Re: [time-nuts] WWVB Measurements
> Pretty much before all these switching power supplies and cpfls etc. Does anybody know what frequency CPFLs are using today? I remember that we had some (non-compact) ceiling fluorescents at work with "electronic" ballasts that were in the 50-60 KHz range. That was 5 years ago. I wonder if all that junk will eventually migrate to well above 60 KHz to take advantage of the smaller magnetics and open up WWVB again. -- 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] WWVB Measurements
Chris, The beginning of the second, and the starting of the 10ms samples is detected with a tight asm loop. (Soon to be replaced with a high priority interrupt line) Once detected the sample portion of the state machine runs at 10ms. And terminates at the 990ms (99th sample), I process the received bit and go back to the wait_for_start state. My thoughts are that the second starts are where the accuracy needs to be. I'm starting to get an idea of its pps accuracy (or do I really mean "stability" ?). I ran a quick test having the mcu measure what it thinks the length of a second is using the internal timers (auto reloading). I need to do more research on how to properly characterize it. -lenny On 3/27/11, Chris Albertson wrote: > On Sat, Mar 26, 2011 at 4:31 PM, Lenny Story wrote: >> Chris, >> My design isn't really that sophisticated hardware wise. Its an 8051 >> variant, and the CMMR-60P which can be obtained from Sparkfun.com. I do >> wind my own antenna, which is just a quad, made from PVC and a metal >> electrical box. The circuit sits in the center. It's done with a 2.5 >> inch >> square, 4 layer board from pcbexpress.com. >> The software samples the bit signal coming from the CMMR, every 10 ms >> (essentially), and uses a 100 bit array to qualify it using a weighting >> algorithm. The start of the bit train, and with it the sequence of 10ms >> samples, is essentially polled very fast to catch the beginning of the >> second as soon as possible. > > So you are looking at the output bit of the CMMR-60 once every 10 ms? > Then I'm guessing you will not get uS level precision. > The software I'm writing runs under Linux and reads the bit every 1 > msBut I was wondering if I should do better and try for uS level > timing > > I think your success with receivig WWVB must be the antenna. Could > you say more about it. > = > Chris Albertson > Redondo Beach, California > -- Sent from my mobile device ___ 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] WWVB Measurements
Indeed those posts are from 2003 the car plant could be closed these days. But I do indeed receive wwvb I think pretty well with a loop and preamp. Its always been a challenge on the east coast and even Michigan when I first started tinkering way to many years ago. Pretty much before all these switching power supplies and cpfls etc. Regards On Sun, Mar 27, 2011 at 9:03 PM, Hal Murray wrote: > > bro...@pacific.net said: > > John Mills (THE NTP guru) has written a number of papers on and built > > examples of a matched filter type receiver for the HF station WWV, but > the > > ideas would also be applicable to a WWVB receiver. The performance he > gets > > from WWV would knock your socks off so I expect a WWVB version would be > > even better. In addition there are some things that could be done to > > improve it. > > I assume you mean Dave Mills rather than John. > http://www.ece.udel.edu/~mills/index.html > > He's basically given up on WWVB. In his area, there is too much crap > around > 60 KHz, mostly from switching power supplies. > http://lists.ntp.org/pipermail/questions/2003-August/000106.html > http://lists.ntp.org/pipermail/questions/2006-April/009958.html > > > > -- > 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. > ___ 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] WWVB Measurements
bro...@pacific.net said: > John Mills (THE NTP guru) has written a number of papers on and built > examples of a matched filter type receiver for the HF station WWV, but the > ideas would also be applicable to a WWVB receiver. The performance he gets > from WWV would knock your socks off so I expect a WWVB version would be > even better. In addition there are some things that could be done to > improve it. I assume you mean Dave Mills rather than John. http://www.ece.udel.edu/~mills/index.html He's basically given up on WWVB. In his area, there is too much crap around 60 KHz, mostly from switching power supplies. http://lists.ntp.org/pipermail/questions/2003-August/000106.html http://lists.ntp.org/pipermail/questions/2006-April/009958.html -- 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] HP-5335A Fail Code
On 03/27/2011 11:56 PM, Gordon Batey wrote: Thanks for your interest Magnus. I am entering the diagnostic start codes as you mentioned at the bottom of your email but all I get are a series of seemingly random numbers. I do have a second similar counter to refer to, so that helps. The manual seems to indicate that the problem may be in the MRC or A4U7. Not I need to see how to see which one. Hope for the A4U7, as it is much more likely to be replaceable. Also consider that the MRC (A4U6) is sitting in a IC holder, so oxide on any of the data bus pins for instance would help to distort the picture. Signature analysis is what I would attempt here. Not many have those toys these days. I recently got one from a clean-up, and realized what it was. :) 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] Upgrading TS2100 from TCXO to OCXO
