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

Re: Interference from PC?

Expand Messages
  • Frank Brickle
    ... noise ... Exactly, and this is one tough sucker to get rid of. The soundcard is one of the most vulnerable spots for letting in spurious signals. Most
    Message 1 of 41 , Sep 18, 2005
    • 0 Attachment
      --- In softrock40@yahoogroups.com, Bill Tracey <kd5tfd@a...> wrote:
      > ...the gunk you see near the center frequency with or w/o hardware
      > attached is an artifact of the signal processing architecture, and
      noise
      > near DC on the audio input (ie 60 hz hum,. etc)...

      Exactly, and this is one tough sucker to get rid of.

      The soundcard is one of the most vulnerable spots for letting in
      spurious signals. Most soundards get around the problem by rolling off
      the frequency response below 100Hz or so.

      Rolling off is not the same as eliminating, however, and when you can
      mix the residual spurious signals up into the center of the passband,
      they're conspicuous weak signals just like anything else would be.

      It is possible through DSP magic to subtract out the gunk, but you pay
      for it with a higher MDS. Preferable on the whole to use a better
      soundcard.

      73
      Frank
      AB2KT
    • Bob Hillard
      Rein, When I operate on the low bands (40M thru 160M) I have to turn off my PC s. In fact I sometimes have had to unplug them completely, as the power supply
      Message 41 of 41 , Oct 29, 2005
      • 0 Attachment
        Rein,

        When I operate on the low bands (40M thru 160M) I have to turn off my
        PC's. In fact I sometimes have had to unplug them completely, as the
        power supply isn't completely off when the On/Off switch is in the Off
        position.

        I found the problem to be caused by the computer's switching power
        supply. In fact I lost a power supply in one of my computers recenly,
        and replaced it with a better grade supply, and then was happy to find
        that the noise from that computer was gone.

        Try unplugging your computer completely and see if that quiets things
        down.

        Bob WA6UFQ

        --- In softrock40@yahoogroups.com, "observer35" <rein0zn@i...> wrote:
        >
        > Hi all,
        >
        > Just new to the group.
        >
        > Does anybody experience interference from the PC on 40 meters?
        >
        > What about noise and garbage on the 5 V USB line?
        >
        > 73 Rein W6/PA0ZN
        >
        > http://www.nitehawk.com/linrad_dat/
        >
      Your message has been successfully submitted and would be delivered to recipients shortly.