Re: [time-nuts] New WWVB modulation format receivers (NOT)
Am Fri, 21 Feb 2014 11:42:05 -0800 (PST) schrieb Bob Albert bob91...@yahoo.com: Oops yes I goofed, it's 500 MHz. 500 GHz is beyond state of the art I would think. Depends on your circuit development skills. Bipolars with gain at 500GHz are in principle possible, both in III/V-semiconductors (InP comes to mind, but even GaAs might do the trick), and in SiGe this is currently under research. But you're right, 500GHz at system level is extremely difficult, I'm not aware of any reasonable demonstration. 5THz (= Far Infrared) is much easier in that regard... So GPS satellites are NIST in miniature it seems. That's a lot of payload but now I have to see how to gain access to it. Well, NIST does more than just time, while GPS essentialy is just that: a precise clock that is also used to calculate positions. Florian ___ time-nuts mailing 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] New WWVB modulation format receivers
: paul swedpaulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] New WWVB modulation format receivers Message-ID: cad2jfahzvjsz1vzihbh05bwnc+dhd2glqstv1cajc40ue1-...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 Clint I don't know if it was me or not the said the doubling scheme did not work. It does work but profoundly unreliably at least on the east coast. If you miss one cycle of carrier you loose phase making it useless. Jfor here on Time nuts and I tried a lot of things to get around the issues because simple is best. Now I do know that folks much closer to wwvb use the doubling method. Someone posted that here. You brought up a really interesting comment on the mix down method and I have been curious about that and thinking about it. Especially since we are looking for a 1Hz phase flip. You mention the 60.003 crystal as an oscillator or filter? Very hard to get those today, not so as little as 5 years ago. I found an ebay supplier that sold something like 25 for $5 so picked up a pack hoping that some crystals would actually work as a filter in the RF chain and they actually do, but you actually have to hand pick them. As an oscillator pretty poor behavior. I have released a RF frontend design to time nuts some 6 months ago and also a traditional costas loop using cd 4000 series chips. It does work and does hold phase over multiple days. It can get tripped up. But all in all for literally a few dollars does well. But I absolutely believe there is a better way as you are suggesting. Regards Paul. WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
On 2/20/14, 8:51 PM, Bob Camp wrote: Hi You can get parts in the 18 bit and up range for not a whole lot of money with rational sample rates for a WWVB receiver. Analog Devices and Linear Tech both make some interesting looking parts. They get you into the =100 db dynamic range area. Yes. 192ksps is considered audio and is now available as a common part for consumer devices. Or go with a 1-bit part and then decimate the hell out of the result. Even with a lower bit count part, you pick up some bits in the downsampling process. As long as you have enough noise to keep things moving, you can track pretty far down into the crud. GPS receivers do that sort of thing all the time. Since this is slow audio after the CIC decimator, things like ARM chips probably have enough DSP horsepower to do what you need to do. The decimator it’s self is not terribly taxing if you don’t go too crazy with the rate change. This all makes more sense to me than hacking a bunch of op amps and filter hardware. Use a low bit-depth but fast part then decimate. If it is fast enough you can get by with very simple anti-alias filtering. Like you said, if you have enough noise to randomize the LSB you are good to go. I bet that the AMBCB provides more than enough randomization power. And if it doesn't, just inject enough broadband noise to randomize the LSB. The rest is just SMOP. Just for giggles I took a look at the output of the ADC on my Hermes board. The input is my Pixelsat loop which is broadband from 50kHz to 30MHz. (It has significant output down to below 20kHz.) The ADC of my Hermes HPSDR board is being fed with the raw output of the antenna with no filtering so the ADC is seeing everything from DC to 60MHz that comes out of the antenna. Peak ADC level at my location is -40dBFS. I live about 35km N of San Antonio so my location is neither particularly RF quiet nor noisy. Seems like the 16-bit ADC has plenty of headroom. I hear WWVB very handily on this setup and I am seeing -83dBm out of my antenna for WWVB on peaks. (Actually the S:N is pretty good at over 16dB in a 300Hz bandwidth.) This is near noon local time. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On 2/20/14, 10:35 PM, Graeme Zimmer wrote: I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything Where are you? It must be deaf as a post. Most ham receivers that purport to have coverage down there really don't. I thought my Flex 5000 should hear that handily but all it ever heard were images of the AM-BCB. The HPSDR Hermes board in my ANAN-10 hears WWVB a treat. Direct Down Conversion (DDC) is your friend and anyone considering playing with this stuff really needs to be thinking about a DDC receiver. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On 2/20/14, 11:08 PM, John Marvin wrote: I have an OpenHPSDR Hermes and it has no problem receiving WWVB; however, since I live in Fort Collins - Colorado, part of the success might just be the strong signal. I wonder if I could just stick a piece of wire into one of the channel inputs of a 192Khz sample rate audio interface (especially if it had a good low noise mic preamp) and decode WWVB from baseband audio! Yes, presuming that the mic preamp doesn't cut off near 20kHz. Some do. 192kHz sampling ADCs are not all equal in their performance up there. Just because they sample that fast doesn't mean they are flat out to the Nyquist frequency. Just remember it is a spec game with the audio ADC people. Sure they may sample at 192kHz but many (most?) really are no better than those that sample at 48kHz or even those that sample at 44.1kHz. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Sorry for comming late to the party... This may be relevant: http://phk.freebsd.dk/loran-c/CW/ The basic idea is that you use a high-rate ADC, something like 1MS/s and then you average into for instance a 1msec = 1.000 samples circular buffer. That gives you a very narrow comb filter for all frequencies which are a multiple of 1 kHz, and extracting the phase from, for instance the 60 kHz WWVB carrier will be trivial. In the example above, the buffer were w full second long, 1.000.000 samples, this reveals the per-second modulation of the carrier, and allows you to extract any (averaged) signal on an integral Hz carrier frequency. There are Arm chips out there now with 1MSPS*12bit ADCs that's plenty for this kind of stuff. (see also: http://phk.freebsd.dk/AducLoran/) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On 2/20/14, 11:35 PM, Hal Murray wrote: Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? Sure, the Shannon-Hartley Theorem. See: http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
NOTE: THE FIRST FIVE LINKS DID NOT SHOW AS COMPLETE ADDRESSES -- I AM NOT SURE WHY, SO YOU WILL HAVE TO COPY THE LINE AND INSERT INTO YOUR URL LINE. Hi Bob, Here are a couple of HP Appnotes, in PDF form, that will get you started in your quest. Some of the references to standard frequency transmissions may be somewhat outdated but the overall data is still valid. The first one is the original publication done in the early 1960's and the next two are a rewrite done in the 1970's. http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52_Frequency_and_Time_Standards_5989-6171EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52-1_Frequency_and_Time_Standards_5989-6183EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52-2_Frequency_and_Time_Standards_5989-6247EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/The_Science_Of_Timekeeping.pdf And finally, here is an appnote about counters, generally, that is worth reading http://www.ko4bb.com/Manuals/HP_Agilent/HP_AN200_frequency_counters_1997.pdf There are plenty of other publications, but no need to overload you too early in the game. The stuff above will give you a basic understanding of the fundementals of which your questions to this list are centered omn. 73BillWB6BNQ Bob Albert wrote: My TS-940S acts as though it receives okay at 60 kHz. Not great sensitivity but it does receive. Most HP GPS receivers are expensive ($400?). I was hoping to get some results with what I have, although I'm willing to cobble up some circuitry. I assume if I can receive the signal, I can figure out how to decode it and/or use it as is. How does one use a 1 pps signal to get precise frequency measurement? Maybe use it as a time base for a counter? My counter has 1 pps as well as 0.1 pps for 10-second count. I would assume signal fading would cause some timing uncertainty due to finite rise and fall time. And at 60 kHz I think rise and fall time would be long. I will look through the archives. Bob On Thursday, February 20, 2014 10:12 PM, Hal Murray hmur...@megapathdsl.net wrote: jim...@earthlink.net said: I sample at 100 kHz with 16 bits on a teensy3.. Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it that matters) Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? I know of one special case. If your ADC is only 1 bit, you don't have to worry about AGC. