On 6 September 2011 23:02, Chris Albertson <albertson.ch...@gmail.com>wrote:
> > Why don't the manufacturers provide the PPS signal to the serial port > > themselves? Is it meant to be NMEA only? > > If cost is an issue there are even lower priced options then the one > from Sure Electronics. Older Moterola UT+ receivers sell for $18. > These actually have better specs and the signals are all run out to a > 10-pin header, no soldering. > I second this. I am looking at a Motorola Oncore UT+ unit I got on ebay for about 10 USD. I believe the antenna cost me 7 USD. :-) A quick trip to the local electronics shop and with a bit of soldering I have a board that gets the power from USB and returns the GPS signals to NTP. Oncore is connected to this board by a flat 10 wire cable. Quite neat! :-) The performance is quite impressive: oncore# uptime; ntpq -p; ntpdc -c kerninfo 12:02AM up 2:07, 1 user, load averages: 0.00, 0.00, 0.00 remote refid st t when poll reach delay offset jitter ============================================================================== oGPS_ONCORE(0) .GPS. 0 l 7 16 377 0.000 -0.001 0.001 canon.inria.fr .GPSi. 1 u 34 64 377 49.054 0.621 0.383 ptbtime1.ptb.de .PTB. 1 u 36 64 377 66.475 0.864 0.316 ntp.ien.it .CTD. 1 u 6 64 377 52.064 0.452 0.263 ntp02.oal.ul.pt 194.117.9.138 2 u 27 64 377 9.486 0.565 0.453 ntp04.oal.ul.pt 194.117.9.138 2 u 34 64 377 10.109 -0.831 0.235 Router7.Lisboa. 193.136.250.246 2 u 27 64 377 8.181 0.508 0.258 Router15.Porto. 193.136.250.246 2 u 13 64 377 12.538 0.528 0.129 pll offset: -8.37e-07 s pll frequency: -32.057 ppm maximum error: 0.004234 s estimated error: 1e-06 s status: 2107 pll ppsfreq ppstime ppssignal nano pll time constant: 4 precision: 1e-09 s frequency tolerance: 496 ppm pps frequency: -32.057 ppm pps stability: 0.016 ppm pps jitter: 1.811e-06 s calibration interval: 256 s calibration cycles: 50 jitter exceeded: 5 stability exceeded: 0 calibration errors: 3 I've tried Garmin 18 LVC and Sure. Not want to start a war here but for the specifications and price Oncore beats both. :-) Just my 2c. Cheers, Miguel _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions