Re: [time-nuts] WWVB and Free Democracies Survival
Offhand I'd estimate it would be easier for some "bad guys" to put a crude A-bomb on top of a SCUD and put America into the horse and buggy age with an EMP attack than to take out a significant number of GPS satellites. NLK in Washington state has been off the for almost two months now. Depending on which list one looks at, NLK transmits on 24.8 with 300 to 1000 kilowatts. Perhaps NLK could be retuned to send the WWVB signal. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc "The High Reliability Software" 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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 a different approach to d-bpsk-r (cheating)
Might loose the signal not unusual and it did shift +5-8 us tonight aligned to the diurnal shift. So maybe this is not so crazy of an approach. Regards Paul On Sat, Jul 14, 2012 at 5:53 PM, Bob Camp wrote: > Hi > > Well between now and midnight, you will completely loose signal at least > once. It's a pretty dramatic amplitude dip as sunset gets right to the > "wrong" place. > > Bob > > On Jul 14, 2012, at 4:56 PM, paul swed wrote: > > > Bob > > Yes nights are bad for me, east coast and MSF interference. > > So it could be any number of 60 KHz crossing its just odd it lined up the > > way it did and I double confirmed that I was not doing something silly > like > > using alternate triggers. > > > > Very careful analysis does show a 1-2 us jitter and at diurnal shift I > > really expect something to change it has to. > > Regards > > Paul. > > > > On Sat, Jul 14, 2012 at 4:32 PM, Bob Camp wrote: > > > >> Hi > >> > >> The "zero crossing" is very arbitrary. If it's correct at the transmit > >> site, it will then be off everywhere else by the speed of light / > distance. > >> You will appear to be correct once every wavelength away from Colorado > >> (roughly every 3 miles). You won't really be correct because you are > >> looking at a different zero crossing. > >> > >> As long as you don't have sunset or sunrise between you and the > >> transmitter, WWVB is reasonably stable. At night you will get more > signal, > >> but also can have some skywave "stuff" in the mix. > >> > >> Bob > >> > >> On Jul 14, 2012, at 3:50 PM, paul swed wrote: > >> > >>> OK have been doing a lot of experimenting. > >>> I was curious what is the GPS tick in relationship to wwvb. Especially > >>> since it is a reliable 1 sec marker. > >>> Using a Tbolt since everyone has one on the list. ;-) And monitoring > the > >> 10 > >>> us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at > >> least > >>> 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick > >>> rising edge. Expected some form of drift. > >>> > >>> Would not have actually thought there should be such a relationship or > >> its > >>> truly pot luck today. > >>> WWVB today is also not running bpsk. > >>> > >>> Should such a relationship actually exist? > >>> There is a clue in a 1985 article in ham radio magazine. > >>> It went something like this. At any given instant the 60 Khz may > jitter. > >>> But for every 1 sec period there will be exactly 60,000 cycles. > >>> > >>> If it does stay aligned, then the cheating d-bpsk-r gets to be > >> interesting > >>> and very implementable. > >>> > >>> The approach using a micro to sample a squared up 60 Khz after the > Tbolt > >>> tic. > >>> Perform 2-3 1 usec samples in the leading 90 degree signal. > >>> Decide is it a 0 or 1 phase. > >>> Select a inverted or non inverted 60 Khz into the output path to > >> maintain a > >>> constant phase 60 Khz for the old recvrs. > >>> > >>> Sure its cheating. But if this relationship is real I should be able to > >>> implement the answer very quickly as a proof point. > >>> > >>> Have not heard if the NIST testing is completed or when the next one > is. > >>> But for today all of the rcvrs are working just fine. > >>> Regards > >>> Paul > >>> WB8TSL > >>> ___ > >>> 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. > ___ 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 and Free Democracies Survival
Perry you mean like the 10' X 10' loop I put up? It has about 800 ft of wire. Brang the daytime signal fro 30 uv to an easy 60 +. Compared to a 2.5 ft loop. Yes higher power would be good. Regards paul On Sat, Jul 14, 2012 at 9:43 PM, Perry Sandeen wrote: > GM List, > > What has not been mentioned so far is national security needs of the > democratic nations of the world for uninterrupted accurate time/frequency > information that is not subject to interference or destruction by those > nations diametrically opposed to personal freedom. > > The United States GPS system is an unparalleled success providing > inexpensive time and frequency standards worldwide and it is relied on for > innumerable critical tasks. > > But it requires using satellites. They are subject to destruction or > degradation from the ground over the sovereign territory by those rouge > states that would be so inclined. The ability to destroy a satellite from > the earth has already ben demonstrated by one nation. There are numerous > reports of shall we say *Malicious Tinkering* on other satellites. > > Setting aside the enormous expense, technical difficulties such as the > need for sophisticated and extremely limited amount of rocket launches > available make the system unsustainable to GPS satellites continued > destruction or degradation from a land based source. > > The need for a strong viable redundancy is totally unfathomed upon those > in the current applicable leadership of the US government. One proof of > this was the shutting down of Loran C to save $35 M a year in a spending > amount of several trillion dollars a year. > > But Loran C gave us the best and cheapest redundant alternative to GPS and > perhaps might be revived. > > A viable WWVB signal, while a very poor third choice, provides an > alternate backup for GPS and in a strange way that could provide protection > at least for the USA GPS system. Here’s why. It still is very difficult > and expensive to damage/destroy satellites. That there are viable > alternatives based on unassailable sovereign territory may discourage the > rogue states from making such an effort. > > WWVB has a historically transmitted power of 50KW. This is the maximum AM > broadcast band signal transmission power allowed in the USA IIRC for about > 75 years. NIST sates the WWVB antennas having efficiencies of around 57 > per cent. > > Improved transmitting tube technology would easily allow more output > power. For example Riydah, Saudi Arabia transmits 2 MW on 1201 KHz and is > heard often in North America with a R-390A receiver. > > So a massive increase from 50KW to say for example to 500KW and or the > relocation of the transmitter and antennas to a more geographical central > U.S. state location (such as Iowa) could extend the 100 micro-volt per > meter signal level radiation pattern over the entire western hemisphere and > provide a high enough micro-volt per meter signal that receivers could > phase lock on the signal in North America and would not be subject to > problems of diurnal shift or the new modulation scheme. > > Baring an improved WWVB signal strength us time nuts may be forced to > install 20 to 30 ft. loop antennas when the new system is finalized for an > adequate signal. > > Regards, > > Perry Sandeen > > > ___ > 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] WWVB and Free Democracies Survival
GM List, What has not been mentioned so far is national security needs of the democratic nations of the world for uninterrupted accurate time/frequency information that is not subject to interference or destruction by those nations diametrically opposed to personal freedom. The United States GPS system is an unparalleled success providing inexpensive time and frequency standards worldwide and it is relied on for innumerable critical tasks. But it requires using satellites. They are subject to destruction or degradation from the ground over the sovereign territory by those rouge states that would be so inclined. The ability to destroy a satellite from the earth has already ben demonstrated by one nation. There are numerous reports of shall we say *Malicious Tinkering* on other satellites. Setting aside the enormous expense, technical difficulties such as the need for sophisticated and extremely limited amount of rocket launches available make the system unsustainable to GPS satellites continued destruction or degradation from a land based source. The need for a strong viable redundancy is totally unfathomed upon those in the current applicable leadership of the US government. One proof of this was the shutting down of Loran C to save $35 M a year in a spending amount of several trillion dollars a year. But Loran C gave us the best and cheapest redundant alternative to GPS and perhaps might be revived. A viable WWVB signal, while a very poor third choice, provides an alternate backup for GPS and in a strange way that could provide protection at least for the USA GPS system. Here’s why. It still is very difficult and expensive to damage/destroy satellites. That there are viable alternatives based on unassailable sovereign territory may discourage the rogue states from making such an effort. WWVB has a historically transmitted power of 50KW. This is the maximum AM broadcast band signal transmission power allowed in the USA IIRC for about 75 years. NIST sates the WWVB antennas having efficiencies of around 57 per cent. Improved transmitting tube technology would easily allow more output power. For example Riydah, Saudi Arabia transmits 2 MW on 1201 KHz and is heard often in North America with a R-390A receiver. So a massive increase from 50KW to say for example to 500KW and or the relocation of the transmitter and antennas to a more geographical central U.S. state location (such as Iowa) could extend the 100 micro-volt per meter signal level radiation pattern over the entire western hemisphere and provide a high enough micro-volt per meter signal that receivers could phase lock on the signal in North America and would not be subject to problems of diurnal shift or the new modulation scheme. Baring an improved WWVB signal strength us time nuts may be forced to install 20 to 30 ft. loop antennas when the new system is finalized for an adequate signal. Regards, Perry Sandeen ___ 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 a different approach to d-bpsk-r (cheating)
