Re: [time-nuts] Looking for HP5359A manual
In message [EMAIL PROTECTED], Magnus Danielson wri tes: http://rubidium.dyndns.org/~magnus/electronics/HP5359A-draft.pdf In addition to manuals, we should start to preserve the (EP)ROM contents of these instruments, early generation EPROMS are reaching end of life in a lot of systems. I already had to replace the 2732's in my HP8568B some time ago. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP 8924C's on ebay
In message [EMAIL PROTECTED], John Ackermann N8UR writes: One thing to be very carefull about with these, is that they can function as bona-fide base-stations if you hand them an antenna. I don't need to draw you a picture. The ad claims it's a derivative of the HP 8920B, and it looks like it. Several of us here in Dayton have 8920A or B units, and they are a very nice general purpose service monitor. I belive there is a difference in the RF frontends, but most of the difference is a matter of software. It would be interesting if somebody tried to convert a cellphone unit to 8920A to see if it was possible. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] EU funds Galileo
Javier wrote: As a hard working ES tax payer, I think that the funds are right there :) I prefer not to have exlusive dependence on DoD... You are dreaming if you think DOD won't deactivate Galileo if they need to. -Chuck Harris ___ 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] EU funds Galileo
As a hard working ES tax payer, I think that the funds are right there :) I prefer not to have exlusive dependence on DoD... Javier Rob Kimberley escribió: As a hard working UK tax payer, I'd rather my money was spent elsewhere - I'm more than happy with GPS! Rob K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Magnus Danielson Sent: 30 November 2007 09:33 To: time-nuts@febo.com Subject: [time-nuts] EU funds Galileo Hi! Just heard this and here is some details: http://investing.reuters.co.uk/news/articleinvesting.aspx?type=allBreakingNe wsstoryID=2007-11-29T235046Z_01_L29893386_RTRIDST_0_EU-GALILEO-UPDATE-3.XML Looks like it just became likelier that we will have those Galileo birds. Cheers, Magnus ___ 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 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] EU funds Galileo
As a hard working US tax payer, I'm happy that someone is paying for an excuse to buy another disciplined oscillator one day... lots more plots, quibbling about differences in the 10 decimal point, etc. jeff Javier wrote: As a hard working ES tax payer, I think that the funds are right there :) I prefer not to have exlusive dependence on DoD... Javier Rob Kimberley escribió: As a hard working UK tax payer, I'd rather my money was spent elsewhere - I'm more than happy with GPS! Rob K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Magnus Danielson Sent: 30 November 2007 09:33 To: time-nuts@febo.com Subject: [time-nuts] EU funds Galileo Hi! Just heard this and here is some details: http://investing.reuters.co.uk/news/articleinvesting.aspx?type=allBreakingNe wsstoryID=2007-11-29T235046Z_01_L29893386_RTRIDST_0_EU-GALILEO-UPDATE-3.XML Looks like it just became likelier that we will have those Galileo birds. Cheers, Magnus ___ 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 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] Of rubidium life and piggy-bank anemia....
