[time-nuts] Phase, One edge or two? (was Digital mixing with a D Flip Flop)
Bob Camp
kb8tq at n1k.org
Wed Oct 22 20:38:47 EDT 2014
Hi
> On Oct 22, 2014, at 5:57 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
>
>
> tvb at LeapSecond.com said:
>> 2) For long-term analysis, even 1 PPS is overkill. Having more data may not
>> improve your oscillator drift plot at all. This is because the frequency is
>> a moving target. Ever more precise measurements of a moving target are
>> wasted; they don't add any clarity to the overall trend. Consider measuring
>> a 10811 for a year. Do you need to follow its phase or frequency every 100
>> ns? Or second? Or minute? Maybe as little as one data point per day is more
>> than enough to make a perfectly accurate long-term frequency drift plot.
>
> You need more than 1 sample per day for ADEV plots left of 100,000 K seconds.
>
> Suppose you have lots and lots of data at, say, 1 second samples. You can
> turn that into an ADEV plot. Does anybody scan the data in clumps, say a
> day, to see if the short-tau picture changes over time?
ADEV most certainly does change with time, even for short tau’s.
Bob
>
>
> --
> These are my opinions. I hate spam.
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
More information about the time-nuts
mailing list