Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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=self-winding+clock+company

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

You are really late to this party. Current comptition is how many diffenent types of clocks can be driven with PoE -- 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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

> 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 >

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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,

Re: [time-nuts] How did they distribute time in the old days?

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: >

Re: [time-nuts] How did they distribute time in the old days?

- 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 Clock

Re: [time-nuts] How did they distribute time in the old days?

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

Re: [time-nuts] How did they distribute time in the old days?

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...