Re: [time-nuts] Time Code generator
Magnus Danielson wrote: On 12/08/2010 07:18 PM, jimlux wrote: Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. No, not all digital video. The time-code is optional in many of the transfer formats. You're right.. I was thinking more that analog certainly isn't always timecoded, but at least for digital, there's an inherent frame counter, and dropped/doubled/partial frames are unusual in digital video systems. They're positively frequent in analog systems (esp consumer vhs!) But you'd still get caught if the frame rate isn't the same across your system (which is often the case) Consumer gear also usually doesn't have any ability to gen-lock. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. Analog black-bursts is still here. I think that's the video equivalent of the 10MHz reference distribution. ___ time-nuts mailing 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] Time Code generator
On 12/09/2010 02:46 PM, jimlux wrote: Magnus Danielson wrote: On 12/08/2010 07:18 PM, jimlux wrote: Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. No, not all digital video. The time-code is optional in many of the transfer formats. You're right.. I was thinking more that analog certainly isn't always timecoded, but at least for digital, there's an inherent frame counter, There is as inherent frame counting in the analog PAL and NTSC signals as there is for their digital counter-part in SDI. and dropped/doubled/partial frames are unusual in digital video systems. Not after the frame-store farm... They're positively frequent in analog systems (esp consumer vhs!) But you'd still get caught if the frame rate isn't the same across your system (which is often the case) Inside a production location yes, as the house clock dictates the time for all equipment... but not between the production locations, the solution being the use of a frame-store farm to clean the incoming signal into the local house-clock phase and frequency. A number of false starts to align things to GPS have been attempted, but there has been some speed in the development. One progress was the definition of the SMPTE EPOCH in SMPTE 404M (which bounced the trial publication after feedback from a time-nut asking what time-zone the midnight of 1 Jan 1958 was being referenced, naturally it was UTC midnight which was intended and thus the Zulu time-zone). The idea with the SMPTE EPOCH (defined to where TAI and UTC align up) is that all sample-rates, line-rate, frame-rates etc. for all signals has T=0 at that time and then just follow the development of TAI, while the time of day would follow UTC. Consumer gear also usually doesn't have any ability to gen-lock. Unfortunately. Some of it is hackable thought. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. Analog black-bursts is still here. I think that's the video equivalent of the 10MHz reference distribution. It is. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time Code generator
When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' Sent from my Verizon Wireless BlackBerry -Original Message- From: Collins, Graham coll...@navcanada.ca Sender: time-nuts-boun...@febo.com Date: Fri, 3 Dec 2010 07:28:13 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Time Code generator On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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] Time Code generator
scmcgr...@gmail.com wrote: When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. IRIG is uncommon in the audio/video industry, but still used in the telemetry and lab environment (IRIG is the Inter-Range Instrumentation Group, at White Sands Missile Range, after all). I confess I doubt anyone is still using magnetic tape with FM subcarriers on the range these days, but you never know.. government facilities tend to use really old equipment for a long, long time since the accounting rules don't use depreciation (you buy it once, and it's free after that), there's limited capital budgets for replacement, but often labor is available to repair/limp along. At JPL, we use IRIG to transfer time around between racks, particularly for things like MIL-STD-1553B monitors, which timestamp the bus traffic to the nearest microsecond or fraction, sync'd by the IRIG input. There's something really convenient about needing just one cable/fiber to perform the function. Audio LTC is encoded differently than IRIG.. Biphase manchester, different bit stream, different time encoding, etc. Conceptually similar though. Any programmable hardware that can generate IRIG can probably generate LTC as well. OTOH, if you built your IRIG generator out of discrete 7400 series TTL, you've got a lot of white wires to convert to LTC. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' Sent from my Verizon Wireless BlackBerry -Original Message- From: Collins, Graham coll...@navcanada.ca Sender: time-nuts-boun...@febo.com Date: Fri, 3 Dec 2010 07:28:13 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Time Code generator ___ time-nuts mailing 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] Time Code generator
