Hi Nate, Nice page. Thanks for sharing your work.
The Nortel units are a reasonable and slightly cheaper alternative to a TBolt, if you don't mind the much larger size, mass, and non-standard connector issues. The performance depends somewhat on which vendor's oscillator was used. I tested a bunch here: http://www.leapsecond.com/pages/nortel/ For NTP none of these plots matter (most GPSDO are a thousand to a million times more stable than NTP or a PC can handle). /tvb ----- Original Message ----- From: "Nathaniel Bezanson" <mys...@telcodata.us> To: <time-nuts@febo.com> Sent: Monday, May 25, 2015 7:08 PM Subject: [time-nuts] pp2s? No, 1pps from a Nortel GPSTM! > As anyone with a Nortel GPSTM knows, it's a close cousin to the Thunderbolt > but not exactly identical. Notably, coming from a CDMA environment, the unit > has an "even second" output, aka PP2S, aka 0.5pps, aka 0.5Hz, etc. (Hoping to > make this searchable...) There are software commands to configure this on the > Thunderbolt too, but the GPSTM appears to have this function hard-coded into > the PAL, and it can't be set back to PPS in software. > However, there exists a PPS signal on the PCB, at TP13 between the Trimble > chip and the PAL, discovered by some folks at the hackerspace here, during > some noodling-around with an oscilloscope this afternoon. It's all documented > here: > https://www.i3detroit.org/wiki/Nortel_GPSTM > This is for a NTBW50AA-11 module (single long board), other parts may have > the signal in different places but I bet it's in there. > Enjoy!-Nate B- _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
