Re: [time-nuts] Trimble 1 PPS
Hello, I am fighting to get 1PPS from my Trimble Tbolt GPSDO. Self-survey completed and via software the 1PPS also activated but no1PPS output on the BNC connector. Already tried all the software possibilities but no help the 1PPS 74HC04 driver IC does does not get any input signal. On the Tbolt Monitor program no any fault Any idea??? Thanks and regards, Ernie. ___ 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] Trimble 1 PPS
Sorry but forget to mention the Unit NOT from TAPR -Original Message- From: [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Thu, 20 Nov 2008 10:20 am Subject: Re: [time-nuts] Trimble 1 PPS Hello, I am fighting to get 1PPS from my Trimble Tbolt GPSDO. Self-survey completed and via software the 1PPS also activated but no1PPS output on the BNC connector. Already tried all the software possibilities but no help the 1PPS 74HC04 driver IC does does not get any input signal. On the Tbolt Monitor program no any fault Any idea??? Thanks and regards, Ernie. ___ 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] Trimble 1 PPS
> the 1PPS 74HC04 driver IC does does not get any input signal. What are you looking at it with? The pulse is only 10 microseconds wide. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] M12+T ASCII interface - I'm confused?
Tom, Thank you for the valuable inputs. I was quietly hoping that I was misunderstanding the protocol in some way. My gut tells me that <@><@> would be believable more than say 95% (if not 99%) of the time. I've got the following observations: - 95% is a bad number in accurate timing applications. - the checksum is one of the few things that are easy to do in VHDL. - one would always miss the first most data stream at startup (not a problem). - the last message in the data stream will always only be decoded on the next second when the new streams are coming through (a potential problem) Thus, I agree: The only real reliable way is to have a lookup of header bytes and data length. Disappointing protocol I must add. I so hoped that this won't be the case. Such is life. Regards, Stephan. 2008/11/19 Tom Van Baak <[EMAIL PROTECTED]> > Stephan, > > Ah, it's not a stupid question -- I think all of us who have written > code to interface with GPS receivers have had to deal with this. > > Some GPS protocols use escape characters, but the Oncore > binary protocol doesn't. There are five clues to robustly parsing > a complete message: > > 1) starts with @@ > 2) ends with > 3) message length is known, based on message header > 4) valid checksum > 5) there may be a pause between sentences > > You can use all of these clues to "sync" to a serial data stream > and accurately determine the start of the next message. > > As you already observed, just looking for @@ or is > not sufficient. Checking for @@ is better, but still not > perfect. To do it right you also need to include message length > and checksum into the calculation. The length is knowable by > looking at the message type in the header as it arrives. > > If you use a millisecond-level serial timeout that can help even > more (since if the first two bytes after a pause are @@ you > know it is a message start, not 16-bits of 0x4040 embedded > binary data). There is a timing gap between some, but not all > messages, so use this technique with care. You can also use > the 1PPS pulse as a start of message hint. > > True, a robust solution is not FPGA-friendly, but probably not > impossible, either. If you can't solve it, consider using a $1 > microcontroller (where this sort of message handling is trivial) > between the receiver and your FPGA which would parse, edit, > or reformat the messages to the FPGA's liking. > > /tvb > > > > Hi All, > > > > Up until now we've been interfacing my Motorola M12+T's using the Oncore > > software. However, at this point we are trying to have it interfaced > > directly to a FPGA. To my mind this should be simple - the commands are > > discriminated (framed) by looking at the start and terminating bytes > > sequences when they enter the FIFO, check summed, decoded etc. > > > > However, I noted something very peculiar about the motorola ASCII > protocol: > > The start bytes @@ and he terminating byte aren't unique with > > respect to the data bytes. For instance one could receive a time of 13hrs > > and 10mins which would look identical to the terminating characters. > > Initially I thought it made sense since the data is also sent in ascii > > format. It appears not to be the case. > > > > It seems to me that the only way in which a command could be robustly > > identified and check summed is when the interface knows the length of the > > expected return. Obviously, the data lengths are dependent on both the > > actual command and the specific request. This type of intelligence is > > cumbersome to implement in FPGAs. > > > > It would be of great help if you could point me in the right direction > here. > > I feel rather stupid in asking such a simple question, but at this point > I > > can't seem to see the light. I'm flabbergasted... > > > > Best regards, > > > > Stephan > > > > ___ > 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] M12+T ASCII interface - I'm confused?
Hi Bruce, Yes - at this point an external processor is not a real option. Are you aware of open source code that I could try out? In hind sight, I should've put a microprocessor core onto the FPGA to do all the management kind of tasks. Regards, Stephan. No need to use an external processor just implement a processor within the FPGA. VHDL code for suitable processors is readily available. Bruce Bruce 2008/11/19 Bruce Griffiths <[EMAIL PROTECTED]> > Tom Van Baak wrote: > > Stephan, > > > > Ah, it's not a stupid question -- I think all of us who have written > > code to interface with GPS receivers have had to deal with this. > > > > Some GPS protocols use escape characters, but the Oncore > > binary protocol doesn't. There are five clues to robustly parsing > > a complete message: > > > > 1) starts with @@ > > 2) ends with > > 3) message length is known, based on message header > > 4) valid checksum > > 5) there may be a pause between sentences > > > > You can use all of these clues to "sync" to a serial data stream > > and accurately determine the start of the next message. > > > > As you already observed, just looking for @@ or is > > not sufficient. Checking for @@ is better, but still not > > perfect. To do it right you also need to include message length > > and checksum into the calculation. The length is knowable by > > looking at the message type in the header as it arrives. > > > > If you use a millisecond-level serial timeout that can help even > > more (since if the first two bytes after a pause are @@ you > > know it is a message start, not 16-bits of 0x4040 embedded > > binary data). There is a timing gap between some, but not all > > messages, so use this technique with care. You can also use > > the 1PPS pulse as a start of message hint. > > > > True, a robust solution is not FPGA-friendly, but probably not > > impossible, either. If you can't solve it, consider using a $1 > > microcontroller (where this sort of message handling is trivial) > > between the receiver and your FPGA which would parse, edit, > > or reformat the messages to the FPGA's liking. > > > > /tvb > > > > > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ 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] M12+T ASCII interface - I'm confused?
Hi Ulrich, Sure - among other things the FPGA keeps a real-time clock. It ticks away on a disciplined clock, but the time and date value is constantly kept in sync with what the GPS spits out as UTC. So, the FPGA catches some of the GPS messages, but also allow for a straight path through to a PC. Everything that comes in is passed on the the PC - this way existing software could still be used to interface with the GPS etc. Stephan. 2008/11/20 Ulrich Bangert <[EMAIL PROTECTED]> > Stephan, > > can you give us a clue what it is all about? What happens with the data > after being decoded by the FPGA? > > Best regards > Ulrich Bangert > > > -Ursprungliche Nachricht- > > Von: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] Im Auftrag von Stephan Sandenbergh > > Gesendet: Mittwoch, 19. November 2008 15:30 > > An: Discussion of precise time and frequency measurement > > Betreff: [time-nuts] M12+T ASCII interface - I'm confused? > > > > > > Hi All, > > > > Up until now we've been interfacing my Motorola M12+T's using > > the Oncore software. However, at this point we are trying to > > have it interfaced directly to a FPGA. To my mind this should > > be simple - the commands are discriminated (framed) by > > looking at the start and terminating bytes sequences when > > they enter the FIFO, check summed, decoded etc. > > > > However, I noted something very peculiar about the motorola > > ASCII protocol: The start bytes @@ and he terminating byte > > aren't unique with respect to the data bytes. For > > instance one could receive a time of 13hrs and 10mins which > > would look identical to the terminating characters. Initially > > I thought it made sense since the data is also sent in ascii > > format. It appears not to be the case. > > > > It seems to me that the only way in which a command could be > > robustly identified and check summed is when the interface > > knows the length of the expected return. Obviously, the data > > lengths are dependent on both the actual command and the > > specific request. This type of intelligence is cumbersome to > > implement in FPGAs. > > > > It would be of great help if you could point me in the right > > direction here. I feel rather stupid in asking such a simple > > question, but at this point I can't seem to see the light. > > I'm flabbergasted... > > > > Best regards, > > > > Stephan > > ___ > > 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] M12+T ASCII interface - I'm confused?
