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NIST Considers East Coast WWVB Broadcast
This comes from the latest RadioWorld NewsBytes:
================================================== ================================ The National Institute of Standards and Technology is considering setting up a U.S. East Coast low-frequency radio station broadcasting NIST time in binary code format to complement the present NIST 60 kHz, WWVB broadcast. "The proposed new East Coast broadcast will operate with the same time code format as the present WWVB signal, however at a different carrier frequency, potentially at 40 kHz," John Lowe, the WWVB station manager, told RW. Eight years ago, the power of the WWVB broadcast out of Colorado was increased from 13 kW to 50 kW and has since been increased to 70 kW, he said; but "even at this power level there are locations on the East Coast that have difficulty consistently receiving the time code." Some advocates say an East Coast broadcast would make the time code easier to receive, increase sales of radio-controlled clocks and spur development of radio-controlled timing devices in appliances and other consumer products. Lowe is seeking comments about the possibility and asks that readers write to him. His e-mail address is . ================================================== ================================ I think this would be very welcome though it would do nothing for those radio-controlled clocks already out there. I also wish that all newly-designed shortwave radios would feature a radio-controlled clock that could show two time zones - the local one and UTC. Best, Joe |
NIST Considers East Coast WWVB Broadcast
On Jan 18, 8:12*am, Joe Analssandrini
wrote: This comes from the latest RadioWorld NewsBytes: =========================================*======= The National Institute of Standards and Technology is considering setting up a U.S. East Coast low-frequency radio station broadcasting NIST time in binary code format to complement the present NIST 60 kHz, WWVB broadcast. "The proposed new East Coast broadcast will operate with the same time code format as the present WWVB signal, however at a different carrier frequency, potentially at 40 kHz," John Lowe, the WWVB station manager, told RW. Eight years ago, the power of the WWVB broadcast out of Colorado was increased from 13 kW to 50 kW and has since been increased to 70 kW, he said; but "even at this power level there are locations on the East Coast that have difficulty consistently receiving the time code." Some advocates say an East Coast broadcast would make the time code easier to receive, increase sales of radio-controlled clocks and spur development of radio-controlled timing devices in appliances and other consumer products. Lowe is seeking comments about the possibility and asks that readers write to him. His e-mail address is . ================================================== =========================*======= I think this would be very welcome though it would do nothing for those radio-controlled clocks already out there. I also wish that all newly-designed shortwave radios would feature a radio-controlled clock that could show two time zones - the local one and UTC. Best, Joe JA, Why not simply add another 50KW Transmitter and a Directional Antenna pointed at the North East / New England Region at the present WWVB Transmission Site ? Or pay half of the cost for Canada set-up a WWVB type Boardcast Transmitter on their side of the Border somewhere near Ottawa. It would serve their geographic needs and our East Coast needs too ~ RHF |
NIST Considers East Coast WWVB Broadcast
Joe Analssandrini wrote:
This comes from the latest RadioWorld NewsBytes: ================================================== ================================ The National Institute of Standards and Technology is considering setting up a U.S. East Coast low-frequency radio station broadcasting NIST time in binary code format to complement the present NIST 60 kHz, WWVB broadcast. "The proposed new East Coast broadcast will operate with the same time code format as the present WWVB signal, however at a different carrier frequency, potentially at 40 kHz," John Lowe, the WWVB station manager, told RW. Eight years ago, the power of the WWVB broadcast out of Colorado was increased from 13 kW to 50 kW and has since been increased to 70 kW, he said; but "even at this power level there are locations on the East Coast that have difficulty consistently receiving the time code." Some advocates say an East Coast broadcast would make the time code easier to receive, increase sales of radio-controlled clocks and spur development of radio-controlled timing devices in appliances and other consumer products. Lowe is seeking comments about the possibility and asks that readers write to him. His e-mail address is . ================================================== ================================ I think this would be very welcome though it would do nothing for those radio-controlled clocks already out there. I also wish that all newly-designed shortwave radios would feature a radio-controlled clock that could show two time zones - the local one and UTC. Best, Joe They could put the new station on 60 kHz as well. If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. This would avoid everyone having to buy new watches. Any commercial entity who really needs accurate time switched over to GPS a decade ago. |