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Hi Bob, Here are a couple of HP Appnotes, in PDF form, that will get you started in your quest. Some of the references to standard frequency transmissions may be somewhat outdated but the overall data is still valid. The first one is the original publication done in the early 1960's and the next two are a rewrite done in the 1970's. http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52_Frequency_and_Time_Standards_5989-6171EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52-1_Frequency_and_Time_Standards_5989-6183EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/HP/HP_AN52-2_Frequency_and_Time_Standards_5989-6247EN.pdf http://www.ko4bb.com/Manuals/05)_GPS_Timing/The_Science_Of_Timekeeping.pdf And finally, here is an appnote about counters, generally, that is worth reading http://www.ko4bb.com/Manuals/HP_Agilent/HP_AN200_frequency_counters_1997.pdf There are plenty of other publications, but no need to overload you too early in the game. The stuff above will give you a basic understanding of the fundementals of which your questions to this list are centered omn. 73BillWB6BNQ Bob Albert wrote: My TS-940S acts as though it receives okay at 60 kHz. Not great sensitivity but it does receive. Most HP GPS receivers are expensive ($400?). I was hoping to get some results with what I have, although I'm willing to cobble up some circuitry. I assume if I can receive the signal, I can figure out how to decode it and/or use it as is. How does one use a 1 pps signal to get precise frequency measurement? Maybe use it as a time base for a counter? My counter has 1 pps as well as 0.1 pps for 10-second count. I would assume signal fading would cause some timing uncertainty due to finite rise and fall time. And at 60 kHz I think rise and fall time would be long. I will look through the archives. Bob On Thursday, February 20, 2014 10:12 PM, Hal Murray hmur...@megapathdsl.net wrote: jim...@earthlink.net said: I sample at 100 kHz with 16 bits on a teensy3.. Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it that matters) Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? I know of one special case. If your ADC is only 1 bit, you don't have to worry about AGC. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Hi Part of the typical receiving process is reducing the bandwidth. With a smaller bandwidth you can get away with a lower sample rate without loosing useful information. The normal approach is to drop the sample rate as you move through the system. When you drop the sample rate (say 4:1) you have some “extra” bits lying around. You could just throw them away. You also could keep them. Depending on what’s going on, you could get two more bits out of the process. Bob On Feb 21, 2014, at 12:35 AM, Hal Murray hmur...@megapathdsl.net wrote: jim...@earthlink.net said: I sample at 100 kHz with 16 bits on a teensy3.. Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it that matters) Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? I know of one special case. If your ADC is only 1 bit, you don't have to worry about AGC. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Well, I used to be able to see LORAN pulses w/ a 3-inch diameter loop and a Tek 7000-series 'scope. WWVB is hard to detect w/ a 3-foot diameter HP shielded loop w/ integral preamp 2 stages of mechanical filters. (HP 117A). The other half ogf the time it was undetectable. Paul S uses a loop that is much larger. -John === I have an OpenHPSDR Hermes and it has no problem receiving WWVB; however, since I live in Fort Collins - Colorado, part of the success might just be the strong signal. I wonder if I could just stick a piece of wire into one of the channel inputs of a 192Khz sample rate audio interface (especially if it had a good low noise mic preamp) and decode WWVB from baseband audio! John AC0ZG On 2/20/2014 9:55 PM, wb6bnq wrote: Hi Zim, With but a very few exceptions most broadband Amateur radfio trancievers do not do well below 500 KHz even though many allow for tuning below 500 KHz. BillWB6BNQ ___ time-nuts mailing 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] New WWVB modulation format receivers
Indeed the old Don Lancaster and Ralph Burhan articles were key to my pre-time nuttery interests. But I am very interested in the psk31 approach. I actually hacked around a bit with several of the Ham programs. But none seemed to allow you to get to just the BPSK raw data. (I could have missed the trick by the way) There were a couple of other items like getting to a 1 Hz rate. But that said that was one of my early attempts. So if you think you can find the old PIC code and update it would be great to see. I am willing to take a solution you build and test it. By that I mean just the pic with whatever you need to make it work Xtal, A/D or such special things. Do not need power supplies, RF frontends etc I have the equipment to quantify behaviors. A caution top consider. The solution must resolve the phase change in about .1-.5 seconds. If the PIC can track the noisey nasty behavior of LF and PSK31 does do quite a good job then doing anything beyond that becomes very very reasonable. Examples locking a local reference, decoding the signal and my very fovorite is restoring all of the old phase tracking receivers back into operation. Regards Paul. WB8TSL On Thu, Feb 20, 2014 at 11:09 PM, d0ct0r t...@patoka.org wrote: Its still interesting to read an article from Radio-Electronics Magazine with date stamp back to August 1973. In that article Don Lancaster explain few classical techniques how to handle WWVB band. Regards, V.P. On 2014-02-20 20:42, Clint Turner wrote: Several years ago I spotted a clever PIC-based software (DSP-ish) approach to WWVB modulation - but it has thusfar defied my attempts to find it via Google. It was from the late 90's, early 2000's - and I may have it in an archive somewhere. The exact details escape me, but I believe that it sampled at 8 kHz and was fed a crystal-filtered WWVB signal at 60 kHz, putting this bandwidth-limited, AGC-leveled signal directly into the PIC's A/D. If I've done my math correctly, that would yield a frequency-inverted alias at 4 kHz. The A/D was then mixed and/or decimated significantly and a simple software-based carrier recovery scheme (a Costas loop, maybe?) was implemented in this rather low-end PIC. Because the TRF bandwidth was on the order of just a few Hertz, it took a fairly trivial amount of horsepower to implement. Presumably, at just one baud it should be practical to do this on more modern PICs and AVRs using the same scheme. The trick to homebrewing this is to find a 60.003 kHz crystal - but one of these could be swiped from a WWVB receiver module, or, perhaps, a source-follower could be used to recover the phase component of the received carrier, tapping off the signal from the BPF itself and making it available to the processor. * * * Another scheme - one that I believe was poo-poohed a while back on this list - is to simply take a bandpass filtered sample of around 60 kHz and throw it into a four-quadrant multiplier to yield a 120 kHz signal sans phase shift. I believe that the initial critique of this was that this was not a particularly good way to recover a weak signal, but I found it to be quite useful on a project some (15) years ago. On this project, I had a 100 kHz pilot carrier modulated with NRZ BPSK telemetry data and this same carrier was used to convey the reference frequency to multiple, simulcast transmitters via a 33cm microwave link. At 100 kHz, I simply had an L/C bandpass filter that was roughly 3-5 kHz wide on the transmit (to control the occupied bandwidth when XOR-gate modulated) and a similar filter on the receive end. Listening to this 100 kHz center frequency, 3-5 kHz bandwidth was a 1496 configured as a multiplier, the output of which was passed through a simple filter constructed using 200 kHz crystals. The 200 kHz from the doubler output was then divided-by-two and used to synchronously demodulate the BPSK data (after being filtered with either a Bessel or Gaussian LPF) and this same recovered 100 kHz signal was then made available to the master 10 MHz frequency reference for locking. What impressed me was the fact that my input signal S/N could go about 40 dB below the detection bandwidth of the BPSK signal and still maintain perfect lock on the 100 kHz carrier, despite the fact that the 1496 - which really doesn't make all that great of a doubler compared with other available (but more expensive!) devices was being pelted with 3-5 kHz of garbage when the S/N was purposely compromised. IIRC, the detection bandwidth of the crystal-based carrier recover filter was on the order of a few 10ths of Hz. Yes, the phase did vary with temperature, but the rate-of-change was fairly slow and this fact was inconsequential in our application. * * * The upshot of this is that it should be quite easy to do a simple doubler-based carrier recovery system at 120 kHz (or something else, if it's frequency-converted) and, since it may be a
Re: [time-nuts] New WWVB modulation format receivers (NOT)
