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.
[time-nuts] While we're discussing backups...
Pointless overkill? Ask those people in New Orleans what happens when originals and backups are kept in the same city. I know of several (ex) businesses that wisely kept their backups in different buildings there... all were lost. Ask my friends in Jarrell, Texas (or what's left of them after a tornado leveled the city)... one friend kept backups at his and his parent's house... a lifetime's work lost... not to mention a lot of friends and family. All legitimate disaster plans specify that backups (and contingency operating sites) are not to be kept in the same geographic area. Failure to do so in a corporate setting would expose you to major liability claims. Your comment has to be one of the silliest, most shortsighted, that I have ever seen posted anywhere... That has to be the silliest thing I've ever seen posted to this list. Even by time-nut standards of pointless overkill. _ Talk to your Yahoo! Friends via Windows Live Messenger. Find out how. http://www.windowslive.com/explore/messenger?ocid=TXT_TAGLM_WL_messenger_yahoo_082008 ___ 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] While we're discussing backups...
Never been a fan of clone backups, unless it's a primary server and you have identical machines available. As for backups in distant cities or protected storage vaults, I'd sorta think that depends on what you really need... Another issue with clone backups of system drives, is that I've seen more Windows internal-corruption failures then pure drive/computer failures. And if your OS is already starting to die when you made your last backup, it doesn't help very much. I've got a USB bookshelf drive, together with an old workstation with big drives for a duplicate backup. For most apps, I don't try to clone a drive, but backup the install for the apps, together with any keys. Given Window's scattered installation stuff, critical apps are in VmWare sessions, that can easily be backed up and restored to any machine. Any work-in-progress gets backed up every few hours to a memory stick. I feel those two types of backup are really needed, especially having one that's easy and very fast to do. Gerry ___ 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] TBolt question
Ah, excellent. I'm also a TAPR member. Thank you. Tom Van Baak wrote: >> I missed out on the group buy because I didn't hear >> about it until it was over. >> >> I'm looking at the one that fluke is selling on eBay, >> version 3.00. Has anyone had any problems with these? >> >> Mike - AA8K > > Stay tuned; if all works out TAPR will get another batch by > mid-September. > > /tvb > > ___ 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!!!
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] E-5680A C-field trimer ??
Mark, which pot is it ? Rex and myself bought units that were not programmable. Both of us have tweaked the pots and have not seen any change in drift. I turned pots 1 turn per day and did phase observations, over the course of a week. They guy that sold these units on ebay claimed they were programmable but could not produce the information. Its been noted he has changed his ebay user name about every 6 months (that might give you an idea about his operation - he also complained about whiny time-nuts postings about his operation). Mark Sims wrote: > Actually the 5680A and 5650A units that have the DDS do have a C-field pot. > The DDS is only accurate to 0.01 Hz. They set the C-field to minimum, > program the DDS constant that gets the closest to the desired freq into the > CPU chip (this is what gets reported by the "S" command), then they tweak > the C-field to get the unit exactly on freq. The reference freq reported by > the "S" command is NOT the reference freq that the unit is shipped adjusted > to. > > > >> There are several models of the 5680A. A lot use the DDS circuits to >> set the output frequencies and they do not have C field adjustments. >> > > > _ > Get thousands of games on your PC, your mobile phone, and the web with > Windows®. > http://clk.atdmt.com/MRT/go/108588800/direct/01/ > ___ > 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] While we're discussing backups...
On Mon, 25 Aug 2008 22:30:33 +, Mark Sims <[EMAIL PROTECTED]> wrote: > >Any backup that is stored in the same city as the original (some would say >within 100 miles of the city) is NOT a backup. It is just a disk waiting for >a (real) disaster. No fire proof safe, baggie, etc is a substitute for >physical distance. That has to be the silliest thing I've ever seen posted to this list. Even by time-nut standards of pointless overkill. 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 In theory, there is no difference between theory and practice. In practice, there is. ___ 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] While we're discussing backups...
