Re: [time-nuts] 10544 TCXO used in H/P 5245L counter
Subject: [time-nuts] 10544 TCXO used in H/P 5245L counter I`m looking for a pdf of the schematic of the motherboard that the 10544 frequency reference plugs onto in the H/P 5245L counter. This is the one that has a 723N, and a 7490N to produce a 100KHz reference. Something is amiss with this board. Thankyou.Don. Don, The 10544 oscillator outputs 10 MHz, so the output from the 7490 would be 1MHz, not 100KHz. if that's what you're seeing, then it's working properly. Cheers, David dgminala at mediacombb dot net ___ 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] Loran?
Thomas A Frank wrote: I await the day when someone opines as to the number of angels that can dance on the head of a GPS antenna. Oh dear, now I have this vision in my head of a bunch of angels impaled upon the antennas of a GPS satellite, much like how some of the folks who get involved in the Running of the Bulls end up. Sounds like the question of how many parking meter fairies can dance atop a Chicago parking pay box (with uncalibrated clock). HINT: This is why I have a WWVB watch and avoid metered parking spaces! ___ 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] 10544 TCXO used in H/P 5245L counter
Odd I see the oscillator is 1 Mhz driving various ddas as they used to call them. Did not think a 10544 could work in one of these counters. Must have been a later version. Regards Paul. On Fri, Dec 24, 2010 at 7:24 AM, Dave M dgmin...@mediacombb.net wrote: Dave M wrote: Subject: [time-nuts] 10544 TCXO used in H/P 5245L counter I`m looking for a pdf of the schematic of the motherboard that the 10544 frequency reference plugs onto in the H/P 5245L counter. This is the one that has a 723N, and a 7490N to produce a 100KHz reference. Something is amiss with this board. Thankyou.Don. Don, The 10544 oscillator outputs 10 MHz, so the output from the 7490 would be 1MHz, not 100KHz. if that's what you're seeing, then it's working properly. I forgot to include a URL to the manual. It's right there on the HP/Agilent web site at http://cp.literature.agilent.com/litweb/pdf/05245-9044.pdf. David dgminala at mediacombb dot net ___ 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] 10544 TCXO used in H/P 5245L counter
Ooops I see it was a update on page 204 roughly. So what are you running into as a issue. Could take offline if you would like. Regards Paul. On Fri, Dec 24, 2010 at 9:39 AM, paul swed paulsw...@gmail.com wrote: Odd I see the oscillator is 1 Mhz driving various ddas as they used to call them. Did not think a 10544 could work in one of these counters. Must have been a later version. Regards Paul. On Fri, Dec 24, 2010 at 7:24 AM, Dave M dgmin...@mediacombb.net wrote: Dave M wrote: Subject: [time-nuts] 10544 TCXO used in H/P 5245L counter I`m looking for a pdf of the schematic of the motherboard that the 10544 frequency reference plugs onto in the H/P 5245L counter. This is the one that has a 723N, and a 7490N to produce a 100KHz reference. Something is amiss with this board. Thankyou.Don. Don, The 10544 oscillator outputs 10 MHz, so the output from the 7490 would be 1MHz, not 100KHz. if that's what you're seeing, then it's working properly. I forgot to include a URL to the manual. It's right there on the HP/Agilent web site at http://cp.literature.agilent.com/litweb/pdf/05245-9044.pdf. David dgminala at mediacombb dot net ___ 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] Us Time Nuts and... Wrist Watches.
Le 24/12/2010 18:00, Michael Poulos a écrit : We all enjoy good accurate time keeping. :) What is your favorite watch? My watch (so far) is a Casio WaveCeptor digital watch that gets the WWVB signal and calibrates itself Not sure I have a favorite. I can't find any that do what exactly what I want, but I did go somewhat gaga the other day and got a Citizen Chronomaster (calibre A660). Spec'd to +- 5 secs a year without recourse to GPS/radio references. I always have three or four running at any one time in a desk drawer. And a few , well quite a lot really, in reserve. ___ 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] Us Time Nuts and... Wrist Watches.
