[time-nuts] 1PPS for the beginner

Björn bg at lysator.liu.se
Wed Aug 15 12:42:46 EDT 2018


> On 15 Aug 2018, at 14:46, Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:
> 
> --------
> In message <CAJqU6XP6ZOygUD0xyCZaVk90Hss=H9sMqHn+ZYFgLwtXPMkGcg at mail.gmail.com>, Peter Vince writes:
> 
>> I was astonished to see the pulse-width in the document defined from the
>> base of the (sharp-cornered!) edges, and not the mid-point - totally
>> impractical!
> 
> Given that the output is not specified into a defined impedance,
> termination or even cable-length, I don't think specifying the
> mid-point would be any more practical.

It says into 50ohms. 10V into 50ohms are certainly archaic by today’s signal levels.

20us (+50%-20%) - 16us to 30us is indeed very wide.

The boss signing the document has dual Master of Science degrees... there were certainly engineers contributing to the document.

Are there any better standards around?

/Björn 






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