Hi Well between now and midnight, you will completely loose signal at least once. It's a pretty dramatic amplitude dip as sunset gets right to the "wrong" place. Bob On Jul 14, 2012, at 4:56 PM, paul swed wrote: > Bob > Yes nights are bad for me, east coast and MSF interference. > So it could be any number of 60 KHz crossing its just odd it lined up the > way it did and I double confirmed that I was not doing something silly like > using alternate triggers. > > Very careful analysis does show a 1-2 us jitter and at diurnal shift I > really expect something to change it has to. > Regards > Paul. > > On Sat, Jul 14, 2012 at 4:32 PM, Bob Camp wrote: > >> Hi >> >> The "zero crossing" is very arbitrary. If it's correct at the transmit >> site, it will then be off everywhere else by the speed of light / distance. >> You will appear to be correct once every wavelength away from Colorado >> (roughly every 3 miles). You won't really be correct because you are >> looking at a different zero crossing. >> >> As long as you don't have sunset or sunrise between you and the >> transmitter, WWVB is reasonably stable. At night you will get more signal, >> but also can have some skywave "stuff" in the mix. >> >> Bob >> >> On Jul 14, 2012, at 3:50 PM, paul swed wrote: >> >>> OK have been doing a lot of experimenting. >>> I was curious what is the GPS tick in relationship to wwvb. Especially >>> since it is a reliable 1 sec marker. >>> Using a Tbolt since everyone has one on the list. ;-) And monitoring the >> 10 >>> us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at >> least >>> 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick >>> rising edge. Expected some form of drift. >>> >>> Would not have actually thought there should be such a relationship or >> its >>> truly pot luck today. >>> WWVB today is also not running bpsk. >>> >>> Should such a relationship actually exist? >>> There is a clue in a 1985 article in ham radio magazine. >>> It went something like this. At any given instant the 60 Khz may jitter. >>> But for every 1 sec period there will be exactly 60,000 cycles. >>> >>> If it does stay aligned, then the cheating d-bpsk-r gets to be >> interesting >>> and very implementable. >>> >>> The approach using a micro to sample a squared up 60 Khz after the Tbolt >>> tic. >>> Perform 2-3 1 usec samples in the leading 90 degree signal. >>> Decide is it a 0 or 1 phase. >>> Select a inverted or non inverted 60 Khz into the output path to >> maintain a >>> constant phase 60 Khz for the old recvrs. >>> >>> Sure its cheating. But if this relationship is real I should be able to >>> implement the answer very quickly as a proof point. >>> >>> Have not heard if the NIST testing is completed or when the next one is. >>> But for today all of the rcvrs are working just fine. >>> Regards >>> Paul >>> WB8TSL >>> ___ >>> 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] WWVB a different approach to d-bpsk-r (cheating)
Paul, On 07/14/2012 10:56 PM, paul swed wrote: Bob Yes nights are bad for me, east coast and MSF interference. So it could be any number of 60 KHz crossing its just odd it lined up the way it did and I double confirmed that I was not doing something silly like using alternate triggers. As your house and antenna rig (nice antenna by the way) lies 2795060 m away from the WWVB transmitter house (approximation for north and south antenna phase-center to get a first measure) and considering that each 60 kHz cycle takes about 5 km (4996.54 m will do for approximation) it is not strange that they line up for you, as you are 559.399 cycles away from the WWVB antenna, and there are numbers of factors I haven't corrected for, like actual speed of light. How much ground wave are you seeing? Cheers, Magnus Very careful analysis does show a 1-2 us jitter and at diurnal shift I really expect something to change it has to. The amount of ionospheric reflection will most probably be part of it. 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 a different approach to d-bpsk-r (cheating)
Bob Yes nights are bad for me, east coast and MSF interference. So it could be any number of 60 KHz crossing its just odd it lined up the way it did and I double confirmed that I was not doing something silly like using alternate triggers. Very careful analysis does show a 1-2 us jitter and at diurnal shift I really expect something to change it has to. Regards Paul. On Sat, Jul 14, 2012 at 4:32 PM, Bob Camp wrote: > Hi > > The "zero crossing" is very arbitrary. If it's correct at the transmit > site, it will then be off everywhere else by the speed of light / distance. > You will appear to be correct once every wavelength away from Colorado > (roughly every 3 miles). You won't really be correct because you are > looking at a different zero crossing. > > As long as you don't have sunset or sunrise between you and the > transmitter, WWVB is reasonably stable. At night you will get more signal, > but also can have some skywave "stuff" in the mix. > > Bob > > On Jul 14, 2012, at 3:50 PM, paul swed wrote: > > > OK have been doing a lot of experimenting. > > I was curious what is the GPS tick in relationship to wwvb. Especially > > since it is a reliable 1 sec marker. > > Using a Tbolt since everyone has one on the list. ;-) And monitoring the > 10 > > us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at > least > > 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick > > rising edge. Expected some form of drift. > > > > Would