Me too... :) El 24/12/2010 19:08, Mark J. Blair escribió: I stopped wearing a watch many years ago. I suppose I'm not really a time nut; I'm a 1/time nut. -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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] Us Time Nuts and... Wrist Watches.
An Omega Seamaster here. It was losing about a minute a month when it went back to Switzerland for routine cleaning, etc. Now it is losing about 2 seconds a week. And that is plenty good enough for a mechanical movement of modest cost. Happy holidays, everyone!!! On Fri, Dec 24, 2010 at 1:33 PM, Javier Herrero jherr...@hvsistemas.eswrote: Me too... :) El 24/12/2010 19:08, Mark J. Blair escribió: I stopped wearing a watch many years ago. I suppose I'm not really a time nut; I'm a 1/time nut. -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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] Us Time Nuts and... Wrist Watches.
Orbiting this at a distance of roughly ninety-eight million miles is an utterly insignificant little blue-green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea. - Dougles Adams, The Hitchhiker's Guide to the Galaxy On 25/12/2010, Javier Herrero jherr...@hvsistemas.es wrote: Me too... :) El 24/12/2010 19:08, Mark J. Blair escribió: I stopped wearing a watch many years ago. I suppose I'm not really a time nut; I'm a 1/time nut. -- Javier HerreroEMAIL: jherr...@hvsistemas.com Chief Technology Officer HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Us Time Nuts and... Wrist Watches.
At 21:05 24/12/2010, you wrote: Orbiting this at a distance of roughly ninety-eight million miles is an utterly insignificant little blue-green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea. - Dougles Adams, The Hitchhiker's Guide to the Galaxy 42! (that may be the answer to the quest for the ultimate precise clock, who knows) 73 and Merry Christmas to the group - Marco Zaphod IK1ODO ___ 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] Us Time Nuts and... Wrist Watches.
My favorite watch is to stand outside on a quiet night and watch the snow fall silently. It is a rare time-less moment. Best wishes for the solstice celebration of your choice, or as we used to say 60 years ago, Merry Christmas. Bill Hawkins -Original Message- From: Michael Poulos Sent: Friday, December 24, 2010 11:01 AM We all enjoy good accurate time keeping. :) What is your favorite watch? ___ 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] Us Time Nuts and... Wrist Watches.
On Dec 24, 2010, at 12:00 PM, Michael Poulos wrote: We all enjoy good accurate time keeping. :) What is your favorite watch? My watch (so far) is a Casio WaveCeptor digital watch that gets the WWVB signal and calibrates itself that I bought for $50 at a WalMart - the price of one Chicago parking ticket. Less than half a second off at any time, it is plenty accurate. The one exact drawback is that during night driving, you can't read it when you need to check the time. The lesser drawback is that it is not dressy. A nice dressy radio controlled watch would be that Citizen EcoDrive watch shown on those adverts during football games. If it has glow in the dark hands and 5 minute markers it would be great if expensive. So, let's have it with the best watch for a time nut! (not including Tom van Baak's REAL atomic watch) I would suggest that the best watch for a time-nut is either the long out of production Synchronar, or one of the NIXIE tube watches that are presently being made (by list members, I think). Unlike most quartz watches that utilize a 32768 Hz crystal, the Synchronar operates up around 700 kHz. One of the built in functions is the ability to adjust the divider in steps of 8 seconds per year to fine tune the timing. Mine has consistently been within 4 seconds over the course of a year for the last 20ish years (since the third year I had it, as I spent the first two adjusting it). Sadly, they are rather uncommon and expensive when you find one...so much so that I rarely wear mine. In its stead, a YES (by Wild Seed) is my usual watch. Not terribly accurate (it runs a good 5-10 seconds per month fast), but it does a wonderful job of displaying sunrise, sunset, moon rise, moon set, and moon phase. I've accepted the somewhat reduced accuracy for that capability. Would I be expelled from the club if I admitted my dress watch was a Waltham pocket watch made in 1864 (not a typo), and that I was very happy with its 5-10 second per day accuracy? I should be quite pleased if I work as well when I'm 156 years old. 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] Us Time Nuts and... Wrist Watches.
