Re: [time-nuts] Homebrew WWVB TX simulator?
Hal, The NIST web page is here: http://www.nist.gov/physlab/div847/grp40/wwvb.cfm [and the iers page and the historic leap second list, in a subsequent message.] I assume you can find the fine print there, but they probably aren't easily machine readable. Yes, sure, I know about those resources. You're right, they're meant for eyeballs, not code. I remember seeing the IERS bulletin taped to the wall at WWVH the first time I visited, back in the late 80s or maybe early 90s. Back then, someone had to drive out to the site on the UTC day before a leap second (typically new year's eve) and flip a toggle switch to insert the :60. And then (harder, given parties and hangovers) the next day to prevent another from happening the next UTC midnight (2PM Hawaiian time). I did a bit more digging on the NIST site, and it appears that you can get the Leap info, DST-pending info and DUT1 (current but not pending) info via ACTS, the modem dialup service. But none of the internet services include those. There is a site name acts.nist.gov in the DNS, but nothing responds on any of the usual ports. So maybe they intend to work on this issue. The NTP package includes a utility to generate the audio for WWV. It's util/tg2.c in any recent NTP source package. Yup. Only tg.c in the production release, but tg2.c is in the development tarball -- hadn't seen the improved version. It looks like it does a good job on the IRIG and IEEE stuff. But the WWV / WWVH is kinda minimal. It says it is intended to test the detector code, but doesn't include the 500, 600 and 440 Hz tones, which it ought to for a proper test. Also, no double ticks for the DUT1, and no voice announcements. My own tcg code does all that, and adjusts for WWV vs WWVH tone schedule and tick frequency. (Not ready to release to the world, though. I should think about that.) This was written back when the RFP went out for the current generators to replace the Audichron drum announcers and add the new code stuff. I built a prototype, then decided it was nuts to submit an actual proposal. Tnx again 73, Bob, K1BC ___ 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] Homebrew WWVB TX simulator?
Thanks, all, for the suggestions on my inital post. I didn't mean to drop out of the discussion so abruptly. I had an intense dental session on Tuesday and then immediately came down with some kind of bug that put me out of this world for a couple days. Anyhow, it sounds like there isn't an off-the-shelf (or -bench) solution. So I'll have to warm up the old soldering iron. I've ordered a couple of non-precision 60 kHz oscillators, which will take a month to be built and shipped. That'll give me time to scratch my head about the details. Tnx 73, Bob, K1BC ___ 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] Homebrew WWVB TX simulator?
You are welcome. A month is s long. I guess I am cheap also. 6mc dip osc are common and divide by 100. Digikey X943-NDhttp://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=X943-ND $1.88 stock but they have many others I think the 74ls290 or 390 has 2 decades in it. They make cmos versions also. Regards On Fri, Sep 17, 2010 at 2:49 PM, Bob Clements timen...@clements.orgwrote: Thanks, all, for the suggestions on my inital post. I didn't mean to drop out of the discussion so abruptly. I had an intense dental session on Tuesday and then immediately came down with some kind of bug that put me out of this world for a couple days. Anyhow, it sounds like there isn't an off-the-shelf (or -bench) solution. So I'll have to warm up the old soldering iron. I've ordered a couple of non-precision 60 kHz oscillators, which will take a month to be built and shipped. That'll give me time to scratch my head about the details. Tnx 73, Bob, K1BC ___ 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] Homebrew WWVB TX simulator?
Has anyone built / seen / bought a small simulator for WWVB? I live near Boston, and the WWVB signal is pretty marginal around here. MSF on the same frequency isn't that far away, and local noise is pretty fierce. So now and then one of my WWVB listeners (like my generally nice Junghans wristwatch) gets screwed up. The firmware writers aren't very cautious, and there's no parity bit in the code. So I have the itch to build a micro-power WWVB to set stuff with, without having to wait overnight for one or more nights. Before I dive into such a project, has anyone done/seen such a thing that I could buy or copy? I've got a WWV/WWVH simulator that I wrote (and announced) back when they were about to replace the Audichron drum machines, and I can start from there if necessary. The hardware part seems a bit more interesting, but for this purpose I don't need to derive the carrier from a GPSDO or my ancient Rb oscilator. Tnx, /Rcc Bob Clements, K1BC ___ 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] Homebrew WWVB TX simulator?
