Re: [time-nuts] HP 117/10509a...
Hi On Jul 8, 2012, at 1:17 AM, David J Taylor wrote: As an observer from across the pond: - presumably, the vast majority of users would not be affected. Yes, the wall clock and wrist watch people (I use both) would not be impacted according to NIST. I have seen no reports of, and not observed any impact on my stuff. - is there a technical solution which would be compatible with both old and new methods? Some alternative modulation scheme? The whole format of the change has been under the guise of a government investment in a technology company. That's taken the whole debate about modulation formats out of the public eye. The goals of the new modulation scheme are a bit unclear, so it's difficult to evaluate alternatives. One would *assume* that the cost of silicon to demodulate the new format is a major part of the decision on the new approach. That said, yes there has to be another way to do this that does not nuke the old gear. - is there not a testing period, where results can be fed back as to the compatibility or otherwise of the new scheme? There have been tests. There is no official / formal feedback mechanism for the tests. It's not totally clear what any of the testing results are. One would *guess* that they are testing a silicon implementation of their receiver in the field. One would also *guess* that nothing important is impacted by the modulation. - has there been any official response to your comments that the new scheme stops existing equipment working properly? The response has been: Yes we know this breaks your stuff. They have put that in writing. There is a somewhat vague promise that a box that translates the new format to one the old gear can use could / would / might be developed. No idea at all what such a box would look like or cost. Also no idea how well it would perform. - can you involve your members of the legislature, or would the be either inappropriate or a waste of time? Based on past experience - waste of time, even in an election year. The subject is to hard to understand and not enough voters are impacted. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] HP 117/10509a...
To be very clear here. There is not a box coming from NIST. They do not want the responsibility to maintain what ever it would be. The reason to make the change to the format is for better frequency and time distribution by this channel. It seeks to improve overall system gain and attempts to negate interference from MSF at least in regions of the east. Whats very interesting is that the silicon would in some way recover a carrier to recover the data. If that carrier happened to be on a pin of the chip then you might take advantage of this new method and it could then be used perhaps to drive the old equipment. I certainly have no problem with such an approach. But suspect the rcvr will be multi- and have to saythats not in the ole budget. Further wwvb has not been a great way to distribute frequency for 20 years. We time-nuts all have done far better with GPS. Granted no way to check it against anything else. So I simply do not understand the why of all of this. Not throwing stones here. Its just thats one big electric bill every month and there has to be a bit more clever alternate national freq dist method that would be far more economical and deliver better coverage and interference rejection. Think about it, this new modulation method with say 5 transmitters at lower power. Central site to control stability though at that point lots of other approaches come into play. Oh thats LORAN C sorry. Just very curious as to why the two approaches, especially since we also know eloran is also being explored. All of this is getting wa off topic. Regards Paul On 7/8/2012 6:50 AM, Bob Camp wrote: Hi On Jul 8, 2012, at 1:17 AM, David J Taylor wrote: As an observer from across the pond: - presumably, the vast majority of users would not be affected. Yes, the wall clock and wrist watch people (I use both) would not be impacted according to NIST. I have seen no reports of, and not observed any impact on my stuff. - is there a technical solution which would be compatible with both old and new methods? Some alternative modulation scheme? The whole format of the change has been under the guise of a government investment in a technology company. That's taken the whole debate about modulation formats out of the public eye. The goals of the new modulation scheme are a bit unclear, so it's difficult to evaluate alternatives. One would *assume* that the cost of silicon to demodulate the new format is a major part of the decision on the new approach. That said, yes there has to be another way to do this that does not nuke the old gear. - is there not a testing period, where results can be fed back as to the compatibility or otherwise of the new scheme? There have been tests. There is no official / formal feedback mechanism for the tests. It's not totally clear what any of the testing results are. One would *guess* that they are testing a silicon implementation of their receiver in the field. One would also *guess* that nothing important is impacted by the modulation. - has there been any official response to your comments that the new scheme stops existing equipment working properly? The response has been: Yes we know this breaks your stuff. They have put that in writing. There is a somewhat vague promise that a box that translates the new format to one the old gear can use could / would / might be developed. No idea at all what such a box would look like or cost. Also no idea how well it would perform. - can you involve your members of the legislature, or would the be either inappropriate or a waste of time? Based on past experience - waste of time, even in an election year. The subject is to hard to understand and not enough voters are impacted. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] HP 117/10509a...
Hi I'd bet at least a cold order of fries that what ever chip comes out of this is going to be a cheap one. At least that will be true after a couple years. The target market is wall clocks… Bob On Jul 8, 2012, at 10:29 AM, paul wrote: To be very clear here. There is not a box coming from NIST. They do not want the responsibility to maintain what ever it would be. The reason to make the change to the format is for better frequency and time distribution by this channel. It seeks to improve overall system gain and attempts to negate interference from MSF at least in regions of the east. Whats very interesting is that the silicon would in some way recover a carrier to recover the data. If that carrier happened to be on a pin of the chip then you might take advantage of this new method and it could then be used perhaps to drive the old equipment. I certainly have no problem with such an approach. But suspect the rcvr will be multi- and have to saythats not in the ole budget. Further wwvb has not been a great way to distribute frequency for 20 years. We time-nuts all have done far better with GPS. Granted no way to check it against anything else. So I simply do not understand the why of all of this. Not throwing stones here. Its just thats one big electric bill every month and there has to be a bit more clever alternate national freq dist method that would be far more economical and deliver better coverage and interference rejection. Think about it, this new modulation method with say 5 transmitters at lower power. Central site to control stability though at that point lots of other approaches come into play. Oh thats LORAN C sorry. Just very curious as to why the two approaches, especially since we also know eloran is also being explored. All of this is getting wa off topic. Regards Paul On 7/8/2012 6:50 AM, Bob Camp wrote: Hi On Jul 8, 2012, at 1:17 AM, David J Taylor wrote: As an observer from across the pond: - presumably, the vast majority of users would not be affected. Yes, the wall clock and wrist watch people (I use both) would not be impacted according to NIST. I have seen no reports of, and not observed any impact on my stuff. - is there a technical solution which would be compatible with both old and new methods? Some alternative modulation scheme? The whole format of the change has been under the guise of a government investment in a technology company. That's taken the whole debate about modulation formats out of the public eye. The goals of the new modulation scheme are a bit unclear, so it's difficult to evaluate alternatives. One would *assume* that the cost of silicon to demodulate the new format is a major part of the decision on the new approach. That said, yes there has to be another way to do this that does not nuke the old gear. - is there not a testing period, where results can be fed back as to the compatibility or otherwise of the new scheme? There have been tests. There is no official / formal feedback mechanism for the tests. It's not totally clear what any of the testing results are. One would *guess* that they are testing a silicon implementation of their receiver in the field. One would also *guess* that nothing important is impacted by the modulation. - has there been any official response to your comments that the new scheme stops existing equipment working properly? The response has been: Yes we know this breaks your stuff. They have put that in writing. There is a somewhat vague promise that a box that translates the new format to one the old gear can use could / would / might be developed. No idea at all what such a box would look like or cost. Also no idea how well it would perform. - can you involve your members of the legislature, or would the be either inappropriate or a waste of time? Based on past experience - waste of time, even in an election year. The subject is to hard to understand and not enough voters are impacted. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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
Re: [time-nuts] HP 117/10509a...