John Nantucket's been destroyed a sad day last May. But suppose the property value has gone up now. Regards Paul. On Fri, Feb 21, 2014 at 10:13 AM, J. Forster j...@quikus.com wrote: Well, I used to be able to see LORAN pulses w/ a 3-inch diameter loop and a Tek 7000-series 'scope. WWVB is hard to detect w/ a 3-foot diameter HP shielded loop w/ integral preamp 2 stages of mechanical filters. (HP 117A). The other half ogf the time it was undetectable. Paul S uses a loop that is much larger. -John === I have an OpenHPSDR Hermes and it has no problem receiving WWVB; however, since I live in Fort Collins - Colorado, part of the success might just be the strong signal. I wonder if I could just stick a piece of wire into one of the channel inputs of a 192Khz sample rate audio interface (especially if it had a good low noise mic preamp) and decode WWVB from baseband audio! John AC0ZG On 2/20/2014 9:55 PM, wb6bnq wrote: Hi Zim, With but a very few exceptions most broadband Amateur radfio trancievers do not do well below 500 KHz even though many allow for tuning below 500 KHz. BillWB6BNQ ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Many ham transceivers can tune that low, but they are indeed completely deaf because the input filter (including coupling transformer) takes most of the signal out and the phase noise of the synthesizers cover the rest in noise. Didier KO4BB On February 20, 2014 10:35:06 PM CST, Graeme Zimmer gzim...@wideband.net.au wrote: I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything Where are you? It must be deaf as a post. I can hear WWVB in Australia ! (or at least I could till JJY-60 started in 2001) ... Zim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
At work we have various models of these Selena LED clock displays in the new control center and dispatching rooms: http://www.ledclocks.com/SELENA4x7.pdf We use the bare unit which just has a Cat5 Ethernet jack that syncs to a NTP clock on the network, but they also list options for WWVB, DCF77, various IRIG variants, etc. I have never priced these options. The TrueTime IRIG LED clock displays also show up quite regularly on E-bay etc. if you already have something to generate the IRIG clock (and I'm guessing you have that somewhere Rick! All of our IRIG timecode generators are HP and/or Agilent if I remember.). Tim N3QE On Wed, Feb 19, 2014 at 6:49 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: It may be true that WWVB is sending out a new format, but the receivers for it don't seem to exist. The exclusive rights are held by this company, which is clearly on hold while it tries to find a customer who will pay for a wafer run: http://eversetclocks.com/ I've seen this sort of thing many times before. Don't be surprised if this goes the way of AM stereo, etc. Does anyone have any positive news about this? Rick ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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] New WWVB modulation format receivers (NOT)
Boy do I need to agree with Chris's comments above. If this is anything serious GPS really is the answer in all respects. Yes there is the risk of something happening. But amazingly a lot of the GPS receivers hold onto time pretty well even without GPS. The whole WWVB thing makes sense as a frequency transfer method. But is not at all close to GPS today. Its far more interesting to watch the VLF propagation behaviors and as a sort of backup frequency reference. LORAN C simply kicked butt with what it delivered and was on par with and frankly better then GPS for frequency. At least for me over 20 years of practice. But one day soon eLORAN may just come back its looking positive. Sorry not to change the subject. Regards Paul. On Fri, Feb 21, 2014 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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] New WWVB modulation format receivers (NOT)
I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. I presume that with a reasonable antenna this unit will give me a very precise 10 MHz which I can use to synchronize my counter. I am not sure if my counter will accept that frequency but it shouldn't be a big deal to convert to something it will accept, or use its OCXO as a transfer standard. Bob On Friday, February 21, 2014 8:57 AM, paul swed paulsw...@gmail.com wrote: Boy do I need to agree with Chris's comments above. If this is anything serious GPS really is the answer in all respects. Yes there is the risk of something happening. But amazingly a lot of the GPS receivers hold onto time pretty well even without GPS. The whole WWVB thing makes sense as a frequency transfer method. But is not at all close to GPS today. Its far more interesting to watch the VLF propagation behaviors and as a sort of backup frequency reference. LORAN C simply kicked butt with what it delivered and was on par with and frankly better then GPS for frequency. At least for me over 20 years of practice. But one day soon eLORAN may just come back its looking positive. Sorry not to change the subject. Regards Paul. On Fri, Feb 21, 2014 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Bob Yes they will. But there is a danger here when you say very precise. On Time-Nuts those are very particular words that can carry a very long email thread. You say that the complete solutions are a bit out of range. Today there are lots of solutions if you want use a soldering iron. Each has the trade off of cost effort and accuracy. But say you needed something for amateur radio purposes pretty much any of the solutions are very good. Regards Paul. On Fri, Feb 21, 2014 at 12:47 PM, Bob Albert bob91...@yahoo.com wrote: I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. I presume that with a reasonable antenna this unit will give me a very precise 10 MHz which I can use to synchronize my counter. I am not sure if my counter will accept that frequency but it shouldn't be a big deal to convert to something it will accept, or use its OCXO as a transfer standard. Bob On Friday, February 21, 2014 8:57 AM, paul swed paulsw...@gmail.com wrote: Boy do I need to agree with Chris's comments above. If this is anything serious GPS really is the answer in all respects. Yes there is the risk of something happening. But amazingly a lot of the GPS receivers hold onto time pretty well even without GPS. The whole WWVB thing makes sense as a frequency transfer method. But is not at all close to GPS today. Its far more interesting to watch the VLF propagation behaviors and as a sort of backup frequency reference. LORAN C simply kicked butt with what it delivered and was on par with and frankly better then GPS for frequency. At least for me over 20 years of practice. But one day soon eLORAN may just come back its looking positive. Sorry not to change the subject. Regards Paul. On Fri, Feb 21, 2014 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Back to basics, please. Just how does GPS achieve its precision and accuracy? I presume everything must relate to NIST eventually. Bob On Friday, February 21, 2014 10:04 AM, paul swed paulsw...@gmail.com wrote: Bob Yes they will. But there is a danger here when you say very precise. On Time-Nuts those are very particular words that can carry a very long email thread. You say that the complete solutions are a bit out of range. Today there are lots of solutions if you want use a soldering iron. Each has the trade off of cost effort and accuracy. But say you needed something for amateur radio purposes pretty much any of the solutions are very good. Regards Paul. On Fri, Feb 21, 2014 at 12:47 PM, Bob Albert bob91...@yahoo.com wrote: I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. I presume that with a reasonable antenna this unit will give me a very precise 10 MHz which I can use to synchronize my counter. I am not sure if my counter will accept that frequency but it shouldn't be a big deal to convert to something it will accept, or use its OCXO as a transfer standard. Bob On Friday, February 21, 2014 8:57 AM, paul swed paulsw...@gmail.com wrote: Boy do I need to agree with Chris's comments above. If this is anything serious GPS really is the answer in all respects. Yes there is the risk of something happening. But amazingly a lot of the GPS receivers hold onto time pretty well even without GPS. The whole WWVB thing makes sense as a frequency transfer method. But is not at all close to GPS today. Its far more interesting to watch the VLF propagation behaviors and as a sort of backup frequency reference. LORAN C simply kicked butt with what it delivered and was on par with and frankly better then GPS for frequency. At least for me over 20 years of practice. But one day soon eLORAN may just come back its looking positive. Sorry not to change the subject. Regards Paul. On Fri, Feb 21, 2014 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On Fri, Feb 21, 2014 at 9:47 AM, Bob Albert bob91...@yahoo.com wrote: I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. Watch the thread on this list about the Arduino based GPSDO. I think you can get the price down to $50. If all you need is something to calibrate frequency counter then all you need is 9 to 10 digit accuracy I'm going to do this just to prove it can be done for a low two figure price. But first I have to find a decent crystal oscillator that does not use up 1/2 of my $40 budget. If you want ultimate precision that you need a good GPS antenna in a good location, A high-end timing mode GPS receiver and a high-end double oven quartz oscillator. The cost adds up. But I think if you relax the specifications and shoot only for 9 to 10 digits you can greatly reduce the price. -- 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] New WWVB modulation format receivers (NOT)