Circuit Cellar did an article. Feburary 2010 #235 Page 38. This was a WWV simulator for a 2 part article the 2nd being a receiver. 73s Randall ZL2RJP -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Clements Sent: Wednesday, 15 September 2010 9:10 a.m. To: time-nuts@febo.com Subject: [time-nuts] Homebrew WWVB TX simulator? Has anyone built / seen / bought a small simulator for WWVB? I live near Boston, and the WWVB signal is pretty marginal around here. MSF on the same frequency isn't that far away, and local noise is pretty fierce. So now and then one of my WWVB listeners (like my generally nice Junghans wristwatch) gets screwed up. The firmware writers aren't very cautious, and there's no parity bit in the code. So I have the itch to build a micro-power WWVB to set stuff with, without having to wait overnight for one or more nights. Before I dive into such a project, has anyone done/seen such a thing that I could buy or copy? I've got a WWV/WWVH simulator that I wrote (and announced) back when they were about to replace the Audichron drum machines, and I can start from there if necessary. The hardware part seems a bit more interesting, but for this purpose I don't need to derive the carrier from a GPSDO or my ancient Rb oscilator. Tnx, /Rcc Bob Clements, K1BC ___ 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] Homebrew WWVB TX simulator?
On 09/14/2010 11:10 PM, Bob Clements wrote: Has anyone built / seen / bought a small simulator for WWVB? I live near Boston, and the WWVB signal is pretty marginal around here. MSF on the same frequency isn't that far away, and local noise is pretty fierce. So now and then one of my WWVB listeners (like my generally nice Junghans wristwatch) gets screwed up. The firmware writers aren't very cautious, and there's no parity bit in the code. So I have the itch to build a micro-power WWVB to set stuff with, without having to wait overnight for one or more nights. Before I dive into such a project, has anyone done/seen such a thing that I could buy or copy? I've got a WWV/WWVH simulator that I wrote (and announced) back when they were about to replace the Audichron drum machines, and I can start from there if necessary. The hardware part seems a bit more interesting, but for this purpose I don't need to derive the carrier from a GPSDO or my ancient Rb oscilator. If you don't need a precision carrier, but rather a signal good enough for rough testing then you should not need to do that much other than cooking up a 60 kHz sine oscillator (maybe a simple cos/sin oscillator on op-amps will suffice) and let either a CMOS switch (4066) do the AM-modulation by shorting a resistor or enabling an additional resistor-path into a summing op-amp. Should not consume that many parts. Maybe add some damping stages such that levels can be controlled. Maybe a PIC to do the modulations trains and a serial interface to set it up. In all about 3-4 chips. Should not be too hard. 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] Homebrew WWVB TX simulator?
It should not be hard. I, like you live near Boston. So I built the carrier generator for testing WWVB receivers. Essentially divide ref freq to 20kc X 3 to 60 Khz. I did not modulate it because I was trouble shooting a frequency lock problem. That said modulating it with the IRIGb code would be very reasonable using my favorite pic cpu and basic. The real challenge is running the stream and accepting a good time reference to keep it accurate. I might guess the ole GPS might do. By the way I built a IRIGb gen for the irig clocks I have using a basic stamp2 3-5 years ago. Still running 24 X 7 nicely. Regards On Tue, Sep 14, 2010 at 5:31 PM, Randall Prentice randall.prent...@pscconsulting.com wrote: Circuit Cellar did an article. Feburary 2010 #235 Page 38. This was a WWV simulator for a 2 part article the 2nd being a receiver. 73s Randall ZL2RJP -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Clements Sent: Wednesday, 15 September 2010 9:10 a.m. To: time-nuts@febo.com Subject: [time-nuts] Homebrew WWVB TX simulator? Has anyone built / seen / bought a small simulator for WWVB? I live near Boston, and the WWVB signal is pretty marginal around here. MSF on the same frequency isn't that far away, and local noise is pretty fierce. So now and then one of my WWVB listeners (like my generally nice Junghans wristwatch) gets screwed up. The firmware writers aren't very cautious, and there's no parity bit in the code. So I have the itch to build a micro-power WWVB to set stuff with, without having to wait overnight for one or more nights. Before I dive into such a project, has anyone done/seen such a thing that I could buy or copy? I've got a WWV/WWVH simulator that I wrote (and announced) back when they were about to replace the Audichron drum machines, and I can start from there if necessary. The hardware part seems a bit more interesting, but for this purpose I don't need to derive the carrier from a GPSDO or my ancient Rb oscilator. Tnx, /Rcc Bob Clements, K1BC ___ 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] Homebrew WWVB TX simulator?