On Mon, 25 Aug 2008 17:51:35 -0400, "Bruce Lanning" <[EMAIL PROTECTED]> wrote: >In regard to the below info, I downloaded xxclone and it does appear to be >the type of backup program that I have been looking for, BUT I can not get >my C: drive to come up in the source or the target window. I am running XP >on a COMPAQ Presario if that helps. Could anyone tell me why I can not see >my C: drive. It has my start up info and WINDOWS on it. No idea other than the brand name. Compaqs have a rep for stuff like that. Are you running XP? All bets are off if Vista is involved. I've installed xxclone on a number of client and friends' computers and never had a problem. It just came up and ran. Did you try pressing the disk management button to the right of the source and target slots? That brings up windows disk drive management package. What does it show? Is your C drive an NTFS volume that is showing healthy? Have you turned off any services, particularly windows shadow volume copy service? Some "optimization" websites recommend turning that service off but doing so disables just about every backup or clone package that runs in multi-user mode. Do you have any virus bloat-ware like Norton running? If so, it might be interfering with disk detection. I have the freebie Avast package on my machine and before that AVG (release 8 turned into bloatware so I had to change) running with no problems but given the amount of problems I've had in the past with Norton and MaCaffee, I'd be looking there. Have you tried since rebooting the machine? Kind of an obvious question but I had to ask. As a last resort, you might drop them a support note and ask if they've had any reported problems with your model computer. Maybe they'll have a patch or a work-around. 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 Multitasking: Reading in the bathroom! ___ 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] While we're discussing backups...
On Mon, Aug 25, 2008 at 3:30 PM, Mark Sims <[EMAIL PROTECTED]> wrote:
>
> Any backup that is stored in the same city as the original (some would say
> within 100 miles of the city) is NOT a backup. It is just a disk waiting for
> a (real) disaster. No fire proof safe, baggie, etc is a substitute for
> physical distance.
wrong. or at least not a complete answer.
Any backup that is stored in the same
{state,country,continent,planet,...} as the original (some would say
within {100, 1000, 1, 100, ...} miles of the city) is NOT a
backup. It is just a disk waiting for a (real) disaster. No fire
proof safe, baggie, etc is a substitute for physical distance. And a
copy in a different dimension where different physical laws apply. And
a time machine. And a few deities who owe you favors. ...
Nightly rsyncs of my home boxen to a network storage device offer
enough protection against my most common failure mode: crappy disks
and/or harsh environments. I've lost a half-dozen drives in my
thinkpad over the years, dumping the contents back from the backup is
sufficient. And what if your nightly snapshot is a hundred miles away?
It's still gonna take a few hours to get the image back on to
production hardware to start serving again. Nearby replication is also
critical. Fail over to one of the backup server, and rebuild the
primary at your leisure. Or fail over to the alternate data center.
A backup is something that reduces your chances of being unable to
recover from a set of failures to an acceptably low level. Spend some
time thinking "what could possibly go wrong?", and then decide what
you're going to do about it. Sometimes "ignore it" is an acceptable
answer. Sometimes the right answer is "spend $1B to build multiple
data centers with and have state-of-the-art replication, redundancy
and failover everywhere." It's a matter of what it'll cost you if
something happens vs. what it'll cost to mitigate that.
Also, verifying your backups regularly is important...
--
GDB has a 'break' feature; why doesn't it have 'fix' too?
___
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[time-nuts] While we're discussing backups...
Any backup that is stored in the same city as the original (some would say within 100 miles of the city) is NOT a backup. It is just a disk waiting for a (real) disaster. No fire proof safe, baggie, etc is a substitute for physical distance. _ Get ideas on sharing photos from people like you. Find new ways to share. http://www.windowslive.com/explore/photogallery/posts?ocid=TXT_TAGLM_WL_Photo_Gallery_082008 ___ 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] E-5680A C-field trimer ??
Actually the 5680A and 5650A units that have the DDS do have a C-field pot. The DDS is only accurate to 0.01 Hz. They set the C-field to minimum, program the DDS constant that gets the closest to the desired freq into the CPU chip (this is what gets reported by the "S" command), then they tweak the C-field to get the unit exactly on freq. The reference freq reported by the "S" command is NOT the reference freq that the unit is shipped adjusted to. >There are several models of the 5680A. A lot use the DDS circuits to >set the output frequencies and they do not have C field adjustments. _ Get thousands of games on your PC, your mobile phone, and the web with Windows®. http://clk.atdmt.com/MRT/go/108588800/direct/01/ ___ 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] While we're discussing backups...
