[time-nuts] Low cost synchronization

Magnus Danielson cfmd at bredband.net
Sun Aug 21 13:32:25 EDT 2005

From: "Poul-Henning Kamp" <phk at phk.freebsd.dk>
Subject: Re: [time-nuts] Low cost synchronization 
Date: Sun, 21 Aug 2005 19:21:28 +0200
Message-ID: <58496.1124644888 at phk.freebsd.dk>

> In message <430879AD.6060508 at erols.com>, Chuck Harris writes:
> >Magnus Danielson wrote:
> >
> >>>For any solutions that give you stable frequency
> >>>only (XO, RF carriers, 60 Hz) you will need a way
> >>>to set the initial time and to reset the time when
> >>>the batteries fail.
> >> 
> >> 
> >> For some countries will 60 Hz or 50 Hz no longer be maintained on 24 h basis, so it may be
> >> a bad idea to depend on it.
> >
> For the NordPool area (Norway, Sweden, Denmark, Finland) nobody tried to keep
> the average at 50Hz.

Which is what I recalled that you where saying. This is again my point, that
just because it is in one place, that is not universally true for all places.
The reasoning why people don't care as much should be fairly evident from the
discussion so far.

Also, how do you encode a leapsecond over 50 Hz, 60 Hz or whatever and has it
been done?

Poul-Henning and I both live in the NordPool controlled powergrid.

BTW, measuring the 53rd overtone frequency may not give a clear picture of the
frequency deviations at the base frequency. Overtone spectras experience quite
a different phase shift from the way it is produced by a number of devices
which vector-add to become the seen frequency and phase. Turn on or off a
strong producer of that frequency may shift that phase quite a bit while the
fundamental is barly shifted.


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