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Random Black Lines in Waterfall (Another Newbie Question)

adrian miura
adrian miura Member
edited May 2020 in SmartSDR for Windows
I get these random black lines in the waterfall. Sometime they show up when adjusting the frequency resolution but not always. See picture below



  • Steve N4LQ
    Steve N4LQ Member ✭✭
    edited September 2015
    Looks like random burst of quietness amongst  all that noise.  
  • KY6LA_Howard
    KY6LA_Howard Member ✭✭✭
    edited January 2017
    Most likely dropped packetson ur Ethernet connection Likely causes. Slow computer or slow Ethernet
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    Black lines on the waterfall that correspond to momentary "blips" on the panadapter are usually caused by three things.

    1.) Dropped network packet

    2.) The graphics adapter not rending properly

    3.) Over taxed CPU or a long duration DPC (internal PC system latency)

    In order to narrow down the cause, a detailed description of your PC, the video adapter and how you have the PC and the radio connected in your LAN will be needed.
  • Ian1
    Ian1 Member ✭✭
    edited May 2020
    I vote for item 3 3.) Over taxed CPU or a long duration DPC (internal PC system latency) Ian
  • James Kirk
    James Kirk Member
    edited October 2014
    I was doing a backup and also had several programs running on my PC while operating a 6300 yesterday. My CPU usage was spiking at about 75% and noticed similar black lines on the waterfall. Normally my CPU usage is about 20% max while operating several programs simultaneously, so my vote is number 3 as well.
  • adrian miura
    adrian miura Member
    edited March 2016
    Here is my configuration:

    Flex to computer is direct Ethernet to Ethernet (no switch or router)

    Computer is a Dell Inspiron laptop (Pink hand me down from my daughter)

    I3 M370 2.4GHz, 6 GB ram Graphics using the I3.

    CPU usage ~ 35%

    Looks like number 3 is it. I ran the Intel graphics card test. It was hammering the cpu and got not thin black lines, but large bands.

    Oh well, I don’t think it really affects the use of the radio. I will have to start saving for a new computer.

    Thanks for the rapid response. This is the best community!




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