NIST Considers East Coast WWVB Broadcast
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NIST Considers East Coast WWVB Broadcast
On Jan 19, 5:35*am, David wrote:
Joe Analssandrini wrote: This comes from the latest RadioWorld NewsBytes: ================================================== =========================*======= The National Institute of Standards and Technology is considering setting up a U.S. East Coast low-frequency radio station broadcasting NIST time in binary code format to complement the present NIST 60 kHz, WWVB broadcast. "The proposed new East Coast broadcast will operate with the same time code format as the present WWVB signal, however at a different carrier frequency, potentially at 40 kHz," John Lowe, the WWVB station manager, told RW. Eight years ago, the power of the WWVB broadcast out of Colorado was increased from 13 kW to 50 kW and has since been increased to 70 kW, he said; but "even at this power level there are locations on the East Coast that have difficulty consistently receiving the time code." Some advocates say an East Coast broadcast would make the time code easier to receive, increase sales of radio-controlled clocks and spur development of radio-controlled timing devices in appliances and other consumer products. Lowe is seeking comments about the possibility and asks that readers write to him. His e-mail address is . ================================================== =========================*======= I think this would be very welcome though it would do nothing for those radio-controlled clocks already out there. I also wish that all newly-designed shortwave radios would feature a radio-controlled clock that could show two time zones - the local one and UTC. Best, Joe They could put the new station on 60 kHz as well. *If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. *This would avoid everyone having to buy new watches. *Any commercial entity who really needs accurate time switched over to GPS a decade ago.- Hide quoted text - - Show quoted text - David, Yeah - There must be some way of 'expanding' the WWVB Broadcast System without requiring a Major Upgrade / Replacement of the basic Receivers for the newer service. ~ RHF |
NIST Considers East Coast WWVB Broadcast
RHF wrote:
Yeah - There must be some way of 'expanding' the WWVB Broadcast System without requiring a Major Upgrade / Replacement of the basic Receivers for the newer service. I wonder if there really is demand for it. Being outside of the U.S., I can't say for sure, but I thought that GPS location was required in cell phones sold there (not here). If that's the case, it would be likley that cheap GPS clocks could be made, and they are not affected by the noise commonly produced by many modern electrical/electronic devices. For the home and many businesses, a WiFi or ethernet clock synchronized using NTP (Network Time Protocol) would be preferable as more and more people have broadband Internet connections which are on all the time. Another option would be to insert time signals in cell phone control channels, if they are not already there. Cell phone receivers are cheap, would not require a service contract as they would never transmit anything, immune to most RFI, and cell phone service covers almost all of the U.S. and most other countries. IMHO it's a case of trying to extend a service that is rarely used (how many people actually have radio synchronized clocks?) and can be easily replaced with much newer and better technologies. I understand that this would require the few people that want synchronized clocks that have not gone to GPS or NTP already to buy new ones, but isn't that the way things are done these days? Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
"Geoffrey S. Mendelson" wrote in message ... RHF wrote: Yeah - There must be some way of 'expanding' the WWVB Broadcast System without requiring a Major Upgrade / Replacement of the basic Receivers for the newer service. I wonder if there really is demand for it. Being outside of the U.S., I can't say for sure, but I thought that GPS location was required in cell phones sold there (not here). If that's the case, it would be likley that cheap GPS clocks could be made, and they are not affected by the noise commonly produced by many modern electrical/electronic devices. You do realize that GPS does not work inside most buildings? |
NIST Considers East Coast WWVB Broadcast
I wonder if there really is demand for it. Being outside of the U.S., I
can't say for sure, but I thought that GPS location was required in cell phones sold there (not here). I think cell phones are normally located through the cell tower network, not through GPS. I could be mistaken. If that's the case, it would be likley that cheap GPS clocks could be made, and they are not affected by the noise commonly produced by many modern electrical/electronic devices. You do realize that GPS does not work inside most buildings? In fact the main selling point of longwave is that it goes through everything (even underground), isn't it? |
NIST Considers East Coast WWVB Broadcast