Thanks for update on current LTC usage!. In the studios I worked in in college with the old type-c decks we did use IRIG-B but even then everyone was moving to VITC. As editing was moving away from the razor blade and tape era to deck to deck on U-Matic decks! Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: jimlux jim...@earthlink.net Date: Wed, 08 Dec 2010 07:20:14 To: scmcgr...@gmail.com; Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] Time Code generator scmcgr...@gmail.com wrote: When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. IRIG is uncommon in the audio/video industry, but still used in the telemetry and lab environment (IRIG is the Inter-Range Instrumentation Group, at White Sands Missile Range, after all). I confess I doubt anyone is still using magnetic tape with FM subcarriers on the range these days, but you never know.. government facilities tend to use really old equipment for a long, long time since the accounting rules don't use depreciation (you buy it once, and it's free after that), there's limited capital budgets for replacement, but often labor is available to repair/limp along. At JPL, we use IRIG to transfer time around between racks, particularly for things like MIL-STD-1553B monitors, which timestamp the bus traffic to the nearest microsecond or fraction, sync'd by the IRIG input. There's something really convenient about needing just one cable/fiber to perform the function. Audio LTC is encoded differently than IRIG.. Biphase manchester, different bit stream, different time encoding, etc. Conceptually similar though. Any programmable hardware that can generate IRIG can probably generate LTC as well. OTOH, if you built your IRIG generator out of discrete 7400 series TTL, you've got a lot of white wires to convert to LTC. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' Sent from my Verizon Wireless BlackBerry -Original Message- From: Collins, Graham coll...@navcanada.ca Sender: time-nuts-boun...@febo.com Date: Fri, 3 Dec 2010 07:28:13 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Time Code generator ___ time-nuts mailing 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] Time Code generator
Adding time code to video would be redundant. All video is already time coded. It turns out the time code is required to support editing. Editors don't actually move bits of video data around. What they do is create and modify an EDL which is a text file with a list of all the cuts and effects to be applied. The cuts are defined by the time. For example a close up of an actor's face might be specified at camera roll XX from time T1 to time T2. Later during final rendering the software will search the video data for frames with the required time codes But many consumer level cameras fake it by defining time = zero at the start of a tape or the first frame in memory. If absolute time needs to be record on a consumer level camera then I'd shoot a few frames of a digital clock and then later in a video editor adjust the time code OK, all that said there is a group of people who routinely record WWV audio on their video. Amateur occultation timers do this. These people use video cameras through telescopes to record when a asteroid passes in front of a star and blocks its light. This can produce very acuate orbital data for the asteroid and if enough people all over the world record it you can even deduce the shape of the asteroid. On Wed, Dec 8, 2010 at 5:27 AM, scmcgr...@gmail.com wrote: When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' Sent from my Verizon Wireless BlackBerry -Original Message- From: Collins, Graham coll...@navcanada.ca Sender: time-nuts-boun...@febo.com Date: Fri, 3 Dec 2010 07:28:13 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Time Code generator On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing 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] Time Code generator
Professional cameras have a integrated VITC generator which in addition to the time add the frame index to the time code which allows for creation of frame level Edit Decision Lists. Consumer cameras cheat and synthesize time. If you run a consumer tape through a professional system you will not have a time index. And one will need to be added Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: Chris Albertson albertson.ch...@gmail.com Date: Wed, 8 Dec 2010 08:54:15 To: scmcgr...