Magne Mæhre wrote: Ulrich Bangert wrote: Use the three-cornered-hat method to rank your clocks! The literature seems to say that you need to do the measurements simultanously to get good results from the TCH method. I guess most of us have only one TIC at home, so I wonder how the results will be affected by taking them one at a time ? --Magne ___ 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. So use a gate array to implement a multichannel time stamp device. 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] HP 8924C's on ebay
There is a lot of commonality between the various 892x test sets. When I get some time, I'll ping my buddy that was sales manager for the line at (HP)Agilent Spokane division. I know we've talked some about it in the past, but don't remember enough details to make any binding comments! Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Javier Sent: Friday, November 30, 2007 4:37 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 8924C's on ebay That would be nice... to bring a more useful life to my 8922Ss, but I've not been yet able to gather too much information about them. Regards, Javier, EA1CRB Poul-Henning Kamp escribió: It would be interesting if somebody tried to convert a cellphone unit to 8920A to see if it was possible. ___ 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] Looking for HP5359A manual
From: Poul-Henning Kamp [EMAIL PROTECTED] Subject: Re: [time-nuts] Looking for HP5359A manual Date: Fri, 30 Nov 2007 20:34:20 + Message-ID: [EMAIL PROTECTED] In message [EMAIL PROTECTED], Magnus Danielson wri tes: http://rubidium.dyndns.org/~magnus/electronics/HP5359A-draft.pdf In addition to manuals, we should start to preserve the (EP)ROM contents of these instruments, early generation EPROMS are reaching end of life in a lot of systems. I already had to replace the 2732's in my HP8568B some time ago. I agree. I have been thinking the same for some time now. We may have all the spare components for normal logic and most analogue, but programmable stuff is fairly easy to restore if you only have the images. EPROMs is not always as stable as the surrounding logic. There will always be unobtainables thought. But for EPROMs it feels so stupid since it is so easy to fix. Cheers, Magnus ___ 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] Looking for HP5359A manual
Bruce Lane has an EPROM repository, and I have one too: http://www.ko4bb.com/cgi-bin/manuals.pl Go to 5) ROM Images It could use more submissions, there are MANY more manuals than ROM images. I will put the HP 5370A ROMs there soon. You can upload to your heart content :-) Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Poul-Henning Kamp Sent: Friday, November 30, 2007 2:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Looking for HP5359A manual In message [EMAIL PROTECTED], Magnus Danielson wri tes: http://rubidium.dyndns.org/~magnus/electronics/HP5359A-draft.pdf In addition to manuals, we should start to preserve the (EP)ROM contents of these instruments, early generation EPROMS are reaching end of life in a lot of systems. I already had to replace the 2732's in my HP8568B some time ago. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] More details on IEEE Spectrum clock competition
Philip, I think this sounds pretty reasonable, here's my 2-cents worth. I think calibration should be part of delivering the clock. You can imagine a designer developing elaborate models for the timebase and you don't want to stifle creativity here. I think calibration is part of the delivered clock and not done by the judges. The clock should be settable by a layperson, but I think you should let people go wild calibrating the clock. The two big enemies the designer fights will likely be environmental and aging. I think you've covered a good environmental specification, but aging should be incorporated into the contest. For example, a temp compensated xtal oscillator my be calibrated to well less than 0.1 ppm and look really fantastic for a few days, but the crystal might age 2-3 ppm over the first year of operation. I imagine running the contest over a few months. At some submission date the clocks are collected at your office, set to the current time, and left to run for a few months (or however much time you have). At the end of 3-months all of the clocks are measured and a winner is picked. Maybe you can publish intermediate results for dramatic effect. Tom Van Baak has a nice story on his website about how he got interested in precision timing, http://www.leapsecond.com/. He wanted a clock that would be accurate to better than 1-second over a year so that he could appreciate and adjust the clock during a leapsecond. I don't know how, but I think that it might be possible to build a clock for this contest that meets that criteria. If so, I think the entries need a feature for measuring accuracy more precisely. I suggest requiring that the entires have a BNC connector that outputs a TTL level pulse once per second, the rising edge of the signal marks the beginning of a second (this is usually just called a PPS signal). The accuracy of the clock can be done visually to 1s resolution, finer measurement can be done with comparison against PPS from a GPS receiver. jeff [EMAIL PROTECTED] wrote: A number of people have asked for more details on IEEE Spectrum's digital clock competition, so we've formulated the following list. Throughout, the idea is to build a clock that an ordinary person would want to use, in an ordinary home. That's why we want a display that can be read with ease from across a room. Operating environment and other specs for IEEE Spectrum's Digital Clock Competition: --between 10 and 50 degrees C --between 0 and 100 percent relative humidity --with seven-segment LED display, no smaller than 0.56 inches --no limit on power --calibration should be within the grasp of a layman --lacking an oscilloscope here in the office, we will check accuracy against a WWVB or GPS signal (other suggestions--even volunteers to help in the judging--are welcome) --parts to be available from any of the big distributors (RadioShack, Mouser, DigiKey, Maplin, etc.) or, in sufficient quantities (100s, say) from a surplus store Philip E. Ross Senior editor IEEE Spectrum Magazine 212 419 7562 http://www.spectrum.ieee.org ___ 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] OT: Prologix GPIB and HP3478A...It's Alive!!!