If anybody has a TS2100 that came from the factory with an OCXO, can you telnet into the unit and run the following command? root eng ee info This appears to be some sort of factory-configured personality of the board. My TS2100-GPS unit with a TCXO has an info value of 0024. A TS2100-IRIG unit (no GPS) with a TCXO has a value of . I'm curious whether any of those bits correspond to the oscillator type or if all that needs to be changed is the gain. Thanks, -Bob ___ 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-5335A Fail Code
Thanks for your interest Magnus. I am entering the diagnostic start codes as you mentioned at the bottom of your email but all I get are a series of seemingly random numbers. I do have a second similar counter to refer to, so that helps. The manual seems to indicate that the problem may be in the MRC or A4U7. Not I need to see how to see which one. Thanks again, 73 Gordon WA4FJC == Date: Sun, 27 Mar 2011 13:57:16 +0200 From: Magnus Danielson To: time-nuts@febo.com Subject: Re: [time-nuts] HP-5335A Fail Code Message-ID: <4d8f261c.7090...@rubidium.dyndns.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Gordon, On 03/15/2011 12:52 AM, Gordon Batey wrote: > Greetings to the Time Nuts List > > I have a HP-5335A counter that has worked well for me for several years. > Now when turning it on I get a Fail 4.6 readout on the display. > > The manual indicates that a 4.6 fail code indicates > > "MRD Counter problem in Reg-E or T" > > I found in the manual that you should run diagnostic 9 and 10 for this > condition. > > Test 9 returns many changing 4 decimal place numbers 10.abcd , 12.defg , > 14.xqrg etc. > > Test 10 returns many changing one decimal place numbers ie 15.9 , 16.1 , > 16.4 , 15.8 etc > > Any thoughts or recommendations on pining down the cause and solution for > this > condition would be appreciated. I have been looking at this email since it hit my inbox. I can't quite match the readings you have made with what the Diagnostic 9 (8-284) and 10 (8-286) does, it rather matches the manual tests 9 (4.70) and 10 (4.74). I just ran Diag 9 and Diag 10 on my 5335A and they didn't say anything else than "PASS". Unless you found it you need to hit: To enter diag mode SCALE SMOOTH 9 9 ENTER To do diag 9 SCALE 9 ENTER and to do diag 10 SCALE 1 0 ENTER 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] WWVB Measurements
Hi Lenny: The CMMR-60P is an analog circuit designed for very low power consumption. That translates to very high impedance circuitry. I've been playing with them for years. When I first tried them the reception was not 24/7, but rather mainly centered around local midnight, but the current batch gets good reception inside 24/7 with the stock small loop-stick antenna. Therefore I have stopped working on a larger ferrite loop antenna. Note they have app notes describing the ideal impedance for an antenna to optimize the performance with the CMMR-60P. One of the limits on the antenna is it's temperature stability. That was one of the areas I started to look into for the larger loop. http://www.prc68.com/I/Loop.shtml John Mills (THE NTP guru) has written a number of papers on and built examples of a matched filter type receiver for the HF station WWV, but the ideas would also be applicable to a WWVB receiver. The performance he gets from WWV would knock your socks off so I expect a WWVB version would be even better. In addition there are some things that could be done to improve it. Have Fun, Brooke Clarke http://www.PRC68.com Lenny Story wrote: Chris, Regarding the decoding method. As i stated earlier, i'm using a CMMR-60p, which seems to just be a small DSP. If i am remotely successful at my current version, my thoughts are that i would replace the CMMR with a similar DSP, and just FFT the crap out of the signal at 60khz... but i have no serious experience at this... so i could be just talking air here... -Lenny On Sat, Mar 26, 2011 at 6:54 PM, Chris Albertson wrote: Lenny, You are ahead of me by many months. I'm building a WWVB receiver also. Actually I expect I will need to build several before I get 24x7 coverage. My breadboard works only at night in the So. California area. My plan is to place the entire receiver, antenna and all on a mast far from the house and use an RS422 serial line to send the data back to a computer indoors. Do you intend to publish your work? I'd be most interested in how you decode the signal. I'm conflicted between two approaches (1) To declare the signal "invalid" if there is any error at all or (2) to try and extract as much signal out of the noise as I can. I may do the latter and then have some kind of quality indicator.The WWV audio decoder built into the NTP reference implementation can extract time code from what sounds like white noise and static to the human ear using sophisticated DSP. My first receiver will use #1. About measuring the PPS.If you had a nice HP Universal counter with a computer interface that would be best. You put the PPS from a good GPS on one channel and the PPS from WWVB on the other. Lacking that and if you only need to get down to uS level you can use two serial