never been revisited.

    Some people say use the Tracking Notch Filter. It does work better. But, it is nearly impossible to use with the M model radios standalone. Plus, the TNF wasn't intended for that purpose. The ANF should just work like it does in any modern transceiver.

    There are several basic features/functions that don't work to their full potential. It saddens me that whomever is in control of development priorities at Flex Radio doesn't seem to understand that.



  • N5NHJ
    N5NHJ Member ✭✭✭


    Thank you for explaining and confirming my observation. I agree that the ANF is more effective with a carrier closer to the edge of the passband filter, but overall, not as effective as other, even very unexpensive, modern transceivers.

    Also, not very effective with multiple carriers.


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