Re: [time-nuts] I now have a clock accurate to 10E-6!!!
You are a lucky man with foresight! One of the many bruises I have accumulated over years of kicking myself relates to passing up on an offer to obtain a couple of those. I do have a rather mundane grandfather clock which would benefit from the 1 pps treatment though. Just need to pursuade the domestic engineering manager.. Morris Date: Mon, 25 Aug 2008 17:40:14 +1000 From: Jim Palfreyman [EMAIL PROTECTED] Subject: [time-nuts] I now have a clock accurate to 10E-6!!! To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=iso-8859-1 Hi Folks, Well I've had the best weekend since I've just acquired a pendulum clock that used to be a telecommunication time standard in the 50s. It is a German made Siemens pendulum master clock that is about 150cm high and has a full-length seconds pendulum which is about a metre long. It is powered by 48V to automatically wind the weight up and will maintain time for about 8 hours without power. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
Congratulation Jim, you really have a nice pendulum!!! pf (Pierre-François) F5BQP - Original Message - From: Jim Palfreyman [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, August 25, 2008 10:01 AM Subject: Re: [time-nuts] I now have a clock accurate to 10E-6!!! And one more showing the coil that steers the pendulum. __ Information NOD32 3383 (20080824) __ Ce message a ete verifie par NOD32 Antivirus System. http://www.nod32.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
Jim Palfreyman wrote: Here's an an extra photo showing the clock mechanism after the face and hands have been removed. Jim Almost identical to the master clock(s) that were used to synchronise the British Railways station clocks in about 1980. A 48v 1pps was distributed by private wire to many stations and platforms. Keeping all of the clocks in synch was a full time job. As a young hard up engineer I recall being quite jealous of the engineer who got paid overtime twice a year to manually do the daylight saving correction :-) It was replaced by a new system with digital displays on the platforms and I kicked myself years later for not keeping one of the old pulse clocks for posterity. Regards Paul -- 73 de Paul GW8IZR IO73TI http://www.gw8izr.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
Jim; Congratulations, that is a really nice looking clock! You may have a real gem there. While the movement doesn't look like anything special, the pendulum looks like a Riefler. Which is something quite special...sort of like having a Thunderbolt inside your bedside alarm clock... Tom Frank On Aug 25, 2008, at 3:40 AM, Jim Palfreyman wrote: Hi Folks, Well I've had the best weekend since I've just acquired a pendulum clock that used to be a telecommunication time standard in the 50s. It is a German made Siemens pendulum master clock that is about 150cm high and has a full-length seconds pendulum which is about a metre long. It is powered by 48V to automatically wind the weight up and will maintain time for about 8 hours without power. The pendulum has an adjustment to raise and lower the 7.5kg weight to calibrate the clock. One full turn of this knob will advance or retard the clock by 40 seconds per day. It is graduated into 100 divisions enabling you to adjust it within 0.4 seconds per day. Half way up the pendulum is a little tray where you can deposit small weights for your final adjustment (and most importantly without stopping the pendulum!) Even though it's a master clock it is also designed to be synchronised to another master clock and so there is an armature on the pendulum that can be steered by a magnetic coil. I have no documentation on this bit, but when I figure it out I naturally shall be driving it from a 1PPS reference. (See photo.) There are numerous contacts that are designed to open/shut at various times including every second, every thirty seconds and minute. The photo shows the mechanism behind the clock face. By connecting the seconds contact up to my 5370B I tuned it quite quickly to be accurate to about a second a day. Which is about 10 microseconds per pendulum swing! I'm impressed a tick tock clock can do that. (Although it pales into insignificance compared to what Harrison accomplished.) It is beautifully constructed and now one of my prized possessions! (I'll put some more photos in another post.) Regards, JimIMGP4585.jpg___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
On Mon, 25 Aug 2008 17:40:14 +1000, Jim Palfreyman [EMAIL PROTECTED] wrote: Hi Folks, Well I've had the best weekend since I've just acquired a pendulum clock that used to be a telecommunication time standard in the 50s. Nice. I'd love to have a photo of that with both the clock and the rack of HP goodies both showing. Move to the right a little, maybe use a tripod and turn off the flash to get more uniform lighting and the result would be a wonderful contrast between old and new. John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com -- best little blog on the net! Tellico Plains, Occupied TN *fas-cism* (fash'iz'em) n. A system of government that exercises a dictatorship of the extreme right, typically through the merging of state and business leadership, together with belligerent nationalism. -- The American Heritage Dictionary, 1983 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