Hi Abdul and Group, I'm beginning to feel like I am a manic depressive.. I keep going from the lowest lows to the highest highs... Well things are pretty high right now. Here's how I got there: First, I took my Prologix adapter apart to have a look see under the microscope. ... Abdul probably won't speak to me ever again after I describe what I did... But I'm an engineer. I can't help myself. It's in my genes. In looking the board over over, I discovered that one of the data pins on the GPIB connector was bent out of line where it passed into the board. A classic sign of solder blocked hole that prevented the pin from passing through the board and getting soldered. This is it, I thought. The pin even wiggled funny. So I needed to take the thumb screws out and get to the bottom side of the board and repair the joint. Well, Abdul obviously didn't want me to do that, as he epoxied a nut onto each screw to keep it retained... a little over kill there Abdul. I like that! If you ever run into something like this, your soldering iron can be your friend... that and a little patience. I heated the nut until it was smoking hot, and screwed the thumb screw right out... Sounds much easier than it really was... That's where the patience part comes in. After I got the board out, I discovered something odd, the pin that was bent up stuck through the board enough so that Abdul had clipped off the excess after soldering the board. Hmmm? Well, I sucked out the joint, straightened the pin, resoldered it, and tested the silly thing anyway... Hope springs eternal, as they say. It worked! My 7854 was up and running, and being controlled, and all of that really neat stuff, and t h e n, i t w a si g n o r i n g e v e r y t h i n gt h a t I s e n t t o i t... Damn! We are hitting one of those lows again. So, I plugged my trusty HP85B into the scope, and tried to control the scope, and ... it didn't work either! It's getting a little hard for me to escape the conclusion that there is something wrong with my scope, and it's an intermittent too... I love problems that are intermittent. They allow me to waste inordinate amounts of time, speak new swear words I don't usually use.. All that kind of stuff that makes it feel good to be a man. The first place I decided to look was the 7854's GPIB connector, since the problem seemed to have something to do with exercising the connector. When I got the connector where I could see it, I noticed that Tektronix committed a major fooboo with this connector. They needed it to stick out from the board a little bit further than the solder tails would allow, so they checked to see that nobody was looking, and just soldered the pads with the solder tails somewhat below the surface... Not a great recipe for success... Or as someone once said it was one of those things that puts the suck in success. I sucked out all of the joints, and made triple damn sure that the new joints were getting properly wetted with solder, and made a little fillet on the other side of the board, and tried things out...and... It works!!! Remember what I said about manic-depressive? Well this is one of those high times. It seems to be ok. Now we just have to let it run for a while. With any luck at all, it will work long enough that I will completely forget I ever went through this series of events. Hopefully I can keep this mess running until I get my Tektronix 547 transformer core experiments finished, my report written, some pretty pictures made, and a couple of transformers rewound We'll see. Thanks Abdul for providing me with such good entertainment! -Chuck Harris Prologix wrote: Hi Chuck, Please make sure the adapter is properly seated. Also, see if using a GPIB cable makes a difference. If you are still having trouble I am happy to send you a replacement unit. Regards, Abdul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris This is beginning to look more and more like I have a bad Prologix adapter. Oh Abdul?? -Chuck Harris ___ 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] Of rubidium life and piggy-bank anemia....
