[time-nuts] NTP IRIG config help

Chris Albertson albertson.chris at gmail.com
Mon Mar 7 19:36:49 UTC 2011


There is an NTP email list.   questions at lists.ntp.org

But really, all you need is the 1PPS output and some pool servers.
If you have PPS working then all you need is a way to number the
seconds and "anything" can do that.  Yes the PPS driver works with
other non-NMEA ref clocks

It would be good to get IRIG working.  One thing you don't say is how
you are adjusting the levels.   Is it a digital control or an analog?
In general you want to keep any digital control at maximum.  Reducing
it even a little causes loss of dymanic range and reduces the
effective with (number of bits) of the sample.  In the extream case
your nice 24 bit WAV file is turned into 4-bit wide samples.   Such is
the nature of integer math.

Also if you are using the bui8lt-in sound on some PC, quality varies a
lot. I'd start with a quality external audio interface.  But eiother
way.  I think the first step is to look at the audio.  capture some to
a file then look at the waveform using an audio editor.  Check for a
reasonable amplitude with no clipping.  You will need to adjust the
analog gain to get a good signa


-- 
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Chris Albertson
Redondo Beach, California



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