Geoffrey S. Mendelson wrote:
RHF wrote: Yeah - There must be some way of 'expanding' the WWVB Broadcast System without requiring a Major Upgrade / Replacement of the basic Receivers for the newer service. I wonder if there really is demand for it. Being outside of the U.S., I can't say for sure, but I thought that GPS location was required in cell phones sold there (not here). If that's the case, it would be likley that cheap GPS clocks could be made, and they are not affected by the noise commonly produced by many modern electrical/electronic devices. For the home and many businesses, a WiFi or ethernet clock synchronized using NTP (Network Time Protocol) would be preferable as more and more people have broadband Internet connections which are on all the time. Another option would be to insert time signals in cell phone control channels, if they are not already there. Cell phone receivers are cheap, would not require a service contract as they would never transmit anything, immune to most RFI, and cell phone service covers almost all of the U.S. and most other countries. IMHO it's a case of trying to extend a service that is rarely used (how many people actually have radio synchronized clocks?) and can be easily replaced with much newer and better technologies. I understand that this would require the few people that want synchronized clocks that have not gone to GPS or NTP already to buy new ones, but isn't that the way things are done these days? Geoff. I have about 6 of them. They run for a couple years on a single AA battery. No wires. |
NIST Considers East Coast WWVB Broadcast
"mc" wrote in message . .. I wonder if there really is demand for it. Being outside of the U.S., I can't say for sure, but I thought that GPS location was required in cell phones sold there (not here). I think cell phones are normally located through the cell tower network, not through GPS. I could be mistaken. If that's the case, it would be likley that cheap GPS clocks could be made, and they are not affected by the noise commonly produced by many modern electrical/electronic devices. You do realize that GPS does not work inside most buildings? In fact the main selling point of longwave is that it goes through everything (even underground), isn't it? Absolutely. GPS only works in a clear area with good view to most of the sky (it's even a little less accurate if you're driving through a steep sided canyon). |
NIST Considers East Coast WWVB Broadcast
Brenda Ann wrote:
You do realize that GPS does not work inside most buildings? Sure, and do you realize that 60kHz signals don't work in many buildings, around a lot of modern electronic equipment and so on? If it produces noise that interferes with an AM radio, it will interfere with a 60kHz clock. CFL's are especialy bad. Even if the signal did reach here, which according to the NIST it won't, nothing could receive it over the noise. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
On Sat, 19 Jan 2008 05:35:32 -0800, David wrote:
They could put the new station on 60 kHz as well. If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. This would avoid everyone having to buy new watches. Any commercial entity who really needs accurate time switched over to GPS a decade ago. Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. FWIW, the time obtainable from LORAN-C transmitter sites is an additional 9 seconds ahead of that (23 seconds total), and the international atomic time scale, called TAI for Temps Atomique International and which is a statistical timescale based on a large number of atomic clocks, is currently ahead of UTC by 33 seconds. 73 de John, KC2HMZ |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. That's a software bug. For location purposes, a leap second is a very bad thing when it happens. So it's better for GPS to ignore it, and if you really need accurate time, compenstate for the extra seconds in the routine that takes the GPS data and converts it to whatever you are using it for. It would not take much, a simple calculation of missed leap seconds subtracted from the current GPS time would do it perfectly. I wonder if the NTP (network time protocol) GPS drivers do it already? Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote: Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. I answered that with: That's a software bug. For location purposes, a leap second is a very bad thing when it happens. So it's better for GPS to ignore it, and if you really need accurate time, compenstate for the extra seconds in the routine that takes the GPS data and converts it to whatever you are using it for. According to: http://www.eecis.udel.edu/~mills/leap.html The NTP network automaticly deals with the difference between NTP and GPS times. The web page also states: While of less use to the computer timekeeper, the Global Positioning System (GPS), which is widely used to disseminate standard time, has its own timescale. The GPS timescale is syntonic with TAI, but at a fixed time offset of -19 s from that timescale, apparently because the final system design review was in 1980. GPS clocks typically convert from GPS to UTC for external readings. So someone already thought of it, and it is no longer, and may never have been an issue. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