Ulrich Bangert wrote: Use the three-cornered-hat method to rank your clocks! The literature seems to say that you need to do the measurements simultanously to get good results from the TCH method. I guess most of us have only one TIC at home, so I wonder how the results will be affected by taking them one at a time ? --Magne ___ 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] Of rubidium life and piggy-bank anemia....
Maybe quasi-simultaneously is adequate, using a switch to sample the 3 pairs in rotation. The HP59307A can be used for that under GPIB control. I would think the main reason for doing it simultaneously is so that whatever source of error exists (temperature, vibration, etc) will affect the 3 oscillators the same way. The switch won't help with vibration, but it will help with temperature and other slow changing variables, such as time of day. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Friday, November 30, 2007 11:00 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Of rubidium life and piggy-bank anemia Magne Mæhre wrote: Ulrich Bangert wrote: Use the three-cornered-hat method to rank your clocks! The literature seems to say that you need to do the measurements simultanously to get good results from the TCH method. I guess most of us have only one TIC at home, so I wonder how the results will be affected by taking them one at a time ? --Magne ___ 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. So use a gate array to implement a multichannel time stamp device. 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.
[time-nuts] EU funds Galileo
Hi! Just heard this and here is some details: http://investing.reuters.co.uk/news/articleinvesting.aspx?type=allBreakingNewsstoryID=2007-11-29T235046Z_01_L29893386_RTRIDST_0_EU-GALILEO-UPDATE-3.XML Looks like it just became likelier that we will have those Galileo birds. Cheers, Magnus ___ 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] Looking for HP5359A manual
From: Ulrich Bangert [EMAIL PROTECTED] Subject: [time-nuts] Looking for HP5359A manual Date: Fri, 30 Nov 2007 07:44:22 +0100 Message-ID: [EMAIL PROTECTED] Gentlemen, Ulrich, I just managed to buy an HP5359A time synthesizer on ebay. Has anyone of you a manual for that device in electronic form available that he can share with me? My search at the usual places (Agilent, Didier's pages, Boat anchor manuals) have not led to any result yet. Scott have been working hard on scanning it: http://rubidium.dyndns.org/~magnus/electronics/HP5359A-draft.pdf We are going to send it to Agilent, so you should not have had this problem. There are a few rescanns we are in need for, but maybe I will do them. Cheers, Magnus ___ 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] Looking for HP5359A manual
In message [EMAIL PROTECTED], Ulrich Bangert writes: Gentlemen, I just managed to buy an HP5359A time synthesizer on ebay. Has anyone of you a manual for that device in electronic form available that he can share with me? My search at the usual places (Agilent, Didier's pages, Boat anchor manuals) have not led to any result yet. If all els fails I have a terrible and mangled photocopy, from somebody who obviously had the same problem... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] HP 8924C's on ebay
That would be nice... to bring a more useful life to my 8922Ss, but I've not been yet able to gather too much information about them. Regards, Javier, EA1CRB Poul-Henning Kamp escribió: It would be interesting if somebody tried to convert a cellphone unit to 8920A to see if it was possible. ___ 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] Chronometer contest sponsored by IEEE Spectrum
In my experience watches come from the factory adjusted to gain about 5 seconds a month. The ones I have owned over the years seemed to be fairly stable in that. I have always wished there was a way for someone who is not a watch maker to open up such a watch and turn the trimmer capacitor, there has to be one, to set it right on. Then it would be much easier to tell how the crystal is aging. Regards. Max. K 4 O D S. Email: [EMAIL PROTECTED] Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, [EMAIL PROTECTED] - Original Message - From: Hal Murray [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, November 30, 2007 12:04 PM Subject: Re: [time-nuts] Chronometer contest sponsored by IEEE Spectrum With a little work you might be able to precisely calculate the maxima of the parabola and precisely set the frequency independent of temp and aging. Ha! What's the aging like for watch crystals? What type of cut to watch crystals use? Are there any generalizations about aging? I don't remember any tales of watches changing from good to bad after a couple of years. Surely there are enough geeks who keep an eye on the performance of their watches that somebody would have noticed. Or maybe they setup the initial calibration so it gets better as it ages for the first year... -- 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. -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.16.12/1162 - Release Date: 11/30/2007 9:26 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] Prologix 3478A
