jks

About

Username
jks
Joined
Visits
33,822
Last Active
Roles
Member, Administrator, Moderator
Points
426

Reactions

637Helpful556Awesome

  • CPU load is inversely proportional to the number of receivers?

    jksjks
    It's not that simple. The Kiwi is a very complicated realtime system. There is a careful balance of resources to minimize the cost of the device while maximizing the number of supported channels. This means there is sometimes a tradeoff between FPGA resources and Beagle cpu cycles.

    What you're seeing at first is the GPS acquisition process (very Beagle FFT intensive) being paused when the first connection occurs. And with no connections the audio data pump between FPGA and Beagle is shut off causing a big reduction in system time due to fewer SPI transfers.

    The %load number you show looks like user time only. You have to consider system (kernel) time as well. I see numbers like this:

    #recv %user %sys %idle %busy
    0 96 3 0 100
    1 60 18 20 80
    2 41 23 33 67
    3 41 22 33 67
    4 46 22 30 70

    This is about optimal. For no connections you want to spend all available cycles acquiring new GPS sats for maintaining ADC clock calibration. When there are corrections you want to have some cycles leftover for the portion of extension code that runs on the Beagle.

    dl2sba

  • IBP Button to track beacons

    jksjks
    Peter's IBP scanner is now a built-in extension in the v1.123 release.

    VE3SUN

  • Vote rigging on sdr.hu

    jksjks
    Martin: Done. I forgot you had multiple, switchable antennas.

    Ron: See comments #25 and 26 in this thread. It's an experiment and not many Kiwis have been "rated" yet (the GPS tag is automatic however).

    G8JNJ

  • V1.107 - Daily restart [restart after update also added]

    jksjks
    Okay, in v1.108 there is now an option to reboot the Beagle, rather than simply restart the server, after an update. See the update tab on the admin page.

    G8JNJ

  • Minimum CW bandwidth needs reducing [fixed: min is now 4 Hz]

    jksjks
    v1.107 will let you reduce it to 4 Hz. At this low of a value the filter skirts aren't so great as a percentage of the passband width. But there is a definite signal-to-noise improvement over the previous 50 Hz minimum, so this was a worthwhile change.

    Remember the shortcut of holding down the shift key and click on the zoom in/out icons (+/- magnifying glasses) to easily change the passband width by +/- 80%.


    WA2ZKD