[time-nuts] Re: DIY Low offset Phase Noise Analyzer (Erik, Kaashoek)
yes there are much better signal generators out there, that frequency doubler tuning circuit is for religious people only -- you need to be able to believe, that it could work 73 KJ6UHN Alex On 7/11/2022 12:24 PM, Dave B via time-nuts wrote: On 11/07/2022 08:30, time-nuts-requ...@lists.febo.com wrote: I also measured a Marconi 2022 signal generator and it was possible to lock but the phase noise was terrible with strong factional PLL spurs. Indeed, those signal generators are renown for having "some rather interesting" spectral content... Around, above and often well below the "desired" signal! Not entirely surprising though, if you look at the block diagram of one such. Regards to All. Dave G0WBX(G8KBV) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: Ublox M6T -M8T
Yes, we did, and learned, that the device -- the ublox6 -- forgets the the program very fast, thus we added one arduino, which loads the program into the ublox at every new turn on. By using low output frequency -- 10kHz -- the jitter is low, at higher output frequency the jitter is getting larger, presumably because the internal clock of the ublox is a "free running " crystal oscillator. We did not do any "deep quality investigation" to the output of our 10MHz signal source output, 10 is just used as frequency calibrator for instruments. I made one phase phase comparation, --comparator one input GPS -ublox derived 60kHz the other input is wwvb 60kHz from Fort Collins Colorado, it show the typical phase change during the day of the wwvb. 73 Alexander Pummer[hard ware] + David Fannin [soft ware] On 5/28/2022 10:05 AM, R&M Putz via time-nuts wrote: Has anyone done anything with the Ublox GPS timing receivers? As it appears the Navman with the 10khz outputs seem to be drying up, I'm wondering about the Time Pulse 2 output being set to 10 Khz or 100 Khz. Thoughts anyone? Rich W9ENG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: +1/f of transistors
Noise in Physical Systems Including 1,f Noise, Biological Systems and Membranes : 10th International Conference, August 21-25, 1989, Budapest, Hungary 1990 https://www.google.com/books/edition/Noise_in_Physical_Systems/WyVbzgEACAAJ?hl=en On 4/9/2022 11:35 AM, Lux, Jim wrote: On 4/9/22 10:03 AM, use...@teply.info wrote: On 09.04.22 15:31, Richard (Rick) Karlquist wrote: I am seeing a lot of unsupported "theories" about what should be done to make devices with low 1/f noise. It might be instructive for everyone to read Marv Keshner's PhD dissertation (Stanford) discussing 1/f noise. He looks at all kinds of theories and shows that there is no valid cookbook for how to make low 1/f noise devices. It's the classic non reproducible process. I remember an FCS talk many years ago that NIST guru Fred Walls gave with some theory on how to get low 1/f noise. Unlike his other papers which were well received (and rightly so), this one was rapidly debunked. I felt bad for Fred, getting out too far over his skills. Thanks for the hint towards the thesis, I'll ask our library to fetch a copy. Recently I was discussing some measurement results with my colleagues as we're trying to come up with a low noise JFET which can successfully be integrated into a SiGe BiCMOS process, and quite often we're also struggling to identify why exactly variant A has significantly lower noise than variant B, or why a new approach does not improve noise the way it was expected. So from a manufacturing process design point of view, achieving low 1/f noise indeed is closer to sheer dumb luck than the proverbial "more art than science" suggest. This is very, very true. Some manufacturers get very low noise or very low leakage (or both), essentially by being "lucky". From what I've been told, there's no good models, nor predictions - so people share "lore" of "if you get these 2N FETs from the mfr in England, they're really good" until they aren't. There isn't enough market for these, so I suspect research money to "solve the problem" isn't available. Like all those microwave MMICs with low noise, they worry about 100 MHz and up (if not 1GHz), they certainly don't worry (or control) for noise at 5 MHz, or where the 1/f knee is. So just because you got good results with a batch of them, the next batch might not. It's not even clear you could come up with a standardized test method, because the noise depends on a lot of other factors (drain current, for instance). ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Looking for a new GNSS-receiver for a diciplined oscillator - Which one to buy?
Hi Ulf, do not give up so simple, often it could be repaired, what kind of GPS receiver do you have? 73 KJ6UHN Alex On 3/11/2022 4:56 AM, Ulf Kylenfall via time-nuts wrote: Greetings forum, Since my GPS-receiver ceased operation recently, I need to purchasea new one. Please suggest a suitable module preferably from DigiKey sinceI have a customer account with them. 1PPS and a computer interface to check the performance is needed. Cheers Ulf KylenfallSM6GXV ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Fwd: Re: local WWVB ?