not have actually thought there should be such a relationship or > its > > truly pot luck today. > > WWVB today is also not running bpsk. > > > > Should such a relationship actually exist? > > There is a clue in a 1985 article in ham radio magazine. > > It went something like this. At any given instant the 60 Khz may jitter. > > But for every 1 sec period there will be exactly 60,000 cycles. > > > > If it does stay aligned, then the cheating d-bpsk-r gets to be > interesting > > and very implementable. > > > > The approach using a micro to sample a squared up 60 Khz after the Tbolt > > tic. > > Perform 2-3 1 usec samples in the leading 90 degree signal. > > Decide is it a 0 or 1 phase. > > Select a inverted or non inverted 60 Khz into the output path to > maintain a > > constant phase 60 Khz for the old recvrs. > > > > Sure its cheating. But if this relationship is real I should be able to > > implement the answer very quickly as a proof point. > > > > Have not heard if the NIST testing is completed or when the next one is. > > But for today all of the rcvrs are working just fine. > > Regards > > Paul > > WB8TSL > > ___ > > 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] WWVB a different approach to d-bpsk-r (cheating)
Hi The "zero crossing" is very arbitrary. If it's correct at the transmit site, it will then be off everywhere else by the speed of light / distance. You will appear to be correct once every wavelength away from Colorado (roughly every 3 miles). You won't really be correct because you are looking at a different zero crossing. As long as you don't have sunset or sunrise between you and the transmitter, WWVB is reasonably stable. At night you will get more signal, but also can have some skywave "stuff" in the mix. Bob On Jul 14, 2012, at 3:50 PM, paul swed wrote: > OK have been doing a lot of experimenting. > I was curious what is the GPS tick in relationship to wwvb. Especially > since it is a reliable 1 sec marker. > Using a Tbolt since everyone has one on the list. ;-) And monitoring the 10 > us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at least > 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick > rising edge. Expected some form of drift. > > Would not have actually thought there should be such a relationship or its > truly pot luck today. > WWVB today is also not running bpsk. > > Should such a relationship actually exist? > There is a clue in a 1985 article in ham radio magazine. > It went something like this. At any given instant the 60 Khz may jitter. > But for every 1 sec period there will be exactly 60,000 cycles. > > If it does stay aligned, then the cheating d-bpsk-r gets to be interesting > and very implementable. > > The approach using a micro to sample a squared up 60 Khz after the Tbolt > tic. > Perform 2-3 1 usec samples in the leading 90 degree signal. > Decide is it a 0 or 1 phase. > Select a inverted or non inverted 60 Khz into the output path to maintain a > constant phase 60 Khz for the old recvrs. > > Sure its cheating. But if this relationship is real I should be able to > implement the answer very quickly as a proof point. > > Have not heard if the NIST testing is completed or when the next one is. > But for today all of the rcvrs are working just fine. > Regards > Paul > WB8TSL > ___ > 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] Advanced TBolt tuning using LH
Lady Heather is great tool to use for setting up a TBolt to make it much better than it's default settings. I've also learned several other tuning tricks to further improve a TBolt's performance, many of which would only be of interest to the extreme TBolt Nut. For example, The LadyHeather plot at: http://www.febo.com/pipermail/time-nuts/attachments/20120712/03b0a3f0/attachment-0001.gif shows a well set up TBolt, but it can be made even better with some advanced fine tweaking of its settings. Note before being concerned with any of the following advanced tuning items, It is important that all the things LH can set are done first, like the need to have a good position set and ... and ... and ... 0) I wonder why the "sat count" plot is turned off. I find that plot to be a very useful tool. For one thing, it makes sure the setting are never causing the TB to be using just one signal and therefore in danger of going into holdover. 1) Lowering the elevation mask from 39 to more like 15 to 25 will increase the number of satellites used. This tends to reduce the phase noise a little, and it especially reduces some small spikes in the phase plot that are caused when satellites are switched in and out. My goal is to keep a min of 4 or 5 satellites in use at all times. I'm guessing if the "sat count" plot was visible, it would show as few as two satellites are being use at some points, and that some of the short phase spikes are happening when switching between say 2 to 3 or 3 to2 satellites. 2) Along with #1, the AMU should be raised from 1.0 to more like 6 to 7.x to lock out any signal below ~38 dBc This will reduce the "bad satellite signals" that lower the elevation mask tends to let in. 3) To reduce that plots ~5ns daily phase ripple which is caused by the control loop trying to keep up with the daily DAC ripple, reduce the damping setting from 1.0 to 0.7. That will speed up the phase correction time by about two to one without effecting the control loop's TC and allow the control loop to change the DAC voltage faster as necessary without causing as much phase error to occur. 