@gmail.com; Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] Time Code generator Adding time code to video would be redundant. All video is already time coded. It turns out the time code is required to support editing. Editors don't actually move bits of video data around. What they do is create and modify an EDL which is a text file with a list of all the cuts and effects to be applied. The cuts are defined by the time. For example a close up of an actor's face might be specified at camera roll XX from time T1 to time T2. Later during final rendering the software will search the video data for frames with the required time codes But many consumer level cameras fake it by defining time = zero at the start of a tape or the first frame in memory. If absolute time needs to be record on a consumer level camera then I'd shoot a few frames of a digital clock and then later in a video editor adjust the time code OK, all that said there is a group of people who routinely record WWV audio on their video. Amateur occultation timers do this. These people use video cameras through telescopes to record when a asteroid passes in front of a star and blocks its light. This can produce very acuate orbital data for the asteroid and if enough people all over the world record it you can even deduce the shape of the asteroid. On Wed, Dec 8, 2010 at 5:27 AM, scmcgr...@gmail.com wrote: When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' Sent from my Verizon Wireless BlackBerry -Original Message- From: Collins, Graham coll...@navcanada.ca Sender: time-nuts-boun...@febo.com Date: Fri, 3 Dec 2010 07:28:13 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Time Code generator On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing 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] Time Code generator
Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. Record that video on an analog 1/2 or 3/4 deck and you need the timecode on the longitudinal audio track. Yes, primarily as you say, to support editing. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. But many consumer level cameras fake it by defining time = zero at the start of a tape or the first frame in memory. If absolute time needs to be record on a consumer level camera then I'd shoot a few frames of a digital clock and then later in a video editor adjust the time code That would work..(e.g. it's just like slating at the beginning of a film take) Sometimes it would be more convenient to just record an audio timecode on the audio track. Where I could see timecode being handy is when you're trying to do automated processing. I worked on a system 15 years ago where we had 100 cameras, and we did the alignment by hand, and it was pretty painful. What's easy when syncing A and B roll gets tedious when there's 100 takes you're essentially cutting together. I think there's also a lot of utility in figuring a way to do it in the consumer electronics space. Say I was doing a radio interferometer kind of experiment and just wanted to do a poor man's VLBI, using a GPSDO at each station for time sync. OK, all that said there is a group of people who routinely record WWV audio on their video. Amateur occultation timers do this. These people use video cameras through telescopes to record when a asteroid passes in front of a star and blocks its light. This can produce very acuate orbital data for the asteroid and if enough people all over the world record it you can even deduce the shape of the asteroid. ___ time-nuts mailing 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] Time Code generator
On 12/08/2010 02:27 PM, scmcgr...@gmail.com wrote: When audio/video time code is specified if its on a audio track its called LTC or Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days as it went out of common use about the time 1 reel to reel was discontinued. Most common today on NTSC is VITC or vertical interval time code. Its encoded as a series of pulses in the vertical blanking interval. The display is generally called a 'Screen Burner' LTC (Linear Time Code) and VITC (Video Time Code) is both being part of SMPTE 12M-1-2008 which is the time-code formats for audio, film and video recordings. LTC is NOT IRIG-B, but a distinct code (I just checked the respective standards to be sure). LTC enumerate picture frames and the rate changes between 24 frames/s, 25 frames/s, 30/1,001 frames/s or 30 frames/s. IRIG-B is quite unfit for this. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time Code generator
On 12/08/2010 07:18 PM, jimlux wrote: Chris Albertson wrote: Adding time code to video would be redundant. All video is already time coded. All *digital* video is timecoded.. No, not all digital video. The time-code is optional in many of the transfer formats. Record that video on an analog 1/2 or 3/4 deck and you need the timecode on the longitudinal audio track. Yes, primarily as you say, to support editing. It's been 12 years since I sat in an edit bay, so I'll bet that analog gear is pretty much out of the picture by now, though. Analog black-bursts is still here. But many consumer level cameras fake it by defining time = zero at the start of a tape or the first frame in memory. If absolute time needs to be record on a consumer level camera then I'd shoot a few frames of a digital clock and then later in a video editor adjust the time code That would work..