HI, I have a Citizen Skyhawk A-T. Fantatasic watch and always accurate. If only I could remember how to use all of its functions Have a great Christmas New Year Doug G4DZU -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Michael Poulos Sent: 24 December 2010 17:01 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Us Time Nuts and... Wrist Watches. We all enjoy good accurate time keeping. :) What is your favorite watch? My watch (so far) is a Casio WaveCeptor digital watch that gets the WWVB signal and calibrates itself that I bought for $50 at a WalMart - the price of one Chicago parking ticket. Less than half a second off at any time, it is plenty accurate. The one exact drawback is that during night driving, you can't read it when you need to check the time. The lesser drawback is that it is not dressy. A nice dressy radio controlled watch would be that Citizen EcoDrive watch shown on those adverts during football games. If it has glow in the dark hands and 5 minute markers it would be great if expensive. So, let's have it with the best watch for a time nut! (not including Tom van Baak's REAL atomic watch) ___ 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] Us Time Nuts and... Wrist Watches.
Hi Tom: Seeing the mention of Waltham reminded me that I just posted a video of a Waltham 8-Day clock running at: http://www.prc68.com/I/8day.html in UV light with a piezo contact microphone. Also a 1 sec time exposure. Have Fun, Brooke Clarke http://www.PRC68.com Thomas A Frank wrote: On Dec 24, 2010, at 12:00 PM, Michael Poulos wrote: We all enjoy good accurate time keeping. :) What is your favorite watch? My watch (so far) is a Casio WaveCeptor digital watch that gets the WWVB signal and calibrates itself that I bought for $50 at a WalMart - the price of one Chicago parking ticket. Less than half a second off at any time, it is plenty accurate. The one exact drawback is that during night driving, you can't read it when you need to check the time. The lesser drawback is that it is not dressy. A nice dressy radio controlled watch would be that Citizen EcoDrive watch shown on those adverts during football games. If it has glow in the dark hands and 5 minute markers it would be great if expensive. So, let's have it with the best watch for a time nut! (not including Tom van Baak's REAL atomic watch) I would suggest that the best watch for a time-nut is either the long out of production Synchronar, or one of the NIXIE tube watches that are presently being made (by list members, I think). Unlike most quartz watches that utilize a 32768 Hz crystal, the Synchronar operates up around 700 kHz. One of the built in functions is the ability to adjust the divider in steps of 8 seconds per year to fine tune the timing. Mine has consistently been within 4 seconds over the course of a year for the last 20ish years (since the third year I had it, as I spent the first two adjusting it). Sadly, they are rather uncommon and expensive when you find one...so much so that I rarely wear mine. In its stead, a YES (by Wild Seed) is my usual watch. Not terribly accurate (it runs a good 5-10 seconds per month fast), but it does a wonderful job of displaying sunrise, sunset, moon rise, moon set, and moon phase. I've accepted the somewhat reduced accuracy for that capability. Would I be expelled from the club if I admitted my dress watch was a Waltham pocket watch made in 1864 (not a typo), and that I was very happy with its 5-10 second per day accuracy? I should be quite pleased if I work as well when I'm 156 years old. 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. ___ 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] 10544 TCXO used in H/P 5245L counter
Hi, I have a copy of the retrofit pages that went with the 10544A install for the HP 5245A. There were LOTS of these installed in the 5245 series after the original oscillators started failing. Give me a day or so to hunt it up and I'll share it. It has the schematics of the interface board. Corby Dawson Obama Urges Homeowners to Refinance If you owe under $729k you probably qualify for Obama's Refi Program http://thirdpartyoffers.juno.com/TGL3141/4d150d6425a7e8583f9st06duc ___ 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] Us Time Nuts and... Wrist Watches
Sorry i do not respond much. I have a Synchronar. I am currently wearing a Breitling Aerospace. Ronald ___ 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] Us Time Nuts and... Wrist Watches.
