Loading ...
Sorry, an error occurred while loading the content.

Re: Question about image rejection

Expand Messages
  • warrenallgyer
    Mike When you see identical images and the IQ balance controls cannot null one out then there are one of two problems: 1) One channel is missing from the
    Message 1 of 3 , Jan 22, 2013
    • 0 Attachment
      Mike

      When you see identical images and the IQ balance controls cannot null one out then there are one of two problems:

      1) One channel is missing from the Softrocks to the computer, or

      2) The sound card input is mono.

      Some sound cards are fixed to mono in the hardware and some have a software stereo/mono switch.

      Take a pair of iPod ear buds and plug into the Line In jack on the Softrocks. You should hear sounds in both ears. If not, then the problem is in the rig. If so then you need to be sure your soundcard is actually stereo capable, then check the settings.

      Good luck!

      Warren Allgyer - W8TOD

      --- In softrock40@yahoogroups.com, Michael Walker wrote:
      >
      > I have my RXTX Ensemble up and running, but I notice that I can clearly see
      > the image and the image signals. This is both in HDSDR and SDR-Radio 1.5.
      >
      > Swapping the IQ signals doesn't seem to change anything. Could this be
      > that my sound card is not stereo?
      >
      > Or, am I missing anything else obvious. Don't hesitate to point me to a
      > document on how to get rid of the image.
      >
      > I will try the 10khz signal insertion test tomorrow, but thought I would
      > ask in advance.
      >
      > Mike va3mw
      >
    • Alan
      ... Subject: [softrock40] Question about image rejection ... Mike, You say you can see the image. But is the image say, 20-30dB less? HDSDR has manual
      Message 2 of 3 , Jan 22, 2013
      • 0 Attachment
        ----- Original Message -----
        Subject: [softrock40] Question about image rejection


        >I have my RXTX Ensemble up and running, but I notice that I can clearly see
        > the image and the image signals. This is both in HDSDR and SDR-Radio 1.5.
        >
        > Swapping the IQ signals doesn't seem to change anything. Could this be
        > that my sound card is not stereo?
        >

        Mike,

        You say you can see the image.
        But is the image say, 20-30dB less?
        HDSDR has manual rejection (skew). I'm not sure about SDR-Radio 1.5, I think that needed a procedure to reduce image. SDR-Radio 2.0
        is automatic.

        73 Alan G4ZFQ
      Your message has been successfully submitted and would be delivered to recipients shortly.