Hi, NMEA would have been nice - but this is a timing application. Stephan. 2008/11/19 Stanley Reynolds <[EMAIL PROTECTED]> > Looking at the user guide which is the extent of my experience. Would the > position version of the M12+ be a better choice for your application ? That > is trade NMEA-0183 for all the timing features ? > > Stanley > > Link to user guide : > http://www.synergy-gps.com/images/stories/guides/m12+userguide.pdf > > > > > > > > From: Stephan Sandenbergh <[EMAIL PROTECTED]> > To: Discussion of precise time and frequency measurement < > time-nuts@febo.com> > Sent: Wednesday, November 19, 2008 8:29:59 AM > Subject: [time-nuts] M12+T ASCII interface - I'm confused? > > Hi All, > > Up until now we've been interfacing my Motorola M12+T's using the Oncore > software. However, at this point we are trying to have it interfaced > directly to a FPGA. To my mind this should be simple - the commands are > discriminated (framed) by looking at the start and terminating bytes > sequences when they enter the FIFO, check summed, decoded etc. > > However, I noted something very peculiar about the motorola ASCII protocol: > The start bytes @@ and he terminating byte aren't unique with > respect to the data bytes. For instance one could receive a time of 13hrs > and 10mins which would look identical to the terminating characters. > Initially I thought it made sense since the data is also sent in ascii > format. It appears not to be the case. > > It seems to me that the only way in which a command could be robustly > identified and check summed is when the interface knows the length of the > expected return. Obviously, the data lengths are dependent on both the > actual command and the specific request. This type of intelligence is > cumbersome to implement in FPGAs. > > It would be of great help if you could point me in the right direction > here. > I feel rather stupid in asking such a simple question, but at this point I > can't seem to see the light. I'm flabbergasted... > > Best regards, > > Stephan > ___ > 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] M12+T ASCII interface - I'm confused?
> My gut tells me that <@><@> would be believable > more than say 95% (if not 99%) of the time. I've got the following > observations: I suggest that you debug things in software and then figure out how to implement that algorithm in the FPGA. You can rearrange code and try again to make it easier to move your code to the FPGA. Searching for <@><@> means you will wait for the start of the next packet before processing the current one. > the checksum is one of the few things that are easy to do in VHDL. So what. What are you going to do with the rest of the data? In the old days (TTL DIPs) we used to build microcoded machines rather than real CPUs. They were tuned to the specific problem. That was before c took over, at least with the people I worked with. That general style actually fits fairly well into a FPGA. The key idea is that it lets you think of the problem as software rather than hardware. That's usually a lot simpler if your state machine has many states that mostly map to something like a program counter. I'll say more if anybody wants. I think Xilinx had an app note. You have to write the microcode and you probably have to write an assembler. (We just grabbed one from a previous project and hacked it to fit our new machine.) These days it may be better to through a few more gates at the problem and use a real CPU that runs c. RS-232 shouldn't make any bit errors if you are running at sensible speed/distances. It shouldn't get any byte errors unless your hardware/OS is broken or your user code can't get enough CPU cycles. So it's reasonable to assume that most of the data will be clean. (not perfect, but good enough so you don't have to even think about complicated error recovery.) If I wanted to process that stuff, I'd have a mode bit: hunt vs in-sync. (This is assuming I really do understand the packet format.) In hunt mode, I'd scan for @@, assume that was the start of a packet, then grab the command bytes, lookup the length, and read that much. If the checksum matched, and the next two bytes were , I'd switch to in-sync and process the packet. If not, go back and try again. If I didn't recognize the command bytes, stay in hunt mode and go back to looking for @@. When in-sync mode, I'd read two bytes, check for @@, grab the command bytes, lookup the length, read that much, check the checksum, check for ... If anything didn't check, I'd raise a flag and switch back to hunt mode. That flag shouldn't ever go off. That mode bit is mostly for thinking. The code may fold together so you don't need it. But something similar may be needed for debugging. You want to flag an error if something goes wrong after you have gotten in sync. You don't want to raise an alarm until you do get in sync. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] M12+T ASCII interface - I'm confused?
Hi Stephan, I have been asking my question because I wanted to learn whether an FPGA was really needed. Don't understand me wrong, I am a dedicated user of XILINX and ALTERA FPGAs and CPLDs myself, but sometimes a $2 microcontroller will do the job better than any FPGA. It is correct that you may put a 32 bit micro + numerous peripherals say in an XC3S400 and still it is half-empty for other purposes. I also use technology like that. However it is not ALWAYS better. Even the bigger FPGAs do not have enough RAM as that you could hold the embedded firmware + the RAM needed for the application in it. That calls for external RAM. Also be prepared NOT to fit the complete firmware into the FPGA's configuration device. One must be lucky if a kind of bootloader fits into the FPGA configuration that enables the FPGA (once that it is configured) to load the "real" firmware from an external memory device like a serial EEPROM. You see that there are a number of trade offs and one has to think very carefully which solution is the best overall compromise. Best regards Ulrich Bangert > -Ursprungliche Nachricht- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von Stephan Sandenbergh > Gesendet: Donnerstag, 20. November 2008 11:48 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] M12+T ASCII interface - I'm confused? > > > Hi Ulrich, > > Sure - among other things the FPGA keeps a real-time clock. > It ticks away on a disciplined clock, but the time and date > value is constantly kept in sync with what the GPS spits out as UTC. > > So, the FPGA catches some of the GPS messages, but also allow > for a straight path through to a PC. Everything that comes in > is passed on the the PC - this way existing software could > still be used to interface with the GPS etc. > > Stephan. > > 2008/11/20 Ulrich Bangert <[EMAIL PROTECTED]> > > > Stephan, > > > > can you give us a clue what it is all about? What happens with the > > data after being decoded by the FPGA? > > > > Best regards > > Ulrich Bangert > > > > > -Ursprungliche Nachricht- > > > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > > > Im Auftrag von Stephan Sandenbergh > > > Gesendet: Mittwoch, 19. November 2008 15:30 > > > An: Discussion of precise time and frequency measurement > > > Betreff: [time-nuts] M12+T ASCII interface - I'm confused? > > > > > > > > > Hi All, > > > > > > Up until now we've been interfacing my Motorola M12+T's using the > > > Oncore software. However, at this point we are trying to have it > > > interfaced directly to a FPGA. To my mind this should be simple - > > > the commands are discriminated (framed) by looking at the > start and > > > terminating bytes sequences when they enter the FIFO, > check summed, > > > decoded etc. > > > > > > However, I noted something very peculiar about the motorola ASCII > > > protocol: The start bytes @@ and he terminating byte > aren't > > > unique with respect to the data bytes. For instance one could > > > receive a time of 13hrs and 10mins which would look > identical to the > > > terminating characters. Initially I thought it made sense > since the > > > data is also sent in ascii format. It appears not to be the case. > > > > > > It seems to me that the only way in which a command could be > > > robustly identified and check summed is when the > interface knows the > > > length of the expected return. Obviously, the data lengths are > > > dependent on both the actual command and the specific > request. This > > > type of intelligence is cumbersome to implement in FPGAs. > > > > > > It would be of great help if you could point me in the right > > > direction here. I feel rather stupid in asking such a simple > > > question, but at this point I can't seem to see the light. I'm > > > flabbergasted... > > > > > > Best regards, > > > > > > Stephan > > > ___ > > > 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] M12+T ASCII interface - I'm confused?
Stephan Sandenbergh wrote: > Hi Bruce, > > Yes - at this point an external processor is not a real option. > > Are you aware of open source code that I could try out? > > In hind sight, I should've put a microprocessor core onto the FPGA to do all > the management kind of tasks. > > Regards, > > Stephan. > Stephan If you dont wish to use Alteras Nios processor or Xilinx's Picoblaze or Microblaze, VHDL for a Forth processor has been posted at: http://www.ultratechnology.com/4thvhdl.htm Other open source cores can be found here: http://www.opencores.org/browse.cgi/filter/category_microprocessor Bruce ___ 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] Trimble 1 PPS
100MHz HP digital scope. -Original Message- From: Hal Murray <[EMAIL PROTECTED]> To: Discussion of precise time and frequency measurement Sent: Thu, 20 Nov 2008 10:59 am Subject: Re: [time-nuts] Trimble 1 PPS > the 1PPS 74HC04 driver IC does does not get any input signal. What are you looking at it with? The pulse is only 10 microseconds wide. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Oh the horror
- Original Message - From: "Neon John" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" Sent: Thursday, November 20, 2008 4:29 AM Subject: Re: [time-nuts] Oh the horror [...] > > When the aroma of blue smoke wafted through the air, I'd usually get > company > for some commiseration, a good back rub and sometimes other condolences. > A > properly spec'ced wife-mate is worth more than even a hydrogen maser. Especially if her has long-term stability as well... > > > IMO of course. > > John > -- > John De Armond > See my website for my current email address > http://www.neon-john.com > http://www.johndearmond.com <-- best little blog on the net! > Tellico Plains, Occupied TN > I'm so cool, I'm afraid to catch cold. > > > ___ > 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] Trimble 1 PPS
-Original Message- From: [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Thu, 20 Nov 2008 10:45 am Subject: Re: [time-nuts] Trimble 1 PPS Sorry but forget to mention the Unit NOT from TAPR -Original Message- From: [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Thu, 20 Nov 2008 10:20 am Subject: Re: [time-nuts] Trimble 1 PPS Hello, I am fighting to get 1PPS from my Trimble Tbolt GPSDO. Self-survey completed and via software the 1PPS also activated but no1PPS output on the BNC connector. Already tried all the software possibilities but no help the 1PPS 74HC04 driver IC does does not get any input signal. On the Tbolt Monitor program no any fault Any idea??? Thanks and regards, Ernie. ___ 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] M12+T ASCII interface - I'm confused?