Steve, After you're done chuckling, note that one man's utterly insignificant is another group's passion. A 6 foot person vs. 98 million miles is 6 / (9.8e7 * 5280), or 1.16e-11, a unitless number that's well within our range of expertise and fascination; neither utterly nor insignificant. The number is half a day of a 10811 aging spec; a month of rubidium frequency drift; a cesium in need of big C-field adjustment; one microsecond per day; 0.1 Hz at 10 GHz; the typical short-term peak-to-peak frequency stability of a TBolt, etc. To further appreciate the level at which we work play, if 1e-11 is the ratio of a man standing compared to the sun, then 1e-12 is about 6 inches (like waving your hands) and 1e-13 is about half an inch (like blinking your eyes). /tvb - Original Message - From: Steve Rooke sar10...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, December 24, 2010 12:05 PM Subject: Re: [time-nuts] Us Time Nuts and... Wrist Watches. Orbiting this at a distance of roughly ninety-eight million miles is an utterly insignificant little blue-green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea. - Dougles Adams, The Hitchhiker's Guide to the Galaxy ___ 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] how to open a Trimble mushroom ?
More goodies from storage I have a few 'special' Trimble mushroom GPS's. I'm trying to open one up but can't seem to get very far. I've pulled all the tabs out but still can't pry the case open. They interface between the two sections doesn't look welded or glued. Here a couple picts http://petelancashire.com/gallery/main.php?g2_itemId=21208 The data on these guys was trashed long ago when the company closed up. I could not locate it anywhere. ___ 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] [Fwd: Re: 7/18 connectors]
Original Message Subject: Re: 7/18 connectors From:Lance Collister w...@q.com Date:Fri, December 24, 2010 12:44 To: Don Latham d...@montana.com -- timenuts: apparently the rfsupplier site is compromised don merry christmas to all http://safeweb.norton.com/report/show?url=http:%2F%2Fwww.rfsupplier.com%2Findex.php%3Fcpath=84 Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.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] how to open a Trimble mushroom ?
My Sainted Grandmother had a favorite saying ... ...Don't force it, get a bigger hammer... 73 es HH, Dick, W1KSZ -Original Message- From: Pete Lancashire p...@petelancashire.com Sent: Dec 24, 2010 3:00 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] how to open a Trimble mushroom ? More goodies from storage I have a few 'special' Trimble mushroom GPS's. I'm trying to open one up but can't seem to get very far. I've pulled all the tabs out but still can't pry the case open. They interface between the two sections doesn't look welded or glued. Here a couple picts http://petelancashire.com/gallery/main.php?g2_itemId=21208 The data on these guys was trashed long ago when the company closed up. I could not locate it anywhere. ___ 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.
[time-nuts] Favorite Watch?
GM List, Food For Thought. Not a criticism of any list member! Citizen CTQ57-0953 Chronomaster (calibre A660) Price: $2,699.00 Nice Watch: $100 PLUS Christmas Dinner at the Homeless Mission feeding 966 @ $2.69 each Totals $2,699.00 Decisions Decisions Decisions Merry Christmas, Perrier ___ 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] Merry 55555
In case you didn't notice -- this year Christmas falls on the beautiful looking MJD 5. Some of the newcomers to the group may not be familiar with MJD (Modified Julian Date). It's used extensively in the timing community (see http://tycho.usno.navy.mil/mjd.html). For those of you with vintage Trak 6460 time scale generators (see http://www.leapsecond.com/pages/trak6460) a special treat will occur at 13:20:00 UTC* on Christmas day. The time at the tone will be 5.5. Once in a lifetime. That's 620AM local time at NIST and 820AM for USNO (send us a video/photo from the time scale room if you can). /tvb * Picky astronomers in the group may want to adjust their MJD photo by 135 milliseconds to account for today's DUT1. (see http://maia.usno.navy.mil/ser7/ser7.dat) ___ 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] Merry 55555
Lady Heather will display the date (but not fractional time) in MJD with /DM ___ 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] Merry 55555
Lady Heather will display the date (but not fractional time) in MJD with /DM Anyone with a browser can try this one... http://www.leapsecond.com/java/nixie.htm Or the mobile phone version: http://leapsecond.com/m/mjd.htm /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.
