wwv performance on debian etch - NTP

This is a discussion on wwv performance on debian etch - NTP ; I have a ramsey wwv receiver with the mod suggested by steven bjork (resistor +capacitor between pins 1 & 12 of the LM389). My hardware is an Asus pundit system whose primary purpose is a PVR (myth TV). 2.6.18 kernel. ...

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Thread: wwv performance on debian etch

  1. wwv performance on debian etch


    I have a ramsey wwv receiver with the mod suggested by steven bjork
    (resistor +capacitor between pins 1 & 12 of the LM389). My hardware
    is an Asus pundit system whose primary purpose is a PVR (myth TV).
    2.6.18 kernel.

    I've got a good strong signal (40 dB if I'm reading it right)

    54430 55860.013 127.127.36.0 0 2007 330 15:31:00 S -2 0 127 WV15 82
    0 127.1 51
    2
    54430 55862.013 127.127.36.0 wwv5 001f 251 2517 3037/24.4 4463/18.1
    WV15 ffbf 99
    5604/40.0 WH15 0000 0 8/-22.2

    Is this good offset & jitter? I also have 4random servers from
    pool.ntp.org:

    remote refid st t when poll reach delay
    offset jitter
    ================================================== ============================
    +clock.trit.net 192.12.19.20 2 u 128 512 377 37.035
    2.014 0.308
    +hydrogen.cert.u 216.218.254.202 2 u 14 512 377 39.356
    2.776 0.391
    208-75-85-61.sl 82.211.81.145 3 u 626 1024 0 0.000
    0.000 0.000
    -guinness.mcguyv 67.128.71.76 2 u 124 512 377 61.183
    -13.006 1.277
    *WWV_AUDIO(0) .WV15. 0 l 2 64 377 0.000
    1.081 0.064

    neat stuff.

    Dave




  2. Re: wwv performance on debian etch

    David,

    Your first two servers are in the mix with the WWV driver and could be
    causing some offset. To avoid this, put noselect options for all servers
    except WWV for test. When signals are good, I generally get within 0.1
    ms in both offset and jitter with respect to a PPS from GPS.

    To get to this degree, you need accurate propagation delay to well
    within 1 ms. Note that, as it says in the driver HTML page, this is good
    enough to follow the ionosphere wanders up durint the day and down at
    night over a range of about 1 ms. This is for a two-hop F2-layer path,
    which is common here on the right coast. If you are in E-layer range,
    the difference can be more dramatic.

    Dave

    david.margrave@gmail.com wrote:
    > I have a ramsey wwv receiver with the mod suggested by steven bjork
    > (resistor +capacitor between pins 1 & 12 of the LM389). My hardware
    > is an Asus pundit system whose primary purpose is a PVR (myth TV).
    > 2.6.18 kernel.
    >
    > I've got a good strong signal (40 dB if I'm reading it right)
    >
    > 54430 55860.013 127.127.36.0 0 2007 330 15:31:00 S -2 0 127 WV15 82
    > 0 127.1 51
    > 2
    > 54430 55862.013 127.127.36.0 wwv5 001f 251 2517 3037/24.4 4463/18.1
    > WV15 ffbf 99
    > 5604/40.0 WH15 0000 0 8/-22.2
    >
    > Is this good offset & jitter? I also have 4random servers from
    > pool.ntp.org:
    >
    > remote refid st t when poll reach delay
    > offset jitter
    > ================================================== ============================
    > +clock.trit.net 192.12.19.20 2 u 128 512 377 37.035
    > 2.014 0.308
    > +hydrogen.cert.u 216.218.254.202 2 u 14 512 377 39.356
    > 2.776 0.391
    > 208-75-85-61.sl 82.211.81.145 3 u 626 1024 0 0.000
    > 0.000 0.000
    > -guinness.mcguyv 67.128.71.76 2 u 124 512 377 61.183
    > -13.006 1.277
    > *WWV_AUDIO(0) .WV15. 0 l 2 64 377 0.000
    > 1.081 0.064
    >
    > neat stuff.
    >
    > Dave
    >
    >
    >


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