> Tom, > > Thank you for the valuable inputs. I was quietly hoping that I was > misunderstanding the protocol in some way. > > My gut tells me that <@><@> would be believable more than > say 95% (if not 99%) of the time. I've got the following observations: > > - 95% is a bad number in accurate timing applications. You misunderstand. You can get as close to 100% as you want. Some of us have logged data from M12+ receivers without error for weeks or months -- gigabytes, error-free. > - the checksum is one of the few things that are easy to do in VHDL. > > - one would always miss the first most data stream at startup (not a > problem). Correct, not a problem. Note NMEA, TSIP, and any other GPS protocol has the same feature, right? > - the last message in the data stream will always only be decoded on the > next second when the new streams are coming through (a potential problem) Not true. You can process the entire message as soon as the checksum matches. Do you see why? If you're brave you can process the message, byte by byte, field by field, as it arrives in real time and use the checksum as a commit. > Thus, I agree: The only real reliable way is to have a lookup of header > bytes and data length. Disappointing protocol I must add. A protocol like NMEA (ascii at 4800 baud) doesn't have sufficient bandwidth to accomodate all the data from a timing receiver. So Motorola (and Trimble, etc.) all have binary protocols (~2x the density of ascii) and higher baudrates. > I so hoped that this won't be the case. Such is life. > > Regards, > > Stephan. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble 1 PPS
I have to apologize because it was my failure to set up this Digital storage HP scope. Now I got the 1 PPS.it is working. Rgds Ernie. -Original Message- From: Hal Murray <[EMAIL PROTECTED]> To: Discussion of precise time and frequency measurement Sent: Thu, 20 Nov 2008 10:59 am Subject: Re: [time-nuts] Trimble 1 PPS > the 1PPS 74HC04 driver IC does does not get any input signal. What are you looking at it with? The pulse is only 10 microseconds wide. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Fwd: M12+T ASCII interface - I'm confused?
Hi, Now I'm slightly confused: > > > My gut tells me that <@><@> would be believable more than > > say 95% (if not 99%) of the time. I've got the following observations: In the above I assumed no data length checking is employed. > > > > - 95% is a bad number in accurate timing applications. > > You misunderstand. You can get as close to 100% as you > want. Some of us have logged data from M12+ receivers without > error for weeks or months -- gigabytes, error-free. Sure, I assume you refer to the case when you check the data length as well? I meant that the <@><@> byte string could also potentially exist in the data itself, but only in very rare cases (from there the 95% thumb suck). > > > - the checksum is one of the few things that are easy to do in VHDL. > > > > - one would always miss the first most data stream at startup (not a > > problem). > > Correct, not a problem. Note NMEA, TSIP, and any other > GPS protocol has the same feature, right? > > > - the last message in the data stream will always only be decoded on the > > next second when the new streams are coming through (a potential problem) > > Not true. You can process the entire message as soon as > the checksum matches. Do you see why? > > If you're brave you can process the message, byte by byte, > field by field, as it arrives in real time and use the checksum > as a commit. Again, the checksum could be part of the data string - so without checking the data length you'll be waiting for the @@ (less probable to exist in data). > > > Thus, I agree: The only real reliable way is to have a lookup of header > > bytes and data length. Disappointing protocol I must add. > Stephan ___ 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] Fwd: M12+T ASCII interface - I'm confused?
Stephan Sandenbergh wrote: > Hi, > > Now I'm slightly confused: > >>> My gut tells me that <@><@> would be believable more than >>> say 95% (if not 99%) of the time. I've got the following observations: > > In the above I assumed no data length checking is employed. > >>> - 95% is a bad number in accurate timing applications. >> You misunderstand. You can get as close to 100% as you >> want. Some of us have logged data from M12+ receivers without >> error for weeks or months -- gigabytes, error-free. > > Sure, I assume you refer to the case when you check the data length as > well? I meant that the <@><@> byte string could also > potentially exist in the data itself, but only in very rare cases > (from there the 95% thumb suck). No it cannot. It would be:<@><@><@><@>... As I understand it, they use a byte stuff code, where any of the "special" bytes must be doubled if they are in the data And, there must be a data area length check or you could get into some truly pathological situations. -Chuck Harris ___ 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] M12+T ASCII interface - I'm confused?
Hi Stephan: I've heard from Art at Synergy that the latest i-Lotus versions of the M12+T receivers have NMEA enabled. That's to say you can switch to that protocol. Have Fun, Brooke Clarke http://www.prc68.com Stephan Sandenbergh wrote: > Hi, > > NMEA would have been nice - but this is a timing application. > > Stephan. > > 2008/11/19 Stanley Reynolds <[EMAIL PROTECTED]> > >> Looking at the user guide which is the extent of my experience. Would the >> position version of the M12+ be a better choice for your application ? That >> is trade NMEA-0183 for all the timing features ? >> >> Stanley >> >> Link to user guide : >> http://www.synergy-gps.com/images/stories/guides/m12+userguide.pdf >> >> >> >> >> >> >> >> From: Stephan Sandenbergh <[EMAIL PROTECTED]> >> To: Discussion of precise time and frequency measurement < >> time-nuts@febo.com> >> Sent: Wednesday, November 19, 2008 8:29:59 AM >> Subject: [time-nuts] M12+T ASCII interface - I'm confused? >> >> Hi All, >> >> Up until now we've been interfacing my Motorola M12+T's using the Oncore >> software. However, at this point we are trying to have it interfaced >> directly to a FPGA. To my mind this should be simple - the commands are >> discriminated (framed) by looking at the start and terminating bytes >> sequences when they enter the FIFO, check summed, decoded etc. >> >> However, I noted something very peculiar about the motorola ASCII protocol: >> The start bytes @@ and he terminating byte aren't unique with >> respect to the data bytes. For instance one could receive a time of 13hrs >> and 10mins which would look identical to the terminating characters. >> Initially I thought it made sense since the data is also sent in ascii >> format. It appears not to be the case. >> >> It seems to me that the only way in which a command could be robustly >> identified and check summed is when the interface knows the length of the >> expected return. Obviously, the data lengths are dependent on both the >> actual command and the specific request. This type of intelligence is >> cumbersome to implement in FPGAs. >> >> It would be of great help if you could point me in the right direction >> here. >> I feel rather stupid in asking such a simple question, but at this point I >> can't seem to see the light. I'm flabbergasted... >> >> Best regards, >> >> Stephan >> ___ >> 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] I'm back! And I need a receiver...
Fellow clock-tickers, I have returned from a most worthwhile Mexico vacation! It was great fun, but I'm glad to be home. With that said - Murphy struck, hard, the day before I left by taking out the GPS receiver (again!) in my Odetics 425 clock. I'm beginning to wonder if this was a common failure for these units. In any case -- Does anyone have a spare Magellan model OEM 5000 module that I could convince you to part with? Failing that -- I'm not optimistic about being able to modify the Odetics to work from a more modern NMEA-output module, so it is likely that I would have to replace it. What I'd be looking for is a rackmounted unit, no more than 4U high, that can put out disciplined 10MHz and IRIG-B time code. A Trak Systems 882x series would be nice, but I know how popular those are. Thanks much. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." ___ 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] Fwd: M12+T ASCII interface - I'm confused?
>> You misunderstand. You can get as close to 100% as you >> want. Some of us have logged data from M12+ receivers without >> error for weeks or months -- gigabytes, error-free. > > Sure, I assume you refer to the case when you check the data length as > well? I meant that the <@><@> byte string could also > potentially exist in the data itself, but only in very rare cases > (from there the 95% thumb suck). Yes, you must use the data length. These are *packets*; all of which have their own fixed length. See pages 30, 31 of the M12+ user manual. >> If you're brave you can process the message, byte by byte, >> field by field, as it arrives in real time and use the checksum >> as a commit. > > Again, the checksum could be part of the data string - so without > checking the data length you'll be waiting for the @@ (less probable > to exist in data). No no, the checksum is a designated byte at a known offset within the packet. You first read the whole packet. Then you validate the checksum byte and/or do other sanity checks on the data. You don't just go looking through all the bytes in the packet for any old byte that equals some value. Maybe re-read Hal's message where he talked about a hunt and sync mode. That got the point across nicely. I hope you end up liking the binary format; I'm not sure how it could be improved. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] To improve a Tbolt?