Well if we are talking about $50 then you have my attention. No I am not afraid to use a soldering iron. Amateur radio is not my main interest here. I have the same compulsion many of you out there seem to have, that if I can get more accuracy I want it. I get that content smile on my face when my counter reads a string of zeroes on a measurement that is supposed to do just that. I am doing a lot better than 1 ppm right now. I have my counter and signal generator agreeing within about 1 Hz at over 500 GHz. When I get one beat in 10 seconds against 20 MHz WWV I have 5 ppb I think. I am close to that but it gets sticky using 20 MHz to communicate, plus the signal is only available in my location for a few hours on most days. I am doing similar things with voltage but you can't communicate voltage over the radio so I don't have that kind of agreement, more like 50 ppm. It's all in fun; I have no legitimate need for this accuracy. Bob On Friday, February 21, 2014 10:26 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Fri, Feb 21, 2014 at 9:47 AM, Bob Albert bob91...@yahoo.com wrote: I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. Watch the thread on this list about the Arduino based GPSDO. I think you can get the price down to $50. If all you need is something to calibrate frequency counter then all you need is 9 to 10 digit accuracy I'm going to do this just to prove it can be done for a low two figure price. But first I have to find a decent crystal oscillator that does not use up 1/2 of my $40 budget. If you want ultimate precision that you need a good GPS antenna in a good location, A high-end timing mode GPS receiver and a high-end double oven quartz oscillator. The cost adds up. But I think if you relax the specifications and shoot only for 9 to 10 digits you can greatly reduce the price. -- 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] New WWVB modulation format receivers (NOT)
500 GHz ? Really? How? Even counting 100 GHz is pushing it. You mean MHz, no? -John == Well if we are talking about $50 then you have my attention. No I am not afraid to use a soldering iron. Amateur radio is not my main interest here. I have the same compulsion many of you out there seem to have, that if I can get more accuracy I want it. I get that content smile on my face when my counter reads a string of zeroes on a measurement that is supposed to do just that. I am doing a lot better than 1 ppm right now. I have my counter and signal generator agreeing within about 1 Hz at over 500 GHz. When I get one beat in 10 seconds against 20 MHz WWV I have 5 ppb I think. I am close to that but it gets sticky using 20 MHz to communicate, plus the signal is only available in my location for a few hours on most days. I am doing similar things with voltage but you can't communicate voltage over the radio so I don't have that kind of agreement, more like 50 ppm. It's all in fun; I have no legitimate need for this accuracy. Bob On Friday, February 21, 2014 10:26 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Fri, Feb 21, 2014 at 9:47 AM, Bob Albert bob91...@yahoo.com wrote: I looked on line and it seems that these receivers are available for about $150 and up. A little out of my price range right now but I'll keep my eyes open. Watch the thread on this list about the Arduino based GPSDO. I think you can get the price down to $50. If all you need is something to calibrate frequency counter then all you need is 9 to 10 digit accuracy I'm going to do this just to prove it can be done for a low two figure price. But first I have to find a decent crystal oscillator that does not use up 1/2 of my $40 budget. If you want ultimate precision that you need a good GPS antenna in a good location, A high-end timing mode GPS receiver and a high-end double oven quartz oscillator. The cost adds up. But I think if you relax the specifications and shoot only for 9 to 10 digits you can greatly reduce the price. -- 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] New WWVB modulation format receivers (NOT)
500GHz? You must mean 50GHz. Because 1Hz at 500GHz is 2E-12. (You're already there at your goal.) And what frequency counter are you using at half a THz? :- ) (My highest freq 2-way ham contact has been on 403GHz and that took me years to make.) -Brian, WA1ZMS/4 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Albert Sent: Friday, February 21, 2014 1:41 PM To: Chris Albertson; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] New WWVB modulation format receivers (NOT) Well if we are talking about $50 then you have my attention. No I am not afraid to use a soldering iron. Amateur radio is not my main interest here. I have the same compulsion many of you out there seem to have, that if I can get more accuracy I want it. I get that content smile on my face when my counter reads a string of zeroes on a measurement that is supposed to do just that. I am doing a lot better than 1 ppm right now. I have my counter and signal generator agreeing within about 1 Hz at over 500 GHz. When I get one beat in 10 seconds against 20 MHz WWV I have 5 ppb I think. I am close to that but it gets sticky using 20 MHz to communicate, plus the signal is only available in my location for a few hours on most days. I am doing similar things with voltage but you can't communicate voltage over the radio so I don't have that kind of agreement, more like 50 ppm. It's all in fun; I have no legitimate need for this accuracy. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Am Thu, 20 Feb 2014 16:02:03 -0500 schrieb Chuck Harris cfhar...@erols.com: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Actually, I was referring to the price tag associated with having a custom chip done... ;-) I fully agree that the computing shouldn't be an issue for anything nowadays. Why bother with a hardware solution when software can do it more easily? Nuts answer: because we can? Florian -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Oops yes I goofed, it's 500 MHz. 500 GHz is beyond state of the art I would think. So GPS satellites are NIST in miniature it seems. That's a lot of payload but now I have to see how to gain access to it. Bob On Friday, February 21, 2014 11:17 AM, Florian Teply use...@teply.info wrote: Am Thu, 20 Feb 2014 16:02:03 -0500 schrieb Chuck Harris cfhar...@erols.com: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Actually, I was referring to the price tag associated with having a custom chip done... ;-) I fully agree that the computing shouldn't be an issue for anything nowadays. Why bother with a hardware solution when software can do it more easily? Nuts answer: because we can? Florian -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Hi Paul: The problem with GPS is you don't get the DST bits. For the OP that's OK, but if you want local time it isn't. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html paul swed wrote: Boy do I need to agree with Chris's comments above. If this is anything serious GPS really is the answer in all respects. Yes there is the risk of something happening. But amazingly a lot of the GPS receivers hold onto time pretty well even without GPS. The whole WWVB thing makes sense as a frequency transfer method. But is not at all close to GPS today. Its far more interesting to watch the VLF propagation behaviors and as a sort of backup frequency reference. LORAN C simply kicked butt with what it delivered and was on par with and frankly better then GPS for frequency. At least for me over 20 years of practice. But one day soon eLORAN may just come back its looking positive. Sorry not to change the subject. Regards Paul. On Fri, Feb 21, 2014 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com wrote: Bob, If you are looking for an accurate, easy to use timing signal then GPS is the one you want. WWV and WWVB are what I call legacy signals and while they might be accurate when broadcast there is propagation delay and unknown atmospheric and ionospheric conditions. But the question is How accurate do you need? If a few tens of milliseconds is good enough then running NTP over the internet will work and if you already have an internet connection it's free. If you need a few nanoseconds then GPS is what you want. Using your beat with WWV as a benchmark. You were getting about one part in a million accuracy. It is VERY easy to do 10,000 times better than that with GPS. On Thu, Feb 20, 2014 at 8:19 PM, Bob Albert bob91...@yahoo.com wrote: I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. -- 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. ___ time-nuts mailing 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] New WWVB modulation format receivers
