[time-nuts] Leapsecond data online

John Ackermann N8UR jra at febo.com
Sat Dec 31 21:55:36 EST 2005


I'll turn this into a proper web page tomorrow, but I've uploaded .wav
and .mp3 files of WWVB, CHU, WWV-5MHz, and WWV-10MHz as well as data
logs of the Spectracom 8170, Z3801A, and Linux system time (from the
program posted on the NTP list earlier today).  All are cut down to show
about one minute either side of 0000Z, except the Spectracom which
covers out to 0005 to catch its update at 00:03:59.

http://www.febo.com/time-freq/leapsecond-2005/

You might have fun with the audio files as they are all quite precisely
aligned with each other in time (within the limits of the 8000Hz sample
rate).  The four receivers fed a single four-channel sound card and
audio recorder program.  There are a couple of screenshots of the
recording software (Audacity under Linux) in action.

You'll note a few hundred milliseconds delay between the two WWV
signals.  Apart from any propagation differences between 5 and 10MHz,
the 10MHz signal came from my SDR-1000 software defined radio which has
quite a bit of latency due to the audio processing in the PC (a
different machine than the one used for recording).  The 5MHz signal
came from a Yaesu FT-817, a traditional radio.  The WWVB and CHU signals
came from a pair of HP 3586C selective level meters.

John





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