4) That TB has LH's active temperature controller holding the sensor temperature constant, but to further improve the TB's sensitivity to room temperature changes, which in turn will reduce the ~150uV daily DAC ripple cycles, which in turn will further reduce the phase variations. There are additional things that can be done. a) Lower the room temperature variations at the Tbolt, OR b) change the relative effect the cooling fan has on the OCXO vs. sensor location by changing the direction of the air flow or adding a little more or less heat sink / insulator to one side or the other of the TB's case. 5) Increasing the TC from 500 to 999 will cut the higher freq short term DAC noise in half, which has a direct effect on the OXCO noise below the TC frequency. I find that using the extended TC method with a TC of 1500 to 2000 works best after doing 1 - 4 above. Also, increasing the TC can help because the TB will not follow the GPS's hr to hr noise variations so closely. But to see the positive effect of that, an external reference source like a high stable CS or RB is needed. All LH can do is tell you how close the TB's OCXO is following the GPS. The problem is that the GPS's ~10ns PP phase noise can still be pretty noisy at 1000 seconds compared to a good OXCO in a great environment. 6) The most obvious, and maybe the lest possible thing to do is to get rid of the South West signal blockage or reflection. Looks like some sort of tall narrow close in obstruction. If the antenna can not be moved or raised to avoid the obstruction, maybe a chain saw would help, or a tree trimmer? Maybe some C4? 7) I find that turning on LH's display filter to about 100 second makes LH's plots more closely match the external real world data coming out of the TB. 8) I like to see the Osc plot turned on with its trend line visible, but with its gain turned down and its offset set so the plot is near the top of the graph and out of the way from the other plots. Sometimes the Osc plot will show things that I miss in the other plots. 9) I like to use view times set in Hours, i.e. 360, 480, 720 and 1440, and make the max data saved time longer than the 3 days default. I use 30 days, to better see which things are daily cycles, and to be able to view backward into the past. This is especially important when comparing the long term effect when fine tuning the things above. Isn't it fun being nuts with too much spare time? ws * ___ 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] Phase modulation detection/NIST plan
On Sat, Jul 14, 2012 at 06:15:14AM -0700, J. Forster wrote: > I don't see why school crossing signs, water sprinklers, street or outdoor > lighting need 1 second timing. Ten minutes, or a photocell, would be more > than adequate. While there are many many other applications, the issue for most of these devices is not 1 second accuracy, but automagic setting of the time without operator intervention or manual procedure required. For many ordinary folks the always slightly different push button gyrations required to set the time on a device with limited buttons and display are all too often a complete barrier to getting the time set right (this is the VCR "blinking 12:00AM" phenomenon). And in outside environments clock oscillator thermal behavior will ensure something preset to the correct will wander pretty far out quite quickly (plus of course DST needs to be set too). And working with only approximate time is another source of terrible confusion for users... if they set it to go off at exactly 11 PM and it goes off at 11:08 PM they are likely going to be confused and frustrated... especially if difficult or even impossible steps are required to correct the time. Photocells don't work for situations where the desired on or off times are civil times (not turning on the water sprinklers until 11 PM for example or turning off the tennis court lights at 10 PM)... at best it takes lots of software to convert light and dark from them to anything approximating a 10 minute accurate estimate of the time of day and shadows and sun angles and so forth ensure that this is never going to be particularly accurate. > Synchronized traffic lights, perhaps. But there are other cheaper, ways of > doing that like a simple radio link. I refuse to believe that a reliable mile or more range RF link would be cheaper than a loopstick and maybe a couple of passives tied to pins on a SOC chip... and there are all those situations where even a mile isn't enough or obstacles or RFI block ISM band links. -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either." ___ 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] WWVB a different approach to d-bpsk-r (cheating)