Hi Paul, Without digging through the archives, I'll rely on your memory of that past thread! The scheme of using the doubler relied on the 100 kHz carrier recovery relied on the fact that the 200 kHz bandpass filters, being based on quartz crystals, was extremely narrow - on the order of fractions of Hz. This effectively made them frequency-selective integrators (not the right word, but you get the idea...) and they were effectively immune to noise pulses as they simply could not react quickly. IIRC - and I'll have to review my old notes - I used the first 200 kHz crystal as a series element and then passed it to a source-follower and then a bipolar amplifier with ridiculous gain (e.g. grounded emitter, high collector resistance) to form a limiter - and then ran it through another 200 kHz crystal and JFET/limiter. It took a couple of seconds for the outputs of the two limiters to saturate due to the narrow bandwidth and it was extremely tolerant of amplitude variations. There was a phase shift with different amplitude levels, but since, on an FM microwave link the amplitude wasn't going to change much, that - and the phase shift related to temperature - was inconsequential. On this simple recover scheme you could remove the input carrier for nearly a second (or blot it out with noise) and there would be almost no measurable effect on the output, aside from a phase shift of a few 10's of degrees which quickly rectified itself once the signal was returned. Had added some better tuning of the resonators I could have likely minimized this. (I happened to have these 200 kHz HC-6 style units in my semi-large collection of 40-80's vintage crystals.) The trick to replicating such a filter would be to find a suitable bandpass filter for the doubled frequency - in this case, a 120.005 kHz crystal (or thereabouts) - but it should be practical to convert the previously-filtered 60 kHz signal to a frequency for which a suitable crystal could be located. The 60.003 kHz crystal to which I referred was a bandpass filter rather than an oscillator: The TRF units found in WWVB clocks use these since most standard 60.000 kHz units end up being low in frequency when used in this sort of mode and they are a bit tricky to pull this far. Rather than try to find such a crystal I would probably throw together a Tayloe commutating mixer with RC lowpass filtering with a time constant of a hundred milliseconds or so - this, filter/mixer being clocked at the nominal 60 kHz receive signal. I would then follow it with another commutating mixer to translate the quadrature signal to any convenient frequency (say, audio - no doubt available from the 4060 or 4040 counter I'd be using!) where I would then do my frequency doubling and then follow it by yet another extremely narrow filter - this time, using an 8-capacitor SCF where I could set the detection bandwidth to a tiny fraction of 1 Hz just using a bunch of electrolytics! It should be easy to set the carrier detection bandwidth to be a fraction of the information bandwidth so that reliable carrier recovery can be maintained under any conditions under which the BPSK data could be recovered. (An example of an 8-capacitor Roanoake type SCF may be seen here: http://ka7oei.com/emm2a_scf.html ) This recovered (and slightly filtered) signal, divided-by-two, could then be used to synchronously demodulate the original frequency-converted signal, at which point one should have a reasonable representation of the phase (and amplitude) of the transmitted signal - albeit, delayed by a fairly consistent amount. Of course, all of this could be done by throwing a 16 bit A/D and DSP chip at it, but sometimes there's a simple pleasure in doing it with a bunch of 4000 CMOS and a few op-amps, handing the recovered baseband off to a PIC or Arduino only at the very end! * * * Many years ago I built a WWVB carrier recovery circuit using just a single-stage LC bandpass filter (to get rid of the VLF powerhouses) and an NE565 phase detector along with a 6 MHz VCXO divided down to 60 kHz as the comparison. What amazed me was that even with the practically nonexistant filtering in front of the '565 (you really couldn't see the 60 kHz carrier with the oscilloscope) that '565 would always find its way into lock over time - and then it would stay firmly there owing to that effect that occurs in which the effective loop bandwidth seems to decrease once lock has been achieved. (WWVB's 45 degree phase shift ID would always throw it for a loop, though - pun intended!) 73, Clint KA7OEI Date: Thu, 20 Feb 2014 22:10:26 -0500 From: paul swedpaulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] New WWVB modulation format receivers Message-ID: cad2jfahzvjsz1vzihbh05bwnc+dhd2glqstv1cajc40ue1-...@mail.gmail.com Content-Type: text/plain; charset=ISO
Re: [time-nuts] New WWVB modulation format receivers
of the VLF powerhouses) and an NE565 phase detector along with a 6 MHz VCXO divided down to 60 kHz as the comparison. What amazed me was that even with the practically nonexistant filtering in front of the '565 (you really couldn't see the 60 kHz carrier with the oscilloscope) that '565 would always find its way into lock over time - and then it would stay firmly there owing to that effect that occurs in which the effective loop bandwidth seems to decrease once lock has been achieved. (WWVB's 45 degree phase shift ID would always throw it for a loop, though - pun intended!) 73, Clint KA7OEI Date: Thu, 20 Feb 2014 22:10:26 -0500 From: paul swedpaulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] New WWVB modulation format receivers Message-ID: CAD2JfAhZvjSZ1vZiHBH05BwNc+DHd2gLQsTv1cAJc40UE1-gjw@mail. gmail.com Content-Type: text/plain; charset=ISO-8859-1 Clint I don't know if it was me or not the said the doubling scheme did not work. It does work but profoundly unreliably at least on the east coast. If you miss one cycle of carrier you loose phase making it useless. Jfor here on Time nuts and I tried a lot of things to get around the issues because simple is best. Now I do know that folks much closer to wwvb use the doubling method. Someone posted that here. You brought up a really interesting comment on the mix down method and I have been curious about that and thinking about it. Especially since we are looking for a 1Hz phase flip. You mention the 60.003 crystal as an oscillator or filter? Very hard to get those today, not so as little as 5 years ago. I found an ebay supplier that sold something like 25 for $5 so picked up a pack hoping that some crystals would actually work as a filter in the RF chain and they actually do, but you actually have to hand pick them. As an oscillator pretty poor behavior. I have released a RF frontend design to time nuts some 6 months ago and also a traditional costas loop using cd 4000 series chips. It does work and does hold phase over multiple days. It can get tripped up. But all in all for literally a few dollars does well. But I absolutely believe there is a better way as you are suggesting. Regards Paul. WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
I am wondering if it's a tough road to get precise time and frequency. How precise do you want? How much money do you have? 1/2 :), but you are asking on the time-nuts list so you should expect answers like that. I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? The buzzword for the usual approach is GPSDO. 2 models are often available surplus (aka not expensive for the value) from cell phone towers. Google for HP Z3801A and Trimble Thunderbolt. I am sure this subject has been covered but I don't know how to find it. This list is archived. The headers in list mail contain things like: List-archive: http://www.febo.com/pipermail/time-nuts That has everything batched by month, and sorted by Thread, Subject, Author, and Date. Poke around a bit and you will get a feel for things. It doesn't have a search facility. Google works well to search the time-nuts archives. You can add time-nuts as a search term which might find a message in a site that archives list traffic, or you can add site:febo.com to restrict the search to the official archive. http://comments.gmane.org/gmane.comp.time.nuts/25812 -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
One of the simplest ways to receive VLF signals is to buy a surplus Selective Level Meter. They were an important piece of test equipment used by the analog line-line telephony people. Now of course, surplus to requirements. If you hunt around they can be found at very low prices. ... Zim ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
jim...@earthlink.net said: I sample at 100 kHz with 16 bits on a teensy3.. Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it that matters) Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? I know of one special case. If your ADC is only 1 bit, you don't have to worry about AGC. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
that is perhaps another 60kHz station they have one in England too! 73 KJ6HN Alex On 2/20/2014 8:35 PM, Graeme Zimmer wrote: I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything Where are you? It must be deaf as a post. I can hear WWVB in Australia ! (or at least I could till JJY-60 started in 2001) ... Zim ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
My TS-940S acts as though it receives okay at 60 kHz. Not great sensitivity but it does receive. Most HP GPS receivers are expensive ($400?). I was hoping to get some results with what I have, although I'm willing to cobble up some circuitry. I assume if I can receive the signal, I can figure out how to decode it and/or use it as is. How does one use a 1 pps signal to get precise frequency measurement? Maybe use it as a time base for a counter? My counter has 1 pps as well as 0.1 pps for 10-second count. I would assume signal fading would cause some timing uncertainty due to finite rise and fall time. And at 60 kHz I think rise and fall time would be long. I will look through the archives. Bob On Thursday, February 20, 2014 10:12 PM, Hal Murray hmur...@megapathdsl.net wrote: jim...@earthlink.net said: I sample at 100 kHz with 16 bits on a teensy3.. Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it that matters) Can somebody give me a lesson in the tradeoffs between number of bits and sampling rate? I know of one special case. If your ADC is only 1 bit, you don't have to worry about AGC. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Or a discreet receiver using time-nut available stuff. NIST should be the one that owns the format and they have published it. Regards Paul On Thu, Feb 20, 2014 at 1:45 AM, Richard (Rick) Karlquist rich...@karlquist.com wrote: On 2/19/2014 9:10 PM, John Marvin wrote: I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John They have exclusive rights to the IP core for their IC. I guess someone else could design their own IC... Rick ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Sounds like a great Kickstarter project for some time nuttiers. On 2/19/2014 9:10 PM, John Marvin wrote: I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John They have exclusive rights to the IP core for their IC. I guess someone else could design their own IC... Rick -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida jleik...@leikhim.com 407-982-0446 WWW.LEIKHIM.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] New WWVB modulation format receivers (NOT)