(e.g. it's just like slating at the beginning of a film take) Sometimes it would be more convenient to just record an audio timecode on the audio track. Where I could see timecode being handy is when you're trying to do automated processing. I worked on a system 15 years ago where we had 100 cameras, and we did the alignment by hand, and it was pretty painful. What's easy when syncing A and B roll gets tedious when there's 100 takes you're essentially cutting together. For Cameras it is not actual time which is important, but frame and line alignment needs to be aligned. Digital video mixers has line-stores on the input, so the cameras only needs to be synced to within a few lines such that the line-store can solve the rest. If you fail syncing up you need to use a frame-store, which you try to avoid since it adds 40 ms of delay and you drop/duplicate frames. Even if you cut between the frames on the editing line, it is still a degradation you want to avoid, so syncing cameras is a good thing. Taking the effort to sync up kind of make sense when you look on the alternatives. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time Code generator
Thanks all for their comments on this topic. Over the weekend I spent much time messing about with the NTP stuff and the NMEAGps application. NMEAGps does just as described and does make a nice IRIG-B signal through a PC's sound card. Unfortunately you cannot specifiy which of several soundcard interfaces you want it to use, it will use the one as set as the default which for my use does not work so well. Set up on a second PC set up as a NTP server and time code generator may just be answer. Some more thought is needed before I figure out how to make it do what I want or to dismiss it. There is also the possibility of adapting tc as suggested by Chris A. Cheers, Graham -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: December 3, 2010 18:03 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time Code generator You computer can generate time code audio signals and if you are keeping the computer's clock sync'd with NTP then those generated time codes will be reasonably accurate.The time code generator is distributed with the NTP software along with other misc. tools. It's a free download if you don't have it. The code is I think the same as sent by WWV. It is some IRIG version. It hing the name of the time code generator is just tc.There is a good chance you alreasy have this but if not it's in the NTP source distribution OK I just looked it up. The filename is .../util/tg.c and here is a quote from the file * This program can generate audio signals that simulate the WWV/H * broadcast timecode. Alternatively, it can generate the IRIG-B * timecode commonly used to synchronize laboratory equipment. later NTP can read back this time code and sync a clock to it. We do this all the time when recording rocket telemetry at work. It works pretty much exactly the way the OP wanted I thing this implementation in tg.c is good to about 1 millisecond -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing 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] Time Code generator
Would Virtual Audio Cable (VAC) software provide the routing neccessary for your application ? Stan, W1LE On 12/6/2010 8:12 AM, Collins, Graham wrote: Thanks all for their comments on this topic. Over the weekend I spent much time messing about with the NTP stuff and the NMEAGps application. NMEAGps does just as described and does make a nice IRIG-B signal through a PC's sound card. Unfortunately you cannot specifiy which of several soundcard interfaces you want it to use, it will use the one as set as the default which for my use does not work so well. ___ time-nuts mailing 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] Time Code generator
Hello The Net: Another possible application is for a pocket digital recorder to generate a serial time code, record it, and also allow 2 channels channels (stereo) of simultaneous audio recording. One pocket digital recorder I am looking at is the Olympus model WS-500 (~ 70$ at New Egg) It may not have Time-Nut (10 to the minus 12) accuracy but it would serve my purpose when recording/logging satellite QSO's in a portable operation with a hand held full duplex, dual band walkie talkie and a hand held/pointed dual band yagi antenna. Audio receive from the satellite downlink would be fed into one audio channel and uplink audio would go to the other audio channel. I could also live with only one audio channel for the downlink. On playback the recorder indicates actual time of the recording being played back. After the satellite pass, transcribe the recoded info, or archive it in a digital file. The digital recorder is pocket size allowing hands free operation. One hand to operate the transceiver and the other hand pointing the antenna. I have not bought one yet, but I suspect the archived audio file would allow time stamping to be played back in the common PC media player applications. Is the serial time code IRIG-A/B/C ? maybe not, but I can live with the existing time code format.. Stan, W1LE Cape Cod FN41sr On 12/3/2010 7:28 AM, Collins, Graham wrote: On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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] Time Code generator