I have been reading with interest John Miles' page about his Tbolt 'upgrade'. http://www.thegleam.com/ke5fx/tbolt.htm I have a newly acquired Tbolt here, and also have lying around an almost identical 10811-60111 OCXO which I am considering using with it, exactly as John describes. However my Tbolt is of a later vintage than John's (2005 date code) and I wonder if that would show as big an improvement as John reports. The on board OCXO on this one has a Trimble sticker on it, but otherwise looks similar to the one pictured on John's page. The GPS receiver area of my board also looks very different, but I don't think this would have any effect. Not having the sort of phase noise measuring facilities here to be able to test it, I am wondering if anyone else has done this with a similar vintage Tbolt, and could say if it is likely to show as big an improvement as John seems to be getting. I was a little surprised at the amount of short term variation, of the order of minutes duration, that I was seeing on another Tbolt when using it to set a Rb standard. The obvious answer to my question is to try it and see, but I'd appreciate hearing from anyone who has tried it! Dan ___ 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] I'm back! And I need a receiver...
In a message dated 20/11/2008 17:16:18 GMT Standard Time, [EMAIL PROTECTED] writes: What I'd be looking for is a rackmounted unit, no more than 4U high, that can put out disciplined 10MHz and IRIG-B time code. A Trak Systems 882x series would be nice, but I know how popular those are. - I thought that too but make sure you're getting what you expect. At the end of last month I bought a Trak 8821B-7 via the usual place, others here may well have bid on it too, it didn't have the display but I'd already got an IRIG-B display unit so no problem there, or so I thought. It turned out to be a base station special, with an original Trak fitted 16.384MHz oscillator and with the IRIG-B and divided frequency outputs not fitted. Bit of an expensive mistake that one:-( Sorry to hear the 5000 module didn't survive too long. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWV / WWVH / WWVB
Hello all, Thank you to everyone that has helped (and some that continue to help) me with my GPSDO equipment post... I've got a few leads out there and hopefully I'll be able to get ahold of some of these units soon... I really am looking forward to getting to work with some other GPSDO's. Anyway, on to the reason for this post... I'd like to get some receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I know that HEARING them may not be a 'normal' request, but I just would like to monitor the audio as well as being able to decode the signals... I guess the first thing to take care of is receiving the signals. Can anyone recommend decent receivers for these stations? I guess the list of frequencies would be: o WWVB = 60 KHz o WWV = 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz o WWVH = 2.5 MHz, 5 MHz, 10 MHz, or 15 MHz Hmm, I just noticed that WWV and WWVH overlap... How in the heck do you differentiate between the two stations if they broadcast on all the same channels? Anyway, I wouldn't mind a kit type of project that would let me receive these signals... Maybe I'll check out Ramsey Electronics, Rainbow Kits, Velleman, et al. Surely one of them has kits for these broadcast ranges. Can anyone suggest a kit, or project listed online with schematics and parts lists, or I guess even reasonably priced commercial units? If I can't get radios that have built in decoders for these stations, I'd be happy just receiving their audio and then trying to build my own decoder using a PIC or something... Thanks for any advice. Brad ___ 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] WWV / WWVH / WWVB
Brad Stockdale wrote: [ ... ] > Anyway, on to the reason for this post... I'd like to get some > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > know that HEARING them may not be a 'normal' request, but I just > would like to monitor the audio as well as being able to decode the signals... broadcast ranges. [ ... ] > Can anyone suggest a kit, or project listed online with > schematics and parts lists, or I guess even reasonably priced commercial > units? > > If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... If you don't mind a big, heavy box, the HP 3586[A,B,C] selective voltmeters are absolutely wonderful tools for any sort of LF/HF measurement. They tune from 20 Hz to 32 MHz and have narrow 20 and 400 Hz filter bandwidths, as well as a voice-bandwidth filter (the width depends on the model and option). They read amplitude to 0.01 dB and can count a received carrier to 0.1 Hz frequency resolution. They have a speaker and line-level audio output, but no decoder. They also have a GPIB connector, so you can use a computer to tune and read frequency and amplitude. The "C" model is the best for lab use, because it has 50/75/600 ohm input options, and uses standard BNC and binding post input connectors. The A and B models were designed for telco use and have slightly weird input impedances and connectors, but nothing to stop them from still being very useful. They sometimes go on eBay for <$200, which is a steal in my book. They weigh about 50 pounds, though, so aren't exactly portable. John ___ 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] WWV / WWVH / WWVB
On Thu, Nov 20, 2008 at 10:40 AM, Brad Stockdale <[EMAIL PROTECTED]> wrote: >o WWVB = 60 KHz I bought a nice little module from digi-key to handle this. 561-1014-ND, under $11 including the ferrite antenna. >o WWV = 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz >o WWVH = 2.5 MHz, 5 MHz, 10 MHz, or 15 MHz > >Hmm, I just noticed that WWV and WWVH overlap... How in the heck > do you differentiate between the two stations if they broadcast on > all the same channels? different gender of voice, and they don't talk at the same time. >Can anyone suggest a kit, or project listed online with > schematics and parts lists, or I guess even reasonably priced commercial > units? See the above digi-key module. hang it off an arduino or something... >If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... lots of existing work to build on http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/glcd_dcf77/index.html http://www.schatenseite.de/binaryclock.html?&L=2 -- GDB has a 'break' feature; why doesn't it have 'fix' too? ___ 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] WWV / WWVH / WWVB
The ticks are diferent frequency tines. From: http://tf.nist.gov/timefreq/general/pdf/1383.pdf : The most frequent sounds heard on WWV and WWVH are the seconds pulses. These pulses are heard every second except on the 29th and 59th seconds of each minute. The first pulse of each hour is an 800 ms pulse of 1500 Hz. The first pulse of each minute is an 800 ms pulse of 1000 Hz at WWV and 1200 Hz at WWVH. The remaining second pulses are short audio bursts (5 ms pulses of 1000 Hz at WWV and 1200 Hz at WWVH) that sound like the ticking of a clock. John WA4WDL - Original Message - From: "Brad Stockdale" <[EMAIL PROTECTED]> To: Sent: Thursday, November 20, 2008 1:40 PM Subject: Re: [time-nuts] WWV / WWVH / WWVB > Hello all, > >Thank you to everyone that has helped (and some that continue to > help) me with my GPSDO equipment post... I've got a few leads out > there and hopefully I'll be able to get ahold of some of these units > soon... I really am looking forward to getting to work with some other > GPSDO's. > >Anyway, on to the reason for this post... I'd like to get some > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > know that HEARING them may not be a 'normal' request, but I just > would like to monitor the audio as well as being able to decode the > signals... > >I guess the first thing to take care of is receiving the signals. > Can anyone recommend decent receivers for these stations? I guess the > list of frequencies would be: > > o WWVB = 60 KHz > o WWV = 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz > o WWVH = 2.5 MHz, 5 MHz, 10 MHz, or 15 MHz > >Hmm, I just noticed that WWV and WWVH overlap... How in the heck > do you differentiate between the two stations if they broadcast on > all the same channels? > >Anyway, I wouldn't mind a kit type of project that would let me > receive these signals... Maybe I'll check out Ramsey Electronics, > Rainbow Kits, Velleman, et al. Surely one of them has kits for these > broadcast ranges. > >Can anyone suggest a kit, or project listed online with > schematics and parts lists, or I guess even reasonably priced commercial > units? > >If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... > >Thanks for any advice. > > Brad > > > > ___ > 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] WWV / WWVH / WWVB
Brad Stockdale wrote: How in the heck do you differentiate between the two stations if they broadcast on all the same channels? Brad - Regarding WWV and WWVH, take a look at http://tf.nist.gov/timefreq/general/broadcast.htm#1 and http://tf.nist.gov/timefreq/general/broadcast.htm#7 Ed ___ 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] I'm back! And I need a receiver...
Bruce, Four years ago, I planned to build a three-rack time standard system similar to the one at Fort Collins. It was "a bridge too far" and now I have a surplus of Datum time code generators in the 9100, 9200, and 9300 series. Many of them do IRIG-B and have an external input for 1 MHz. The three best units would have been the system clock displays. They do not have disciplined oscillators, but there are empty card sockets for anything you care to add, like a divide by ten for 10 MHz. Units are less than 4U, some are only 1U high. Units are available for a third of a C note, or four for the whole note. Bill Hawkins -Original Message- From: Bruce Lane Sent: Thursday, November 20, 2008 11:15 AM Failing that -- I'm not optimistic about being able to modify the Odetics to work from a more modern NMEA-output module, so it is likely that I would have to replace it. What I'd be looking for is a rackmounted unit, no more than 4U high, that can put out disciplined 10MHz and IRIG-B time code. A Trak Systems 882x series would be nice, but I know how popular those are. ___ 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] I'm back! And I need a receiver...
Do you need the one with the two boards piggypacked (main board and smaller RF voard) or the single board version.I tried to email you directly, but your overly paranoid email blocker gets in the way... _ Color coding for safety: Windows Live Hotmail alerts you to suspicious email. http://windowslive.com/Explore/Hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_safety_112008 ___ 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] WWV / WWVH / WWVB
Are you open to vacuum tube equipment? I have a set with a 2" scope tube that let me see the phase shift between WWV and WWVH when propagation conditions brought them both to Minneapolis. Also a Specific Products WWV receiver. Also have an HP 117A VLF Comparator, but not the preamp and loop. Bill Hawkins -Original Message- From: Brad Stockdale Sent: Thursday, November 20, 2008 12:41 PM Anyway, on to the reason for this post... I'd like to get some receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I know that HEARING them may not be a 'normal' request, but I just would like to monitor the audio as well as being able to decode the signals... ___ 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] Fwd: M12+T ASCII interface - I'm confused?
