[time-nuts] 60 Hz line quirks, anybody recognize this stuff?

J. Forster jfor at quikus.com
Sat Sep 1 13:45:54 UTC 2012


> More... OOPS
>
> You might try logging the output of an audio oscillator, Even an HP 200
> would work.
>
> -John
>
> =================
>
>
>> I agree: I don't think this is possible on a power line. Better to use a
>> second sampling unit to check.
>>
>> On Sat, Sep 1, 2012 at 3:30 PM, J. Forster <jfor at quikus.com> wrote:
>>
>>> IMO, you have an instrumentation issue. I don't think the power grid
>>> can
>>> do anything like that.
>>>
>>> YMMV,
>>>
>>> -John
>>>
>>> ===============
>>>
>>>
>>>
>>> > The context is using the 60 Hz line for timing.
>>> >
>>> > I'm feeding 60 Hz from a wall wart transformer into a modem control
>>> signal
>>> > that the kernel PPS stuff watches.  Mostly, it works as expected, but
>>> > occasionally, it picks or drops a cycle.
>>> >
>>> > In order to understand what was going on, I fed the same signal into
>>> the
>>> > audio input and setup a job to capture the audio.  Here is an example
>>> of
>>> a
>>> > pick:
>>> >
>>> http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a-pick.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a0.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a1.png
>>> >
>>> > OK, that somewhat makes sense.
>>> >
>>> >
>>> > Something happened several days ago.  I used to get picks/drops
>>> rarely,
>>> > say
>>> > ballpark of 1 a month.  Now I'm getting 10 or 20 per day.  So I
>>> started
>>> > looking closer.
>>> >
>>> > I'm now seeing stuff like this.  I've got lots and lots of examples.
>>> I
>>> > added
>>> > a second PC with different hardware.  It sees the same stuff.
>>> >
>>> > Does anybody recognize this?
>>> >
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-a0.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-b0.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-c0.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-d0.png
>>> > http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-e0.png
>>> >
>>> >
>>> > --
>>> > 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.
>>> >
>>> >
>>>
>>>
>>>
>>> _______________________________________________
>>> 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.
>>>
>> _______________________________________________
>> 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.
>>
>>
>
>
>
> _______________________________________________
> 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