I have a little piezo sounder on the PPS from a t/bolt. It runs off a
cmos gate, I can not remember whether I put some pulse stretching in,
but it needs an on/off switch or the ticking will drive you mad.
This is great to use with the UTC time on LH. You look at the time,
then keep counting with the audible ticks to guide you while you
check your analogue clocks.
I also have a BCD counter dividing the 10MHz from the T/Bolt that
drives a time display. As well, the milliseconds, 100 microseconds,
or 10s of microseconds are counted and
can be latched by a proximity switch into a homebrew BCD DAC which is
recorded by a HOBO logger to give very accurate logging of phase for
whichever clock the proximity is clipped to.
It is all low power, saves serious frequency counters, PC et. al. so
you can log continuously for years without a major power bill.
cheers, Neville Michie
On 30/01/2011, at 4:16 AM, scmcgr...@gmail.com wrote:
Ah now from time nuttery to horology. There are those of us who
tinker with analog clocks as well...
Generally we 'beat' clocks against 'standard' clocks or more
recently a pc application with a microphone over long periods of
time generally at least a week and commonly a month.
Scott
Sent from my Verizon Wireless BlackBerry
-----Original Message-----
From: Chris Albertson <albertson.ch...@gmail.com>
Sender: time-nuts-boun...@febo.com
Date: Thu, 27 Jan 2011 15:52:49
To: Discussion of precise time and frequency measurement<time-
n...@febo.com>
Reply-To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Subject: Re: [time-nuts] Clock Calibration
On Thu, Jan 27, 2011 at 12:55 PM, Perry Sandeen
<sandee...@yahoo.com> wrote:
...how the heck they were able to calibrate a clock to
milliseconds per day back then?
Let it run for 1,000 days, then you only need to be able to measure to
the nearest second to get to ms per day. Or maybe you can measure to
0.1 seconds so it only takes 100 days.
The trouble is that using this method you don't know the average
error. A good example is an eccentric gear that makes a second hand
run fast then slow but if averaged over a long period is near perfect.
I doubt they were able to catch stuff like that.
--
=====
Chris Albertson
Redondo Beach, California
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