Hello Stefan,
Indeed you would need a soundcard with stereo input - one channel for
the PPS (with NMEA added, if required), and the other for the VLF
receiver (or any other signal to be analysed). If the PC's system time
can be guaranteed to be less than 0.5 seconds off the true value, NMEA
would not be required because in that case, the software could 'guess'
the right time belonging to the rising edge of the GPS sync pulse. But
decoding the NMEA sentences along with the precise pulse leaves nothing
to fate, and such a system will work without internet sync'd time, etc.
Am 10.04.2011 14:16, schrieb Stefan Schäfer:
Wolf,
Does the Rockwell Jupiter TU30 GPS module (used by DF6NM, OE3GHB and
me and others) provide this NMEA informations too?
I don't know, but most likely, yes. If you have the Jupiter's tech
specs, you can find out if the unit sends NMEA through the serial
output, or if it can be convinced to do so. Again, it's not ultimately
necessary to have the NMEA strings (with date+time) but it would be very
handy for some applications (consider portable operation w/o internet link).
And how will we feed the informations to SpecLab? You mentioned the
soundcard, but how is this possible?
As mentioned on the website - see link in my earlier post. All it takes
is a resistive voltage divider / adder.
We would at least need a stereo soundcard, right?
Unfortunately, yes. It you be too difficult to 'subtract' the GPS
(PPS+NMEA) signal from the analog signal fed into the same soundcard
channel.
73,
Wolf DL4YHF .
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