Hi I would bet that the basic electrical definition of the "skinny" PPS dates at least to the mid 50's if not earlier.
Bob On May 14, 2012, at 3:20 PM, Magnus Danielson wrote: > Mark, Azelio and Björn, > > On 05/14/2012 06:33 PM, b...@lysator.liu.se wrote: >> Mark& Azelio, >> >> Or even 10V into 50ohm, 20us... See figure 3-4 in ICD-GPS-060. >> >> http://www.navcen.uscg.gov/pdf/gps/ICD-GPS-060B.pdf >> >> More modern 3-5.5V into 50ohm, 20us. >> >> http://contracting.tacom.army.mil/majorsys/jab/DAGR%20Interface%20Specification.pdf >> >> Above are two standards demanding short skinny 1PPS pulses. Are there any >> other standards with distinct shape requirements on 1PPS pulses? > > You need to look at MIL STD 188/155 which if I recall things was initially > formed in the 60thies. > > An AccuBeat presentation actually says that the PPS was originally defined in > it. > > The MIL STD 188/155 is actually a 10 V peak level, so it was much hotter than > we are used to know. It specified 5 MHz as base frequency, or power of 2 > multiples (10, 20, 40 MHz... ). > > It was later reformulated in the PTTI spec, which ICD GPS 060 is a derivate. > The 50 ns rise and 1 us fall slopes comes from that spec. > > I was not able to find MIL STD 188-155 on the net right now, but I have been > able to download it before, so if someone is a more lucky it should surface. > I should have my download somewhere. > > Cheers, > Magnus > > _______________________________________________ > 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. _______________________________________________ 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.
