[time-nuts] Mains as time-reference

[Javier Herrero]

One of your references links to a nice real time graph for UK :)

http://www.nationalgrid.com/uk/Electricity/Data/Realtime/Frequency/Freq60.htm

I've looked to see if Red Eléctrica de España, the equivalent 
organisation here, provides same data... but nothing interesting to 
time-nuts, only electrical production and demand graphs (and a very 
politically correct graph of corresponding estimates of CO2 emissions).

Regards,

Javier

El 29/12/2010 20:01, Tom Van Baak escribió:
> Magnus,
>
> See fellow mains measurement men:
>
> http://www.xs4all.nl/~rjoris/gridfrequency.html
> http://www.vf.utwente.nl/~ptdeboer/misc/mains.html
> http://www.leapsecond.com/pages/mains/
>
> /tvb
>
> ----- Original Message ----- From: "Magnus Danielson" 
> <magnus at rubidium.dyndns.org>
> To: "Discussion of precise time and frequency measurement" 
> <time-nuts at febo.com>
> Sent: Wednesday, December 29, 2010 10:45 AM
> Subject: [time-nuts] Mains as time-reference
>
>
>> Fellow time-nuts,
>>
>> Just for fun I have been looking at the mains as a time-reference.
>>
>> I've used an OSA 8600 as reference and divided down to PPS by a 
>> TADD-2. While not absolute time reference, it is way quieter than the 
>> mains so I think it is good enough to have some fun at least. Just to 
>> illustrate the issue.
>>
>> I use a HP5335A to measure the time from PPS to rising edge of 50 Hz 
>> as being accessible through a transformer.
>>
>> The ADEV has a peak at 30 s measuring 2,3E-4 and another at 6000 s 
>> measuring 4,3E-4.
>>
>> The phase changes over -0.11923 to +10,979 so a time difference 
>> peak-to-peak of 11,098 seconds.
>>
>> While I could refine my measurements to ensure trigger jitter is not 
>> causing any major issues, the ADEV slope from 1 s is rising rather 
>> than lowering, so it rather seems like source behaviour dominates.
>>
>> While this attempt is a hack, I hope it inspires people to fiddle 
>> around a little. :)
>>
>> Cheers,
>> Magnus
>
>
>
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