Geoffrey S. Mendelson wrote:
If it produces noise that interferes with an AM radio, it will interfere with a 60kHz clock. CFL's are especialy bad. This has not been my experience. I have CFLs everywhere except in the fridge and in the oven. They don't make any significant noise. My neighbors' lamp dimmers and motion detectors produce way more noise than my RF light bulbs. I have an "atomic" clock on my bench at work, inside a steel framed office structure, inside a big tilt-up warehouse, and that clock manages to set itself about 3 times a week. GPS receivers cannot run for a year on a single AA battery. |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
On Sat, 19 Jan 2008 05:35:32 -0800, David wrote: They could put the new station on 60 kHz as well. If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. This would avoid everyone having to buy new watches. Any commercial entity who really needs accurate time switched over to GPS a decade ago. Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. Easily compensated for in the software. http://www.ese-web.com/ |
NIST Considers East Coast WWVB Broadcast
On Sun, 20 Jan 2008 05:51:02 -0800, David wrote:
John Kasupski wrote: On Sat, 19 Jan 2008 05:35:32 -0800, David wrote: They could put the new station on 60 kHz as well. If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. This would avoid everyone having to buy new watches. Any commercial entity who really needs accurate time switched over to GPS a decade ago. Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. Easily compensated for in the software. Well, that part of it is, but see my reply to Geoffrey's posts on the subject. There are other issues with using GPS as a time standard, which are related to the quality of the algorithms GPS receivers use to process data received from the satellites, as well as variations in the circuitry used to control receivers' internal clocks. 73 DE John, KC2HMZ |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
On Sun, 20 Jan 2008 05:51:02 -0800, David wrote: John Kasupski wrote: On Sat, 19 Jan 2008 05:35:32 -0800, David wrote: They could put the new station on 60 kHz as well. If they can't get them adequately synchronized they could alternate every 30 minutes or whatever. This would avoid everyone having to buy new watches. Any commercial entity who really needs accurate time switched over to GPS a decade ago. Joke's on them. GPS time is implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. Since it is not updated with leap seconds, GPS is currently ahead of UTC by 14 seconds. Easily compensated for in the software. Well, that part of it is, but see my reply to Geoffrey's posts on the subject. There are other issues with using GPS as a time standard, which are related to the quality of the algorithms GPS receivers use to process data received from the satellites, as well as variations in the circuitry used to control receivers' internal clocks. 73 DE John, KC2HMZ Did you visit the ESE web site? They make the master clocks used in broadcasting (and a lot of public service and labs) and they have very well thought-out innards. Is GPS like NTP in as they just give a raw number of seconds since a certain date and that the receiver computes the real time from that, based on its firmware? |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
On Sun, 20 Jan 2008 15:19:06 +0000 (UTC), (Geoffrey
S. Mendelson) wrote: John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". Well, my comments about GPS stemmed from David's comments that "Any commercial entity who really needs accurate time switched over to GPS a decade ago." But you're right, this has drifted off the topic of the original post to the thread, which was related to consumer devices - and David's comment downthread is also correct in pointing out that there are GPS receivers (such as those made by ESE) that are properly designed and can, in fact, provide a GPS time and frequency standard that is traceable to a national or international time standard. So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. Yes, assuming it can get a signal...which problem exists with the WWVB-based devices as well (and which was the whole point of the article cited by the OP). If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. FWIW, this Wikipedia article states that around 80% of the world's population enjoys mobile phone coverage as of 2006 and that this is expected to increase to 90% by the year 2010: http://en.wikipedia.org/wiki/Mobile_phone Despite that claim, even here in the United States there is still a significant amount of territory away from major cities and interstate highways where no wireless phone will work at all - but radios will work, and consumers have other sources for getting the correct time provided that they aren't too lazy to do it themselves rather than expecting every device they own to do it for them. IOW, self-setting clocks as consumer items are a convenience, not a necessity. I'd be more concerned about wireless phones not working due to the fact that this renders them useless for placing emergency calls, rather than because it prevents these devices from updating their time displays. 73 DE John, KC2HMZ |