> Sure, I assume you refer to the case when you check the data length as > well? I meant that the <@><@> byte string could also > potentially exist in the data itself, but only in very rare cases > (from there the 95% thumb suck). The checksum byte can have any value. You can't use it to help you get in sync since you don't know (and can't compute) what it is unless you have the rest of the packet and then you are already in sync. Once you get in sync, you don't look for any patterns inside the packet. You read a few byes to figure out how long the packet is, read the rest of the packet, then do some sanity checks. Since the RS-232 level stuff should be error free, the sanity checks will almost never fail. If they do, it means somebody tripped over a cable or a lightning bolt hit. (Or you have a bug in your software.) Flag an error, somehow, so you know you have a problem. I'm thinking of something like a LED with a software or pushbutton reset. Then go back to the beginning and try to get in sync again. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Fwd: M12+T ASCII interface - I'm confused?
> I hope you end up liking the binary format; I'm not sure how it could > be improved. It's a bit ugly that you have to do a table lookup in the packet type to get the length. That makes it harder to split the transport layer out into a separate chunk of software. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWV / WWVH / WWVB
Greetings... I have a used, untested 60 KHz preamp board (no case) for the hp 117A VLF receiver. It is the early model using two 13CW4 nuvistors and a mechanical filter. If anyone is interested, please contact me directly. Regards, Peter Bill Hawkins wrote: > Are you open to vacuum tube equipment? > > I have a set with a 2" scope tube that let me see the phase shift > between WWV and WWVH when propagation conditions brought them both > to Minneapolis. Also a Specific Products WWV receiver. > > Also have an HP 117A VLF Comparator, but not the preamp and loop. > > Bill Hawkins > > -Original Message- > From: Brad Stockdale > Sent: Thursday, November 20, 2008 12:41 PM > > Anyway, on to the reason for this post... I'd like to get some > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > know that HEARING them may not be a 'normal' request, but I just would > like to monitor the audio as well as being able to decode the signals... > > > > > ___ 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] WWV / WWVH / WWVB
That is due to the wonders of HF propagation.WWV is in Ft Collins WWVH is in Hawaii so coverage is largely restricted to Asia/Pacific region somewhere on NIST's site there is a propagation prediction for all the stations. On Thu, Nov 20, 2008 at 1:40 PM, Brad Stockdale <[EMAIL PROTECTED]> wrote: > Hello all, > >Thank you to everyone that has helped (and some that continue to > help) me with my GPSDO equipment post... I've got a few leads out > there and hopefully I'll be able to get ahold of some of these units > soon... I really am looking forward to getting to work with some other > GPSDO's. > >Anyway, on to the reason for this post... I'd like to get some > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > know that HEARING them may not be a 'normal' request, but I just > would like to monitor the audio as well as being able to decode the signals... > >I guess the first thing to take care of is receiving the signals. > Can anyone recommend decent receivers for these stations? I guess the > list of frequencies would be: > >o WWVB = 60 KHz >o WWV = 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz >o WWVH = 2.5 MHz, 5 MHz, 10 MHz, or 15 MHz > >Hmm, I just noticed that WWV and WWVH overlap... How in the heck > do you differentiate between the two stations if they broadcast on > all the same channels? > >Anyway, I wouldn't mind a kit type of project that would let me > receive these signals... Maybe I'll check out Ramsey Electronics, > Rainbow Kits, Velleman, et al. Surely one of them has kits for these > broadcast ranges. > >Can anyone suggest a kit, or project listed online with > schematics and parts lists, or I guess even reasonably priced commercial > units? > >If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... > >Thanks for any advice. > > Brad > > > > ___ > 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] WWV / WWVH / WWVB
Hi Brad: To get the best s/n radio you need to have good narrow filters. The NRD-545 uses DSP for the IF filters and so can be adjusted to a 10 Hz bandwidth. This is the lowest IF bandwidth I know of in any HF receiver including the high end and military models. The only things with narrower bandwidths are the HP/Agilent 4395A in spectrum analyzer mode where there is a 1 Hz bandwidth or the PC sound card spectrum analyzers where you can get sub Hertz bandwidths. http://www.prc68.com/I/NRD545.shtml http://www.prc68.com/I/4395A.shtml#SA The 114BR Time Comparator was used with WWV and WWVH in conjunction with a receiver and scope. http://www.prc68.com/I/TF_rack.html You could duplicate the function of the HP 114 using a variable time delay for phase comparison. The antenna is about as important as the receiver for HF and LF signals. For HF I really like the B&W Terminated Folded dipoles. Chirp receiver testing showed them to be far superior to every thing else. http://www.prc68.com/I/RCS-5A.shtml#Ant The trick to getting a PIC to decode the subcarrier data would be best done by audio filtering prior to amplitude detection. I haven't worked with the DSPics but that would allow doing better filtering in the PIC. http://www.prc68.com/I/TF_rack.html For WWVB the amplitude changes but the carrier is always there. Starting Jan 1 2006 the modulation depth was changed from 10 to 17 dB, see: http://tf.nist.gov/timefreq/general/pdf/2139.pdf It's very important that you filter out close by RF signals. Here is a 0 to 200 kHz spectrum plot: http://www.prc68.com/I/Spec_0002.shtml you can see that there are plenty of signals there. Have Fun, Brooke Clarke http://www.prc68.com Brad Stockdale wrote: > Hello all, > > Thank you to everyone that has helped (and some that continue to > help) me with my GPSDO equipment post... I've got a few leads out > there and hopefully I'll be able to get ahold of some of these units > soon... I really am looking forward to getting to work with some other > GPSDO's. > > Anyway, on to the reason for this post... I'd like to get some > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > know that HEARING them may not be a 'normal' request, but I just > would like to monitor the audio as well as being able to decode the signals... > > I guess the first thing to take care of is receiving the signals. > Can anyone recommend decent receivers for these stations? I guess the > list of frequencies would be: > > o WWVB = 60 KHz > o WWV = 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz > o WWVH = 2.5 MHz, 5 MHz, 10 MHz, or 15 MHz > > Hmm, I just noticed that WWV and WWVH overlap... How in the heck > do you differentiate between the two stations if they broadcast on > all the same channels? > > Anyway, I wouldn't mind a kit type of project that would let me > receive these signals... Maybe I'll check out Ramsey Electronics, > Rainbow Kits, Velleman, et al. Surely one of them has kits for these > broadcast ranges. > > Can anyone suggest a kit, or project listed online with > schematics and parts lists, or I guess even reasonably priced commercial > units? > > If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... > > Thanks for any advice. > > Brad > > > > ___ > 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] M12+T ASCII interface - I'm confused?