orts in a Linux box and use PPS line disciplin on each oert the kernal will time stamp the PPS when they happen and software can read and log the time stamps. Use the command "ldattach pps" for each serial port. Good to about 1 uSwhich for WWVB might be enough On Sat, Mar 26, 2011 at 1:26 PM, Lenny Story wrote: Greetings All, This is my first post to this board. I've completed the first run of a WWVB receiver board and Antenna (custom wound quad). Its an 8051 microcontroller, with a serial port really, but it can decode the signal accurately pretty much all day long. (I'm just north of boston, MA). I'm wanting to evaluate its performance, my guess is i'll have to produce a plot of its PPS. In reading the LeapSecond.com site (awesome btw), the "Allen Deviation" is used. As this is my first technical, experience in this area, is there a resource or method that is preferred by those who know this technology ? The code reports the time delta between each detected second. If i log the PPS deltas for an entire day (or week) of detected signal, is that enough data to start figuring out how to do the "Allen Deviation" calculations ? Any resources can you recommend to figuring out the graphs i need to produce ? Thanks in advance for your help ! -Lenny Story ___ 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. -- = Chris Albertson Redondo Beach, California ___ 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] more on lightsquared
http://www.pnt.gov/interference/lightsquared/ btw if i'm raising the list noise level too much let me know and I'll not mention LS again -pete ___ 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] HG 414A Rubidium
On 03/27/2011 08:15 PM, Greg Broburg wrote: Do you believe the numbers? Considering that I haven't had the manuals in readable form for making a serious overhaul I am not judging it just yeat. It's a 19 year old device. I know it has some problems, among those it has a HF on top of the 5 MHz and 10 MHz outputs, so making quality measurements isn't easy... on the level that the 10 MHz taken straight into the SR-620 says something like 11 MHz... but treating it slightly (through a TADD-2 modded for clock output) makes reading reliable. It seems to sit stable there so it behaves locked but off mark. I want to fix that and whatever other things there is before I judge it. These things doesn't ring major warning-bells for me. I've seen old equipment before, so it's more a matter of having the time to find it and solve it properly. Part of the problem is that the technical manual is in German and the schematics and supporting documentation is in russian. Neither of these languages is among the onces I master, so I think I will focus on getting rough translation first. I haven't figured out where the C-field adjustment is. So... it is premature to make such a judgement of believing the numbers, any Rubidium out of tune and in need of service can be this much off. 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] Clean up
Still finding stuff. Manuals for Austron 2010B, FTS 4000/5000, FTS4500 and a control Panel for the FTS4500. Please contact me direct. Bert Kehren Miami ___ 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] HG 414A Rubidium
Do you believe the numbers? Greg On 3/27/2011 10:41 AM, Magnus Danielson wrote: Fellow time-nuts, I just did a quick-and dirty (i.e. Google Translate) translation of the german manual brief (2 pages theory and 2 pages short-form manual). I think it will be sufficiently enlightening. http://rubidium.dyndns.org/~magnus/time/C1-78/ You will find my hand-typed in German variant as well as translated variant. More to come. 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.
Re: [time-nuts] HG 414A Rubidium
Fellow time-nuts, I just did a quick-and dirty (i.e. Google Translate) translation of the german manual brief (2 pages theory and 2 pages short-form manual). I think it will be sufficiently enlightening. http://rubidium.dyndns.org/~magnus/time/C1-78/ You will find my hand-typed in German variant as well as translated variant. More to come. 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] HP-5335A Fail Code
Gordon, On 03/15/2011 12:52 AM, Gordon Batey wrote: Greetings to the Time Nuts List I have a HP-5335A counter that has worked well for me for several years. Now when turning it on I get a Fail 4.6 readout on the display. The manual indicates that a 4.6 fail code indicates "MRD Counter problem in Reg-E or T" I found in the manual that you should run diagnostic 9 and 10 for this condition. Test 9 returns many changing 4 decimal place numbers 10.abcd , 12.defg , 14.xqrg etc. Test 10 returns many changing one decimal place numbers ie 15.9 , 16.1 , 16.4 , 15.8 etc Any thoughts or recommendations on pining down the cause and solution for this condition would be appreciated. I have been looking at this email since it hit my inbox. I can't quite match the readings you have made with what the Diagnostic 9 (8-284) and 10 (8-286) does, it rather matches the manual tests 9 (4.70) and 10 (4.74). I just ran Diag 9 and Diag 10 on my 5335A and they didn't say anything else than "PASS". Unless you found it you need to hit: To enter diag mode SCALE SMOOTH 9 9 ENTER To do diag 9 SCALE 9 ENTER and to do diag 10 SCALE 1 0 ENTER 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.