NIST Considers East Coast WWVB Broadcast
On Sun, 20 Jan 2008 06:40:03 -0800, David wrote:
Did you visit the ESE web site? They make the master clocks used in broadcasting (and a lot of public service and labs) and they have very well thought-out innards. Yes, and yes. I never meant to insinuate that it was impossible to obtain an accurate time standard using GPS. I did mean to point out that to do so requires a properly designed receiver, which goes way beyond the type of consumer-grade device the original poster had in mind when telling us about NIST's plans to possibly add an east coast equivalent to WWVB. Is GPS like NTP in as they just give a raw number of seconds since a certain date and that the receiver computes the real time from that, based on its firmware? Well...I'd have to say yes, since they are both based on the same standard, which is TAI. As I understand things, NTP actually references the UTC time scale with a refined version of Marzullo's Algorithm called the intersection algorithm. Like the original Marzullo's algorithm, the intersection algorithm is used to select from among several sources for estimating accurate time. It supports leap seconds, and the sources it uses can include atomic clocks, GPS clocks or other radio clocks, computers that are directly connected to such devices, and/or computers that are able to use the Internet to poll computers that are directly connected to such devices. UTC (again as I understand things) is defined by a large collection (about 300) of atomic clocks in over 50 national laboratories worldwide, using the atomic time scale TAI (Temps Atomique International, or International Atomic Time). TAI is sort of based on counting seconds, in that it counts something called SI seconds, which are defined in relationship to the radiation state of the Cesium-133 atom by international agreement. UTC is then derived from TAI, and is periodically updated with leap seconds in order to more closely track time standards based on the Earth's rotation. I think I pretty much explained how GPS receivers estimate the time in my previous reply upthread to a post by Geoffrey, so I won't repeat all that again here, but when all is said and done, a fixed 19 second offset from TAI gives GPS time. UTC and TAI were synchronized to an exact fixed offset of 33 seconds at the end of 1971. So the answer to your question. I would conclude that GPS and NTP are alike in that both are synchronized to the same international standard, based on cesium atomic clocks. JK |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
Yes, assuming it can get a signal...which problem exists with the WWVB-based devices as well (and which was the whole point of the article cited by the OP). That is a problem of any radio based device, whether it uses GPS, 60kHz (or the European equivalent) signals, cell phone, etc. I understand that analog TV signals in the U.S. also had time coding in them to eliminate the flashing "12:00" problem. Of course that's about to go away, and I have no idea if U.S. HDTV signals include time coding or not. When someone asked on another list about this several months ago, so that he could get an heirloom digital clock to receive the 60kHz signals in a place that was too well shielded and electricaly noisy, I looked into generating the time signals with a PC. :-) Programing wise it was simple, one could take the system clock and build the data stream. If it was kept in sync with NTP, it would be close enough for those clocks that only display to minute or second resolution. The problem for me was building a transmitter, because such parts are almost impossible to get locally, and I had no clock to test it and not much chance of getting one. At some point I would like to build and market a WiFi NTP clock, but that has to wait. IOW, self-setting clocks as consumer items are a convenience, not a necessity. I'd be more concerned about wireless phones not working due to the fact that this renders them useless for placing emergency calls, rather than because it prevents these devices from updating their time displays. Good point. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
NIST Considers East Coast WWVB Broadcast
Geoffrey S. Mendelson wrote:
John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. Much of the western USA has no cellular service period. |
NIST Considers East Coast WWVB Broadcast
John Kasupski wrote:
IOW, self-setting clocks as consumer items are a convenience, not a necessity. I'd be more concerned about wireless phones not working due to the fact that this renders them useless for placing emergency calls, rather than because it prevents these devices from updating their time displays. 73 DE John, KC2HMZ I like my atomic clocks and my atomic watches because they are always correct, without having to use the internet. I have always insisted on having the correct time (see Ken Nordine). The example of the clock that only set itself 3 times a week was to show that they can work inside a commercial building, albeit not terribly well. If you're between Tucson and El Paso, or between El Paso and Laredo, etc., you'd best be carrying a 4 Watt CB radio for emergencies. That fancy telephone is very hit and miss. |
TIME : To The Nearest Minute - Is Good Enough For Me !