IMO, a better way to provide the service would be to just turn a couple of LORAN-C stations back on. But that would be a tacit admission of another stupid government screwup. This WWVB scheme can possibly be spun as an 'improvement'- hence politically less distasteful, even if more expensive for the users. YMMV. , -John To be very clear here. There is not a box coming from NIST. They do not want the responsibility to maintain what ever it would be. The reason to make the change to the format is for better frequency and time distribution by this channel. It seeks to improve overall system gain and attempts to negate interference from MSF at least in regions of the east. Whats very interesting is that the silicon would in some way recover a carrier to recover the data. If that carrier happened to be on a pin of the chip then you might take advantage of this new method and it could then be used perhaps to drive the old equipment. I certainly have no problem with such an approach. But suspect the rcvr will be multi- and have to saythats not in the ole budget. Further wwvb has not been a great way to distribute frequency for 20 years. We time-nuts all have done far better with GPS. Granted no way to check it against anything else. So I simply do not understand the why of all of this. Not throwing stones here. Its just thats one big electric bill every month and there has to be a bit more clever alternate national freq dist method that would be far more economical and deliver better coverage and interference rejection. Think about it, this new modulation method with say 5 transmitters at lower power. Central site to control stability though at that point lots of other approaches come into play. Oh thats LORAN C sorry. Just very curious as to why the two approaches, especially since we also know eloran is also being explored. All of this is getting wa off topic. Regards Paul On 7/8/2012 6:50 AM, Bob Camp wrote: Hi On Jul 8, 2012, at 1:17 AM, David J Taylor wrote: As an observer from across the pond: - presumably, the vast majority of users would not be affected. Yes, the wall clock and wrist watch people (I use both) would not be impacted according to NIST. I have seen no reports of, and not observed any impact on my stuff. - is there a technical solution which would be compatible with both old and new methods? Some alternative modulation scheme? The whole format of the change has been under the guise of a government investment in a technology company. That's taken the whole debate about modulation formats out of the public eye. The goals of the new modulation scheme are a bit unclear, so it's difficult to evaluate alternatives. One would *assume* that the cost of silicon to demodulate the new format is a major part of the decision on the new approach. That said, yes there has to be another way to do this that does not nuke the old gear. - is there not a testing period, where results can be fed back as to the compatibility or otherwise of the new scheme? There have been tests. There is no official / formal feedback mechanism for the tests. It's not totally clear what any of the testing results are. One would *guess* that they are testing a silicon implementation of their receiver in the field. One would also *guess* that nothing important is impacted by the modulation. - has there been any official response to your comments that the new scheme stops existing equipment working properly? The response has been: Yes we know this breaks your stuff. They have put that in writing. There is a somewhat vague promise that a box that translates the new format to one the old gear can use could / would / might be developed. No idea at all what such a box would look like or cost. Also no idea how well it would perform. - can you involve your members of the legislature, or would the be either inappropriate or a waste of time? Based on past experience - waste of time, even in an election year. The subject is to hard to understand and not enough voters are impacted. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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
Re: [time-nuts] HP 117/10509a...
Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Now that starts to become really a lot of fun. I already built a much larger antenna 10 ft by 10 ft loop 25 turns... Lot of gain added. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10
Re: [time-nuts] HP 117/10509a...
Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10 MHz), delay it by storing samples in RAM for one bit time of the low speed code and use that entire interval to decide which phase you were
Re: [time-nuts] HP 117/10509a...
- Original Message - From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, July 07, 2012 11:30 AM Subject: Re: [time-nuts] HP 117/10509a... Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Regards Paul Hi Paul et. al., Is there any farther information on Loran or eLoran? Is it dead for good? Regards, Tom ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Not a peep. They may still be testing but I needed to use the feedline for the new 10ft loop for wwvb. Need to get loran cooking again. On Sat, Jul 7, 2012 at 11:44 AM, Tom Miller tmil...@skylinenet.net wrote: - Original Message - From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, July 07, 2012 11:30 AM Subject: Re: [time-nuts] HP 117/10509a... Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Regards Paul Hi Paul et. al., Is there any farther information on Loran or eLoran? Is it dead for good? Regards, Tom __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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] HP 117/10509a...
Hi It *may* turn out to be easier to receive and demodulate the new signal, then use it to de-bpsk the signal to an older box than to try to strip the bpsk. I agree that they may not change anything, but I'd hate to get it all running and have them make a change. Bob On Jul 7, 2012, at 11:30 AM, paul wrote: Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Now that starts to become really a lot of fun. I already built a much larger antenna 10 ft by 10 ft loop 25 turns... Lot of gain added. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous
Re: [time-nuts] HP 117/10509a...
Why bother? If you have to build/buy a new receiver to make your old receiver work, why not just use the new receiver? YMMV, -John === Hi It *may* turn out to be easier to receive and demodulate the new signal, then use it to de-bpsk the signal to an older box than to try to strip the bpsk. I agree that they may not change anything, but I'd hate to get it all running and have them make a change. Bob On Jul 7, 2012, at 11:30 AM, paul wrote: Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Now that starts to become really a lot of fun. I already built a much larger antenna 10 ft by 10 ft loop 25 turns... Lot of gain added. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the
Re: [time-nuts] HP 117/10509a...
Hi … because some want to keep the old stuff going. It's a hobby. Indeed my interest would mainly be in simply building a new (cheap) receiver. Bob On Jul 7, 2012, at 12:22 PM, J. Forster wrote: Why bother? If you have to build/buy a new receiver to make your old receiver work, why not just use the new receiver? YMMV, -John === Hi It *may* turn out to be easier to receive and demodulate the new signal, then use it to de-bpsk the signal to an older box than to try to strip the bpsk. I agree that they may not change anything, but I'd hate to get it all running and have them make a change. Bob On Jul 7, 2012, at 11:30 AM, paul wrote: Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Now that starts to become really a lot of fun. I already built a much larger antenna 10 ft by 10 ft loop 25 turns... Lot of gain added. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc)
Re: [time-nuts] HP 117/10509a...
John I am with Bob on this. Its to keep the gear ticking and an alternate to GPS (Sort of). But there is a huge difference between this and LORAN C. Here there is an opportunity to evolve as compared to LORAN that was simply killed. Further maybe even obtain better performance. But thats far from my concern right now. I simply want to get the systems back online to watch propagation behaviors as I have for years. Maybe in the future there will be a $7 chip set that magically does whats been written by nist/John Lowe. Or like someone suggested we get the dtv tuner coupon. :-) Not likely. But it does truly seem possible to succeed on this. Maybe its our skills that are insufficient to pull this off. But I haven't given up at all. Just delayed with family... Can't wait to heat the soldering iron up late next week. Regards Paul On Sat, Jul 7, 2012 at 1:26 PM, Bob Camp li...@rtty.us wrote: Hi … because some want to keep the old stuff going. It's a hobby. Indeed my interest would mainly be in simply building a new (cheap) receiver. Bob On Jul 7, 2012, at 12:22 PM, J. Forster wrote: Why bother? If you have to build/buy a new receiver to make your old receiver work, why not just use the new receiver? YMMV, -John === Hi It *may* turn out to be easier to receive and demodulate the new signal, then use it to de-bpsk the signal to an older box than to try to strip the bpsk. I agree that they may not change anything, but I'd hate to get it all running and have them make a change. Bob On Jul 7, 2012, at 11:30 AM, paul wrote: Pretty sure NIST will not do anything. Just to set expectations. We are fortunate that to some extent John Lowe is responding to questions. But we are on our own. I think the big lesson I have already learned is that there are lots of standard approaches to solving the problem Micros FPGAs dpll pll. But the fun comes in when you account for the 17 db amplitude variation for modulation. With propagation, with BPSK and sprinkle in noise thats higher in level then the signal that contains impulse and random crud. Now that starts to become really a lot of fun. I already built a much larger antenna 10 ft by 10 ft loop 25 turns... Lot of gain added. Regards Paul On 7/6/2012 11:28 AM, Bob Camp wrote: Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS
Re: [time-nuts] HP 117/10509a...
