I heard of a system used in Melbourne between two major stations using
pulses in a pipe of water to sync. I suppose that pulses travel much faster
in water being incompressible, so better accuracy!
Tom Harris
On 20 October 2015 at 07:00, Brian Inglis
wrote:
> On 2015-10-15 08:32, Tom Van Baak
On 2015-10-15 08:32, Tom Van Baak wrote:
Nick Sayer writes:
The WU standard time service goes back further than the turn of the 20th
century. It started in 1870.
Also, for a screen full of irresistible SWCC photos, try this:
https://www.google.com/search?tbm=isch&q=self-winding+clock+company
The SWCC clock time synch coils were wired in series. Voltage varied with
the number of clocks in the circuit. It takes about 300ma to drive the
coil. Do a Google search for "swcc synchronizing coil voltage" to see a
thread where I talk about this on the NAWCC clock message board. Also the
clocks h
I have a synchronome clock built for the British Post Office.
I find that the 10V or so that a USB to serial adapter can produce can
trigger the solenoid, if allowed to charge a capacitor for the intervening
minute. The effect is that I can print a single character once a minute at
a low bit rate
Hi Don:
I've got a number of SWCC clocks and 3V doesn't work for any of them. I've done a number of experiments and a higher
voltage and series resistor makes a huge improvement.
Mail_Attachment --
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.ht
I drive one of my Self Winding Clock Company/Western Union clocks using the NTP
server I built using a Trimble Thunderbolt and a Soekris Net4501. I use a GPIO
line to drive a simple transistor switch using the same 3 volt battery that I
also use do power the winder. The pulse from the GPIO pin i
Nick Sayer writes:
> The WU standard time service goes back further than the turn of the 20th
> century. It started in 1870.
See also: http://leapsecond.com/history/usno.htm
> I’ve always wanted to get my hands on one of those clocks and come up with a
> circuit to recreate
> the synchronizatio
You are really late to this party. Current comptition is how many diffenent
types of clocks can be driven with PoE&NTP -- know someone trying to do Nixie
with it.
Sent from my iPhone
> On Oct 14, 2015, at 09:42, Nick Sayer via time-nuts
> wrote:
>
>
>> On Oct 14, 2015, at 4:42 AM, billrich
Hi, Brooke,
My self winding clock synchronizes fine on three volts. I built a
synchronizer using a PIC controller with a 32KHz quartz crystal, running
on three volts. You might want to carefully check the coil and
connections on yours. By the way, the winding coils also are running on
three v
ssage-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke
Sent: Wednesday, October 14, 2015 2:02 PM
To: Nick Sayer; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How did they distribute time in the old days?
Hi Nick:
One of my Self Winding
bow...@gmail.com said:
> I never figured out if it was using line frequency zero crossings for
> seconds or if it was leaking as DEC fixed it not long after it was
> installed. (And it was moved to a different phase of the power system than
> the clocks...)
I remember a story from ages ago... A
Precise time (and time zones) and the relationship with the telegraph were
a side effect of the railroads. You need to keep time (and keep on time) in
order to avoid collisions on single tracked main lines.
On Wed, Oct 14, 2015 at 12:42 PM, Nick Sayer via time-nuts <
time-nuts@febo.com> wrote:
>
And to tie this back to the UPS thread, at university, the Simplex clock sync
signal made our Vax 11/730 TOD clock run wy fast.
I never figured out if it was using line frequency zero crossings for seconds
or if it was leaking as DEC fixed it not long after it was installed. (And it
was mo
On 2015-10-14 10:42, Nick Sayer via time-nuts wrote:
On Oct 14, 2015, at 4:42 AM, billriches wrote:
Not milisecond time distribution but time related!
In the early half of the 1900s Western Union was in the time business. They
would rent businesses such as banks, office buildings, etc cloc
The Western Union clocks were still in use at broadcast stations in the
early 1970s. One problem was that the reset pulse and resulting jump in
time would come exactly on the hour, when you were trying to synchronize
with a network news broadcast that began at the network's version of 00:00.
ABC a
The book "Einstein's Clocks, Poincare's Maps" describes a pneumatic time
sync method for the public clocks on poles in the city of Paris, France
in the late 1800s. Pneumatic clocks were made and used in the US for a
while. Got one from the four letter auction site and dreamed of making a
pneumatic
Hi Nick:
One of my Self Winding Clock Co. (WU) clocks was taken down yesterday for
painting.
When put up one of the Ken's Clock Synchronizers was installed and the hands moved to align with the heart shaped cam it
uses, but it never worked.
The problem was it used a 4.5 Volt signal which can de
A friend of mine built a clock that they used to time-sync a lot of those
stations. It was basically a nice OCXO built into an ammunition can. They
flew it to various stations around the world. One particular trip to sync the
stations in the mid-east was particularly interesting... ammo can
> On Oct 14, 2015, at 4:42 AM, billriches wrote:
>
> Not milisecond time distribution but time related!
>
> In the early half of the 1900s Western Union was in the time business. They
> would rent businesses such as banks, office buildings, etc clocks for a few
> dollars a month. These were
e and frequency measurement"
Cc:
Sent: Wednesday, October 14, 2015 6:12 AM
Subject: [time-nuts] How did they distribute time in the old days?
hol...@hotmail.com said:
Somewhat time-nut related... the project main application needed
millisecond consistent (not necessarily accurate) ti
Not milisecond time distribution but time related!
In the early half of the 1900s Western Union was in the time business. They
would rent businesses such as banks, office buildings, etc clocks for a few
dollars a month. These were pendulum wall clocks that had 2 #6 dry cell
batteries inside tha
As recently as 1987, there was poor to no absolute time synchronization at
the world's underground neutrino detectors. When light and neutrino fronts
from supernova SN1987A arrived, the best they were able to put absolute
timestamps on neutrino events was about 1 minute.
Even after the neutrino ar
Hi,
They used (late 1970's) WWV or WWVH to sync up the time. There was
fancy system that used a neon on a rotating disc rather like an early
depth sounder. Neon flashed with seconds beep. There was a way of
rotating the field that drove the disk to advance/delay the system to
set it fairly accur
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1964-07.pdf
On 10/13/2015 10:12 PM, Hal Murray wrote:
hol...@hotmail.com said:
Somewhat time-nut related... the project main application needed
millisecond consistent (not necessarily accurate) time stamps on a
world-wide network. That was in th
hol...@hotmail.com said:
> Somewhat time-nut related... the project main application needed
> millisecond consistent (not necessarily accurate) time stamps on a
> world-wide network. That was in the pre-gps, pre-fiber, pre-historic
> before-times. I don't think that they ever quite got there.
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