[time-nuts] 60Hz More or Less

[Tom Van Baak]

Hi Ed,

Welcome to the group and thanks for sharing that 60 Hz mains
project. Nice use of a 5316B and Prologix adapter to collect the
frequency data and Python and JavaScript to display live plots.

Is there a URL for the raw data files (the YYYMMMDDHH.DAT
files mentioned in code_2.txt)? I'd like to compare yours with the
Western Power Grid that data I collect here in Seattle.

On your gauge/hertz.html page, how do you compute the "grid
time error" value and have you compared it with a kitchen wall
clock? What date/time did you reset the value to zero?

I collect my data slightly differently and so it will be interesting
to see how making measurements with a periodic frequency
counter compare with direct timing measurements of phase.

I agree with your comment about "7 seconds a day". See also:
http://www.leapsecond.com/pages/mains/

Thanks,
/tvb

----- Original Message ----- 
From: "Ed Mersich" <wa6rzw at comcast.net>
To: <time-nuts at febo.com>
Sent: Sunday, April 01, 2012 3:18 PM
Subject: [time-nuts] 60Hz More or Less


> My Heathkit, and other AC clocks have been broken for months now. I started
> a project to figure out how bad it was. It's getting interesting as I am
> approaching my goal of coding a software emulation of an AC line clock.
> During the process I developed a couple of web pages to help me understand
> the problem better. Frequency meter:
> http://wa6rzw.homelinux.net/addon/grid/gauge/hertz.html 
> 
> Grid history graph:
> http://wa6rzw.homelinux.net/addon/grid/graph/wgraph_1.html 
> 
> 
> 
> The meter requires a real HTML5 browser, anything but MSIE.  
> 
> 
> 
> When I started this my goal was to provide an external reference source to
> the Heathkit CG-1005, so that it will keep correct time.  Since I began I
> have considered a number of hardware solutions to correct or modify the
> Heathkit.  I think I am dragging my feet because there are no replacement
> clock chips (in case of disaster,) to be found for this model. At the moment
> I am thinking about modifying a DC-AC inverter and syncing it to an audio
> oscillator, (don't laugh, my Heathkit 30 year old audio generator is way
> better, more stable, than the grid). 
> 
> 
> 
> 73, Ed - WA6RZW