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Built-in noise canceller

KD0RC
KD0RC Broomfield, COMember, Super Elmer Moderator

I don't think this is a new idea, but I thought I would float it again. I have huge noise sources at my location, so I use a Timewave ANC-4 noise canceller. I also need it to operate while camping in my 5th wheel camper due to the noise from battery chargers, solar and the inverter (not to mention all that same stuff from other campers). When I am local to the radio, the ANC-4 does a pretty good job of knocking out the crud I pick up from errant electronics. It is pretty touchy to operate, but it does work.

When I am operating remotely, however, I cannot adjust the ANC-4, so I am stuck with some pretty bad noise that could otherwise be nulled out. I would like to see noise cancelling implemented in the Flex radios and accessed via SmartSDR so that noise cancelling is not dependent on external, local equipment. I would guess phase and amplitude controls would be all that is needed from an operation standpoint, but with only the ANC-4 in my experience, perhaps there is something more or better that could be implemented in DSP. I would love it if it could be set up so that the op could choose which antenna is the noise antenna to get the most flexibility from it.

I am not sure if this would even be possible on rigs like the 6400 that only have one SCU, but if so, it would make life MUCH better in the environments that I (and presumably many others) operate in.

73 & thanks for your consideration,

Len, KD0RC

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8 votes

Open for Comments · Last Updated

Comments

  • Bill N3HQB
    Bill N3HQB Member ✭✭

    The ANC-4 does a good job. I cascade two of them (the original JPS version), one with an indoor noise antenna and one with an outdoor noise antenna. I can get a complete or nearly complete null with this combination. I also use a KD9SV BF-981 preamp for 75 and 160 (available through DX Engineering). I use a WEMO to power them on and off remotely. As your post indicates, they are not remotely tunable, so when operating remote, I try to anticipate the frequency I intend to use which may require noise phasing. Because I have a 6300 (without the RX Ant. in/out jacks) I use an MFJ 1708B and send the Rx SDR back to the Flex ANT2 SO-239. (I wish all Flex transceivers had RX in/out jacks like the 6500, 6700 and my previous Icom IC-765.) Bill N3HQB, Hagerstown, MD


  • KD0RC
    KD0RC Broomfield, COMember, Super Elmer Moderator

    Wow, very interesting Bill. It never occurred to me to cascade them. At my station, I have the noise ant running in a loop around my networking gear, then outside along my deck rail. It gets most of it, but there are some pretty bad "growlers" that I cannot quite null out. I also find that if I get rid of one of these things, another one is untouched. If I null that one then the other comes back. I attribute that to noise in my shack vs noise from the neighbors.

    73,

    Len

  • Dan Trainor
    Dan Trainor Member ✭✭

    I think if they build in the noise cancelling into the internal digital processing of 6600 with a RX noise antenna and diversity phasing with a nice graphical control like that of SDRPlay/SDRUno or Anan 7000, and others. This capability should be implemented in DSP SW and not external boxes. As it would work better, be more flexible and updatable. And work in a remote context. It would be a game changer as most of us live in a RFI high-density areas now. It is an obvious feature choice for next release as its value is so high in relation to the cost of implementing the algorithm which is by now well known. dan WA1QZX

  • KD0RC
    KD0RC Broomfield, COMember, Super Elmer Moderator

    Well said Dan! Can you click the little up arrow on the vote for this? I think Flex uses the votes to help decide which ideas to apply time to.

    73,

    Len

  • IZ1OQT
    IZ1OQT Member ✭✭
    Totally agree.
  • KF4HR
    KF4HR Member ✭✭

    Adding a phase noise reduction feature is a major plus. Worked great on PowerSDR. I (uh... probably many) have been wishing FRS would incorporate such a feature into SSDR. While I applaud the after-market innovation add-on, I suspect I'm not the only one thinking it's a **** shame this feature isn't already built into SmartSDR software.

  • KF4HR
    KF4HR Member ✭✭

    I recently added an ANC-4 to my 6700. The unit does reduce overall noise, particularly on the low bands, although I was surprised to learn the ANC-4 introduces a 6 db signal loss.

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