How did they distribute time in the old days?
holrum@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.
World wide seismology took off in the early 1970s as background for nuclear
underground non-testing treaties. Both the US and the USSR had to be sure
they could detect the opponents tests and distinguish tests from earthquakes.
We had seismic stations scattered around the globe.
Does anybody know how they distributed time back then and/or how accurately
they could do it?
Google says the speed of sound in rock is 6-8 km/s so 10 ms error would be
100 meters. That seems like a reasonable ballpark.
--
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On 10/13/2015 10:12 PM, Hal Murray wrote:
holrum@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.
World wide seismology took off in the early 1970s as background for nuclear
underground non-testing treaties. Both the US and the USSR had to be sure
they could detect the opponents tests and distinguish tests from earthquakes.
We had seismic stations scattered around the globe.
Does anybody know how they distributed time back then and/or how accurately
they could do it?
Google says the speed of sound in rock is 6-8 km/s so 10 ms error would be
100 meters. That seems like a reasonable ballpark.
--
Howard L. Davidson
hld42@att.net
Well I dont know if it was used for that but the16kHz VLF station at Rugby
call-sign GBR was rebuilt in 1967 and the output tank circuit stiffened to
provide better phase stability specifically foe international time standard
comparison. The transmitter was used for initial comparisons between NPL and
NBS (later NIST) time standards. It was also the starting point for the
Omega nav system. Prior to that accurate time data was passed over twisted
pairs in UK and probably Europe.
Alan
G3NYK
----- Original Message -----
From: "Hal Murray" hmurray@megapathdsl.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Cc: hmurray@megapathdsl.net
Sent: Wednesday, October 14, 2015 6:12 AM
Subject: [time-nuts] How did they distribute time in the old days?
holrum@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.
World wide seismology took off in the early 1970s as background for
nuclear
underground non-testing treaties. Both the US and the USSR had to be sure
they could detect the opponents tests and distinguish tests from
earthquakes.
We had seismic stations scattered around the globe.
Does anybody know how they distributed time back then and/or how
accurately
they could do it?
Google says the speed of sound in rock is 6-8 km/s so 10 ms error would be
100 meters. That seems like a reasonable ballpark.
--
These are my opinions. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
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 accurately.
Cheers,
Will
On 14/10/15 18:12, Hal Murray wrote:
holrum@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.
World wide seismology took off in the early 1970s as background for nuclear
underground non-testing treaties. Both the US and the USSR had to be sure
they could detect the opponents tests and distinguish tests from earthquakes.
We had seismic stations scattered around the globe.
Does anybody know how they distributed time back then and/or how accurately
they could do it?
Google says the speed of sound in rock is 6-8 km/s so 10 ms error would be
100 meters. That seems like a reasonable ballpark.
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 that would wind them every hour or so. The clocks were
connected to the WU telegraph line and for a minute before and after the
top of the hour all traffic on the circuit would stop. Exactly at the top
of the hour they would push a pulse of 50 ? volts or so over the line and it
would reset the clock to the top of the hour.
Eventually WU decided to get out of the time business and stopped the
service and they said all the customers could keep their clocks. It was
said that at the end of that day many clocks were seen going home with some
of the workers!
I purchased one of these clocks about 15 years ago from a North New Jersey
junk dealer who had obtained several hundred of them. My clock has a 1929
scratch mark inside and
is still ticking away. These clocks were made by the Self Winding Clock
Company and more information can be seen in the book "American Clocks Volume
2 " by Tran Duy Ly (page 177). It loses or gains about a minute a month
depending on the moon phase or sunspots. You can see a pic of the clock on
qrz.com under my call sign.
73,
Bill, WA2DVU
Cape May
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
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 arrivals they may have been able to back-correct
timestamps on the Kamiokande data to within milliseconds, but a power
failure a few days after SN1987A detection prevented this.
The timescales that the Kamiokande and IMB neutrino detectors were
originally designed to measure? Circa 10 to the 31st years!
Today the realtime neutrino detectors are tied together into a network to
look for neutrino bursts in realtime, and even determine direction to point
optical telescopes. The neutrino burst for a SN1987A type event precedes
the optical detectability by a few hours.
Tim N3QE
On Wednesday, October 14, 2015, Hal Murray hmurray@megapathdsl.net wrote:
holrum@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.
World wide seismology took off in the early 1970s as background for nuclear
underground non-testing treaties. Both the US and the USSR had to be sure
they could detect the opponents tests and distinguish tests from
earthquakes.
We had seismic stations scattered around the globe.
Does anybody know how they distributed time back then and/or how accurately
they could do it?
Google says the speed of sound in rock is 6-8 km/s so 10 ms error would be
100 meters. That seems like a reasonable ballpark.
