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26Re: [SpectrumLab] Not too proud...

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  • wolf_dl4yhf
    Sep 1, 2010
      Hello Michael,

      Nice to meet you here.. and don't worry about not discovering a method
      for the 10-minute sync'd QRSS screen... the important function is simply
      not mentioned in the manual. I had to dig it out in the sourcecode myself.

      You wrote (at the old Spectrum Lab forum) :
      > I'm trying to setup a special mode for QRSS reception based on the predefined QRSS3 mode. This special mode needs to have the following parameters...
      > Waterfall width = 10 minutes non-scrolling.
      > Screen must begin on an integer 10 minute interval.
      > Must capture the screen to a file and begin a new screen at integer 10 minute intervals... i.e. using the retriggerable timer function.
      > The purpose is to enable detection of extremely weak periodic signals that begin on and repeat at integer 10 minute intervals.
      > Seems like it should be a fairly straightforward use of Speccie's macro language but my addled oldster brain is having a hard time wrapping itself around the problem.
      > Hope someone can help with this.
      > 73,
      > 'Bear' NH7SR
      I would start with the sample application
      "configurations\TrigSpectTest1.usr" which hopefully is still in the
      installation archive (if not please let me know).
      In that configuration, the spectrogram runs in 'radar sweep'
      (non-scrolling mode), and it's controlled by the universal trigger
      function (one sweep is initiated by a trigger event). The trigger itself
      is signal level controlled. Change this, by disconnecting the input to
      the trigger in the circuit window, and/or by setting the trigger level
      to an unreasonably large value (so the trigger never fires from the
      input signal).
      Then, the "Conditional Actions" can be used to fire a trigger event once
      every 10 minutes (see notes further below). The trick is, and this is
      MISSING in the help system, the following command:


      When executing this command, a trigger event is fired as if the trigger
      function has detected it. In the configuration mentioned above, the
      spectrogram screen waits for a trigger (after a full screen sweep has
      finished), so trigger.now re-triggers it (to begin a new sweep).

      How to trigger every ten minutes ? Here is a simple example for the
      "Conditional Events" (you can copy and save it as "TenMinuteTrigger.txt"
      and load it into the conditional action table):

      ; Exported "Conditional Actions" for Spectrum Lab

      if( always ) then TenMinToggler = (int(now/600))&1
      if( initialising ) then OldToggler=TenMinToggler
      if( TenMinToggler<>OldToggler ) then trigger.now
      if( TenMinToggler<>OldToggler ) then capture
      if( TenMinToggler<>OldToggler ) then OldToggler=TenMinToggler

      The expression "(int(now/600))&1" produces a flag which toggles between
      0 and 1 every ten minutes ("now" is the current PC time in Unix format,
      actually a count of seconds since January 1st, 1970;
      and the "&" operator is a BITwise AND combination... the result can only
      be zero or one. BIT of a brain teaser, too.. ).

      Whenever the value of this "toggler" changes, a trigger event is fired,
      which can be used to start a new sweep in the spectrogram. The same way
      (with one additional line in the 'conditional actions', you can let the
      program save a screenshot of the waterfall display). The command is
      simply "capture", explained somewhere in the SL manual:


      Hope this helps - at least a bit !

      73 / 72,
      Wolfgang "Wolf" DL4YHF .