Am Wed, 19 Feb 2014 22:45:56 -0800 schrieb Richard (Rick) Karlquist rich...@karlquist.com: On 2/19/2014 9:10 PM, John Marvin wrote: I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John They have exclusive rights to the IP core for their IC. I guess someone else could design their own IC... Rick Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Paul Swed posted a working, mostly analog, design here maybe 6 months ago. -John = Am Wed, 19 Feb 2014 22:45:56 -0800 schrieb Richard (Rick) Karlquist rich...@karlquist.com: On 2/19/2014 9:10 PM, John Marvin wrote: I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John They have exclusive rights to the IP core for their IC. I guess someone else could design their own IC... Rick Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL On Thu, Feb 20, 2014 at 4:02 PM, Chuck Harris cfhar...@erols.com wrote: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
At least on the Atlantic coast, the WWVB signal levels jump all over the place, certainly 40 dB and maybe more. If a receiver cannot deal w/ that w/o losing lock, it's nearly useless. OTOH, LORAN was always a whopping signal. -John Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL On Thu, Feb 20, 2014 at 4:02 PM, Chuck Harris cfhar...@erols.com wrote: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Totally agree with you John as I learned. I knew it was a variable but I have seen nights that were crazy and do fit your 40 db. I redesigned the AGC to account for that in the fr front end actually. Regards Paul On Thu, Feb 20, 2014 at 4:34 PM, J. Forster j...@quikus.com wrote: At least on the Atlantic coast, the WWVB signal levels jump all over the place, certainly 40 dB and maybe more. If a receiver cannot deal w/ that w/o losing lock, it's nearly useless. OTOH, LORAN was always a whopping signal. -John Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL On Thu, Feb 20, 2014 at 4:02 PM, Chuck Harris cfhar...@erols.com wrote: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
The large amplitude swings happen on a very short time scale too. Certainly 1 second at times. -John Totally agree with you John as I learned. I knew it was a variable but I have seen nights that were crazy and do fit your 40 db. I redesigned the AGC to account for that in the fr front end actually. Regards Paul On Thu, Feb 20, 2014 at 4:34 PM, J. Forster j...@quikus.com wrote: At least on the Atlantic coast, the WWVB signal levels jump all over the place, certainly 40 dB and maybe more. If a receiver cannot deal w/ that w/o losing lock, it's nearly useless. OTOH, LORAN was always a whopping signal. -John Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL On Thu, Feb 20, 2014 at 4:02 PM, Chuck Harris cfhar...@erols.com wrote: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Hi Paul, could you give a hint how long ago you released the front end to T_N? thanks Neville Michie (Sydney) On 21/02/2014, at 8:29 AM, paul swed wrote: Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL On Thu, Feb 20, 2014 at 4:02 PM, Chuck Harris cfhar...@erols.com wrote: At 60KHz, it shouldn't be out of range of most general purpose CPU's, and even the most pathetic DSP. Why bother with a hardware solution when software can do it more easily? -Chuck Harris Florian Teply wrote: Well, if someone comes up with a circuit, I could check how much chip area that would consume in a 250nm SiGe BiCMOS... Shouldn't be out of range for a serious time nut ;-) Florian ___ time-nuts mailing 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] New WWVB modulation format receivers
Several years ago I spotted a clever PIC-based software (DSP-ish) approach to WWVB modulation - but it has thusfar defied my attempts to find it via Google. It was from the late 90's, early 2000's - and I may have it in an archive somewhere. The exact details escape me, but I believe that it sampled at 8 kHz and was fed a crystal-filtered WWVB signal at 60 kHz, putting this bandwidth-limited, AGC-leveled signal directly into the PIC's A/D. If I've done my math correctly, that would yield a frequency-inverted alias at 4 kHz. The A/D was then mixed and/or decimated significantly and a simple software-based carrier recovery scheme (a Costas loop, maybe?) was implemented in this rather low-end PIC. Because the TRF bandwidth was on the order of just a few Hertz, it took a fairly trivial amount of horsepower to implement. Presumably, at just one baud it should be practical to do this on more modern PICs and AVRs using the same scheme. The trick to homebrewing this is to find a 60.003 kHz crystal - but one of these could be swiped from a WWVB receiver module, or, perhaps, a source-follower could be used to recover the phase component of the received carrier, tapping off the signal from the BPF itself and making it available to the processor. * * * Another scheme - one that I believe was poo-poohed a while back on this list - is to simply take a bandpass filtered sample of around 60 kHz and throw it into a four-quadrant multiplier to yield a 120 kHz signal sans phase shift. I believe that the initial critique of this was that this was not a particularly good way to recover a weak signal, but I found it to be quite useful on a project some (15) years ago. On this project, I had a 100 kHz pilot carrier modulated with NRZ BPSK telemetry data and this same carrier was used to convey the reference frequency to multiple, simulcast transmitters via a 33cm microwave link. At 100 kHz, I simply had an L/C bandpass filter that was roughly 3-5 kHz wide on the transmit (to control the occupied bandwidth when XOR-gate modulated) and a similar filter on the receive end. Listening to this 100 kHz center frequency, 3-5 kHz bandwidth was a 1496 configured as a multiplier, the output of which was passed through a simple filter constructed using 200 kHz crystals. The 200 kHz from the doubler output was then divided-by-two and used to synchronously demodulate the BPSK data (after being filtered with either a Bessel or Gaussian LPF) and this same recovered 100 kHz signal was then made available to the master 10 MHz frequency reference for locking. What impressed me was the fact that my input signal S/N could go about 40 dB below the detection bandwidth of the BPSK signal and still maintain perfect lock on the 100 kHz carrier, despite the fact that the 1496 - which really doesn't make all that great of a doubler compared with other available (but more expensive!) devices was being pelted with 3-5 kHz of garbage when the S/N was purposely compromised. IIRC, the detection bandwidth of the crystal-based carrier recover filter was on the order of a few 10ths of Hz. Yes, the phase did vary with temperature, but the rate-of-change was fairly slow and this fact was inconsequential in our application. * * * The upshot of this is that it should be quite easy to do a simple doubler-based carrier recovery system at 120 kHz (or something else, if it's frequency-converted) and, since it may be a bit tricky to find a cheap 120.006 kHz crystal, use an SCF clocked from a VCXO (or a simple fractional divider/DDS implemented in software) to provide a very narrow detection bandwidth that would satisfy the dynamics associated with the usable signal range over which the WWVB carrier could be reconstructed and the phase data could likely be recovered. The AM output of a standard WWVB clock module could then be used to aid in the windowing of a synchronous demodulator integrate-and-dump filter to recover the phase information and make these two pieces available to something like a PIC or an AVR/Arduino for crunching. In the (likely!) event of a signal that was too weak to recover the amplitude information from the broader-bandwidth WWVB receiver module it should be practical to oversample (say, by 8x) the output of the synchronous demodulator and then infer the timing of the phase change over a period of time since the minimum period of this is well known (1 second!) and such timing could be (initially) autonomously applied with very good stability until the timing of the phase change resolved itself - something that could be correlated with a statistical analysis of the output of the amplitude detector, as well. To a large degree, this sounds like a candidate for a front end consisting of good old 4000 CMOS logic and a few op amps with the output handed off to a fairly low-end, cheap processor module! 73, Clint KA7OEI
Re: [time-nuts] New WWVB modulation format receivers (NOT)