OK have been doing a lot of experimenting. I was curious what is the GPS tick in relationship to wwvb. Especially since it is a reliable 1 sec marker. Using a Tbolt since everyone has one on the list. ;-) And monitoring the 10 us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at least 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick rising edge. Expected some form of drift. Would not have actually thought there should be such a relationship or its truly pot luck today. WWVB today is also not running bpsk. Should such a relationship actually exist? There is a clue in a 1985 article in ham radio magazine. It went something like this. At any given instant the 60 Khz may jitter. But for every 1 sec period there will be exactly 60,000 cycles. If it does stay aligned, then the cheating d-bpsk-r gets to be interesting and very implementable. The approach using a micro to sample a squared up 60 Khz after the Tbolt tic. Perform 2-3 1 usec samples in the leading 90 degree signal. Decide is it a 0 or 1 phase. Select a inverted or non inverted 60 Khz into the output path to maintain a constant phase 60 Khz for the old recvrs. Sure its cheating. But if this relationship is real I should be able to implement the answer very quickly as a proof point. Have not heard if the NIST testing is completed or when the next one is. But for today all of the rcvrs are working just fine. Regards Paul WB8TSL ___ 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] Solar flare alert
On 7/14/12 9:19 AM, Joseph Gray wrote: Perhaps some of the cellular bands aren't affected, perhaps some are. I don't know the specific cause of yesterday's loss.. GPS uses around 1200/1500 MHz. The phone in question uses 850/1900 Mhz bands, so I think we're in the neighborhood. GPS signals pass through the ionosphere which greatly affected by solar weather. Terrestrial cellphone signals do not pass through the ionosphere, so flares don't necessarily change things. There is anecdotal evidence, though, that solar activity can change the environmental RF background noise level, and that could have an effect on cellphone link margins. ___ 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] Solar flare alert
Perhaps some of the cellular bands aren't affected, perhaps some are. I don't know the specific cause of yesterday's loss.. GPS uses around 1200/1500 MHz. The phone in question uses 850/1900 Mhz bands, so I think we're in the neighborhood. Joe Gray W5JG On Sat, Jul 14, 2012 at 9:35 AM, Alan Melia wrote: > Joe, Cellphone frequencies are little affected by ionospheric effects, so I > would be surprised if that was an effect though GPS is a different matter, > or sat-phone. > > Alan > G3NYK > > - Original Message - From: "Joseph Gray" > To: "Discussion of precise time and frequency measurement" > > Sent: Saturday, July 14, 2012 4:40 AM > Subject: Re: [time-nuts] Solar flare alert > > > >> I read about it yesterday. I suspect that we may already be seeing >> some radio interference. At work this afternoon, my cell phone lost >> signal entirely a few times. Although I don't get a great signal at >> work, it has never lost signal completely before. >> >> Joe Gray >> W5JG >> >> On Fri, Jul 13, 2012 at 8:50 PM, Mark Sims wrote: >>> >>> >>> There was a blurb on the news tonight about a big honkin' solar flare >>> that is due to arrive around 6:00 AM tomorrow morning. It's supposed to be >>> strong enough to produce auroras visible as far south as the Gulf of Mexico >>> and to mess up GPS... >>> ___ >>> 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] Solar flare alert...not quite
Looks like this flare was a non-event: http://www.jackson-labs.com/images/gpsstat.htm On Jul 14, 2012, at 7:49, "Alan Melia" wrote: > It's not actually a flare.that has been and gobe it a great bif glob of > plasma, ejected by the same region. Spaceweather.com has a reputation for > over-hyping these CME events. I could cause problems but there are a lot of > conditions to be met before it is a disaster. Enjoy the aurora :-)) > > Alan > G3NYK > - Original Message - From: "Mark Sims" > To: > Sent: Saturday, July 14, 2012 3:50 AM > Subject: [time-nuts] Solar flare alert > > >> >> There was a blurb on the news tonight about a big honkin' solar flare that >> is due to arrive around 6:00 AM tomorrow morning. It's supposed to be >> strong enough to produce auroras visible as far south as the Gulf of Mexico >> and to mess up GPS... >> ___ >> 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] Solar flare alert
Joe, Cellphone frequencies are little affected by ionospheric effects, so I would be surprised if that was an effect though GPS is a different matter, or sat-phone. Alan G3NYK - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" Sent: Saturday, July 14, 2012 4:40 AM Subject: Re: [time-nuts] Solar flare alert I read about it yesterday. I suspect that we may already be seeing some radio interference. At work this afternoon, my cell phone lost signal entirely a few times. Although I don't get a great signal at work, it has never lost signal completely before. Joe Gray W5JG On Fri, Jul 13, 2012 at 8:50 PM, Mark Sims wrote: There was a blurb on the news tonight about a big honkin' solar flare that is due to arrive around 6:00 AM tomorrow morning. It's supposed to be strong enough to produce auroras visible as far south as the Gulf of Mexico and to mess up GPS... ___ 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] Sigem SGM5610 GPS module AKA MKN5610
