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] Looking for WWVB digital wall clock with digital 24 hour UTC display
rich...@karlquist.com said: I want to use WWVB because I want to be able to mention to visitors that the clock links to an ensemble of 5071A cesium standards, and I was one of the designers of the 5071A, the actual atomic clock. ... Neat. What does the Air Force use as a reference for GPS? Maybe you need two clocks. :) -- 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] Looking for WWVB digital wall clock with digital 24hour UTC display
From: Richard (Rick) Karlquist Can anyone recommend a atomic wall clock that displays in digital 24 hour UTC? Looking for largest possible digits and LED preferred over LCD, under $100. Any brands to avoid? Rick == Rick, you could make your own with a Raspberry Pi and TV: http://www.satsignal.eu/raspberry-pi/DigitalClock.html David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TIC model
R2 is dominated by the adc sample switch on resistance and thus has a relatively high tempco (~4000ppm/C). C2 has a relatively low tempco (~100ppm/C or so) To reduce the effect of the sample switch on resistance tempco on the gain tempco of the TIC R1 C1 need to be proportioned so that R2 has little effect on the gain temcpo. R1 = 470 ohm, C1 = 1nF (NPO) appears to be about right for a 2.5MHz synchroniser clock and the PIC you intend to use. This should reduce the effect of the sample switch on resistance tempco by a factor of 10 or more. The minimum value of R1 is governed by the output resistance of the tristate buffer and its tempco. Bruce Bob Stewart wrote: Hi Bruce, What are the tradeoffs with using different values for R1? I have no practical experience at this, so all I can do is rely on the models. Does the fact that R2 is in the PIC, and C1 is so tiny, make the value of R1 of less importance? On my PIC, they list C1 as 5pf, R2 as effectively about 7K, and C2 120pf. Bob From: Bruce Griffithsbruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurementtime-nuts@febo.com Sent: Tuesday, February 18, 2014 9:35 PM Subject: Re: [time-nuts] TIC model The attached circuit schematic illustrates how this might be implemented. Faster logic devices can be substituted. R2, C2 approximate the equivalent input circuit of the ADC. R2, C2 values will vary for each ADC. The Shift register which acts as a synchroniser and produces various trigger signals is clocked at 10MHz (assumed to be the uP instruction cycle clock rate) The RC network charge time varies between 1 and 2 shift register clock periods ( ie a charge time from 100ns to 200ns). Sampling a time stamp counter clocked at the same frequency as the shift register is only required if the GPSDO local oscillator has a potential initial offset of 100ppb or more. If missing PPS detection is required then a PPS time stamp counter with a range of several seconds is desirable. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] TIC model
Now you've lost me. What 2.5 MHz synchronizer clock? Everything I have external to the PIC is 10MHz. The PIC is running HSPLL at 40MHz, though I don't think that makes any difference to this. Bob From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, February 20, 2014 3:07 AM Subject: Re: [time-nuts] TIC model R2 is dominated by the adc sample switch on resistance and thus has a relatively high tempco (~4000ppm/C). C2 has a relatively low tempco (~100ppm/C or so) To reduce the effect of the sample switch on resistance tempco on the gain tempco of the TIC R1 C1 need to be proportioned so that R2 has little effect on the gain temcpo. R1 = 470 ohm, C1 = 1nF (NPO) appears to be about right for a 2.5MHz synchroniser clock and the PIC you intend to use. This should reduce the effect of the sample switch on resistance tempco by a factor of 10 or more. The minimum value of R1 is governed by the output resistance of the tristate buffer and its tempco. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 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] Looking for WWVB digital wall clock with digital 24 hour UTC display
Other than WWVB-based frequency references/clocks that lock onto the 60 kHz carrier itself, I'm not aware of any WWVB-based clocks that were the slightest-bit affected by format change (e.g. the addition of the low-rate BPSK): Please point me to any references to the contrary if you find them. Co-incident with the WWVB format change there were a number of WWVB clocks that quit working - namely, a few of the older SkyScan models, but this had nothing at all to do with the format change, but rather an error in the silicon that caused them to fail to automatically set themselves (after initially doing so when first powered-up). For WWVB, the timing of the manifestation of this bug was most unfortunate and there is/was quite a bit of information on the net that continues to propel this myth. Being a bit of a nerd and Time Nut I went out of my way to determine the actual cause of this problem. There is this: http://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html In this, I determined that at least with this receiver, its detection bandwidth was far too wide to be adversely affected by the phase reversal which - in theory - could skew the timing of the recovered amplitude waveform of the time code modulation. From this I concluded that the TRF receivers used by these inexpensive clocks weren't likely to be affected in the least by the BPSK. And secondly, there is this: http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html In short, I created my own, local WWVB signal and demonstrated to my satisfaction that the real problem with these particular clocks was that they couldn't tolerate dates beyond a certain range. A shame, too, since these same clocks will happily display UTC with no DST - although they would sync at Midnight and early morning for their set time zone which means that they would sync during daylight hours: Not a problem here in Utah where we have mV/m signal levels, but it could be disastrous for stations farther east where usable signals are available only in the wee hours of the morning! (These clocks also had a bug that would cause them to delay a day during the spring change onto DST - disconcerting on the morning of the time change if it was set to local time with DST!) 73, Clint KA7OEI 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 ___ time-nuts mailing 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] TIC model
For a 10MHz synchroniser clock A C1 value of around 220pF or so should be appropriate. The exact value depends on the ADC reference voltage. A n ADC reference less than 5V may be useful. I'll run some simulations to check the sensitivity to R2's tempco. Bruce Bob Stewart wrote: Now you've lost me. What 2.5 MHz synchronizer clock? Everything I have external to the PIC is 10MHz. The PIC is running HSPLL at 40MHz, though I don't think that makes any difference to this. Bob From: Bruce Griffithsbruce.griffi...@xtra.co.nz To: Bob Stewartb...@evoria.net; Discussion of precise time and frequency measurementtime-nuts@febo.com Sent: Thursday, February 20, 2014 3:07 AM Subject: Re: [time-nuts] TIC model R2 is dominated by the adc sample switch on resistance and thus has a relatively high tempco (~4000ppm/C). C2 has a relatively low tempco (~100ppm/C or so) To reduce the effect of the sample switch on resistance tempco on the gain tempco of the TIC R1 C1 need to be proportioned so that R2 has little effect on the gain temcpo. R1 = 470 ohm, C1 = 1nF (NPO) appears to be about right for a 2.5MHz synchroniser clock and the PIC you intend to use. This should reduce the effect of the sample switch on resistance tempco by a factor of 10 or more. The minimum value of R1 is governed by the output resistance of the tristate buffer and its tempco. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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.