Hi Stephan: I was wrong about the stuffing. Got confused with other protocols. All the Motorola @@ packets are a fixed length. Have Fun, Brooke Clarke http://www.prc68.com Brooke Clarke wrote: > Hi Stephan: > > Check the manual for "stuffing", it's not a Thanksgiving term here but has to > do with what happens when a byte in a binary data stream (the data in the > Motorola protocol is all binary, not ASCII) is the same as the ASCII "@" > character. This means that the length of a packet is variable and depends on > the actual data inside the packet. But you know the minimum length if you > know > the packet ID. > > To start look for the string @@ and the next characters (maybe 2 or 4 > hex characters) are the packet ID. Sometimes this happens inside a packet > because that's what the data looks like. But go with it and if it's wrong > the > program will cycle around to where you are on packet boundaries. > > > Have Fun, > > Brooke Clarke > http://www.prc68.com > > Stephan Sandenbergh wrote: >> Hi All, >> >> Up until now we've been interfacing my Motorola M12+T's using the Oncore >> software. However, at this point we are trying to have it interfaced >> directly to a FPGA. To my mind this should be simple - the commands are >> discriminated (framed) by looking at the start and terminating bytes >> sequences when they enter the FIFO, check summed, decoded etc. >> >> However, I noted something very peculiar about the motorola ASCII protocol: >> The start bytes @@ and he terminating byte aren't unique with >> respect to the data bytes. For instance one could receive a time of 13hrs >> and 10mins which would look identical to the terminating characters. >> Initially I thought it made sense since the data is also sent in ascii >> format. It appears not to be the case. >> >> It seems to me that the only way in which a command could be robustly >> identified and check summed is when the interface knows the length of the >> expected return. Obviously, the data lengths are dependent on both the >> actual command and the specific request. This type of intelligence is >> cumbersome to implement in FPGAs. >> >> It would be of great help if you could point me in the right direction here. >> I feel rather stupid in asking such a simple question, but at this point I >> can't seem to see the light. I'm flabbergasted... >> >> Best regards, >> >> Stephan >> ___ >> 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] WWV / WWVH / WWVB
Oh my... The HP 3586 looks like a gorgeous piece of equipment. It'd look very impressive in my (hopefully) growing rack of time/frequency gear... I just checked on eBay right now and didn't see any available right this second, but I will put in a saved search for them so I can get email alerts... Do you know of any good (reasonably priced) used equipment dealers that I should also be looking at for HP test equipment? I know there's shops that specialize in used test gear, but I just don't know their addresses... I'll google around right now and see what I can come up with, but if anyone has any suggestions that they have delt with before and been satisfied, I'd like to hear. Thanks for the great idea! I hope I can track one of these down sooner or later. Regards, Brad At 01:55 PM 11/20/2008, you wrote: >Brad Stockdale wrote: >[ ... ] > > Anyway, on to the reason for this post... I'd like to get some > > receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I > > know that HEARING them may not be a 'normal' request, but I just > > would like to monitor the audio as well as being able to decode > the signals... >broadcast ranges. > >[ ... ] > > Can anyone suggest a kit, or project listed online with > > schematics and parts lists, or I guess even reasonably priced > commercial units? > > > > If I can't get radios that have built in decoders for these > > stations, I'd be happy just receiving their audio and then trying to > > build my own decoder using a PIC or something... > >If you don't mind a big, heavy box, the HP 3586[A,B,C] selective >voltmeters are absolutely wonderful tools for any sort of LF/HF >measurement. They tune from 20 Hz to 32 MHz and have narrow 20 and 400 >Hz filter bandwidths, as well as a voice-bandwidth filter (the width >depends on the model and option). They read amplitude to 0.01 dB and >can count a received carrier to 0.1 Hz frequency resolution. > >They have a speaker and line-level audio output, but no decoder. They >also have a GPIB connector, so you can use a computer to tune and read >frequency and amplitude. > >The "C" model is the best for lab use, because it has 50/75/600 ohm >input options, and uses standard BNC and binding post input connectors. > The A and B models were designed for telco use and have slightly weird >input impedances and connectors, but nothing to stop them from still >being very useful. > >They sometimes go on eBay for <$200, which is a steal in my book. They >weigh about 50 pounds, though, so aren't exactly portable. > >John > >___ >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. > >__ Information from ESET NOD32 Antivirus, version of virus >signature database 3628 (20081120) __ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.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.
Re: [time-nuts] WWV / WWVH / WWVB
Tucker Electronics is probably the biggest US used test gear vendor, but there are others. I've dealt once or twice with TekNet with good results. However, most of the used equipment folks are selling to commercial entities and their prices can be large multiples of the eBay going rate. So be prepared for sticker shock. BTW, I used a couple of 3586s to record audio from the 2005 leap second event -- One was tuned to 60 kHz for WWVB and the other to CHU. (Having run out of 3586s at that point, I used my ham gear for WWV 5 and 10 MHz. You can see and hear the results at http://www.febo.com/pages/leapsecond_2005/ John Brad Stockdale wrote: > Oh my... The HP 3586 looks like a gorgeous piece of equipment. It'd > look very impressive in my (hopefully) growing rack of time/frequency gear... > > I just checked on eBay right now and didn't see any available right > this second, but I will put in a saved search for them so I can get > email alerts... > > Do you know of any good (reasonably priced) used equipment dealers > that I should also be looking at for HP test equipment? I know > there's shops that specialize in used test gear, but I just don't > know their addresses... I'll google around right now and see what I > can come up with, but if anyone has any suggestions that they have > delt with before and been satisfied, I'd like to hear. > > Thanks for the great idea! I hope I can track one of these down > sooner or later. > > Regards, > Brad > > > At 01:55 PM 11/20/2008, you wrote: >> Brad Stockdale wrote: >> [ ... ] >>> Anyway, on to the reason for this post... I'd like to get some >>> receivers so I can HEAR and USE the WWVB, WWV, and WWVH signals... I >>> know that HEARING them may not be a 'normal' request, but I just >>> would like to monitor the audio as well as being able to decode >> the signals... >> broadcast ranges. >> >> [ ... ] >>> Can anyone suggest a kit, or project listed online with >>> schematics and parts lists, or I guess even reasonably priced >> commercial units? >>> If I can't get radios that have built in decoders for these >>> stations, I'd be happy just receiving their audio and then trying to >>> build my own decoder using a PIC or something... >> If you don't mind a big, heavy box, the HP 3586[A,B,C] selective >> voltmeters are absolutely wonderful tools for any sort of LF/HF >> measurement. They tune from 20 Hz to 32 MHz and have narrow 20 and 400 >> Hz filter bandwidths, as well as a voice-bandwidth filter (the width >> depends on the model and option). They read amplitude to 0.01 dB and >> can count a received carrier to 0.1 Hz frequency resolution. >> >> They have a speaker and line-level audio output, but no decoder. They >> also have a GPIB connector, so you can use a computer to tune and read >> frequency and amplitude. >> >> The "C" model is the best for lab use, because it has 50/75/600 ohm >> input options, and uses standard BNC and binding post input connectors. >> The A and B models were designed for telco use and have slightly weird >> input impedances and connectors, but nothing to stop them from still >> being very useful. >> >> They sometimes go on eBay for <$200, which is a steal in my book. They >> weigh about 50 pounds, though, so aren't exactly portable. >> >> John >> >> ___ >> 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. >> >> __ Information from ESET NOD32 Antivirus, version of virus >> signature database 3628 (20081120) __ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.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. ___ 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] WWV / WWVH / WWVB
At 03:37 PM 11/20/2008, you wrote: >I just checked on eBay right now and didn't see any available right >this second, but I will put in a saved search for them so I can get >email alerts... I take it back... There are a few. Sorry about that! Brad ___ 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] WWV / WWVH / WWVB
At 01:55 PM 11/20/2008, you wrote: >I bought a nice little module from digi-key to handle this. >561-1014-ND, under $11 including the ferrite antenna. Interesting little module. Cheap too! Looking over the datasheet right now. Thanks for the pointer. Brad ___ 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] WWV / WWVH / WWVB
At 02:24 PM 11/20/2008, you wrote: >Are you open to vacuum tube equipment? Surely. Tubes are another interest of mine, but I only really deal with audio stuff. One of my ham friends tried to ease my fear of RF equipment by telling me that RF gear was basically just audio gear with chokes/coils and tuned circuits. Didn't help aleviate my hesitation of getting into it. Haha. >I have a set with a 2" scope tube that let me see the phase shift >between WWV and WWVH when propagation conditions brought them both >to Minneapolis. Also a Specific Products WWV receiver. Do you happen to have a make/model of this neat sounding receiver with the scope built in? Thanks, Brad ___ 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] WWV / WWVH / WWVB
On Thu, 2008-11-20 at 15:51 -0500, Brad Stockdale wrote: > > At 01:55 PM 11/20/2008, you wrote: > > >I bought a nice little module from digi-key to handle this. > >561-1014-ND, under $11 including the ferrite antenna. > > > Interesting little module. Cheap too! Looking over the datasheet > right now. Thanks for the pointer. Here is a euro-alternative that for a multitude of frequencies http://www.hkw-elektronik.de/englisch/products/assemblys.php I built a few receivers from this design http://www.buzzard.me.uk/jonathan/radioclock.html using HKW-modules. -- Björn ___ 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] WWV / WWVH / WWVB
Brad, I started with audio in 1950, got into receivers, never got into transmitters, except some carrier current stuff. Only real difference in receivers is the concept of tuned circuits for selectivity as opposed to wide-band audio. Well, there's also detection and AGC. Um, and mixing (hetrodyning) or regeneration. Probably other stuff as well. Actually, audio amps are pretty simple compared to 25 tube military receivers of the 50s. And receivers are simpler than Caesium or Rubidium standards, or precision frequency synthesizers. The receiver that showed phase shift is a Lavoie LA800, s/n 125. Receives WWV or WWVH on 5 or 15 MHz. Takes 0.05 to 10 MHz from your standard and generates 10 MHz for the circular sweep. Beam is intensity modulated by received signal cleverly converted to 10 MHz. Easier to see phase shift than Lissajous method. The Specific Products receiver is the WWVC, with filters. Receives WWV/H on 2.5, 5, 10, 15 and 20 MHz. Filters 400 or 600 Hz tones, or ticks, or open for voice. Has audio output. Both have 2" scope and speaker. The WWVC just has X and Y for Lissajous figures. Have manual for each. Bill Hawkins -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brad Stockdale Sent: Thursday, November 20, 2008 2:55 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV / WWVH / WWVB At 02:24 PM 11/20/2008, you wrote: >Are you open to vacuum tube equipment? Surely. Tubes are another interest of mine, but I only really deal with audio stuff. One of my ham friends tried to ease my fear of RF equipment by telling me that RF gear was basically just audio gear with chokes/coils and tuned circuits. Didn't help aleviate my hesitation of getting into it. Haha. >I have a set with a 2" scope tube that let me see the phase shift >between WWV and WWVH when propagation conditions brought them both to >Minneapolis. Also a Specific Products WWV receiver. Do you happen to have a make/model of this neat sounding receiver with the scope built in? Thanks, Brad ___ 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] WWV / WWVH / WWVB
> If I can't get radios that have built in decoders for these > stations, I'd be happy just receiving their audio and then trying to > build my own decoder using a PIC or something... The typical short wave radio will give you audio on WWV/H. WWVB is 60 KHz. Most radios don't go that low. The tiny modules only give you a carrier. If you wanted to hear anything more than clicks, you would have to use that to gate a tone. ntpd has a refclock driver for WWV/H. I've never played with it. http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver36.html >From a quick scan, decoding would probably take more than a PIC. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] TBolt in the house!
Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in China. He nicely gave me the time-nuts discount, and also included a power connector with pigtail leads. Including shipping, it was $175 and it took 7 days to get here in W. Wash. You can find him and these units on eBay at: http://stores.ebay.com/High-precision-Osc-from-China It's date code is 3/19/05. The App Ver is 3.00 6/27/2. GPS Core is 10.02 11/14/1. ID is 96. s/n is 82331036 3/7/5. It's up and running in a top-of-bench way, and I have a few Qs: 1) What are good params to use for the loop to get best frequency acc'y and stability? 2) Is there a firmware upgrade you recommend? 3) What V/Hz figure do you all recommend? It's at what must be a default of -5... 4) DAC voltage is +0.0633... Is this a fairly normal value? 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB adapter, but DSPMon does not see the data at all -- no TX or RX. Does it not work with this vintage/version of TBolt? Best, Dick Moore ___ 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] Where to find surplus telecom standards
> On a slightly different subject, albeit somewhat related... Does > anyone know what HP Z3801A's are worth nowadays? I remember when they > first came on the market, they were around $250, then up to about > $400 or so when supplies got scarce. Not sure what happened after > that... Just kinda curious if I could make some extra money by > selling a couple of my Z3801's and using the profits to buy some > other units to 'play' with... There are a couple for sale at $400 plus $120 shipping from Hong Kong. Since they are still for sale, I'd say the current price is under $500. Assuming it's in reasonable shape, I'll offer $400 plus reasonable shipping. (You save the ebay fees.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TBolt in the house!
Hi Dick: Did you set the COM port number? Right click with the cursor on the window. http://www.prc68.com/I/ThunderBolt.shtml#TBM Have Fun, Brooke Clarke http://www.prc68.com Richard Moore wrote: > Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in > China. He nicely gave me the time-nuts discount, and also included a > power connector with pigtail leads. Including shipping, it was $175 > and it took 7 days to get here in W. Wash. You can find him and these > units on eBay at: http://stores.ebay.com/High-precision-Osc-from-China > > It's date code is 3/19/05. > The App Ver is 3.00 6/27/2. > GPS Core is 10.02 11/14/1. > ID is 96. > s/n is 82331036 3/7/5. > > It's up and running in a top-of-bench way, and I have a few Qs: > 1) What are good params to use for the loop to get best frequency > acc'y and stability? > 2) Is there a firmware upgrade you recommend? > 3) What V/Hz figure do you all recommend? It's at what must be a > default of -5... > 4) DAC voltage is +0.0633... Is this a fairly normal value? > 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB > adapter, but DSPMon does not see the data at all -- no TX or RX. Does > it not work with this vintage/version of TBolt? > > Best, > Dick Moore > > ___ > 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] TBolt in the house!
Unless you are going to use a different OCXO, there is nothing to do except perhaps tell it to save the self-survey results and set your "foilage mode" if desired. They are plug and play. -5 V/Hz is the correct kvco parameter; any changes will either degrade the phase margin and give you a "hump" in your loop response, or lengthen the loop response. And it wouldn't be advisable to alter the loop-time and damping parameters without taking a series of ADEV plots under various GPS reception conditions to make sure you're actually improving things. The DAC voltage on mine is sitting at 0.608664V, with a corresponding DAC value of 8F49D. This is a 20-bit value centered at 0x8. As long as you are between 0x1 (a bit more than -5V) and 0xF (a bit less than +5V) your oscillator has sufficient control range. If it goes closer to 0x0 or 0xF it means you're about to hit the rails, and would need a new OCXO. This *might* happen if you left it running for 30 years. -- john, KE5FX > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of Richard Moore > Sent: Thursday, November 20, 2008 3:28 PM > To: time-nuts@febo.com > Subject: [time-nuts] TBolt in the house! > > > Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in > China. He nicely gave me the time-nuts discount, and also included a > power connector with pigtail leads. Including shipping, it was $175 > and it took 7 days to get here in W. Wash. You can find him and these > units on eBay at: http://stores.ebay.com/High-precision-Osc-from-China > > It's date code is 3/19/05. > The App Ver is 3.00 6/27/2. > GPS Core is 10.02 11/14/1. > ID is 96. > s/n is 82331036 3/7/5. > > It's up and running in a top-of-bench way, and I have a few Qs: > 1) What are good params to use for the loop to get best frequency > acc'y and stability? > 2) Is there a firmware upgrade you recommend? > 3) What V/Hz figure do you all recommend? It's at what must be a > default of -5... > 4) DAC voltage is +0.0633... Is this a fairly normal value? > 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB > adapter, but DSPMon does not see the data at all -- no TX or RX. Does > it not work with this vintage/version of TBolt? > > Best, > Dick Moore > > ___ > 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] WWV / WWVH / WWVB
On Nov 20, 2008, at 4:27 PM, Hal Murray wrote: > > > ntpd has a refclock driver for WWV/H. I've never played with it. > http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver36.html >> I played with it back in the 90's, I hooked up the audio line out from my Yaesu FT-840 to a SPARCstation 20. It does in fact work. But as I remember it consumed pretty much 100% of a 75Mhz SuperSPARC- II CPU. I'm sure a modern CPU would do a much better job. Keep in mind the F/F1/F2 layer that the HF signals use to propagate tends to move around a bit. This introduces a variable propagation delay that cannot be entirely corrected. Rob ___ 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] I'm back! And I need a receiver...
Hi, Bill, Thanks for the offer, but I also have a goodly number of the Datum 9300's and similar units. What I really need at the moment is at least a partial "turnkey" solution. Ideally, I want to fix the Odetics clock as it has been very reliable outside of the GPS receiver. I know if I look long enough, I'll find something. *** REPLY SEPARATOR *** On 20-Nov-08 at 13:11 Bill Hawkins wrote: >Bruce, > >Four years ago, I planned to build a three-rack time standard system >similar to the one at Fort Collins. It was "a bridge too far" and now >I have a surplus of Datum time code generators in the 9100, 9200, and >9300 series. Many of them do IRIG-B and have an external input for 1 >MHz. >The three best units would have been the system clock displays. > >They do not have disciplined oscillators, but there are empty card >sockets for anything you care to add, like a divide by ten for 10 MHz. > >Units are less than 4U, some are only 1U high. > >Units are available for a third of a C note, or four for the whole note. > >Bill Hawkins > > >-Original Message- >From: Bruce Lane >Sent: Thursday, November 20, 2008 11:15 AM > > Failing that -- I'm not optimistic about being able to modify >the Odetics to work from a more modern NMEA-output module, so it is >likely that I would have to replace it. What I'd be looking for is a >rackmounted unit, no more than 4U high, that can put out disciplined >10MHz and IRIG-B time code. A Trak Systems 882x series would be nice, >but I know how popular those are. > > > >___ >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. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m "Quid Malmborg in Plano..." ___ 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] Do any regulations or laws require time to be accurate within 'x' seconds?
This is about the most I've found. http://tf.nist.gov/timefreq/general/pdf/2125.pdf -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gretchen Baxter Sent: Monday, November 03, 2008 9:03 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Do any regulations or laws require time to be accurate within 'x' seconds? Greetings, There are a lot of regulations that mandate synchronized time. But do any of these regulations or laws require time to be accurate within 'x' seconds? Such as, 'time much be synchronized within 5 seconds of GPS time. Thanx, Gretchen ___ 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] Fwd: M12+T ASCII interface - I'm confused?
tvb wrote: > I hope you end up liking the binary format; I'm not sure how it could > be improved. IIRC, there's no length field in the packet; so you have to know the length of all the messages you might possibly rx, even if you are interested in just a few of them. -ch ___ 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] Fwd: M12+T ASCII interface - I'm confused?