On Jan 20, 7:19*am, (Geoffrey S. Mendelson) wrote:
John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel *N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog athttp://geoffstechno.livejournal.com/ JK & GSM, Where Do You Find The Time "Tick-Tock" - To Argue . . . The Finer Points of Time Down To The Nearest Second ? :o) And the Reality -is- for most Non-Techincal Consumers of Time : Time that 'is' "Accurate to the Nearest Minute" is Good Enough. =SO= For Them - Any Time In-Accuracy Less-Than 31 Seconds : Is To The Nearest Minute. -and- That Is Good Enough For Me ~ RHF David is Right : An Atomic Clock that resets itself a few times a Week and uses a single set of Batterys {runs independently} that Lasts for a Year of more : Meets the Needs of Non-Techincal Consumers of Time. -But- Then Again - Any common Consumer Product that has a Time Display and is "Accurate to the Nearest Minute" also Meets the Needs of Non-Techincal Consumers of Time. |
TIME : To The Nearest Minute - Is Good Enough For Me !
RHF wrote: On Jan 20, 7:19 am, (Geoffrey S. Mendelson) wrote: John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog athttp://geoffstechno.livejournal.com/ JK & GSM, Where Do You Find The Time "Tick-Tock" - To Argue . . . The Finer Points of Time Down To The Nearest Second ? :o) And the Reality -is- for most Non-Techincal Consumers of Time : Time that 'is' "Accurate to the Nearest Minute" is Good Enough. =SO= For Them - Any Time In-Accuracy Less-Than 31 Seconds : Is To The Nearest Minute. -and- That Is Good Enough For Me ~ RHF David is Right : An Atomic Clock that resets itself a few times a Week and uses a single set of Batterys {runs independently} that Lasts for a Year of more : Meets the Needs of Non-Techincal Consumers of Time. -But- Then Again - Any common Consumer Product that has a Time Display and is "Accurate to the Nearest Minute" also Meets the Needs of Non-Techincal Consumers of Time. Heck, I remember when folks were making fun of my big GMT clock here in the shack, but it keeps on a rockin' and a tick-tock'in, and has been for almost 25 years now. Put in a new battery once a year, set it to WWV every few weeks and that's good enough for me! dxAce Michigan USA |
NIST Considers East Coast WWVB Broadcast
On Jan 20, 11:49*am, (Geoffrey S. Mendelson) wrote:
John Kasupski wrote: Yes, assuming it can get a signal...which problem exists with the WWVB-based devices as well (and which was the whole point of the article cited by the OP). That is a problem of any radio based device, whether it uses GPS, 60kHz (or the European equivalent) signals, cell phone, etc. I understand that analog TV signals in the U.S. also had time coding in them to eliminate the flashing "12:00" problem. Of course that's about to go away, and I have no idea if U.S. HDTV signals include time coding or not. When someone asked on another list about this several months ago, so that he could get an heirloom digital clock to receive the 60kHz signals in a place that was too well shielded and electricaly noisy, I looked into generating the time signals with a PC. :-) Programing wise it was simple, one could take the system clock and build the data stream. If it was kept in sync with NTP, - it would be close enough for those clocks that only display - to minute or second resolution. Yes there is the practical consideration that most common Consumer Products that have a Time Display "Only" display the Time-to-the-Minute {No Seconds} and therefore Time that is "Accurate to the Nearest Minute" meets the Needs of these Non-Techincal Consumers of Time. |
NIST Considers East Coast WWVB Broadcast
In article , David
wrote: Geoffrey S. Mendelson wrote: John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. Much of the western USA has no cellular service period. Most of the population is on the coast and has cell service. -- Telamon Ventura, California |
NIST Considers East Coast WWVB Broadcast