Collins, Graham wrote: On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Not free, but might get you started on what to look for http://www.greenlake-eng.com/gle_tcsw_data_sheet_1-0.htm Dave Mills and the NTP folks at U Delaware have http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver6.html for generators http://www.wraith.sf.ca.us/ntp/index.html#test-tones http://www.visualgps.net/NMEATime/default.htm $15, which is probably cheaper than your time to write something or find something that already exists and try to fix it. If you move away from IRIG, there's also MIDI time code (used when we used to record things on, gasp, analog magnetic tape, and you wanted to keep the MPU-401 based sequencer running right), and various SMPTE AES/EBU time codes used in the audio recording world. ___ time-nuts mailing 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] Time Code generator
I have used nematime over the years it does indeed work well. I have not checked mine was win98 and I used it on an old laptop. But it worked very well. Think I was using it for IRIG B which is an excellant timecode for recording on an audio track. On Fri, Dec 3, 2010 at 11:13 AM, jimlux jim...@earthlink.net wrote: Collins, Graham wrote: On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Not free, but might get you started on what to look for http://www.greenlake-eng.com/gle_tcsw_data_sheet_1-0.htm Dave Mills and the NTP folks at U Delaware have http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver6.html for generators http://www.wraith.sf.ca.us/ntp/index.html#test-tones http://www.visualgps.net/NMEATime/default.htm $15, which is probably cheaper than your time to write something or find something that already exists and try to fix it. If you move away from IRIG, there's also MIDI time code (used when we used to record things on, gasp, analog magnetic tape, and you wanted to keep the MPU-401 based sequencer running right), and various SMPTE AES/EBU time codes used in the audio recording world. ___ time-nuts mailing 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] Time Code generator
Jim and Paul, Thanks for your comments. I have had a quick look at NmeaTime because of your suggestion and it looks promising. It will require a further look later this evening when I can spend the time to do so. So far it looks like it will do just what I want and perhaps even what Stan, W1LE is looking for. That notwithstanding, any other comments or suggestions are also welcome. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: December 3, 2010 11:14 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time Code generator Collins, Graham wrote: On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Not free, but might get you started on what to look for http://www.greenlake-eng.com/gle_tcsw_data_sheet_1-0.htm Dave Mills and the NTP folks at U Delaware have http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver6.html for generators http://www.wraith.sf.ca.us/ntp/index.html#test-tones http://www.visualgps.net/NMEATime/default.htm $15, which is probably cheaper than your time to write something or find something that already exists and try to fix it. If you move away from IRIG, there's also MIDI time code (used when we used to record things on, gasp, analog magnetic tape, and you wanted to keep the MPU-401 based sequencer running right), and various SMPTE AES/EBU time codes used in the audio recording world. ___ time-nuts mailing 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] Time Code generator
At 07:28 AM 12/3/2010, Collins, Graham wrote... Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? SMPTE linear may work for you. Look here: http://ltcsmpte.sourceforge.net/ ___ time-nuts mailing 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] Time Code generator
Thanks Mike, I will have a look. Cheers, Graham -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike S Sent: December 3, 2010 12:57 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time Code generator At 07:28 AM 12/3/2010, Collins, Graham wrote... Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? SMPTE linear may work for you. Look here: http://ltcsmpte.sourceforge.net/ ___ time-nuts mailing 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] Time Code generator