Chuck et al I connected my Prologx 3.12 to the 3478A, ran 7470.exe and the 3478A's TLK icon came on straight away, with the RMT icon coming on a few seconds later. Repeated it for good measure with the same result. 7470.exe reported an error saying that it was talking to unsupported device '0.43700E.00' or something similar so the Prologix was getting some data from the 3478A. Looks like the Prologix adapter is OK. regards Grant Hi Grant, It is an axiom of the GPIB world that if a device gets addressed, it will sit up at attention and wait for commands. The 3478A shows that it is waiting by lighting up a couple of annunciators on the bottom row of the LCD that you never see otherwise. All you have to do to test whether the Prologix can work with your 3478A is address it. So, if you change the 3478A's address to match your HP analyzer's, and then run John's program, you should see these annunciators light up. The 3478A won't do anything useful that way, but it will prove that it hears the Prologix, something mine can't do. -Chuck Harris Grant Hodgson wrote: Chuck I've got a Prologix 3.12 and a 3478A; I've only ever used the former with John Ms. s/w and HP analysers. I'll happily test it with the 3478A if you give me some simple instructions for a simple XP user. regards Grant ___ 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] More details on IEEE Spectrum clock competition
A number of people have asked for more details on IEEE Spectrum's digital clock competition, so we've formulated the following list. Throughout, the idea is to build a clock that an ordinary person would want to use, in an ordinary home. That's why we want a display that can be read with ease from across a room. Operating environment and other specs for IEEE Spectrum's Digital Clock Competition: --between 10 and 50 degrees C --between 0 and 100 percent relative humidity --with seven-segment LED display, no smaller than 0.56 inches --no limit on power --calibration should be within the grasp of a layman --lacking an oscilloscope here in the office, we will check accuracy against a WWVB or GPS signal (other suggestions--even volunteers to help in the judging--are welcome) --parts to be available from any of the big distributors (RadioShack, Mouser, DigiKey, Maplin, etc.) or, in sufficient quantities (100s, say) from a surplus store Philip E. Ross Senior editor IEEE Spectrum Magazine 212 419 7562 http://www.spectrum.ieee.org ___ 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] Chronometer contest sponsored by IEEE Spectrum
With a little work you might be able to precisely calculate the maxima of the parabola and precisely set the frequency independent of temp and aging. Ha! What's the aging like for watch crystals? What type of cut to watch crystals use? Are there any generalizations about aging? I don't remember any tales of watches changing from good to bad after a couple of years. Surely there are enough geeks who keep an eye on the performance of their watches that somebody would have noticed. Or maybe they setup the initial calibration so it gets better as it ages for the first year... -- 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] More details on IEEE Spectrum clock competition
over what durration will the clocks accuracy be measured? (seconds, minutes, hours, days, months, (years)? accuracy to be measured before disciplining with GPS, WWVB. calibration should be within the grasp of a layman Could some clarification be given here? I'm thinking that the clock could be self calibrating say automatically or by user button press but this presents a chicken and egg problem in light of the quotes above. Many of the designs I've seen previously keep an internal memory that tracks and allows compensation for parameters such as drift, aging rate, and temp coefficient updating these variables when connected to a known better reference. in this way the accuracy improves with time. while a layman could calibrate this type of clock quite easily (or would not need to as the clock would calibrate itself) any calibration pretty much by definition is a comparison to a better reference (wwvb, gps, hydrogen maser, rubidium, cesium beam, etc.) so how do you expect calibration to be accomplished without, use of a better standard? would such a device be allowed to remember and store calibration factors during its initial calibration or would this fall into the category