"Telamon" wrote in message ... Much of the western USA has no cellular service period. Most of the population is on the coast and has cell service. Until they travel away from the populated areas. Big stretches of Death Valley with no service. May have changed since I was last there in 2000, but there were even quite a few dead spots on the highway between Stockton and Fairfield. By contrast, here in the ROK, we have nearly 100% cell penetration (can't say absolutely 100%, since there is the occasional dead spot inside a building or a tunnel, but even most tunnels have service... they make sure there is a cell tower posted at at least one end of every tunnel). Of course, the states is a much bigger place, so much more difficult to get 100% penetration of service. |
NIST Considers East Coast WWVB Broadcast
Telamon wrote:
Much of the western USA has no cellular service period. Most of the population is on the coast and has cell service. Yeah? That's swell, but we were talking about area. "Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S." |
NIST Considers East Coast WWVB Broadcast
On Jan 20, 12:46*pm, David wrote:
John Kasupski wrote: IOW, self-setting clocks as consumer items are a convenience, not a necessity. I'd be more concerned about wireless phones not working due to the fact that this renders them useless for placing emergency calls, rather than because it prevents these devices from updating their time displays. 73 DE John, KC2HMZ I like my atomic clocks and my atomic watches because they are always correct, without having to use the internet. *I have always insisted on having the correct time (see Ken Nordine). *The example of the clock that only set itself 3 times a week was to show that they can work inside a commercial building, albeit not terribly well. - If you're between Tucson and El Paso, or between El Paso - and Laredo, etc., you'd best be carrying a 4 Watt CB radio - for emergencies. That fancy telephone is very hit and miss. David - Yes the CB Radio is still one of the Best Emergency Back-Up Communications Systems for the majority of Non-Technical Consumers in an Emergency : When the Power Goes Off. RadioShack CB Radios - http://tinyurl.com/35n497 That is very true -IF- you live in many rural and remote areas at the far-end of the Power Line. Either a Car/Truck 12 Volt power source or a spare 12 V Battery is required. ~ RHF |
NIST Considers East Coast WWVB Broadcast
On Jan 20, 4:05*pm, Telamon
wrote: In article , David wrote: Geoffrey S. Mendelson wrote: John Kasupski wrote: Note that we're probably talking errors in the amount of nanoseconds (per second) here, certainly not errors that are going to cause somebody to be ten minutes late for work, but for commercial or scientific applications requiring a time reference that is related directly to a national or international reference, GPS may not necessarily cut the mustard. Yes, but don't loose sight of the fact that this discussion is really about consumer items. One person metioned in a previous post that his clock syncs three times a week, other than that, it "runs free". So IMHO if you build a consumer device that syncs every 5 minutes to a GPS or GPS based standard, it will be a lot more accurate than the average one that syncs every 2-3 days to a radio signal. If it were to sync every minute to a time signal inserted in a cellular control channel, it be even more accurate. Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S. Since it is a receiver it can be broadbanded and if it were to cover the GSM 850/900 mHz and 1800/1900 mHz bands it would work everywhere there is GSM coverage. Except for Estonina and Brazil, an 850/900 mHz receiver would be enough. This does leave out parts of the Pacific Rim (Japan and Korea) and some parts of Oz, but on the whole it cover almost the entire populated earth. Geoff. Much of the western USA has no cellular service period. Most of the population is on the coast and has cell service. -- Telamon Ventura, California- Hide quoted text - - Show quoted text - Telamon, 'Most' Ain't "All" and when there is a major Power Grid disruption you will be yelling into your Celphone : HELP ! - Can Any Body Hear Me ? and nobody will. David was Right the CB Radio is still one of the Best Emergency Back-Up Communications Systems Dollar-for-Dollar for the majority of Non-Technical Consumers in an Emergency : When the Power System Goes Down. RadioShack CB Radios - http://tinyurl.com/35n497 That is very true -IF- you live in many rural and remote areas at the far-end of the Power Line. Either a Car/Truck 12 Volt power source or a spare 12 V Battery is required. ~ RHF |