In message: <[EMAIL PROTECTED]> "christopher hoover" <[EMAIL PROTECTED]> writes: : tvb wrote: : > I hope you end up liking the binary format; I'm not sure how it could : > be improved. : : IIRC, there's no length field in the packet; so you have to know the length : of all the messages you might possibly rx, even if you are interested in : just a few of them. IIRC, you just have to know... Warner ___ 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] Do any regulations or laws require time to be accurate within 'x' seconds?
http://www.oup.com/us/pdf/houp/10_3.pdf OATS Reporting Technical Specifications, NASD OATS == Order Audit Trail System All computer system clocks and mechanical time stamping devices must be synchronized to within three seconds of the National Institute of Standards and Technology (NIST) atomic clock. Any time provider may be used for synchronization, however, all clocks and time stamping devices must remain accurate within a three-second tolerance of the NIST clock. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] M12+T more confusion
Gentlemen: Why would the M12+T swap the order of messages? I write @@Hn and @@Eq in that order to the board and it gives it back to me in reverse order. Tried @@Cf then resending the messages. Still the same. Then did it AND swapped the order of the messages. Still the same. The manual says it's first in, first out regarding the serial buffer. I'm using Labview 8. Norm n3ykf ___ 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] TBolt in the house!
> Message: 2 > Date: Thu, 20 Nov 2008 15:36:48 -0800 > From: Brooke Clarke <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] TBolt in the house! > To: Discussion of precise time and frequency measurement > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi Dick: > > Did you set the COM port number? > Right click with the cursor on the window. > http://www.prc68.com/I/ThunderBolt.shtml#TBM > Yep, Brooke, I did. My ATEN 232>USB adapter looks like Com Port 6 to my windows box, which regularly thinks that it is a Microsoft Ball Point, whatever that is and it's a real pain to straighten that out. I'd like to get rid of the MS Ball Point driver completely if I could find it; any help with that appreciated. > Richard Moore wrote: >> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >> China. He nicely gave me the time-nuts discount, and also included a >> power connector with pigtail leads. Including shipping, it was $175 >> and it took 7 days to get here in W. Wash. You can find him and these >> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >> China >> >> It's date code is 3/19/05. >> The App Ver is 3.00 6/27/2. >> GPS Core is 10.02 11/14/1. >> ID is 96. >> s/n is 82331036 3/7/5. >> >> It's up and running in a top-of-bench way, and I have a few Qs: >> 1) What are good params to use for the loop to get best frequency >> acc'y and stability? >> 2) Is there a firmware upgrade you recommend? >> 3) What V/Hz figure do you all recommend? It's at what must be a >> default of -5... >> 4) DAC voltage is +0.0633... Is this a fairly normal value? >> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >> it not work with this vintage/version of TBolt? >> -- > Message: 3 > Date: Thu, 20 Nov 2008 15:44:49 -0800 > From: "John Miles" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] TBolt in the house! > To: "Discussion of precise time and frequency measurement" > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="us-ascii" > > Unless you are going to use a different OCXO, there is nothing to > do except > perhaps tell it to save the self-survey results and set your > "foilage mode" > if desired. They are plug and play. > > -5 V/Hz is the correct kvco parameter; any changes will either > degrade the > phase margin and give you a "hump" in your loop response, or > lengthen the > loop response. And it wouldn't be advisable to alter the loop-time > and > damping parameters without taking a series of ADEV plots under > various GPS > reception conditions to make sure you're actually improving things. John, thanks for the feedback. I'll leave the V/Hz alone, Any advice on loop time constant and damping? >> -Original Message- >> From: [EMAIL PROTECTED] [mailto:time-nuts- >> [EMAIL PROTECTED] >> Behalf Of Richard Moore >> Sent: Thursday, November 20, 2008 3:28 PM >> To: time-nuts@febo.com >> Subject: [time-nuts] TBolt in the house! >> >> >> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >> China. He nicely gave me the time-nuts discount, and also included a >> power connector with pigtail leads. Including shipping, it was $175 >> and it took 7 days to get here in W. Wash. You can find him and these >> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >> China >> >> It's date code is 3/19/05. >> The App Ver is 3.00 6/27/2. >> GPS Core is 10.02 11/14/1. >> ID is 96. >> s/n is 82331036 3/7/5. >> >> It's up and running in a top-of-bench way, and I have a few Qs: >> 1) What are good params to use for the loop to get best frequency >> acc'y and stability? >> 2) Is there a firmware upgrade you recommend? >> 3) What V/Hz figure do you all recommend? It's at what must be a >> default of -5... >> 4) DAC voltage is +0.0633... Is this a fairly normal value? >> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >> it not work with this vintage/version of TBolt? ___ 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] TBolt in the house!
Give this a try! http://www.synergy-gps.com/images/stories/ShopTalk/disabling%20detection%20of%20microsoft%20ballpoint%20mouse.pdf The serial mouse issue drove me nuts for a while. Norm ___ 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] TBolt in the house!
Hi Dick: Not only the port number but also the serial parameters, see: http://www.prc68.com/I/ThunderBolt.shtml#TBM That's why I gave you the right click hint. Have Fun, Brooke Clarke http://www.prc68.com Richard Moore wrote: >> Message: 2 >> Date: Thu, 20 Nov 2008 15:36:48 -0800 >> From: Brooke Clarke <[EMAIL PROTECTED]> >> Subject: Re: [time-nuts] TBolt in the house! >> To: Discussion of precise time and frequency measurement >> >> Message-ID: <[EMAIL PROTECTED]> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> Hi Dick: >> >> Did you set the COM port number? >> Right click with the cursor on the window. >> http://www.prc68.com/I/ThunderBolt.shtml#TBM >> > > Yep, Brooke, I did. My ATEN 232>USB adapter looks like Com Port 6 to > my windows box, which regularly thinks that it is a Microsoft Ball > Point, whatever that is and it's a real pain to straighten that out. > I'd like to get rid of the MS Ball Point driver completely if I could > find it; any help with that appreciated. > >> Richard Moore wrote: >>> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >>> China. He nicely gave me the time-nuts discount, and also included a >>> power connector with pigtail leads. Including shipping, it was $175 >>> and it took 7 days to get here in W. Wash. You can find him and these >>> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >>> China >>> >>> It's date code is 3/19/05. >>> The App Ver is 3.00 6/27/2. >>> GPS Core is 10.02 11/14/1. >>> ID is 96. >>> s/n is 82331036 3/7/5. >>> >>> It's up and running in a top-of-bench way, and I have a few Qs: >>> 1) What are good params to use for the loop to get best frequency >>> acc'y and stability? >>> 2) Is there a firmware upgrade you recommend? >>> 3) What V/Hz figure do you all recommend? It's at what must be a >>> default of -5... >>> 4) DAC voltage is +0.0633... Is this a fairly normal value? >>> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >>> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >>> it not work with this vintage/version of TBolt? >>> -- > > >> Message: 3 >> Date: Thu, 20 Nov 2008 15:44:49 -0800 >> From: "John Miles" <[EMAIL PROTECTED]> >> Subject: Re: [time-nuts] TBolt in the house! >> To: "Discussion of precise time and frequency measurement" >> >> Message-ID: <[EMAIL PROTECTED]> >> Content-Type: text/plain; charset="us-ascii" >> >> Unless you are going to use a different OCXO, there is nothing to >> do except >> perhaps tell it to save the self-survey results and set your >> "foilage mode" >> if desired. They are plug and play. >> >> -5 V/Hz is the correct kvco parameter; any changes will either >> degrade the >> phase margin and give you a "hump" in your loop response, or >> lengthen the >> loop response. And it wouldn't be advisable to alter the loop-time >> and >> damping parameters without taking a series of ADEV plots under >> various GPS >> reception conditions to make sure you're actually improving things. > > John, thanks for the feedback. I'll leave the V/Hz alone, Any advice > on loop time constant and damping? > >>> -Original Message- >>> From: [EMAIL PROTECTED] [mailto:time-nuts- >>> [EMAIL PROTECTED] >>> Behalf Of Richard Moore >>> Sent: Thursday, November 20, 2008 3:28 PM >>> To: time-nuts@febo.com >>> Subject: [time-nuts] TBolt in the house! >>> >>> >>> Hi, nuts -- I just got my TBolt from h-whole-bunch-of-b's-bob in >>> China. He nicely gave me the time-nuts discount, and also included a >>> power connector with pigtail leads. Including shipping, it was $175 >>> and it took 7 days to get here in W. Wash. You can find him and these >>> units on eBay at: http://stores.ebay.com/High-precision-Osc-from- >>> China >>> >>> It's date code is 3/19/05. >>> The App Ver is 3.00 6/27/2. >>> GPS Core is 10.02 11/14/1. >>> ID is 96. >>> s/n is 82331036 3/7/5. >>> >>> It's up and running in a top-of-bench way, and I have a few Qs: >>> 1) What are good params to use for the loop to get best frequency >>> acc'y and stability? >>> 2) Is there a firmware upgrade you recommend? >>> 3) What V/Hz figure do you all recommend? It's at what must be a >>> default of -5... >>> 4) DAC voltage is +0.0633... Is this a fairly normal value? >>> 5) I downloaded Tboltmon v. 2.60 and it works great with my 232>USB >>> adapter, but DSPMon does not see the data at all -- no TX or RX. Does >>> it not work with this vintage/version of TBolt? > > ___ > 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.