On Thursday, February 20, 2014, J. Forster j...@quikus.com wrote: The large amplitude swings happen on a very short time scale too. Certainly 1 second at times. 8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with AGC? Just make sure the ADC doesn't clip. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Hi You can get parts in the 18 bit and up range for not a whole lot of money with rational sample rates for a WWVB receiver. Analog Devices and Linear Tech both make some interesting looking parts. They get you into the =100 db dynamic range area. Even with a lower bit count part, you pick up some bits in the downsampling process. As long as you have enough noise to keep things moving, you can track pretty far down into the crud. GPS receivers do that sort of thing all the time. Since this is slow audio after the CIC decimator, things like ARM chips probably have enough DSP horsepower to do what you need to do. The decimator it’s self is not terribly taxing if you don’t go too crazy with the rate change. Bob On Feb 20, 2014, at 7:40 PM, Brian Lloyd br...@lloyd.com wrote: On Thursday, February 20, 2014, J. Forster j...@quikus.com wrote: The large amplitude swings happen on a very short time scale too. Certainly 1 second at times. 8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with AGC? Just make sure the ADC doesn't clip. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] New WWVB modulation format receivers
Clint I don't know if it was me or not the said the doubling scheme did not work. It does work but profoundly unreliably at least on the east coast. If you miss one cycle of carrier you loose phase making it useless. Jfor here on Time nuts and I tried a lot of things to get around the issues because simple is best. Now I do know that folks much closer to wwvb use the doubling method. Someone posted that here. You brought up a really interesting comment on the mix down method and I have been curious about that and thinking about it. Especially since we are looking for a 1Hz phase flip. You mention the 60.003 crystal as an oscillator or filter? Very hard to get those today, not so as little as 5 years ago. I found an ebay supplier that sold something like 25 for $5 so picked up a pack hoping that some crystals would actually work as a filter in the RF chain and they actually do, but you actually have to hand pick them. As an oscillator pretty poor behavior. I have released a RF frontend design to time nuts some 6 months ago and also a traditional costas loop using cd 4000 series chips. It does work and does hold phase over multiple days. It can get tripped up. But all in all for literally a few dollars does well. But I absolutely believe there is a better way as you are suggesting. Regards Paul. WB8TSL On Thu, Feb 20, 2014 at 8:42 PM, Clint Turner tur...@ussc.com wrote: Several years ago I spotted a clever PIC-based software (DSP-ish) approach to WWVB modulation - but it has thusfar defied my attempts to find it via Google. It was from the late 90's, early 2000's - and I may have it in an archive somewhere. The exact details escape me, but I believe that it sampled at 8 kHz and was fed a crystal-filtered WWVB signal at 60 kHz, putting this bandwidth-limited, AGC-leveled signal directly into the PIC's A/D. If I've done my math correctly, that would yield a frequency-inverted alias at 4 kHz. The A/D was then mixed and/or decimated significantly and a simple software-based carrier recovery scheme (a Costas loop, maybe?) was implemented in this rather low-end PIC. Because the TRF bandwidth was on the order of just a few Hertz, it took a fairly trivial amount of horsepower to implement. Presumably, at just one baud it should be practical to do this on more modern PICs and AVRs using the same scheme. The trick to homebrewing this is to find a 60.003 kHz crystal - but one of these could be swiped from a WWVB receiver module, or, perhaps, a source-follower could be used to recover the phase component of the received carrier, tapping off the signal from the BPF itself and making it available to the processor. * * * Another scheme - one that I believe was poo-poohed a while back on this list - is to simply take a bandpass filtered sample of around 60 kHz and throw it into a four-quadrant multiplier to yield a 120 kHz signal sans phase shift. I believe that the initial critique of this was that this was not a particularly good way to recover a weak signal, but I found it to be quite useful on a project some (15) years ago. On this project, I had a 100 kHz pilot carrier modulated with NRZ BPSK telemetry data and this same carrier was used to convey the reference frequency to multiple, simulcast transmitters via a 33cm microwave link. At 100 kHz, I simply had an L/C bandpass filter that was roughly 3-5 kHz wide on the transmit (to control the occupied bandwidth when XOR-gate modulated) and a similar filter on the receive end. Listening to this 100 kHz center frequency, 3-5 kHz bandwidth was a 1496 configured as a multiplier, the output of which was passed through a simple filter constructed using 200 kHz crystals. The 200 kHz from the doubler output was then divided-by-two and used to synchronously demodulate the BPSK data (after being filtered with either a Bessel or Gaussian LPF) and this same recovered 100 kHz signal was then made available to the master 10 MHz frequency reference for locking. What impressed me was the fact that my input signal S/N could go about 40 dB below the detection bandwidth of the BPSK signal and still maintain perfect lock on the 100 kHz carrier, despite the fact that the 1496 - which really doesn't make all that great of a doubler compared with other available (but more expensive!) devices was being pelted with 3-5 kHz of garbage when the S/N was purposely compromised. IIRC, the detection bandwidth of the crystal-based carrier recover filter was on the order of a few 10ths of Hz. Yes, the phase did vary with temperature, but the rate-of-change was fairly slow and this fact was inconsequential in our application. * * * The upshot of this is that it should be quite easy to do a simple doubler-based carrier recovery system at 120 kHz (or something else, if it's frequency-converted) and, since it may be a bit tricky to find a cheap 120.006 kHz crystal, use an SCF clocked from a VCXO (or a simple fractional
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Hi Paul, how was that 60kHz RF front end made I was not wit the group six months ego could you please send me a copy/ thank you in advance 73 KJ6UHN Alex On 2/20/2014 1:29 PM, paul swed wrote: Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
Request sent offline. Regards Paul On Thu, Feb 20, 2014 at 9:32 PM, Alex Pummer a...@pcscons.com wrote: Hi Paul, how was that 60kHz RF front end made I was not wit the group six months ego could you please send me a copy/ thank you in advance 73 KJ6UHN Alex On 2/20/2014 1:29 PM, paul swed wrote: Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers
Several years ago I spotted a clever PIC-based software (DSP-ish) approach to WWVB modulation Perhaps it was mine? Years ago I designed a PSK31 decoder using a PIC. It worked very well for fixed frequencies, but I concluded that making it tunable was beyond the resources of the PICs then available. If I remember correctly, it used a simple delay line and multiplied the early and late version of the signal. Most of the overheads were in synchronisation and decoding the Varicode modulation. I imagine it would be fairly easy to get it working for WWVB. All it would take would be sufficient enthusiasm. Something I have a shortage of these days :-) .. Zim VK3GJZ ___ time-nuts mailing 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] New WWVB modulation format receivers
Its still interesting to read an article from Radio-Electronics Magazine with date stamp back to August 1973. In that article Don Lancaster explain few classical techniques how to handle WWVB band. Regards, V.P. On 2014-02-20 20:42, Clint Turner wrote: Several years ago I spotted a clever PIC-based software (DSP-ish) approach to WWVB modulation - but it has thusfar defied my attempts to find it via Google. It was from the late 90's, early 2000's - and I may have it in an archive somewhere. The exact details escape me, but I believe that it sampled at 8 kHz and was fed a crystal-filtered WWVB signal at 60 kHz, putting this bandwidth-limited, AGC-leveled signal directly into the PIC's A/D. If I've done my math correctly, that would yield a frequency-inverted alias at 4 kHz. The A/D was then mixed and/or decimated significantly and a simple software-based carrier recovery scheme (a Costas loop, maybe?) was implemented in this rather low-end PIC. Because the TRF bandwidth was on the order of just a few Hertz, it took a fairly trivial amount of horsepower to implement. Presumably, at just one baud it should be practical to do this on more modern PICs and AVRs using the same scheme. The trick to homebrewing this is to find a 60.003 kHz crystal - but one of these could be swiped from a WWVB receiver module, or, perhaps, a source-follower could be used to recover the phase component of the received carrier, tapping off the signal from the BPF itself and making it available to the processor. * * * Another scheme - one that I believe was poo-poohed a while back on this list - is to simply take a bandpass filtered sample of around 60 kHz and throw it into a four-quadrant multiplier to yield a 120 kHz signal sans phase shift. I believe that the initial critique of this was that this was not a particularly good way to recover a weak signal, but I found it to be quite useful on a project some (15) years ago. On this project, I had a 100 kHz pilot carrier modulated with NRZ BPSK telemetry data and this same carrier was used to convey the reference frequency to multiple, simulcast transmitters via a 33cm microwave link. At 100 kHz, I simply had an L/C bandpass filter that was roughly 3-5 kHz wide on the transmit (to control the occupied bandwidth when XOR-gate modulated) and a similar filter on the receive end. Listening to this 100 kHz center frequency, 3-5 kHz bandwidth was a 1496 configured as a multiplier, the output of which was passed