Yes the pendulum is a 14mm Riefler. I gather that's significant? Jim 2008/8/25 Thomas A. Frank [EMAIL PROTECTED] Jim; Congratulations, that is a really nice looking clock! You may have a real gem there. While the movement doesn't look like anything special, the pendulum looks like a Riefler. Which is something quite special...sort of like having a Thunderbolt inside your bedside alarm clock... Tom Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
I will get that photo for you. (I didn't actually use a flash - that's just the halogen floor light I use to see what I'm doing.) Also, being a keen amateur photographer with some quite decent equipment I'll put some effort in and make it a good one! In that rack actually is a speaking clock (installed in Australia in the 1980s and my other prized possession) that I acquired a few years back along with my recently purchased 5370B timer/counter and 3325B function generator. Jim Nice. I'd love to have a photo of that with both the clock and the rack of HP goodies both showing. Move to the right a little, maybe use a tripod and turn off the flash to get more uniform lighting and the result would be a wonderful contrast between old and new. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] I now have a clock accurate to 10E-6!!!
Folks, I, too, had a great weekend. The Thunderbolt arrived, plugged it in, and it promptly found it's self. I can't wait to put it to work. Thanks to all (TAPR, time-nuts, etc.) for their effort on my behalf. My father (now deceased) collected and repaired clocks for 60 years leaving my brother and I some unique pieces. My prize is a 'FASHION' clock made by the Southern Calendar Clock Company, St. Louis, Mo, patented March 18, 1879. It is a two faced clock with two about ten inch diameter faces, one on top and one on the bottom. The top face displays hours, minutes and seconds, all with 'hands'. The bottom face displays the day of the month, 1 through 31, with a hand that points to the periphery and the month and day of the week in two rectangular openings on either side of the center of the dial. The unique feature is that it keeps long months, short months, and every 4 years, gives February 29 days. It is all mechanical, has two 'springs' for power, one for time and the other to strike the hour of the day. It runs for a week on a single 'wind' and keeps reasonable time. Not to 1 in 10E6 though. Its shortcomings are leap seconds and Daylight Savings Time. Fully manual on those I'm afraid. It is completely mechanical with no electric parts. None the less, quite a piece of work for the 1800's. Thanks again to all for all the work that resulted in the Thunderbolt. I am sure I will have questions in the future but none tonight. Joe -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Palfreyman Sent: Monday, August 25, 2008 2:40 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] I now have a clock accurate to 10E-6!!! Hi Folks, Well I've had the best weekend since I've just acquired a pendulum clock that used to be a telecommunication time standard in the 50s. It is a German made Siemens pendulum master clock that is about 150cm high and has a full-length seconds pendulum which is about a metre long. It is powered by 48V to automatically wind the weight up and will maintain time for about 8 hours without power. The pendulum has an adjustment to raise and lower the 7.5kg weight to calibrate the clock. One full turn of this knob will advance or retard the clock by 40 seconds per day. It is graduated into 100 divisions enabling you to adjust it within 0.4 seconds per day. Half way up the pendulum is a little tray where you can deposit small weights for your final adjustment (and most importantly without stopping the pendulum!) Even though it's a master clock it is also designed to be synchronised to another master clock and so there is an armature on the pendulum that can be steered by a magnetic coil. I have no documentation on this bit, but when I figure it out I naturally shall be driving it from a 1PPS reference. (See photo.) There are numerous contacts that are designed to open/shut at various times including every second, every thirty seconds and minute. The photo shows the mechanism behind the clock face. By connecting the seconds contact up to my 5370B I tuned it quite quickly to be accurate to about a second a day. Which is about 10 microseconds per pendulum swing! I'm impressed a tick tock clock can do that. (Although it pales into insignificance compared to what Harrison accomplished.) It is beautifully constructed and now one of my prized possessions! (I'll put some more photos in another post.) Regards, Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