In regard to the below info, I downloaded xxclone and it does appear to be the type of backup program that I have been looking for, BUT I can not get my C: drive to come up in the source or the target window. I am running XP on a COMPAQ Presario if that helps. Could anyone tell me why I can not see my C: drive. It has my start up info and WINDOWS on it. Bruce Original Message - From: "Neon John" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" Sent: Sunday, August 24, 2008 3:50 PM Subject: Re: [time-nuts] While we're discussing backups... > On Fri, 22 Aug 2008 22:47:12 -0500, Robert Vassar <[EMAIL PROTECTED]> > wrote: > > >>I backup to a USB hard disk. I plug it in, backup, unplug it, de- >>cable and park it in a filing cabinet. The disk spends 99.99% of >>it's life powered off. It should last a decade or more like this, >>but I buy a new disk to replace it every 5 years, regardless if it >>needs it or not. Really critical stuff goes on a CD-R, stored flat >>in a jewel case, and goes in the safe deposit box. > > My laptop is may main computer. My "backup" procedure consists of cloning > the > C: drive using a freebie utility called "xxclone" > (http://www.xxclone.com). > This one is one of the best cloning programs that I've tried and being > free is > a double bonus. > > The target drives are the same brand and size as what is installed in my > laptop. The bare target drive is connected via a USB-to-EDIE interface > cable > that I picked up somewhere on the net for about $20. I use 3 drives in > rotation so that I have 3 generations of drive snapshots at any given > time. > That has saved my cookies more than once when I realized after the last > clone > that I'd deleted something vital. The three "backup" drives stay in my > fireproof safe inside zip-lock bags. The zip-lock bags are vital. I > learned > the hard way during a house fire that even though the fireproof safe > protects > the media from heat, it doesn't protect it from the acidic smoke and steam > that are drawn into the cool interior. > > If the drive in my laptop fails, I don't have to do a restore. I simply > get > the latest clone drive out of the safe and install it in my computer and > I'm > instantly back up and running with the machine state being that of the > last > snapshot. > > I do a weekly clone and a daily differential backup to my linux file > server > running SAMBA using another freebie utility called SyncBack. A flash drive > is > another option for those non-networked computer users. > http://www.2brightsparks.com/. Even when I've been very active, a week's > worth of changes easily fits on a 4 gig flash drive. > > I still have the occasional nightmare when I think about tape backup. > More > accurately, the time wasted verifying each tape and even then, having the > tape > not read about half the time when it was needed. Never again! > > 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 > What do you call a blonde's cranial cavity? Vacuum chamber? > > > ___ > 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. > > > -- > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.524 / Virus Database: 270.6.7/1629 - Release Date: 8/23/2008 > 1:16 PM > ___ 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] hpgps ntp refclock driver and leap second
With the oncore VP in the z3801a isn't this a bug/feature of the Bj command
to announce it as soon as it is available, while other/newer receivers
wait till the month prior? There is even a workaround for this in the
oncore refclock driver.
Scott
Greg Dowd wrote:
> In NTPv4, the warning is propagated as soon as it is available. If it
> were more than 6 months in advance, this could be an issue but that
> hasn't happened yet. NTP also ignores the alternate (Mar/Sept) leap
> windows by design.
>
>
>
> Greg Dowd
> gdowd at symmetricom dot com (antispam format)
> Symmetricom, Inc.
> www.symmetricom.com
> "Everything should be made as simple as possible, but no simpler" Albert
> Einstein
>
>
>> -Original Message-
>> From: [EMAIL PROTECTED]
>> [mailto:[EMAIL PROTECTED] On Behalf Of Scott Mace
>> Sent: Monday, August 25, 2008 8:21 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: [time-nuts] hpgps ntp refclock driver and leap second
>>
>> Shouldn't the hpgps ntp driver wait to raise the leap second
>> flag until a month before the leap second and not whenever
>> the satellite happens
>> to first transmit it? See attached patch.
>>
>> diff -u refclock_hpgps.c.orig refclock_hpgps.c
>> --- refclock_hpgps.c.orig 2008-08-25 09:49:59.0 -0500
>> +++ refclock_hpgps.c2008-08-25 09:56:29.0 -0500
>> @@ -535,7 +535,8 @@
>> switch (leapchar) {
>>
>> case '+':
>> - pp->leap = LEAP_ADDSECOND;
>> + if ((month == 6) || (month == 12))
>> + pp->leap = LEAP_ADDSECOND;
>> break;
>>
>> case '0':
>> @@ -543,7 +544,8 @@
>> break;
>>
>> case '-':
>> - pp->leap = LEAP_DELSECOND;
>> + if ((month == 6) || (month == 12))
>> + pp->leap = LEAP_DELSECOND;
>> break;
>>
>> default:
>>
>> ___
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>> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> ___
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>
>
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Re: [time-nuts] hpgps ntp refclock driver and leap second
In NTPv4, the warning is propagated as soon as it is available. If it
were more than 6 months in advance, this could be an issue but that
hasn't happened yet. NTP also ignores the alternate (Mar/Sept) leap
windows by design.