John I am with Bob on this. Its to keep the gear ticking and an alternate to GPS (Sort of). I agree with that objective, but, I have seen peoplwe take BC-611 radios and put cheap CB into the box. That interests me not in the slightest. But there is a huge difference between this and LORAN C. Here there is an opportunity to evolve as compared to LORAN that was simply killed. I agree the LORAN-C shutdown was idiotic, but NIST is essentially obsoleting all phase tracking receivers by going to BPSK. IMO, it is essentially like the change from LORAN-A to LORAN-C, except that it will happen at some defined date/time rather than over the years. Further maybe even obtain better performance. But thats far from my concern right now. I simply want to get the systems back online to watch propagation behaviors as I have for years. I don't see how. The time transmitted will have the same propagation issues as the 60 kHz, so will be subject to diurnal variations plus ionospheric randomness. Maybe in the future there will be a $7 chip set that magically does whats been written by nist/John Lowe. Or like someone suggested we get the dtv tuner coupon. :-) Not likely. Could well be just an EPROM, but you need all the other stuff to support it... antenna, cables, power supply. A $7 will not be the end of it. YMMV, -John But it does truly seem possible to succeed on this. Maybe its our skills that are insufficient to pull this off. But I haven't given up at all. Just delayed with family... Can't wait to heat the soldering iron up late next week. Regards Paul ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
On Sat, Jul 07, 2012 at 02:23:56PM -0700, J. Forster wrote: I agree with that objective, but, I have seen peoplwe take BC-611 radios and put cheap CB into the box. That interests me not in the slightest. John, Depends. For time of day receivers, a retrofit makes a lot of sense. Otherwise you need to deal with providing your own serial, IRIG, display, etc. outputs. I'm not sure I want to reimplement all that if I can pass the time code through and synthesize the modulation. At least in the short term. Long term, you want to develop the whole thing, but this will get receivers working until that can happen. [Warning: More whining below. :) ] I agree the LORAN-C shutdown was idiotic, but NIST is essentially obsoleting all phase tracking receivers by going to BPSK. IMO, it is essentially like the change from LORAN-A to LORAN-C, except that it will happen at some defined date/time rather than over the years. No, and that's my biggest problem. There /isn't/ a defined date/time. We got a week long experiment, then a month long experiment, then sometime in July or August this becomes permanent. If there had actually been a published timeline, as well as a published specification for the new modulation, so that we had time to work on this in advance, I'd really have no objection. But there are still no docs and we still have no date -- the best we can tell is, the change will happen before there is any additional documentation besides the PTTI paper. Supposedly this is because they are still testing, but who rolls out a change to a production service without knowing what it is until the last minute? Here, a lot of people received their notification from vendors like Spectracom -- why is a vendor notifying me of changes to a government service? Shouldn't NIST do that themselves? Why not a published announcement on the WWVB website? (Not just the testing announcements, but a real notification that a permanent change is pending and what it's going to look like.) Shoot, why not announcements on WWV/H? There's probably a fair bit of overlap in terms of people that use both. After the loss of LORAN, losing the only backup we have, without a defined timeframe, and with no ability to develop a receiver in advance, is really pretty bad. Even USCG gave us some notice. --msa ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Oh my now you are about to get me going but yes indeed. We are paying for the services and yet a new scheme comes out with documentation thats a bit sketchy in areas as I dug in. Some of its obvious on the second or 3rd read but you are still reading between the lines. However there does seem to be a company that will make $ off of the silicon they will develop. Kind of seems out of line. Regards Paul. On Sat, Jul 7, 2012 at 6:54 PM, Majdi S. Abbas m...@latt.net wrote: On Sat, Jul 07, 2012 at 02:23:56PM -0700, J. Forster wrote: I agree with that objective, but, I have seen peoplwe take BC-611 radios and put cheap CB into the box. That interests me not in the slightest. John, Depends. For time of day receivers, a retrofit makes a lot of sense. Otherwise you need to deal with providing your own serial, IRIG, display, etc. outputs. I'm not sure I want to reimplement all that if I can pass the time code through and synthesize the modulation. At least in the short term. Long term, you want to develop the whole thing, but this will get receivers working until that can happen. [Warning: More whining below. :) ] I agree the LORAN-C shutdown was idiotic, but NIST is essentially obsoleting all phase tracking receivers by going to BPSK. IMO, it is essentially like the change from LORAN-A to LORAN-C, except that it will happen at some defined date/time rather than over the years. No, and that's my biggest problem. There /isn't/ a defined date/time. We got a week long experiment, then a month long experiment, then sometime in July or August this becomes permanent. If there had actually been a published timeline, as well as a published specification for the new modulation, so that we had time to work on this in advance, I'd really have no objection. But there are still no docs and we still have no date -- the best we can tell is, the change will happen before there is any additional documentation besides the PTTI paper. Supposedly this is because they are still testing, but who rolls out a change to a production service without knowing what it is until the last minute? Here, a lot of people received their notification from vendors like Spectracom -- why is a vendor notifying me of changes to a government service? Shouldn't NIST do that themselves? Why not a published announcement on the WWVB website? (Not just the testing announcements, but a real notification that a permanent change is pending and what it's going to look like.) Shoot, why not announcements on WWV/H? There's probably a fair bit of overlap in terms of people that use both. After the loss of LORAN, losing the only backup we have, without a defined timeframe, and with no ability to develop a receiver in advance, is really pretty bad. Even USCG gave us some notice. --msa ___ 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] HP 117/10509a...
Maybe only 'favored' people are getting the inside information. It clearly would give a commercial advantage. -John = On Sat, Jul 07, 2012 at 02:23:56PM -0700, J. Forster wrote: I agree with that objective, but, I have seen peoplwe take BC-611 radios and put cheap CB into the box. That interests me not in the slightest. John, Depends. For time of day receivers, a retrofit makes a lot of sense. Otherwise you need to deal with providing your own serial, IRIG, display, etc. outputs. I'm not sure I want to reimplement all that if I can pass the time code through and synthesize the modulation. At least in the short term. Long term, you want to develop the whole thing, but this will get receivers working until that can happen. [Warning: More whining below. :) ] I agree the LORAN-C shutdown was idiotic, but NIST is essentially obsoleting all phase tracking receivers by going to BPSK. IMO, it is essentially like the change from LORAN-A to LORAN-C, except that it will happen at some defined date/time rather than over the years. No, and that's my biggest problem. There /isn't/ a defined date/time. We got a week long experiment, then a month long experiment, then sometime in July or August this becomes permanent. If there had actually been a published timeline, as well as a published specification for the new modulation, so that we had time to work on this in advance, I'd really have no objection. But there are still no docs and we still have no date -- the best we can tell is, the change will happen before there is any additional documentation besides the PTTI paper. Supposedly this is because they are still testing, but who rolls out a change to a production service without knowing what it is until the last minute? Here, a lot of people received their notification from vendors like Spectracom -- why is a vendor notifying me of changes to a government service? Shouldn't NIST do that themselves? Why not a published announcement on the WWVB website? (Not just the testing announcements, but a real notification that a permanent change is pending and what it's going to look like.) Shoot, why not announcements on WWV/H? There's probably a fair bit of overlap in terms of people that use both. After the loss of LORAN, losing the only backup we have, without a defined timeframe, and with no ability to develop a receiver in advance, is really pretty bad. Even USCG gave us some notice. --msa ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Hi … and because the documentation is sketchy, there just *may* be an oh, by the way, we didn't mention it earlier but the new modulation includes ….. sort of thing. Bob On Jul 7, 2012, at 7:53 PM, paul swed wrote: Oh my now you are about to get me going but yes indeed. We are paying for the services and yet a new scheme comes out with documentation thats a bit sketchy in areas as I dug in. Some of its obvious on the second or 3rd read but you are still reading between the lines. However there does seem to be a company that will make $ off of the silicon they will develop. Kind of seems out of line. Regards Paul. On Sat, Jul 7, 2012 at 6:54 PM, Majdi S. Abbas m...@latt.net wrote: On Sat, Jul 07, 2012 at 02:23:56PM -0700, J. Forster wrote: I agree with that objective, but, I have seen peoplwe take BC-611 radios and put cheap CB into the box. That interests me not in the slightest. John, Depends. For time of day receivers, a retrofit makes a lot of sense. Otherwise you need to deal with providing your own serial, IRIG, display, etc. outputs. I'm not sure I want to reimplement all that if I can pass the time code through and synthesize the modulation. At least in the short term. Long term, you want to develop the whole thing, but this will get receivers working until that can happen. [Warning: More whining below. :) ] I agree the LORAN-C shutdown was idiotic, but NIST is essentially obsoleting all phase tracking receivers by going to BPSK. IMO, it is essentially like the change from LORAN-A to LORAN-C, except that it will happen at some defined date/time rather than over the years. No, and that's my biggest problem. There /isn't/ a defined date/time. We got a week long experiment, then a month long experiment, then sometime in July or August this becomes permanent. If there had actually been a published timeline, as well as a published specification for the new modulation, so that we had time to work on this in advance, I'd really have no objection. But there are still no docs and we still have no date -- the best we can tell is, the change will happen before there is any additional documentation besides the PTTI paper. Supposedly this is because they are still testing, but who rolls out a change to a production service without knowing what it is until the last minute? Here, a lot of people received their notification from vendors like Spectracom -- why is a vendor notifying me of changes to a government service? Shouldn't NIST do that themselves? Why not a published announcement on the WWVB website? (Not just the testing announcements, but a real notification that a permanent change is pending and what it's going to look like.) Shoot, why not announcements on WWV/H? There's probably a fair bit of overlap in terms of people that use both. After the loss of LORAN, losing the only backup we have, without a defined timeframe, and with no ability to develop a receiver in advance, is really pretty bad. Even USCG gave us some notice. --msa ___ 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] HP 117/10509a...