WWV is not necessarily audible at all times. 2.5 MHz seems a poor choice because it has 1/4 of the power at the higher frequencies, except 20 MHz. I went through a phase of acquiring Datum time code generators back in 2003. Thought I'd turn them into rack-mounted shack clocks, but never got around to it. These things generate and receive most IRIG frequencies, but IRIG B at 100 HZ is the most commonly used. They come in 1, 2, or 3 rack units height. They're built with late seventies parts on plug-in cards and weigh about 15-20 pounds. Some have crystal ovens at 1 MHz. Most can use an external 1 MHz. You have to preset the time of day and push a start button after a power cycle. Also have some IRIG clocks, which only decode an IRIG signal. I'd like to get these units to people who can use them, so shipping is going to be the main cost. Don't know what it takes to ship to Canada. Bill Hawkins b...@iaxs.net -Original Message- From: Collins, Graham Sent: Friday, December 03, 2010 6:28 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Time Code generator On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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] Time Code generator
The suitability of use of the WWV or CHU audio depends on where you live. I live within ground wave propagation of CHU's transmissions on 3,330khz. A simple receiver would be all I needed to have the audio available to record. I only got off on the tangent of a more proper time code as being an alternative to an audio recording of a time signal with the possibility in that is would be machine readable. As a simple time stamp for making off the air loggings the recording of the WWV or CHU audio is probably quite sufficient. A local machine generated and readable time code just takes the process up a level (or two). And, since the requirement is to be able to do all this while portable or mobile swings it all more in favour of a PC generated time code (less bits and pieces to be carried around and set up) Cheers, Graham -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Hawkins Sent: December 3, 2010 13:34 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Time Code generator WWV is not necessarily audible at all times. 2.5 MHz seems a poor choice because it has 1/4 of the power at the higher frequencies, except 20 MHz. I went through a phase of acquiring Datum time code generators back in 2003. Thought I'd turn them into rack-mounted shack clocks, but never got around to it. These things generate and receive most IRIG frequencies, but IRIG B at 100 HZ is the most commonly used. They come in 1, 2, or 3 rack units height. They're built with late seventies parts on plug-in cards and weigh about 15-20 pounds. Some have crystal ovens at 1 MHz. Most can use an external 1 MHz. You have to preset the time of day and push a start button after a power cycle. Also have some IRIG clocks, which only decode an IRIG signal. I'd like to get these units to people who can use them, so shipping is going to be the main cost. Don't know what it takes to ship to Canada. Bill Hawkins b...@iaxs.net -Original Message- From: Collins, Graham Sent: Friday, December 03, 2010 6:28 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Time Code generator On another list to which I subscribe, the question was asked about the suitability of recording WWV 2.5mhz audio as one track when recording off the air signals of interest as a time reference. The person who asked the question didn't really state his intentions but they seem very similar to my immediate needs. That is, simply a time reference - that is the time, the start of the minute, and periodic references (i.e. seconds) between the announcements. It seems that recording the audio of something like WWV or CHU is ideal. However, another approach would be recording a more proper time code signal as you might have available from a precision clock. Of course, a decoder would also be required. A quick Google search turned up lots of leads which I have yet to sort through. In the interim I thought I would pose the question to the learned members of this group for their suggestions. Keep in mind KISS and that a very high degree of accuracy is not required. Is there an opensource/freeware PC app that will generate an appropriate time code signal that can be recorded on one track of an audio recorder (either PC based i.e. Audacity or standalone) that will also decode via soundcard or other input? Cheers, Graham ve3gtc ___ time-nuts mailing 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] Time Code generator
apropos of the conversation I seem to recall someone having built a PIC or Arduino based widget that was a IRIG generator/receiver.. you'd hook up an external 10 MHz source (something that any time-nut would certainly have.. the problem would be selecting which one to use). I think it used a USB or serial port to do the control function (i.e. setting the time or returning the decoded time) I also ran across a real small FPGA implementation about a year ago, but I can't find it now. I was looking for a decoder I could drop into a Xilinx design to be an enhanced 1pps sort of thing. ___ time-nuts mailing 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] Time Code generator