Randall said: Circuit Cellar did an article. Feburary 2010 #235 Page 38. This was a WWV simulator for a 2 part article the 2nd being a receiver. 73s Randall ZL2RJP Yup, I read that. It didn't have the RF part of the TX. Magnus said: If you don't need a precision carrier, but rather a signal good enough for rough testing then you should not need to do that much other than cooking up a 60 kHz sine oscillator (maybe a simple cos/sin oscillator on op-amps will suffice) and let either a CMOS switch (4066) do the AM-modulation by shorting a resistor or enabling an additional resistor-path into a summing op-amp. Should not consume that many parts. Maybe add some damping stages such that levels can be controlled. Maybe a PIC to do the modulations trains and a serial interface to set it up. In all about 3-4 chips. Should not be too hard. Cheers, Magnus Yup. You're reading my mind. That's nearly exactly what I was thinking of. I was thinking of buying a canned oscillator from someone. Digikey and Mouser don't seem to have that freq, but Intl Crystal will custom-order one for you. Of course, one could go whole hog and put in an ethernet module and send the bits from a server. And add the nice display. And a pushbutton to switch between receiving the real signal and generating the local one and turning on the 60 kHz. I was just wondering whether anyone had built some version of the hardware so I don't have to. Tnx all, /Rcc ___ 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] Homebrew WWVB TX simulator?
Maybe a PIC to do the modulations trains and a serial interface to set it up. In all about 3-4 chips. Should not be too hard. Why do you need more than one chip? Why can't the PIC generate the 60 KHz signal by bit banging a couple of pins? I'm thinking of a 2 or 3 bit D/A with 2 or 3 more pins for the low power portion of the signal. 1 bit might be enough with a good external filter. I wonder what the range would be using 2 feet of wire for an antenna. Do you want to fix your neighbors clocks too? -- 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] Homebrew WWVB TX simulator?
Hal said: I wonder what the range would be using 2 feet of wire for an antenna. Do you want to fix your neighbors clocks too? I don't think any of my neighbors do time better than a millisecond. So as long as the data comes from the main server, (and I get DUT1 right) I should go undetected as an interloper, if not undetected as a transmitter. Which reminds me: Is there an on-line source, machine parseable, for the DUT1 and DST and leap-second warning bits? That would be useful for both the WWV TX and this WWVB TX. Is there a secret NTP++ protocol that I've missed out on? /Rcc ___ 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] Homebrew WWVB TX simulator?
On 09/14/2010 11:49 PM, Hal Murray wrote: Maybe a PIC to do the modulations trains and a serial interface to set it up. In all about 3-4 chips. Should not be too hard. Why do you need more than one chip? Why can't the PIC generate the 60 KHz signal by bit banging a couple of pins? I'm thinking of a 2 or 3 bit D/A with 2 or 3 more pins for the low power portion of the signal. 1 bit might be enough with a good external filter. It may not be the simplest solution to be the minimal chip-count solution. By all means, knock yourself out. My intention was for a simple solution where each part would be simple and clear. If you bit-bang the hell out of a PIC it will be more tedious but you can get the result. I'm proud owner of two TADD-2 PIC-dividers... so I am not against the idea. You can always write software that beeps 12 kHz out of a 48 kHz soundboard (4-sample carrier wave) and then use a transistor as a distortion stage (2N3904?) filter away junk (optional) and use the 5th overtone distortion for carrier. Maybe a diode (1N914 or 1N4148) may work just as well. The tone-lengths is 200 ms, 500 ms and 800 ms so looping the sample stretches should be trivial, as you have 12 waveforms per ms and need to modulate 200 ms and 300 ms stretches of the two amplitude-levels to form the second pulses. I am tempted to try it out with the laptop or builtin audio of a crapiola PC. Should not be too hard. Far simpler than bit-banging a PIC. 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] Homebrew WWVB TX simulator?
Hal said: The NIST web page is here: http://www.nist.gov/physlab/div847/grp40/wwvb.cfm I assume you can find the fine print there, but they probably aren't easily machine readable. Um, that's just a general description -- not the current values. Or did I miss something? /Rcc ___ 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] Homebrew WWVB TX simulator?
On 9/14/2010 5:27 PM, Hal Murray wrote: Is there a secret NTP++ protocol that I've missed out on? Yes, but I can't tell you ;-) -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Homebrew WWVB TX simulator?
Um, that's just a general description -- not the current values. Or did I miss something? Here is a table of leap seconds. ftp://time.nist.gov/pub/leap-seconds.list It gets updated every 6 months or so and contains a use-by date inside so you know when you need to get a new one. The comments tell you how to parse it. They make up a new one with an updated use-by date when a leap-second or or non-leap-second is announced. There is a lot of stuff here: http://maia.usno.navy.mil/ This has UT1-UTC with a 90 day prediction: http://maia.usno.navy.mil/ser7/mark3.out This says -0.1 sec: ftp://hpiers.obspm.fr/iers/bul/buld/bulletind.dat I think it's rounding. -- 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] Homebrew WWVB TX simulator?
Has anyone built / seen / bought a small simulator for WWVB? An example of a PC-based WWVB simulator is here: http://www.leapsecond.com/notes/wwvb1.htm http://www.leapsecond.com/notes/wwvb2.htm You can take the output of this and drive hardware: http://www.leapsecond.com/tools/tco1.c http://www.leapsecond.com/tools/tco2.c /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.
