Hello, this afternoon the post(wo)man handed to me the little box with the PA6H GPS modules. I bought also an antenna with 5mt cable, so I can use it in the "lab". The module is up and running, requiring only 3V3 supply, locking very fast, about 30s from cold start, here is it, working with ext antenna: http://www.flickr.com/photos/14336723@N08/8264614897/
And now I'm trying to setup a logging session to try to log interval measurements with the counter: http://www.flickr.com/photos/14336723@N08/8265684680/ Now this is what I have done, the goal is to try to have some jitter measurements for the PPS output: - A FE5680A is the timebase for the counter - the counter is a Racal Dana 1992 - the FE5680A 1Vpp output is connected directly to rear reference input of the counter - the counter measures the PPS signal from the GPS module, Time interval A, 9 digits (single shot) 1nS resolution. After fighting with the counter's GPIB interface now I'm logging a stream of time intervals. I'm not catching all the pulses, but only one each 2 or 3, depends. - Is this setup enough to get meaningful data? - If so how long should I log the data? - If not what should I modify? - Once collected the data, what kind of analysis should I do? And for who have ever used the Racal Dana 1992 with GPIB interface: I feel dumb, but I could not figure how to poll the instrument for the availability of last data. Now the sequence i do is this: - T1 -> wait for trigger - T2 -> trigger - wait 4 seconds - read result - T2 -> trigger - wait 4s etc... Doing so I catch only part of the pulses, is there a way to make it better? This is a graph of the first thousand records: http://www.flickr.com/photos/14336723@N08/8265826150/ Fabio. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. _______________________________________________ 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.