As an observer from across the pond: - presumably, the vast majority of users would not be affected. - is there a technical solution which would be compatible with both old and new methods? Some alternative modulation scheme? - is there not a testing period, where results can be fed back as to the compatibility or otherwise of the new scheme? - has there been any official response to your comments that the new scheme stops existing equipment working properly? - can you involve your members of the legislature, or would the be either inappropriate or a waste of time? Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Lets see if this comes through. Not sure gmail is sending. As John has mentioned we have been working on this and I have concluded that something needs to keep the local oscillator in 1/2 of the cycle. Hate going back to some vco approach. But that seems to be the case. Tried forcing the miller divider into a given 1/2 cycle and because of its nature really could not. Sometimes it just can't be simple it seems. But I have not at all given up. Several comments. It is a 1hz modulation. The modulation formats quite complex. So setting a clock with it though useful and the future will take some work. The amplitude modulation is still there and as proven still locks the cheapy $12.95 clocks just fine. Itd oes not at all work with spectracoms XXX I am looking for a couple of spectracoms of the 8163 class for experimenting (Self inflicted torture). But I am looking for the ole flea market price. If we can get a fix going I want to confirm the fix works with them also. I have spent a lot of time doing much. But an approach that intrigues me and I have done nothing with is to remember the old phase compare the new phase per cycle and flip the phase back to the old if it changes. This can be a feed forward behavior. Not a PLL style solution. Granted it might take 2or 3 cycles of 60 Khz to get it figured out, but the old receivers most likely would smooth that out. Most likely will do this with a micro or some logic which would be fast. Kind of a missing edge or what direction is the carrier moving in detection approach. Regards Paul WB8TSL On 7/5/2012 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one
Re: [time-nuts] HP 117/10509a...
Hi My *guess* is that $50 is in the ball park for parts cost of a pretty good receiver for the new format. That does not include things like the external standard, antenna, frequency comparison stuff, power or case. I'd bound the range of the guess as $25 to $100. Bob On Jul 5, 2012, at 11:56 PM, J. Forster wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10 MHz), delay it by storing samples in RAM for one bit time of the low speed code and use that entire interval to decide which phase you were seeing and suitably adjust the output phase accordingly when you spit out the samples delayed by one bit time. This later approach would certainly be doable with modern processors mostly in software, certainly so if you could live with say 1-2 MHz sampling of the 60 KHz or so... and quite possibly also pretty nicely with a modest FPGA complete with the sample storage in the chip. Both approaches would be helped a lot if the architecture of the system allows prediction of absolute phase (eg not
Re: [time-nuts] HP 117/10509a...
On 7/5/2012 11:02 PM, David I. Emery wrote: On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10 MHz), delay it by storing samples in RAM for one bit time of the low speed code and use that entire interval to decide which phase you were seeing and suitably adjust the output phase accordingly when you spit out the samples delayed by one bit time. This later approach would certainly be doable with modern processors mostly in software, certainly so if you could live with say 1-2 MHz sampling of the 60 KHz or so... and quite possibly also pretty nicely with a modest FPGA complete with the sample storage in the chip. Both approaches would be helped a lot if the architecture of the system allows prediction of absolute phase (eg not differential encoding of unpredictable messages)... and AFAIK that is not yet set in stone and could be changed to allow this. The intent of both of these schemes would be to ultimately output a De-psk'd signal that older equipment could process using its antique analog circuitry without serious issues. Thus the output would be an attempt at a phase stable corrected version of the original signal... Certainly using a lab reference stable 10 MHz derived 960 Khz or whatever sampling clock to delay the signal one time code bit time should not produce significant 60 KHz phase wanderings at all... David I actually asked this ? to NIST and actually did not get an answer. From their documentation I believe that the the tick can actually be either direction. Its differentially encoded. That to me says it does not have to be in any particular direction. By not establishing a particular bias I believe there is an additional noise margin. Regards Paul ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
You get an idea of the required changes when you look at the 10509A antenna/preamplifier schematics in the 117A manual changes section. There are both versions, nuvistor and FET covered. It's perhaps not as trivial as one might wish. Adrian Ron Ward schrieb: Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
Schematics for all versions of the 10509A antenna: http://www.leapsecond.com/museum/10509a/ /tvb (iPhone4) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
Some time ago I made a 60 kHz antenna by winding a zillion turns of wire on a ferrite loopstick tuned with a padder condenser. This connected to the gate of a 2n4416 or mpf102. This was quite selective and sensitive. On 07/05/2012 02:45 AM, Tom Van Baak (lab) wrote: Schematics for all versions of the 10509A antenna: http://www.leapsecond.com/museum/10509a/ /tvb (iPhone4) ___ 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. -- 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] HP 117/10509a
Ron, I would certainly be interested in any conversion scheme that you come up with. I have 2 117's and hope to get them operational sooner rather than later. -:) Gordon WA4FJC Date: Thu, 5 Jul 2012 00:14:32 -0700 From: Ron Ward n6idl...@comcast.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a Message-ID: A12C52D31F1E4BFB96841D691B4E86DE@RonPC Content-Type: text/plain; charset=us-ascii Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
You do know that neither a 117A or a 207 will work when WWVB changes to BPSK fairy soon? -John === Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
Yes. I would definitely be interested in information on your conversion. Like you I would prefer attempting a successful conversion as I don't have the knowledge to develop one myself. Thanks, Merchison On 2012-07-05 3:14 AM, Ron Ward wrote: Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
NO! WOW! If this is true then you just saved me hours of work and lots of for something that would end up being useless. Will WWVB still be useable for frequency phase comparisons, perhaps by long integrating periods? I spent a lot of time and effort with LORAN and they just killed it. Technology just keeps costing me! Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 6:31 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a You do know that neither a 117A or a 207 will work when WWVB changes to BPSK fairy soon? -John === Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
As John has mentioned all of the old receivers are dead! They will not lock to the new BPSK signal. Though John and I have been working to see what can be done I have to say to date lots of methods have been tried and none really all that successful. These methods include phase lock, squaring/doubling and dividing. The normal types of things used to de-bpsk a signal. Or as I call the system the d-psk-r. I can see how these methods in general work. But the noise hits on the east coast are pretty troubling in causing phase flips. Essentially you need a way to force the the system into one side of the phase always at 120 Khz. So here is the approach I would take. The RF stage you are speaking about has 3 nuvistors and those would easily be replaced by 2 op amps with about 10 db of gain to spare. Simply build 60 KC tuned tanks between stages and you would be in business. I have no idea but the existing L+Cs might be useful here. Then when done you would have a fantastic wwvb signal strength meter and thats all. Its funny on the nuvistors I thought they would be an issue also. But I have been getting them for 2-3 dollars each and they do not really die all that often. On 7/5/2012 8:42 AM, Gordon Batey wrote: Ron, I would certainly be interested in any conversion scheme that you come up with. I have 2 117's and hope to get them operational sooner rather than later. -:) Gordon WA4FJC Date: Thu, 5 Jul 2012 00:14:32 -0700 From: Ron Ward n6idl...@comcast.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a Message-ID: A12C52D31F1E4BFB96841D691B4E86DE@RonPC Content-Type: text/plain; charset=us-ascii Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron ___ 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] HP 117/10509a