through a simple filter constructed using 200 kHz crystals. The 200 kHz from the doubler output was then divided-by-two and used to synchronously demodulate the BPSK data (after being filtered with either a Bessel or Gaussian LPF) and this same recovered 100 kHz signal was then made available to the master 10 MHz frequency reference for locking. What impressed me was the fact that my input signal S/N could go about 40 dB below the detection bandwidth of the BPSK signal and still maintain perfect lock on the 100 kHz carrier, despite the fact that the 1496 - which really doesn't make all that great of a doubler compared with other available (but more expensive!) devices was being pelted with 3-5 kHz of garbage when the S/N was purposely compromised. IIRC, the detection bandwidth of the crystal-based carrier recover filter was on the order of a few 10ths of Hz. Yes, the phase did vary with temperature, but the rate-of-change was fairly slow and this fact was inconsequential in our application. * * * The upshot of this is that it should be quite easy to do a simple doubler-based carrier recovery system at 120 kHz (or something else, if it's frequency-converted) and, since it may be a bit tricky to find a cheap 120.006 kHz crystal, use an SCF clocked from a VCXO (or a simple fractional divider/DDS implemented in software) to provide a very narrow detection bandwidth that would satisfy the dynamics associated with the usable signal range over which the WWVB carrier could be reconstructed and the phase data could likely be recovered. The AM output of a standard WWVB clock module could then be used to aid in the windowing of a synchronous demodulator integrate-and-dump filter to recover the phase information and make these two pieces available to something like a PIC or an AVR/Arduino for crunching. In the (likely!) event of a signal that was too weak to recover the amplitude information from the broader-bandwidth WWVB receiver module it should be practical to oversample (say, by 8x) the output of the synchronous demodulator and then infer the timing of the phase change over a period of time since the minimum period of this is well known (1 second!) and such timing could be (initially) autonomously applied with very good stability until the timing of the phase change resolved itself - something that could be correlated with a statistical analysis of the output of the amplitude detector, as well. To a large degree, this sounds like a candidate for a front end
Re: [time-nuts] New WWVB modulation format receivers (NOT)
I am wondering if it's a tough road to get precise time and frequency. I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything I could guess would be WWVB, just a fair amount of noise. I did calibrate against 20 MHz WWV so that the beat was one every several seconds. Not bad but I think it can be better. I would love to discipline my counter and signal generator time bases to match NIST. Is this possible, and what would I need to do? I am sure this subject has been covered but I don't know how to find it. Bob On Thursday, February 20, 2014 7:20 PM, paul swed paulsw...@gmail.com wrote: Request sent offline. Regards Paul On Thu, Feb 20, 2014 at 9:32 PM, Alex Pummer a...@pcscons.com wrote: Hi Paul, how was that 60kHz RF front end made I was not wit the group six months ego could you please send me a copy/ thank you in advance 73 KJ6UHN Alex On 2/20/2014 1:29 PM, paul swed wrote: Chuck thats easy. Because I could make it work. :-) That said there was a post on time-nuts about LORAN C receiver in software. I responded and have had the great pleasure of communicating with Matthias over the last two weeks. I have learned a lot already and he in return has a tested LORAN C receiver. So with some luck just maybe I can become smart enough to do a better design in software on a $15 micro. You still need the RF frontend section that I released quite a while ago to time-nuts. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New WWVB modulation format receivers (NOT)
I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything Where are you? It must be deaf as a post. I can hear WWVB in Australia ! (or at least I could till JJY-60 started in 2001) ... Zim ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
Hi Zim, With but a very few exceptions most broadband Amateur radfio trancievers do not do well below 500 KHz even though many allow for tuning below 500 KHz. BillWB6BNQ Graeme Zimmer wrote: I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never heard anything Where are you? It must be deaf as a post. I can hear WWVB in Australia ! (or at least I could till JJY-60 started in 2001) ... Zim ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On 2/20/14 4:40 PM, Brian Lloyd wrote: On Thursday, February 20, 2014, J. Forster j...@quikus.com wrote: The large amplitude swings happen on a very short time scale too. Certainly 1 second at times. 8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with AGC? Just make sure the ADC doesn't clip. I sample at 100 kHz with 16 bits on a teensy3.. ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
I have an OpenHPSDR Hermes and it has no problem receiving WWVB; however, since I live in Fort Collins - Colorado, part of the success might just be the strong signal. I wonder if I could just stick a piece of wire into one of the channel inputs of a 192Khz sample rate audio interface (especially if it had a good low noise mic preamp) and decode WWVB from baseband audio! John AC0ZG On 2/20/2014 9:55 PM, wb6bnq wrote: Hi Zim, With but a very few exceptions most broadband Amateur radfio trancievers do not do well below 500 KHz even though many allow for tuning below 500 KHz. BillWB6BNQ ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
I have a wave analyzer which for those who may be unfamiliar with such an instrument is a super het receiver that tunes from 0 to 50 kHz. Mine has enough extra range on the high end to hit 60 kHz.I can connect a 40 foot wire antenna in my attic to its input and receive WWVB here in Kentucky. I can see the variations on the meter or look at the frequency restored output on a scope. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: John Marvin jm-t...@themarvins.org To: time-nuts@febo.com Sent: Thursday, February 20, 2014 11:08 PM Subject: Re: [time-nuts] New WWVB modulation format receivers (NOT) I have an OpenHPSDR Hermes and it has no problem receiving WWVB; however, since I live in Fort Collins - Colorado, part of the success might just be the strong signal. I wonder if I could just stick a piece of wire into one of the channel inputs of a 192Khz sample rate audio interface (especially if it had a good low noise mic preamp) and decode WWVB from baseband audio! John AC0ZG On 2/20/2014 9:55 PM, wb6bnq wrote: Hi Zim, With but a very few exceptions most broadband Amateur radfio trancievers do not do well below 500 KHz even though many allow for tuning below 500 KHz. BillWB6BNQ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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] New WWVB modulation format receivers (NOT)
Wouldn't that be nice! They implement a new format which destroys much of the installed infrastructure, then don't actually produce the 'better replacement'. How very LORAN! -John == It may be true that WWVB is sending out a new format, but the receivers for it don't seem to exist. The exclusive rights are held by this company, which is clearly on hold while it tries to find a customer who will pay for a wafer run: http://eversetclocks.com/ I've seen this sort of thing many times before. Don't be surprised if this goes the way of AM stereo, etc. Does anyone have any positive news about this? Rick ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
actually they are supposed to have general availability by the end of Q1. Will see and have no idea about the cost. Not keeping my fingers crossed at all. Regards Paul. On Wed, Feb 19, 2014 at 7:18 PM, J. Forster j...@quikus.com wrote: Wouldn't that be nice! They implement a new format which destroys much of the installed infrastructure, then don't actually produce the 'better replacement'. How very LORAN! -John == It may be true that WWVB is sending out a new format, but the receivers for it don't seem to exist. The exclusive rights are held by this company, which is clearly on hold while it tries to find a customer who will pay for a wafer run: http://eversetclocks.com/ I've seen this sort of thing many times before. Don't be surprised if this goes the way of AM stereo, etc. Does anyone have any positive news about this? Rick ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John On 2/19/2014 4:49 PM, Richard (Rick) Karlquist wrote: It may be true that WWVB is sending out a new format, but the receivers for it don't seem to exist. The exclusive rights are held by this company, which is clearly on hold while it tries to find a customer who will pay for a wafer run: http://eversetclocks.com/ I've seen this sort of thing many times before. Don't be surprised if this goes the way of AM stereo, etc. Does anyone have any positive news about this? Rick ___ time-nuts mailing 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] New WWVB modulation format receivers (NOT)
On 2/19/2014 9:10 PM, John Marvin wrote: I guess my question is who has the right to grant exclusive rights for the ability to decode a very simple protocol? Was a patent actually granted for this? John They have exclusive rights to the IP core for their IC. I guess someone else could design their own IC... Rick ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