[time-nuts] Merry 55555
Heather now has an option to display MJD.fraction ... but, alas, release won't be for a while... ___ 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] Merry 55555
On Dec 24, 2010, at 8:41 PM, Tom Van Baak t...@leapsecond.com wrote: Lady Heather will display the date (but not fractional time) in MJD with /DM Anyone with a browser can try this one... http://www.leapsecond.com/java/nixie.htm Or the mobile phone version: http://leapsecond.com/m/mjd.htm /tvb And most of the pages on http://febo.com have the MJD of the page load time at the bottom of the menu bar on the left side of the page. John ___ 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] Merry 55555
For those of you with vintage Trak 6460 time scale generators (see http:// www.leapsecond.com/pages/trak6460) a special treat will occur at 13:20:00 UTC* on Christmas day. The time at the tone will be 5.5. Once in a lifetime. Neat find. Thanks for sharing. But you can get more. How many 5s do you want? 13:20 is 13*3600 + 20*60 = 48000 seconds 48000 / 86400 is 5/9 5/9 is 0.5... (repeating fraction) Does the Trak 6460 do the right with leap seconds? What is the right thing? -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Us Time Nuts and... Wrist Watches.
Cook Mike wrote: Le 24/12/2010 18:00, Michael Poulos a écrit : We all enjoy good accurate time keeping. :) What is your favorite watch? My watch (so far) is a Casio WaveCeptor digital watch that gets the WWVB signal and calibrates itself Not sure I have a favorite. I can't find any that do what exactly what I want, but I did go somewhat gaga the other day and got a Citizen Chronomaster (calibre A660). Spec'd to +- 5 secs a year without recourse to GPS/radio references. I always have three or four running at any one time in a desk drawer. And a few , well quite a lot really, in reserve. I guess it depends on the situation you inject yourself into. Except for the two limitations I love that watch. In the case of ANY watch I will want WWVB accuracy like my present watch. Where I work the time clocks are with hundreths and self-calibrate with an atomic clock in Kentucky. I provide a countdown like NASA at the end of a workday. 5.4.3.2.1.Liftoff aka Double-O! Time to go! ___ 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] 10811 changing frequency when load impedance changes ?
Mark Spencer wrote: Seasons greetings. I was pleasantly surprised to find that a new to me HP 5328A had an 10811 in it.(I was expecting the older OCXO..) After leaving it running for a week I adjusted the frequency and while doing so I noticed that the out put frequency changes by a third of a hz or so if I add or remove a 50 ohm load. I'm measuring the frequency at the timebase output connection of the 5328A. Is this to be expected ? Many thanks Mark Spencer ___ 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, that seems to be a couple of orders of magnitude larger than the specs for the 10811A would lead one to believe. Maybe there's a problem with the output buffer amp in the 10811A? Bruce ___ 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] 10811 changing frequency when load impedance changes ?
Thanks.. I'll likely do some more testing with the 50 ohm load in place and see how stable this unit is before investing more time in this. - Original Message From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Fri, December 24, 2010 10:05:51 PM Subject: Re: [time-nuts] 10811 changing frequency when load impedance changes ? Mark Spencer wrote: Seasons greetings. I was pleasantly surprised to find that a new to me HP 5328A had an 10811 in it. (I was expecting the older OCXO..) After leaving it running for a week I adjusted the frequency and while doing so I noticed that the out put frequency changes by a third of a hz or so if I add or remove a 50 ohm load. I'm measuring the frequency at the timebase output connection of the 5328A. Is this to be expected ? Many thanks Mark Spencer ___ 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, that seems to be a couple of orders of magnitude larger than the specs for the 10811A would lead one to believe. Maybe there's a problem with the output buffer amp in the 10811A? Bruce ___ 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] 10811 changing frequency when load impedance changes ?