Hi again: Well I guess I will just use the Fluke 207 and HP117 for local standard comparisons. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 6:31 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a You do know that neither a 117A or a 207 will work when WWVB changes to BPSK fairy soon? -John === Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
Yes they will still work well for that and the 207 does much better then the 117 by about 10 X Regards Paul On 7/5/2012 10:52 AM, Ron Ward wrote: Hi again: Well I guess I will just use the Fluke 207 and HP117 for local standard comparisons. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 6:31 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a You do know that neither a 117A or a 207 will work when WWVB changes to BPSK fairy soon? -John === Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a
Hi: What is the new bandwidth for BPSK WWVB going to be? Why are they going to BPSK, cheaper clocks? How am I going to compare GPS to something to see if GPS is accurate? What about 400.1 MHz GEOS? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul Sent: Thursday, July 05, 2012 7:49 AM To: time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a As John has mentioned all of the old receivers are dead! They will not lock to the new BPSK signal. Though John and I have been working to see what can be done I have to say to date lots of methods have been tried and none really all that successful. These methods include phase lock, squaring/doubling and dividing. The normal types of things used to de-bpsk a signal. Or as I call the system the d-psk-r. I can see how these methods in general work. But the noise hits on the east coast are pretty troubling in causing phase flips. Essentially you need a way to force the the system into one side of the phase always at 120 Khz. So here is the approach I would take. The RF stage you are speaking about has 3 nuvistors and those would easily be replaced by 2 op amps with about 10 db of gain to spare. Simply build 60 KC tuned tanks between stages and you would be in business. I have no idea but the existing L+Cs might be useful here. Then when done you would have a fantastic wwvb signal strength meter and thats all. Its funny on the nuvistors I thought they would be an issue also. But I have been getting them for 2-3 dollars each and they do not really die all that often. On 7/5/2012 8:42 AM, Gordon Batey wrote: Ron, I would certainly be interested in any conversion scheme that you come up with. I have 2 117's and hope to get them operational sooner rather than later. -:) Gordon WA4FJC Date: Thu, 5 Jul 2012 00:14:32 -0700 From: Ron Ward n6idl...@comcast.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a Message-ID: A12C52D31F1E4BFB96841D691B4E86DE@RonPC Content-Type: text/plain; charset=us-ascii Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron ___ 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] HP 117/10509a
Not sure why the email did not send As John has mentioned all of the old receivers are dead! They will not lock to the new BPSK signal. Though John and I have been working to see what can be done I have to say to date lots of methods have been tried and none really all that successful. These methods include phase lock, squaring/doubling and dividing. The normal types of things used to de-bpsk a signal. Or as I call the system the d-psk-r. I can see how these methods in general work. But the noise hits on the east coast are pretty troubling in causing phase flips. Essentially you need a way to force the the system into one side of the phase always at 120 Khz. So here is the approach I would take. The RF stage you are speaking about has 3 nuvistors and those would easily be replaced by 2 op amps with about 10 db of gain to spare. Simply build 60 KC tuned tanks between stages and you would be in business. I have no idea but the existing L+Cs might be useful here. Then when done you would have a fantastic wwvb signal strength meter and thats all. Its funny on the nuvistors I thought they would be an issue also. But I have been getting them for 2-3 dollars each and they do not really die all that often. Regards Paul On 7/5/2012 10:58 AM, Ron Ward wrote: Hi: What is the new bandwidth for BPSK WWVB going to be? Why are they going to BPSK, cheaper clocks? How am I going to compare GPS to something to see if GPS is accurate? What about 400.1 MHz GEOS? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul Sent: Thursday, July 05, 2012 7:49 AM To: time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a As John has mentioned all of the old receivers are dead! They will not lock to the new BPSK signal. Though John and I have been working to see what can be done I have to say to date lots of methods have been tried and none really all that successful. These methods include phase lock, squaring/doubling and dividing. The normal types of things used to de-bpsk a signal. Or as I call the system the d-psk-r. I can see how these methods in general work. But the noise hits on the east coast are pretty troubling in causing phase flips. Essentially you need a way to force the the system into one side of the phase always at 120 Khz. So here is the approach I would take. The RF stage you are speaking about has 3 nuvistors and those would easily be replaced by 2 op amps with about 10 db of gain to spare. Simply build 60 KC tuned tanks between stages and you would be in business. I have no idea but the existing L+Cs might be useful here. Then when done you would have a fantastic wwvb signal strength meter and thats all. Its funny on the nuvistors I thought they would be an issue also. But I have been getting them for 2-3 dollars each and they do not really die all that often. On 7/5/2012 8:42 AM, Gordon Batey wrote: Ron, I would certainly be interested in any conversion scheme that you come up with. I have 2 117's and hope to get them operational sooner rather than later. -:) Gordon WA4FJC Date: Thu, 5 Jul 2012 00:14:32 -0700 From: Ron Ward n6idl...@comcast.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] HP 117/10509a Message-ID: A12C52D31F1E4BFB96841D691B4E86DE@RonPC Content-Type: text/plain; charset=us-ascii Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron ___ 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] HP 117/10509a...
Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
NO! WOW! If this is true then you just saved me hours of work and lots of for something that would end up being useless. It is true. It was discussed a few months ago. I have posted on the testing repeatedly. Will WWVB still be useable for frequency phase comparisons, perhaps by long integrating periods? No. The receivers must be modified or replaced. The mods are non-trivial in practice. I spent a lot of time and effort with LORAN and they just killed it. t least a year ago. -John = Technology just keeps costing me! Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 6:31 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a You do know that neither a 117A or a 207 will work when WWVB changes to BPSK fairy soon? -John === Thanks Charles: I will consider your ideas as they seem to be excellent! I wonder if I could just make the whole unit run off of +24VDC or +12 VDC. I need to look at the schematics and see what would be the best way to proceed. I currently do not have an antenna for WWVB and need to get up and running before I do anything with it. If successful, would anyone want information on my conversion? I also have a fluke 207 that needs to be recapped. Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Charles P. Steinmetz Sent: Wednesday, July 04, 2012 11:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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] HP 117/10509a...