Greg Dowd
gdowd at symmetricom dot com (antispam format)
Symmetricom, Inc.
www.symmetricom.com
"Everything should be made as simple as possible, but no simpler" Albert
Einstein
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Scott Mace
> Sent: Monday, August 25, 2008 8:21 AM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] hpgps ntp refclock driver and leap second
>
> Shouldn't the hpgps ntp driver wait to raise the leap second
> flag until a month before the leap second and not whenever
> the satellite happens
> to first transmit it? See attached patch.
>
> diff -u refclock_hpgps.c.orig refclock_hpgps.c
> --- refclock_hpgps.c.orig 2008-08-25 09:49:59.0 -0500
> +++ refclock_hpgps.c2008-08-25 09:56:29.0 -0500
> @@ -535,7 +535,8 @@
> switch (leapchar) {
>
> case '+':
> - pp->leap = LEAP_ADDSECOND;
> + if ((month == 6) || (month == 12))
> + pp->leap = LEAP_ADDSECOND;
> break;
>
> case '0':
> @@ -543,7 +544,8 @@
> break;
>
> case '-':
> - pp->leap = LEAP_DELSECOND;
> + if ((month == 6) || (month == 12))
> + pp->leap = LEAP_DELSECOND;
> break;
>
> default:
>
> ___
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>
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[time-nuts] hpgps ntp refclock driver and leap second
Shouldn't the hpgps ntp driver wait to raise the leap second flag until
a month before the leap second and not whenever the satellite happens
to first transmit it? See attached patch.
diff -u refclock_hpgps.c.orig refclock_hpgps.c
--- refclock_hpgps.c.orig 2008-08-25 09:49:59.0 -0500
+++ refclock_hpgps.c2008-08-25 09:56:29.0 -0500
@@ -535,7 +535,8 @@
switch (leapchar) {
case '+':
- pp->leap = LEAP_ADDSECOND;
+ if ((month == 6) || (month == 12))
+ pp->leap = LEAP_ADDSECOND;
break;
case '0':
@@ -543,7 +544,8 @@
break;
case '-':
- pp->leap = LEAP_DELSECOND;
+ if ((month == 6) || (month == 12))
+ pp->leap = LEAP_DELSECOND;
break;
default:
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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!!!
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, > > 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. ___ 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] FE-5680A C-field trimer ??
Yes, I forgot about those. If I remember correctly, a -20 option has DDS. It's sometimes hard to tell which one you have without opening it up. My 5680A came from an EBay auction where the seller claimed it was programmable. It wasn't. It has the non-DDS 10 Mhz sine output. However, I think that if the pot is installed, you have an adjustable C-field. I'm not positive about this, though. Bill Ezell -- They said 'Windows or better' so I used Linux. Brian Kirby wrote: There are several models of the 5680A. A lot use the DDS circuits to set the output frequencies and they do not have C field adjustments. Brian - KD4FM wje wrote: Unless you can measure the frequency to at least a few parts in 10e10, you won't see any change. These devices are far more precise than standard frequency counters. You either need something like an HP 5370 or 5371 to measure the difference, or another equally precise oscillator to compare against using a phase meter or your oscilloscope. Bill Ezell -- They said 'Windows or better' so I used Linux. Rex wrote: Have you adjusted it? I tried tweaking that pot on one I had and I didn't see any effect. wje wrote: There's a small hole on the side of the case. This is the trimmer access, at least on mine. Bill Ezell -- They said 'Windows or better' so I used Linux. EMMANOUIL MANTZARAS wrote: Hi Is there any one that knows where is the c-field trimer in the FE-5680A board ?? Thanks sv1bke ___ time-nuts mailing list -- [EMAIL PROTECTED] To unsubscribe, go to [2][2]https://www.febo.com/cgi-bin/mailman/listinfo/time-n uts and follow the instructions there. References 1. [3]mailto:time-nuts@febo.com 2. [4]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list -- [EMAIL PROTECTED] To unsubscribe, go to [6]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- [EMAIL PROTECTED] To unsubscribe, go to [8]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:[EMAIL PROTECTED] 2. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 3. mailto:time-nuts@febo.com 4. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 5. mailto:time-nuts@febo.com 6. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 7. mailto:time-nuts@febo.com 8. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ 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!!!
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" 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!!!
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" > > 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] Efratom LPRO Rubidium Manual
That's the same manual I have on my web site: http://www.ko4bb.com/cgi-bin/manuals.pl Search for LPRO Didier KO4BB > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Bob Martinson > Sent: Monday, August 25, 2008 12:56 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Efratom LPRO Rubidium Manual > > This URL found in EBAY item number listing: 280259311638 > > > http://www.2917.com/EBAY-images/LPRO-101/LPRO-101.PDF > > > > REM > > ___ > 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.
