New 'Beta' with GPS synchronisation & NMEA-decoder via soundcard
- Greetings all,
I have just uploaded a new version (V2.76 b23) to the beta-site. For
those who experiment with the GPS (NMEA) decoder:
The GPS control panel now spits out some 'debugging messages' on its own
'Debug' panel, which may be helpful to find out what's going on
internally. Furthermore, the pps-based sample rate measurement /
"calibrator" now respects the maximum deviation value (entered as 'ppm
of the measured sample rate'). The hard-coded (fixed) internal value may
have been too critical for certain soundcards.
The triggered spectrogram function was also modified: It shows correct
timestamps now when running in GPS-sync'd mode, and (if the GPS is
connected as described below), it uses the very precise GPS time instead
of the poor PC time (which jitters badly even when synchronized via
Details about the GPS receiver requirements, and connection
(note that this only works if the GPS receiver has a pps output, aka
"sync pulse". It does NOT work with an ordinary GPS receiver which only
has a serial output for the NMEA stream)
It's interesting to see the three european time signal transmitters (60,
75, and 77.5 kHz) side-by-side on a fast running 'triggered'
spectrogram, synchronized by the GPS PPS signal: DCF77 begins "exactly"
when it should (as far as the spectrogram allows), which MSF and HBG
arrive a bit later.
My next test needs some more modifications of the internal processing :
It will be to measure the absolute phase of the DCF77 signal (longwave
time signal) over several days, to see the diurnal phase shift.
Have a nice sunday,
73, Wolf DL4YHF .