NIST Considers East Coast WWVB Broadcast
On Jan 20, 5:07*pm, "Brenda Ann" wrote:
"Telamon" wrote in message .... Much of the western USA has no cellular service period. Most of the population is on the coast and has cell service. - Until they travel away from the populated areas. *Big stretches of Death - Valley with no service. May have changed since I *was last there in 2000, - but there were even quite a few dead spots on the highway between Stockton - and Fairfield. By contrast, here in the ROK, we have nearly 100% cell - penetration (can't say absolutely 100%, since there is the occasional dead - spot inside a building or a tunnel, but even most tunnels have service... - they make sure there is a cell tower posted at at least one end of every - tunnel). - Of course, the states is a much bigger place, so much more difficult - to get 100% penetration of service. BAD - 100% Cell Phone Penetration ! - Sort of sounds like . . . the Latest High Tech Sex Crime. :o) ~ RHF |
NIST Considers East Coast WWVB Broadcast
"Telamon" wrote in message ... In article , " wrote: On Jan 20, 8:31 pm, David wrote: "Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S." They may have licenses that allow them to cover 98% of the surface area (to use your number), but actual coverage is nowhere near that. http://www.wireless.att.com/coverageviewer (And this includes both the older 850 MHz and newer 1.9 GHz bands.) That link is not working right now but you can go here http://www.mountainwireless.com/cingular_licenses.shtml Worked fine for me. Looks like a vast difference between the 98% claim and reality. |
NIST Considers East Coast WWVB Broadcast
In article ,
"Brenda Ann" wrote: "Telamon" wrote in message ... In article , " wrote: On Jan 20, 8:31 pm, David wrote: "Last I checked, the AT&T Wireless 850mHz GSM (whatever name it is called now) network covers 98% of the surface area of the U.S." They may have licenses that allow them to cover 98% of the surface area (to use your number), but actual coverage is nowhere near that. http://www.wireless.att.com/coverageviewer (And this includes both the older 850 MHz and newer 1.9 GHz bands.) That link is not working right now but you can go here http://www.mountainwireless.com/cingular_licenses.shtml Worked fine for me. Looks like a vast difference between the 98% claim and reality. It's probably the old version of Safari I'm using then. I've noticed that I have more trouble with some web sites these days as Apple is not supporting this version of the browser any more. The latest operating system Leopard still has some issues and I'll probably wait a little longer to upgrade. -- Telamon Ventura, California |
NIST Considers East Coast WWVB Broadcast
TV stations that synchronize to avoid ATSC into analog interference use
GPS as well. *They have to be within 6 Hz of each other. For that matter, there is an ATSC standard for broadcasting television on a single-frequency network within an area of license. That is, a station would have multiple transmitters (lower power, of course) all broadcasting in sync and on the same frequency (the assigned TV channel). The advantage, besides potentially less expensive transmitter facilities, is that a broadcaster can put up antenna in such a way as to ensure better coverage over their entire market. Yes, there would be destructive interference in places, but since the signal is 6 MHz wide and at 600 MHz, only a small portion of the entire band would be affected at any given location. The error correction takes care of it. The timing requirement for this is quite tight. - Jonathan |
NIST Considers East Coast WWVB Broadcast
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