I thought about doing that but I did not want to spend a lot of time experimenting fruitlessly. Thanks for the encouragement. Merchison On 2012-07-05 11:19 AM, Burt I. Weiner wrote: Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2437/5112 - Release Date: 07/05/12 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
On 7/4/2012 11:09 PM, Charles P. Steinmetz wrote: Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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. I have a PDF document that covers this for Fetrons. This is from Teledyne. It shows some of the more common tube replacements with the circuit and actual device number. Let me know if you would like a copy and I will sent it to you. Or, maybe a better option would be to upload it to something like Didiers site. . . Randy ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Jul 5, 2012, at 11:32 AM, Merchison Burke wrote: I thought about doing that but I did not want to spend a lot of time experimenting fruitlessly. Thanks for the encouragement. Merchison On 2012-07-05 11:19 AM, Burt I. Weiner wrote: Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2437/5112 - Release Date: 07/05/12 ___ 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] HP 117/10509a...
The only ones that will work are very recent designs. The HP 117 and Fluke 207 will not work. Many Spectracoms will not work. A few will. See their web site The Stanford 620 will not, I believe. Some models may. I posted a partial list some time ago. Apparently, NIST is working on a receiver and possibly a retrofit. When it will be available and how much it will cost is TBD. I suspect the 'retrofit' will be the receiver with a 60 kHz output added, nothing more, but don't know. Seems to me, we are down to one egg in one basket. :(( -John Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Jul 5, 2012, at 11:32 AM, Merchison Burke wrote: I thought about doing that but I did not want to spend a lot of time experimenting fruitlessly. Thanks for the encouragement. Merchison On 2012-07-05 11:19 AM, Burt I. Weiner wrote: Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2437/5112 - Release Date: 07/05/12 ___ 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] HP 117/10509a...
Hi Simple answer - they are still playing around with the signal format. It is totally unclear what the final format will really look like. Until they make up their minds there is only one safe bet - the clock on grandma's wall will still handle the wwvb format they use. Anything more complex than that is very much in the who knows category. Bob On Jul 5, 2012, at 1:07 PM, Edgardo Molina wrote: Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Jul 5, 2012, at 11:32 AM, Merchison Burke wrote: I thought about doing that but I did not want to spend a lot of time experimenting fruitlessly. Thanks for the encouragement. Merchison On 2012-07-05 11:19 AM, Burt I. Weiner wrote: Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2437/5112 - Release Date: 07/05/12 ___ 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] HP 117/10509a...
Hi: This is so frustrating! Who makes cheap clocks? CHINA. Who uses phase comparison? DOD, American Colleges and Universities, Laboratories, Astronomers, American Private Industry, Time Nuts, ETC. What is our government doing? They appear to be the best friend Chinese manufacturers ever had! Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 10:29 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a... The only ones that will work are very recent designs. The HP 117 and Fluke 207 will not work. Many Spectracoms will not work. A few will. See their web site The Stanford 620 will not, I believe. Some models may. I posted a partial list some time ago. Apparently, NIST is working on a receiver and possibly a retrofit. When it will be available and how much it will cost is TBD. I suspect the 'retrofit' will be the receiver with a 60 kHz output added, nothing more, but don't know. Seems to me, we are down to one egg in one basket. :(( -John Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Jul 5, 2012, at 11:32 AM, Merchison Burke wrote: I thought about doing that but I did not want to spend a lot of time experimenting fruitlessly. Thanks for the encouragement. Merchison On 2012-07-05 11:19 AM, Burt I. Weiner wrote: Many years ago I had one of these antennas that I used with a Gertsch RLF-1 WWVB receiver. When the Nuvistors became old and feeble I decided to change the 6CW4 Nuvistors to FETs. Being young and foolish and thinking this is basically audio, I went to Radio Shack and got some N-Channel FETs and stuffed the FET's leads into the appropriate Nuvistor socket pins: Gate to Grid, Source to Cathode, and Drain to Plate. As I recall, I had to add a wee bit of capacitance to make it tune back down to 60 KC - back then I didn't know from kHz. I made a voltage divider inside the antenna's junction box to get the higher voltage down to what the FETs wanted. It ran fine for the remaining 8 to10 years that I used the RLF-1's. I forget where the antenna went, but it may still be in use somewhere. At least I hope so. Burt, K6OQK From: Merchison Burke merchi...@yahoo.co.uk To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2437/5112 - Release Date: 07/05/12 ___ 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
Re: [time-nuts] HP 117/10509a...
Hi: This is so frustrating! Agreed. Who makes cheap clocks? CHINA. Who uses phase comparison? DOD, American Colleges and Universities, Laboratories, Astronomers, American Private Industry, Time Nuts, ETC. Not really. They have all drunk the GPS Kool-Aid. To allow a second source for a standard of time interval, carries the implication that GPS is not invulnerable. If that's true, people may wonder what else needs a backup, like navigation? Electric grid synchronization? Phones? What is our government doing? One man, one vote, (one time?). There are a lot more cheap Chinese 'Atomic' clocks sold every day than timing receivers sold in a year. Numbers count. They appear to be the best friend Chinese manufacturers ever had! Certainly true, in The Donald's view. The US government plays checkers, the Chinese and Japanese play Chess... to steal an analogy. US companies, driven by Wall Street quarter-over-quarter greed, think about the next quarter; Asian companies think about the next few decades. The switch to HDTV was supposed to be a giant stimulus for the US electronics industry, hence a US 'standard'. How did that work out? What fraction of HDTVs are US made? YMMV, -John == Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 10:29 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a... The only ones that will work are very recent designs. The HP 117 and Fluke 207 will not work. Many Spectracoms will not work. A few will. See their web site The Stanford 620 will not, I believe. Some models may. I posted a partial list some time ago. Apparently, NIST is working on a receiver and possibly a retrofit. When it will be available and how much it will cost is TBD. I suspect the 'retrofit' will be the receiver with a 60 kHz output added, nothing more, but don't know. Seems to me, we are down to one egg in one basket. :(( -John Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Hi The real question is weather the BPSK will help us get significantly better accuracy out of WWVB or not. If it does, time marches on. If not - total waste of effort. DSP based low frequency receivers are pretty easy to make. You still will need those antennas and preamps to make them work though. If I can get Loran-C type accuracy out of WWVB with the new modulation, I'll certainly build or buy a receiver. Bob On Jul 5, 2012, at 5:43 PM, J. Forster wrote: Hi: This is so frustrating! Agreed. Who makes cheap clocks? CHINA. Who uses phase comparison? DOD, American Colleges and Universities, Laboratories, Astronomers, American Private Industry, Time Nuts, ETC. Not really. They have all drunk the GPS Kool-Aid. To allow a second source for a standard of time interval, carries the implication that GPS is not invulnerable. If that's true, people may wonder what else needs a backup, like navigation? Electric grid synchronization? Phones? What is our government doing? One man, one vote, (one time?). There are a lot more cheap Chinese 'Atomic' clocks sold every day than timing receivers sold in a year. Numbers count. They appear to be the best friend Chinese manufacturers ever had! Certainly true, in The Donald's view. The US government plays checkers, the Chinese and Japanese play Chess... to steal an analogy. US companies, driven by Wall Street quarter-over-quarter greed, think about the next quarter; Asian companies think about the next few decades. The switch to HDTV was supposed to be a giant stimulus for the US electronics industry, hence a US 'standard'. How did that work out? What fraction of HDTVs are US made? YMMV, -John == Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Thursday, July 05, 2012 10:29 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a... The only ones that will work are very recent designs. The HP 117 and Fluke 207 will not work. Many Spectracoms will not work. A few will. See their web site The Stanford 620 will not, I believe. Some models may. I posted a partial list some time ago. Apparently, NIST is working on a receiver and possibly a retrofit. When it will be available and how much it will cost is TBD. I suspect the 'retrofit' will be the receiver with a 60 kHz output added, nothing more, but don't know. Seems to me, we are down to one egg in one basket. :(( -John Dear Group, This thread just saved me from a prospective purchase of an HP 117. Now the big question. Which instruments in general will be affected by the BPSK transition? I have been reading about Kinemetrics 60DC WWVB receiver and clock. It appeals to me if I find one. Will other WWVB instruments not designed specifically for phase comparisons be affected for the WWVB signal modulation changes? Which kind of instruments and interactions with WWVB should I avoid? Thank you. Your comments are surely welcome. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx ___ 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] HP 117/10509a...