Using the FILECROP searching tool a .PDF of 48MB comes out... maybe the size indication is wrong. On Sat, Jul 14, 2012 at 4:42 PM, wrote: > Not sure what you've found that's 48MB, this one is only 1650KB:-) > > _http://rapidshare.com/files/317504924/MKN5610_060502.pdf_ > (http://rapidshare.com/files/317504924/MKN5610_060502.pdf) > > It does mention a software utility called ADK View, but I've never found a > copy of that. > > Regards > > Nigel > GM8PZR > > -- > In a message dated 14/07/2012 15:25:45 GMT Daylight Time, > azelio.bori...@screen.it writes: > > Oh, is it the 48MB .PDF I have just seen? Then no utilities... this is > very > strange. > > ___ > 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] Solar flare alert...not quite
It's not actually a flare.that has been and gobe it a great bif glob of plasma, ejected by the same region. Spaceweather.com has a reputation for over-hyping these CME events. I could cause problems but there are a lot of conditions to be met before it is a disaster. Enjoy the aurora :-)) Alan G3NYK - Original Message - From: "Mark Sims" To: Sent: Saturday, July 14, 2012 3:50 AM Subject: [time-nuts] Solar flare alert There was a blurb on the news tonight about a big honkin' solar flare that is due to arrive around 6:00 AM tomorrow morning. It's supposed to be strong enough to produce auroras visible as far south as the Gulf of Mexico and to mess up GPS... ___ 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] Sigem SGM5610 GPS module AKA MKN5610
Not sure what you've found that's 48MB, this one is only 1650KB:-) _http://rapidshare.com/files/317504924/MKN5610_060502.pdf_ (http://rapidshare.com/files/317504924/MKN5610_060502.pdf) It does mention a software utility called ADK View, but I've never found a copy of that. Regards Nigel GM8PZR -- In a message dated 14/07/2012 15:25:45 GMT Daylight Time, azelio.bori...@screen.it writes: Oh, is it the 48MB .PDF I have just seen? Then no utilities... this is very strange. ___ 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] L/H Screen Resolution setting
I am a bit confused about Lady Heather's settings for screen resolution. /vc=rowsXcols - custom screen size (e.g. /vc=1200x800) My laptop's native resolution is 1280 x 800 pixels but pixels and rows & cols are different measurements right? Is there a correlation? I am getting the "scaled down" window and I can't get the satellite azimuth/elevation plot. Any coaching would be appreciated. 73 Brad Dye, K9IQY ___ 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] Sigem SGM5610 GPS module AKA MKN5610
Oh, is it the 48MB .PDF I have just seen? Then no utilities... this is very strange. On Sat, Jul 14, 2012 at 4:22 PM, Azelio Boriani wrote: > Yes, interesting... I have never downloaded but maybe in those files there > is a utility, a viewer, a document that is useful with other GPS receivers > or even for other purposes. > > > On Sat, Jul 14, 2012 at 4:13 PM, wrote: > >> Just out of interest, does anyone know why the Sigem SGM5610 GPS module, >> later rebranded as the Mobile Knowledge MKN5610, seems to be very >> popular? >> >> I can't find a spec for 1PPS accuracy in either the data sheet or manual >> so wouldn't expect too much demand for timing purposes, but of all the >> files >> I've made available over the past few years via my Rapidshare account this >> one consistently tops the "best seller" list, and I don't recall posting >> notice of its availability anywhere other than here. >> >> Demand for most files tails off as they get uploaded elsewhere and become >> more generally available but this one just continues to flow out the door >> at a steady trickle, it's up to 260 downloads now and with no signs of it >> stopping anytime soon:-) >> >> Regards >> >> Nigel >> GM8PZR >> ___ >> 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] Sigem SGM5610 GPS module AKA MKN5610
Yes, interesting... I have never downloaded but maybe in those files there is a utility, a viewer, a document that is useful with other GPS receivers or even for other purposes. On Sat, Jul 14, 2012 at 4:13 PM, wrote: > Just out of interest, does anyone know why the Sigem SGM5610 GPS module, > later rebranded as the Mobile Knowledge MKN5610, seems to be very popular? > > I can't find a spec for 1PPS accuracy in either the data sheet or manual > so wouldn't expect too much demand for timing purposes, but of all the > files > I've made available over the past few years via my Rapidshare account this > one consistently tops the "best seller" list, and I don't recall posting > notice of its availability anywhere other than here. > > Demand for most files tails off as they get uploaded elsewhere and become > more generally available but this one just continues to flow out the door > at a steady trickle, it's up to 260 downloads now and with no signs of it > stopping anytime soon:-) > > Regards > > Nigel > GM8PZR > ___ > 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] Sigem SGM5610 GPS module AKA MKN5610
Just out of interest, does anyone know why the Sigem SGM5610 GPS module, later rebranded as the Mobile Knowledge MKN5610, seems to be very popular? I can't find a spec for 1PPS accuracy in either the data sheet or manual so wouldn't expect too much demand for timing purposes, but of all the files I've made available over the past few years via my Rapidshare account this one consistently tops the "best seller" list, and I don't recall posting notice of its availability anywhere other than here. Demand for most files tails off as they get uploaded elsewhere and become more generally available but this one just continues to flow out the door at a steady trickle, it's up to 260 downloads now and with no signs of it stopping anytime soon:-) Regards Nigel GM8PZR ___ 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] Phase modulation detection/NIST plan