of discipline? I would say that the initial determination and programming of calibration factors (which will vary among devices) is calibration, after which it becomes discipline as the routine continues to run. What's your interpretation? Eric On Nov 30, 2007 6:43 AM, [EMAIL PROTECTED] wrote: A number of people have asked for more details on IEEE Spectrum's digital clock competition, so we've formulated the following list. Throughout, the idea is to build a clock that an ordinary person would want to use, in an ordinary home. That's why we want a display that can be read with ease from across a room. Operating environment and other specs for IEEE Spectrum's Digital Clock Competition: --between 10 and 50 degrees C --between 0 and 100 percent relative humidity --with seven-segment LED display, no smaller than 0.56 inches --no limit on power --calibration should be within the grasp of a layman --lacking an oscilloscope here in the office, we will check accuracy against a WWVB or GPS signal (other suggestions--even volunteers to help in the judging--are welcome) --parts to be available from any of the big distributors (RadioShack, Mouser, DigiKey, Maplin, etc.) or, in sufficient quantities (100s, say) from a surplus store Philip E. Ross Senior editor IEEE Spectrum Magazine 212 419 7562 http://www.spectrum.ieee.org ___ 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] PM6681 Manual
For those interested, I have uploaded the service manual for the Fluke PM-6681/Pendulum CNT-81 to the k04bb website. Too bad you can't calibrate these beasts yourself, special software is needed. Regards, Stijn Nestra ___ 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] Of rubidium life and piggy-bank anemia....
So use a gate array to implement a multichannel time stamp device. FPGA development boards are readily available and some people consider the price within range. Would digital inputs be good enough? Suppose you feed several 10 MHz signals into a FPGA and program it so each input signal drives a counter. Ignoring implementation details like synchronization, is that good enough to be interesting? I'm assuming you have a PC that grabs all the counters every N ticks/seconds/hours/whatever. Note that there is another clock involved. It's the one driving the FPGA or PC. How much would it help if there was an A/D on each input channel and the FPGA could capture a dozen samples on each signal around the time that it latches a copy the counters? -- 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] Chronometer contest sponsored by IEEE Spectrum
Max Robinson wrote: In my experience watches come from the factory adjusted to gain about 5 seconds a month. The ones I have owned over the years seemed to be fairly stable in that. I have always wished there was a way for someone who is not a watch maker to open up such a watch and turn the trimmer capacitor, there has to be one, to set it right on. Then it would be much easier to tell how the crystal is aging. Regards. Max. K 4 O D S. Not true, its no more difficult to measure the aging if the frequency is slightly high or initially spot on. 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] Of rubidium life and piggy-bank anemia....
Hal Murray wrote: So use a gate array to implement a multichannel time stamp device. FPGA development boards are readily available and some people consider the price within range. Would digital inputs be good enough? Suppose you feed several 10 MHz signals into a FPGA and program it so each input signal drives a counter. Ignoring implementation details like synchronization, is that good enough to be interesting? I'm assuming you have a PC that grabs all the counters every N ticks/seconds/hours/whatever. Note that there is another clock involved. It's the one driving the FPGA or PC. How much would it help if there was an A/D on each input channel and the FPGA could capture a dozen samples on each signal around the time that it latches a copy the counters? Hal Use a mixer for each input frequency source together with an common offset source not an FPGA if you really want high resolution. However you will need to use low phase noise distribution amplifiers with crosstalk and reverse isolation better than 120dB. Feeding several different clocks into the same FPGA is somewhat counterproductive as they will all interact to produce rather high jitter. Using an A/D can be somewhat futile unless it has noise and resolution of an ideal 24bit (or more) ADC. If you want to use an ADC then its best to use a technique employed by the 5120. However a well designed dual/multiple mixer system will outperform this instrument. A well designed zero crossing detector can easily exceed the resolution of virtually any available ADC. 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.