From what I've read, the mods are to improve the Time of Day, not the Time Interval accuracy. In my location (MA) WWVB was never as good as LORAN-C because of propagation issues. -John === Hi The real question is weather the BPSK will help us get significantly better accuracy out of WWVB or not. If it does, time marches on. If not - total waste of effort. DSP based low frequency receivers are pretty easy to make. You still will need those antennas and preamps to make them work though. If I can get Loran-C type accuracy out of WWVB with the new modulation, I'll certainly build or buy a receiver. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
Hi Propagation isn't going to change with modulation format, so that part will still be with us. I'm wondering if some fancy processing on the new code might have some advantages. It's not worth digging into until they have a final format though. Bob On Jul 5, 2012, at 6:19 PM, J. Forster wrote: From what I've read, the mods are to improve the Time of Day, not the Time Interval accuracy. In my location (MA) WWVB was never as good as LORAN-C because of propagation issues. -John === Hi The real question is weather the BPSK will help us get significantly better accuracy out of WWVB or not. If it does, time marches on. If not - total waste of effort. DSP based low frequency receivers are pretty easy to make. You still will need those antennas and preamps to make them work though. If I can get Loran-C type accuracy out of WWVB with the new modulation, I'll certainly build or buy a receiver. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
On 7/5/2012 9:49 AM, Randy D. Hunt wrote: On 7/4/2012 11:09 PM, Charles P. Steinmetz wrote: Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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. I have a PDF document that covers this for Fetrons. This is from Teledyne. It shows some of the more common tube replacements with the circuit and actual device number. Let me know if you would like a copy and I will sent it to you. Or, maybe a better option would be to upload it to something like Didiers site. . . Randy ___ 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. Yes do upload it. I have some Fetrons and want to know what they replace. And in my other life, I ordered some custom Fetrons to replace some WE tubes that was used in WE K carrier. If you don't upload it, send a copy. Bill K7NOM ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
Hi: Yes, please make a .PDF File available! Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of bill Sent: Thursday, July 05, 2012 3:57 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 117/10509a On 7/5/2012 9:49 AM, Randy D. Hunt wrote: On 7/4/2012 11:09 PM, Charles P. Steinmetz wrote: Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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. I have a PDF document that covers this for Fetrons. This is from Teledyne. It shows some of the more common tube replacements with the circuit and actual device number. Let me know if you would like a copy and I will sent it to you. Or, maybe a better option would be to upload it to something like Didiers site. . . Randy ___ 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. Yes do upload it. I have some Fetrons and want to know what they replace. And in my other life, I ordered some custom Fetrons to replace some WE tubes that was used in WE K carrier. If you don't upload it, send a copy. Bill K7NOM ___ 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] HP 117/10509a...
If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. -John === Hi Propagation isn't going to change with modulation format, so that part will still be with us. I'm wondering if some fancy processing on the new code might have some advantages. It's not worth digging into until they have a final format though. Bob On Jul 5, 2012, at 6:19 PM, J. Forster wrote: From what I've read, the mods are to improve the Time of Day, not the Time Interval accuracy. In my location (MA) WWVB was never as good as LORAN-C because of propagation issues. -John === Hi The real question is weather the BPSK will help us get significantly better accuracy out of WWVB or not. If it does, time marches on. If not - total waste of effort. DSP based low frequency receivers are pretty easy to make. You still will need those antennas and preamps to make them work though. If I can get Loran-C type accuracy out of WWVB with the new modulation, I'll certainly build or buy a receiver. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] HP 117/10509a...
WWVB is weak in the Oregon Rain Forest. Oregon Scientific weather station consoles rarely get a good signal at my place. Ditto for a Radio Shack alarm clock. I did get workable reception back in the 70s using a PLL circuit from a book. That was before CFLs and switching power supplies. Loran-C signals were strong enough to overload some active antennas. -- 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] HP 117/10509a...
Hi And possibly if the bpsk does something useful, you can identify a carrier phase slip and correct for it…. Bob On Jul 5, 2012, at 7:19 PM, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. -John === Hi Propagation isn't going to change with modulation format, so that part will still be with us. I'm wondering if some fancy processing on the new code might have some advantages. It's not worth digging into until they have a final format though. Bob On Jul 5, 2012, at 6:19 PM, J. Forster wrote: From what I've read, the mods are to improve the Time of Day, not the Time Interval accuracy. In my location (MA) WWVB was never as good as LORAN-C because of propagation issues. -John === Hi The real question is weather the BPSK will help us get significantly better accuracy out of WWVB or not. If it does, time marches on. If not - total waste of effort. DSP based low frequency receivers are pretty easy to make. You still will need those antennas and preamps to make them work though. If I can get Loran-C type accuracy out of WWVB with the new modulation, I'll certainly build or buy a receiver. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] HP 117/10509a
On 7/5/2012 3:57 PM, bill wrote: On 7/5/2012 9:49 AM, Randy D. Hunt wrote: On 7/4/2012 11:09 PM, Charles P. Steinmetz wrote: Don wrote: the fet breakdown voltage has of course got to be high enough. If the nuvistor is used as a common-cathode or common-grid amplifier, you can cascode the fet with a bipolar to extend its drain voltage range. You will need to come up with an appropriate bias source for the bipolar. Generally, you would want at least 10-15 volts across the FET channel. Choose an appropriate JFET (transconductance, drain current, and gate-drain voltage similar to the nuvistor at the nuvistor's operating point). You can add degeneration (source resistance) to lower the FET's transconductance if it is higher than the nuvistor's. Best regards, Charles ___ 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. I have a PDF document that covers this for Fetrons. This is from Teledyne. It shows some of the more common tube replacements with the circuit and actual device number. Let me know if you would like a copy and I will sent it to you. Or, maybe a better option would be to upload it to something like Didiers site. . . Randy ___ 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. Yes do upload it. I have some Fetrons and want to know what they replace. And in my other life, I ordered some custom Fetrons to replace some WE tubes that was used in WE K carrier. If you don't upload it, send a copy. Bill K7NOM ___ 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. I uploaded the PDF to Didiers' site. Hope this helps some of you out there. . . Randy, KI6WAS ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10 MHz), delay it by storing samples in RAM for one bit time of the low speed code and use that entire interval to decide which phase you were seeing and suitably adjust the output phase accordingly when you spit out the samples delayed by one bit time. This later approach would certainly be doable with modern processors mostly in software, certainly so if you could live with say 1-2 MHz sampling of the 60 KHz or so... and quite possibly also pretty nicely with a modest FPGA complete with the sample storage in the chip. Both approaches would be helped a lot if the architecture of the system allows prediction of absolute phase (eg not differential encoding of unpredictable messages)... and AFAIK that is not yet set in stone and could be changed to allow this. The intent of both of these schemes would be to ultimately output a De-psk'd signal that older equipment could process using its antique analog circuitry without serious issues. Thus the output would be an attempt at a phase stable corrected version of the original signal... Certainly using a lab reference stable 10 MHz derived 960 Khz or whatever sampling clock to delay the signal one time code bit time should not produce significant 60 KHz phase wanderings at all... -- 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.
Re: [time-nuts] HP 117/10509a...