I don't see why school crossing signs, water sprinklers, street or outdoor lighting need 1 second timing. Ten minutes, or a photocell, would be more than adequate. Synchronized traffic lights, perhaps. But there are other cheaper, ways of doing that like a simple radio link. -John === > > d...@dieconsulting.com said: >> There are innumerable applications for low cost low power human level 1 >> second accurate time of day in modern electronic systems - examples are >> traffic lights and school crossing signs and water sprinklers and street >> lights and other outdoor lighting and many others... these systems are >> not >> normally network connected and there is no current wide area technology >> short of power hungry GPS with its weak signals and relatively high cost >> and >> difficult reception from many locations to do this. > > How many of those are really interested in low power? > > The only one I see on your list that might run off batteries is water > sprinklers. All the rest use enough power that a GPS unit would be in the > noise. > > I think the main argument for WWVB receivers vs GPS receivers would be > cost. > In either case, you have to get the antenna outside the metal enclosure > and > that may be the major cost. (I suppose a sprinkler controller could be > mounted in a plastic enclosure.) > > "school crossing signs" is another possibility. In the last year or two, > I've seen several setups around here that have solar powered LEDs mounted > at > street level at pedestrian crossings. They are great at night but not so > great during the day. (But during the day the pedestrians are easier to > see.) > > > > -- > These are my opinions. 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] Phase modulation detection/NIST plan
Hi I think the answer to "how many places would it be used" is to simply count the number of things that have the wrong time on them each time the power burps. There are maybe a dozen gizmos like that in this room (yes I'm in the kitchen). Bob On Jul 14, 2012, at 12:41 AM, Hal Murray wrote: > > d...@dieconsulting.com said: >> There are innumerable applications for low cost low power human level 1 >> second accurate time of day in modern electronic systems - examples are >> traffic lights and school crossing signs and water sprinklers and street >> lights and other outdoor lighting and many others... these systems are not >> normally network connected and there is no current wide area technology >> short of power hungry GPS with its weak signals and relatively high cost and >> difficult reception from many locations to do this. > > How many of those are really interested in low power? > > The only one I see on your list that might run off batteries is water > sprinklers. All the rest use enough power that a GPS unit would be in the > noise. > > I think the main argument for WWVB receivers vs GPS receivers would be cost. > In either case, you have to get the antenna outside the metal enclosure and > that may be the major cost. (I suppose a sprinkler controller could be > mounted in a plastic enclosure.) > > "school crossing signs" is another possibility. In the last year or two, > I've seen several setups around here that have solar powered LEDs mounted at > street level at pedestrian crossings. They are great at night but not so > great during the day. (But during the day the pedestrians are easier to see.) > > > > -- > These are my opinions. 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] Phase modulation detection/NIST plan
On 07/14/2012 06:47 AM, Brooke Clarke wrote: Hi: The key thing GPS is lacking is Daylight Savings Time. WWV & WWVB have the DST bits that allow a clock to show the local time. One reason GPS doesn't have it is that it is not coordinated globally. For instance, US is not shifting DST at the same time as Europe. There is no obvious "right" here. Keeping track of the time-zones and their changes keeps the time-zone folks alert and requires a constant maintenance. Keeping it in the GPS signal would require mapping of position to time-zone area, and only then it could be keyed down. These mappings does not stay stable, so any downlink format would need to describe them and would take considerable time. This is why it is best managed by the user himself. 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] Lock-in amplifier as wwvb receiver
On 14 July 2012 04:04, Bill Fuqua wrote: >Has anyone ever used an Lock-in Amplifier such as > a PAR HR-8 or later models as part of a receiving > system for WWVB? These are mostly used in detecting > weak signals in noise in scientific experiments. Some have used > the analog output to phase lock a voltage controlled > oscillator to the input signal. > > > 73 > Bill wa4lav Slightly different, but here's a video of someone using an Standard Research lock in amp as an AM receiver. http://www.youtube.com/watch?v=8R9bbdAdUHg This particular model is Standard's RF lock in, which IIRC works to 200 MHz. But 60 kHz should be within the range of most lock-in amps. Dave ___ 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.