A PIC or Arduino widget would be perfect (I mess around with both). A quick Google search for Arduino and IRIG-B didn't seem to return much of interest but I will have another look and this time also a search on PIC as well. Cheers, Graham -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: December 3, 2010 13:53 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time Code generator apropos of the conversation I seem to recall someone having built a PIC or Arduino based widget that was a IRIG generator/receiver.. you'd hook up an external 10 MHz source (something that any time-nut would certainly have.. the problem would be selecting which one to use). I think it used a USB or serial port to do the control function (i.e. setting the time or returning the decoded time) I also ran across a real small FPGA implementation about a year ago, but I can't find it now. I was looking for a decoder I could drop into a Xilinx design to be an enhanced 1pps sort of thing. ___ time-nuts mailing 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] Time Code generator
And, since the requirement is to be able to do all this while portable or mobile swings it all more in favour of a PC generated time code (less bits and pieces to be carried around and set up) There is a utility in the ntp package that emits IRIG based on the local clock. Look at .../util/tg2.c A PIC or Arduino widget would be perfect (I mess around with both). A quick Google search for Arduino and IRIG-B didn't seem to return much of interest but I will have another look and this time also a search on PIC as well. You might be able to port that code to PIC/Arduino. Start by ripping out all the options that you don't need and the command line processing and ... It might be a lot of work but the price is right. -- 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] Time Code generator
Dear time-nuts, A PIC based IRIG timecode generator sounds very interesting! Would like to build a new stand-alone IRIG-timecode generator since my Brandywine died Did some Google-searches without succes unfortunately! :-( Best regards, Jeroen -Original Message- From: time-nuts-boun...@febo.com on behalf of Hal Murray Sent: Fri 12/3/2010 8:38 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time Code generator And, since the requirement is to be able to do all this while portable or mobile swings it all more in favour of a PC generated time code (less bits and pieces to be carried around and set up) There is a utility in the ntp package that emits IRIG based on the local clock. Look at .../util/tg2.c A PIC or Arduino widget would be perfect (I mess around with both). A quick Google search for Arduino and IRIG-B didn't seem to return much of interest but I will have another look and this time also a search on PIC as well. You might be able to port that code to PIC/Arduino. Start by ripping out all the options that you don't need and the command line processing and ... It might be a lot of work but the price is right. -- 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] Time Code generator
Jeroen Bastemeijer - EWI wrote: Dear time-nuts, A PIC based IRIG timecode generator sounds very interesting! Would like to build a new stand-alone IRIG-timecode generator since my Brandywine died Did some Google-searches without succes unfortunately! :-( The generator is easy.. counting time in bcd is just arithmetic, then you generate a bit stream, which is 100 bits long, and clock it out. The symbols in the bit stream are either 0.2, 0.5, or 0.8 long (that is, 2,5, or 8 milliseconds. all you have to do is generate 1kHz and amplitude modulate it somehow (I suspect that 2 resistors would do very nicely) You could set up a 2kHz real time interrupt and toggle the output on each RTI. count every other cycle to count the milliseconds and deal with clocking out the symbols/bits Depending on how you want to do it, you can generate the symbols on the fly or just build up 1000 bits (1 per millisecond) and clock them out. Depends on how much RAM you've got, really. ___ time-nuts mailing 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] Time Code generator
You computer can generate time code audio signals and if you are keeping the computer's clock sync'd with NTP then those generated time codes will be reasonably accurate.The time code generator is distributed with the NTP software along with other misc. tools. It's a free download if you don't have it. The code is I think the same as sent by WWV. It is some IRIG version. It hing the name of the time code generator is just tc.There is a good chance you alreasy have this but if not it's in the NTP source distribution OK I just looked it up. The filename is .../util/tg.c and here is a quote from the file * This program can generate audio signals that simulate the WWV/H * broadcast timecode. Alternatively, it can generate the IRIG-B * timecode commonly used to synchronize laboratory equipment. later NTP can read back this time code and sync a clock to it. We do this all the time when recording rocket telemetry at work. It works pretty much exactly the way the OP wanted I thing this implementation in tg.c is good to about 1 millisecond -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