--
These are my opinions. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
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On Oct 14, 2015, at 4:42 AM, billriches bill.riches@verizon.net 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 pendulum wall clocks that had 2 #6 dry cell
batteries inside that would wind them every hour or so. The clocks were
connected to the WU telegraph line and for a minute before and after the
top of the hour all traffic on the circuit would stop. Exactly at the top
of the hour they would push a pulse of 50 ? volts or so over the line and it
would reset the clock to the top of the hour.
The WU standard time service goes back further than the turn of the 20th century. It started in 1870.
I’ve always wanted to get my hands on one of those clocks and come up with a circuit to recreate the synchronization signal for it, probably with a Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at this point, those clocks are quite expensive once they’re reconditioned.
My understanding (perhaps incorrect) was that the sync pulse was once daily and, as you said, would cause the hands to “snap” to 12. The trailing edge of the pulse was synchronized and would release the clock to operate normally.
That they had something as accurate and widespread as it was so early is astonishing.
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 develop the current needed to pull the sync electromagnet the time
constant is far too slow.
I'm going to add a high voltage circuit with series resistor to get the time constant down one or two orders of
magnitude. The key to this is a PCB I make that holds 5 each 9V batteries connected in series, so I'll use one, two or
more of them to get the time constant down.
http://www.prc68.com/P/45VS.html
Before I had the 45 Volt Stick I was considering getting the needed high voltage by charging a cap a minute or two
before the top of the hour and discharging it through a resistor. Here's a video showing that would work.
http://www.prc68.com/I/SWCC.shtml#Experiments_Feb_2014_
Mail_Attachment --
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Nick Sayer via time-nuts wrote:
On Oct 14, 2015, at 4:42 AM, billriches bill.riches@verizon.net 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 pendulum wall clocks that had 2 #6 dry cell
batteries inside that would wind them every hour or so. The clocks were
connected to the WU telegraph line and for a minute before and after the
top of the hour all traffic on the circuit would stop. Exactly at the top
of the hour they would push a pulse of 50 ? volts or so over the line and it
would reset the clock to the top of the hour.
The WU standard time service goes back further than the turn of the 20th century. It started in 1870.
I’ve always wanted to get my hands on one of those clocks and come up with a circuit to recreate the synchronization signal for it, probably with a Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at this point, those clocks are quite expensive once they’re reconditioned.
My understanding (perhaps incorrect) was that the sync pulse was once daily and, as you said, would cause the hands to “snap” to 12. The trailing edge of the pulse was synchronized and would release the clock to operate normally.
That they had something as accurate and widespread as it was so early is astonishing.
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and follow the instructions there.
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 pulse generator synched to 10 MHz. Sadly, the diaphragm in the
pneumatic mechanism had rotted away, so I gave the clock to a friend who
could make it work, but didn't. One pulse advanced the clock one minute.
There was no auxiliary clockwork to keep it running between hourly sync
pulses.
I don't know of any mechanical clocks that sync once a day. IIRC,
Western Union had to send people to advance or retard the hour hand when
daylight savings time became common.
There is something about those clocks that makes a time nut want to
restore one.
Bill Hawkins
-----Original Message-----
From: Nick Sayer via time-nuts
Sent: Wednesday, October 14, 2015 11:42 AM
The WU standard time service goes back further than the turn of the 20th
century. It started in 1870.
I've always wanted to get my hands on one of those clocks and come up
with a circuit to recreate the synchronization signal for it, probably
with a Raspberry Pi running ntpd and a big ol' MOSFET. The problem is
that at this point, those clocks are quite expensive once they're
reconditioned.
My understanding (perhaps incorrect) was that the sync pulse was once
daily and, as you said, would cause the hands to "snap" to 12. The
trailing edge of the pulse was synchronized and would release the clock
to operate normally.
That they had something as accurate and widespread as it was so early is
astonishing.
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:
On Oct 14, 2015, at 4:42 AM, billriches bill.riches@verizon.net 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 pendulum wall clocks that had 2 #6 dry cell
batteries inside that would wind them every hour or so. The clocks were
connected to the WU telegraph line and for a minute before and after the
top of the hour all traffic on the circuit would stop. Exactly at the
top
of the hour they would push a pulse of 50 ? volts or so over the line
and it
would reset the clock to the top of the hour.
The WU standard time service goes back further than the turn of the 20th
century. It started in 1870.
I’ve always wanted to get my hands on one of those clocks and come up with
a circuit to recreate the synchronization signal for it, probably with a
Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at this
point, those clocks are quite expensive once they’re reconditioned.
My understanding (perhaps incorrect) was that the sync pulse was once
daily and, as you said, would cause the hands to “snap” to 12. The trailing
edge of the pulse was synchronized and would release the clock to operate
normally.
That they had something as accurate and widespread as it was so early is
astonishing.
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