Glad to know that it is not finalised as yet. When I read about this wrinkle, I was about to put my units up for sale. Merchison On 2012-07-05 1:54 PM, Bob Camp wrote: Hi Simple answer - they are still playing around with the signal format. It is totally unclear what the final format will really look like. Until they make up their minds there is only one safe bet - the clock on grandma's wall will still handle the wwvb format they use. Anything more complex than that is very much in the who knows category. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
On Thu, Jul 05, 2012 at 04:19:25PM -0700, J. Forster wrote: If propagation goes south, you loose track of the carrier phase, the basis of the system. If your local standard is stable and close to right, that's not a big deal. If not, you can easily go down the garden path. If I read this correctly, you mean you have a 180 degree ambiguity due to the BPSK - obviously losing track of the carrier phase in general with a significantly wrong local standard loses... David, Most of what has been tried is an analog squareing, then a divide by two. No additional PLLs in the system, beyond what is already in the Rx. I have not devoted enough time to this to be absolutely sure but it sure sounds like from what I read that if you know the accurate time to one second it should be possible to unambiguously predict the carrier phase sequences simply because you know the message format exactly, AND you know the exact time of day message that is being transmitted or most of it. The BPSK rate is 1 bit per second, There are 120,000 half cycles in that time. Fades can last seconds, minutes, or hours. It comes down to how long does it take your local standard take to drift roughly 4 uS. At the moment we are not looking at the message at all. Certainly a correlating receiver that uses the message as well as the carrier could be built. But, IMO, that'd be a whole lot easier done from scratch with a micro. The object here is a small, fairly simple, retrofit for the existing receivers. The message format may not be fully defined as yet. The squareing approach is message independant. There are of course two forms of encoding in PSK modulations - absolute, and differential (or transition) ... naively to me it would seem that if absolute encoding is used for this and you know most of the bits of the message most of the time you could predict which phase will be used a lot of the time, and also know when you don't know (message bits you might be uncertain about)... If you used the signal to set your local clock, and knew the format, it should be easy to predict at least a good part, if not all, of the message. Differential encoding has the down side for this that UNLESS you know all previous message bits accurately starting from some phase reference datum you cannot predict what phase is in use at a particular moment. Absolute encoding (eg 0 phase for a 0, 180 for a one) doesn't have that liability and if the time of day message is aligned to, well, the time of day if you know that with reasonable accuracy (and you do since you are being sent it in the first place) you should be able to predict a very large percentage of phases used accurately. Again, deferring to those who have done the experiments (which I have clearly not), it would seem that the ability to predict the phase most of the time would allow creation of a reliable local 60 KHz reference which could be used to disambiguate those bits you don't know apriori My naive scheme would be to drive a balanced modulator on the output of the 60 KHz loop antenna with either two or maybe three values (1 and -1 or 1, 0 and -1) using some cheapie micro (Arduino, PIC etc) with a software PLL to keep the bit timing in sync with the signal. This is what Equatorial did, in TTL, 30+ years ago. For bits that one could not predict, one could either output 0 to the balanced modulator for the entire bit interval which would produce a drop in the 60 KHz carrier, or do a fast timed fraction of a bit look at the output of a synchronous detector and choose the most likely value for the bit and use that, maybe after a brief 0 no carrier interval to avoid a detectable phase glitch. Of course the other approach is to start with the assumption you have a pretty good stable source of clock or you would not be doing this to begin with, and simply A/D the 60 KHz with the stable clock (say at 10 MHz), delay it by storing samples in RAM for one bit time of the low speed code and use that entire interval to decide which phase you were seeing and suitably adjust the output phase accordingly when you spit out the samples delayed by one bit time. This later approach would certainly be doable with modern processors mostly in software, certainly so if you could live with say 1-2 MHz sampling of the 60 KHz or so... and quite possibly also pretty nicely with a modest FPGA complete with the sample storage in the chip. Both approaches would be helped a lot if the architecture of the system allows prediction of absolute phase (eg not differential encoding of unpredictable messages)... and AFAIK that is not yet set in stone and could be changed to allow this. The intent of both of these schemes would be to ultimately output a De-psk'd signal that older equipment could process using its antique analog circuitry without serious issues. Thus the output would be an
Re: [time-nuts] HP 117/10509a...
On Thu, Jul 05, 2012 at 11:13:32PM -0400, Merchison Burke wrote: Glad to know that it is not finalised as yet. When I read about this wrinkle, I was about to put my units up for sale. Put them up for sale. If you can find a buyer. I asked Mr. Lowe this week and was told there'd be no residual carrier or workaround for existing phase locking receivers, even time of day receivers. Debating what to do with mine, really, keep them as nice pieces of hardware (albeit in my own personal museum) -- they can go next to the LORAN and GOES receivers. The pile is getting pretty big these days. Anyone have an OMEGA receiver they want to part with? Sorry, but if you want something besides GPS, you're on your own. The US government has made its priorities clear -- if it's not GPS, it's an 'obsolete waste.' Somehow, we lose out vs 12 million WWVB clocks, despite the fact that not 3 years ago they were willing to obsolete all those clocks with an added 40 or 75 kHz station. At least, as long as 'stimulus' funds were being waved around. Along the lines of developing a receiver: Since they haven't settled on the format, there's no additional documentation available [that was the second part of my question..] I'm torn on the subject anyway...part of me wants the challenge, and part of me thinks that if the format can be changed without a public comment period or a phase out timeframe, that it may not be worth the risk of developing one. As it stands I guess I'm back to WWV/WWVH as a backup. But I can have all the self setting wall-clocks I want -- provided I don't mind flipping them between PST and MST, since few allow you to disable DST. :) --msa ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a...
No residual carrier is required. -John On Thu, Jul 05, 2012 at 11:13:32PM -0400, Merchison Burke wrote: Glad to know that it is not finalised as yet. When I read about this wrinkle, I was about to put my units up for sale. Put them up for sale. If you can find a buyer. I asked Mr. Lowe this week and was told there'd be no residual carrier or workaround for existing phase locking receivers, even time of day receivers. Debating what to do with mine, really, keep them as nice pieces of hardware (albeit in my own personal museum) -- they can go next to the LORAN and GOES receivers. The pile is getting pretty big these days. Anyone have an OMEGA receiver they want to part with? Sorry, but if you want something besides GPS, you're on your own. The US government has made its priorities clear -- if it's not GPS, it's an 'obsolete waste.' Somehow, we lose out vs 12 million WWVB clocks, despite the fact that not 3 years ago they were willing to obsolete all those clocks with an added 40 or 75 kHz station. At least, as long as 'stimulus' funds were being waved around. Along the lines of developing a receiver: Since they haven't settled on the format, there's no additional documentation available [that was the second part of my question..] I'm torn on the subject anyway...part of me wants the challenge, and part of me thinks that if the format can be changed without a public comment period or a phase out timeframe, that it may not be worth the risk of developing one. As it stands I guess I'm back to WWV/WWVH as a backup. But I can have all the self setting wall-clocks I want -- provided I don't mind flipping them between PST and MST, since few allow you to disable DST. :) --msa ___ 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] HP 117/10509a
Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 117/10509a
Hi: I have been thinking of doing the same thing! I have some 2N301 dual gate MOSFET's that I want to use. I would rather consider successful conversions done by others rather than reinvent the wheel. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Merchison Burke Sent: Wednesday, July 04, 2012 8:19 PM To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison ___ 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] HP 117/10509a
You need the gate volt-drain current curves to match the nuvistor grid-plate characteristic and the fet breakdown voltage has of course got to be high enough. I've gotten nuvistors at pretty reasonable cost on ebay... Don Ron Ward Hi: I have been thinking of doing the same thing! I have some 2N301 dual gate MOSFET's that I want to use. I would rather consider successful conversions done by others rather than reinvent the wheel. Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Merchison Burke Sent: Wednesday, July 04, 2012 8:19 PM To: time-nuts@febo.com Subject: [time-nuts] HP 117/10509a Hello, Has anyone successfully replaces the Nuvistors in the 117 and the 10509a with FETs. I would like to replace them with inexpensive FETs instead of buying the expensive Nunistors. Thanks for all help, Merchison ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ 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.