Bruce Griffiths wrote: Mark Spencer wrote: Seasons greetings. I was pleasantly surprised to find that a new to me HP 5328A had an 10811 in it.(I was expecting the older OCXO..) After leaving it running for a week I adjusted the frequency and while doing so I noticed that the out put frequency changes by a third of a hz or so if I add or remove a 50 ohm load. I'm measuring the frequency at the timebase output connection of the 5328A. Is this to be expected ? Many thanks Mark Spencer ___ 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, that seems to be a couple of orders of magnitude larger than the specs for the 10811A would lead one to believe. Maybe there's a problem with the output buffer amp in the 10811A? Bruce The spec for the 10811A actually states that the shift is 5E-10 (5mHz) for a 10% (5 ohm) change in a 50 ohm load and a for a 25% change (250 ohm) in a 1K load A naive extrapolation would suggest a shift of around 20mHz for a 50 ohm to 1K load change your frequency shift (333mHz) is about 15x this. However the 10811A is notorious for injection locking if the reverse isolation of the external circuitry is inadequate. Bruce ___ 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] 10811 changing frequency when load impedance changes ?
Thanks. I'll have to do some more experimenting, in one case I was feeding the time base output of the 5328A into a 1 meg scope input, and using the scope to compare the frequency to my thunderbolt, in the other case I was feeding the time base output into my 5370B set to 50 ohms and using the time interval function of the counter to compare the frquency to the thunderbolt. I couldn't figure out why I was seeing different frequency results on the scope and the 5370B untill i put a 50 ohm terminator in paralel with the scope input then things made sense. I'll try altering the load impedance along the lines shown in the specs and see what the results are. I also noticed that the wave form on the scope was very dirty (ie the peaks were very hard to see), and it cleaned up to a more or less sine wave when I added the 50 ohm terminator, perhaps the 5328A is not properly terminating the 10811. The 10811 seems stable so long as the load impedance does not change so it may still be useable. I'm also wondering if I was getting some injection locking when I was comparing the frequency using the scope, the results seemed very very good, almost to good and the cable between the scope and the 5328A was not seeing 50 ohms at either end which probably wasn't helping either. My elcheapo pre made RG58 patch cords of un known shielding probably aren't helping either. I'll have to make up some proper patch cords using some double shieled cable I've stashed away. - Original Message From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Fri, December 24, 2010 10:42:46 PM Subject: Re: [time-nuts] 10811 changing frequency when load impedance changes ? Bruce Griffiths wrote: Mark Spencer wrote: Seasons greetings. I was pleasantly surprised to find that a new to me HP 5328A had an 10811 in it. (I was expecting the older OCXO..) After leaving it running for a week I adjusted the frequency and while doing so I noticed that the out put frequency changes by a third of a hz or so if I add or remove a 50 ohm load. I'm measuring the frequency at the timebase output connection of the 5328A. Is this to be expected ? Many thanks Mark Spencer ___ 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, that seems to be a couple of orders of magnitude larger than the specs for the 10811A would lead one to believe. Maybe there's a problem with the output buffer amp in the 10811A? Bruce The spec for the 10811A actually states that the shift is 5E-10 (5mHz) for a 10% (5 ohm) change in a 50 ohm load and a for a 25% change (250 ohm) in a 1K load A naive extrapolation would suggest a shift of around 20mHz for a 50 ohm to 1K load change your frequency shift (333mHz) is about 15x this. However the 10811A is notorious for injection locking if the reverse isolation of the external circuitry is inadequate. Bruce ___ 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.
