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Multi-Kiwi Station

WA2ZKDWA2ZKD
in Installation, Antennas and Interference
Is there a way to sync all the channels of multiple kiwis such the the relationship of channels between kiwis is the same as it would be on the same kiwi? I assume that a soldering iron would be involved :-)

Comments

  • n6gnn6gn
    I sometimes run a common GPDSDO derived external 66.660 MHz clock to correct and synch frequency.

    But for time I have no solution that gets multiple kiwiSDRs exactly synchronized.
    WA2ZKD
  • ic8pofic8pof
    HI All, this would be a fine feature request to the developer of CATSYNC DJ0MY.
    I have just wondered about this features some days ago when dreaming of a second KIWI_sdr purchase
    how would be possible to get both sync_ed on the same freq even without an active CAT connection.
    This features would involve also the BFO_freq tuning by a sort of memory and this is a JKS field.
    B)
    73 Phil IC8POF
  • WA2ZKDWA2ZKD
    by sync, I mean the XO freq and phase...
  • n6gnn6gn
    A Bodnar GPSDO + single logic package provides outputs for 3 kiwis easily.. Generally this is accurate to <1 ppb on any connected kiwis. Simply inject the 66.660000 fanned-out external clock into the kiwi via small diameter coax at the pads provided on the kiwi board. See a photo in the Antenna Switch PDF that I recently posted.

    To see the results, you can compare the IQ-extension display at n6gn.no-ip.org:8074 while tuned to WWV's carrier on 25 MHz. (path is ~20kM LOS ) to get an idea of phase stability even when the Bodnar is quite unprotected from temperature changes.

    Essentially this solution is much more accurate and stable than propagation via any ionospheric path.

    I don't know what happens internal to the kiwi's FPGA but multiple kiwis all see the same reference with this method.
  • n6gnn6gn
    Not sure if I got all the parameters in but
    http://n6gn.no-ip.org:8074/?mute&sp&iq&f=25000:0,20&ext=iq,off
    seems to let one examine the phase of the Kiwi w/ Bodnar against US NIST.
    WA2ZKD
  • WA2ZKDWA2ZKD
    I am less concerned about absolute accuracy than the relative accuracy between 3 kiwi
  • n6gnn6gn
    I should think that external clock edges of the same frequency are synchronized to within a fraction of a nanosecond, though I have no way of testing or demonstrating this. If you can provide a two-kiwi test to measure it, I'd be happy to try it.
  • WA2ZKDWA2ZKD
    jimlill.com has 8073, 8074, 8075 ports
  • n6gnn6gn
    How do I measure degree of time-coherence of the clocks and their effects on any interesting received information? In what measurable way does it matter?
  • WA2ZKDWA2ZKD
    receive WWV on 2 time stamped IQ files and look at alignment (?). I know you have WWV on GW so no skywave effects!
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