Forwarded Message Subject:Re: [time-nuts] Re: local WWVB ? Date: Sat, 11 Dec 2021 09:57:49 -0800 From: Alex Pummer To: Attila Kinali Hi Attila, actually there are some repeaters, which do not generate their own carrier, but just receive and amplifying re-radiate the wwvb signal with different polarization, and since the amplified and radiated signal is phase coherent with the original it is not a "newly generated" one. Also if you -- like in many application using that underneath the earth surface -- you could re-radiate the magnetic component only with a loop, and since the length of the loop will be most likely much shorter, than a 1/4 wave length the current along the loop will be constant. To be able to couple to the loop you need to set the receiver's ferrite antenna vertically. That magnetic radiation of the loop will not interfere with the original -- horizontally polarized -- wwvb and outside of the loop the strength of the field will drop very fast, at 1/3 of the loop's radial outside of the loop the field strength is at list 50dB down. Thus, the same loop could work with a Raspberry Pi transmitter without causing any interference or get noticed from anybody outside of the loop Greetings Alex On 12/11/2021 5:43 AM, Attila Kinali wrote: On Fri, 10 Dec 2021 15:54:55 -0500 "Lawrence Brandt" wrote: Has anyone designed and/or sold a "WWVB repeater" device? I can picture a Raspberry Pi which had software to get NTP data or GPS-referenced time, and a small 60 kHz transmitter, which would send the proper WWVB timecode data to the several "atomic clocks" I have around the house. Today, with all the non-licensed wireless stuff we have as gadgets, it doesn't seem to be as obvious as it once was, but: Transmitting on a frequency you don't have the explicit license for is forbidden. And there are some quite hefty fines for that. Especially transmitting on a widely used frequency of an infrastructure service like WWVB might not be looked kindly upon. If you want to lock WWVB clocks that are placed somewhere, where the reception is not good enough. Then you should inject the signal directly into the clock. This way you avoid transmitting. Alternatively, replace the electronics with some 802.15.4 system (e.g., 6LowPan) and distribute time in this network. There are plenty of developer boards available for this kind of stuff, just check adafruit and sparkfun. Attila Kinali -- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Rebroadcasting time signals [WAS: La Crosse Clocks - ]
it is relative problem-less to rebroadcast withe orthogonal polarization
relative to the original vertical polarized signal and using a loop, not
higher than one meter above ground -- magnetic coupling only...' --
around your house, -- don't forget to change the polarization of the
antenna the ferrite- road which receiving the rebroadcasted signal --
driving with one simple amplifier like LM386, gain not much than 10B.
A few meter outside of the loop will be nothing to receive, no
interference, because 60kHz 's wave length is 5km and it is much larger
that any loop which you could put around you house. The receiving
antenna should be set up that way, that it does not have coupling --
magnetic -- to the transmit antenna, high up in the attic above the
center of the loop.
73
KJ6UHN
Alex
On 12/26/2020 10:45 PM, Charles Steinmetz wrote:
Hal wrote:
Transmitting on the same frequency you are receiving on seems like
asking for
troubles.
Difficult perhaps, but not impossible. As /tvb notes, one solution is
time domain multiplexing; and, as Alex says, phase domain multiplexing
is another (although the phase discrimination of 60kHz antennas this
size is problematic). There are others.
How far apart would the antennas have to be? How would you calculate
that
distance? Or what is the right question?
I've watched discussions of this topic for several years, and have
always been surprised that nobody has ever once mentioned the
potential for harmful interference extending beyond one's own
property. (Tom mentioned it today, including the possibility of legal
implications.) This is especially true of people, like some on this
list, who reportedly run a big loop around their house ("so that all
their WWVB clocks can hear it"). But really, any scheme with leakage
can (and likely does) create harmful interference beyond your property.
I can say positively that if anyone who has such a system lived down
the block from me, I would be most unhappy about it and would be in a
very foul mood by the time I figured out what was causing the
interference I was receiving. (I know whereof I speak -- I spent
quite a lot of effort a few years ago chasing down a leaking 10MHz
reference of very dubious quality in use by a local ham nearly a
kilometer from me.)
So, please, if you are going to rebroadcast a time signal to your
receivers, make sure the modulator and RF generator are in
well-RF-sealed enclosures and that you use good coax (or, preferably,
triax) to send the signal to each receiver individually. BTW, this
applies to *any* such signal, not just LF but HF and GNSS
rebroadcasters as well.
Best regards,
Charles
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Re: [time-nuts] Old Crystal.
Using the DG8SAQ Vector Network Analyzer to identify an unknown component https://www.youtube.com/watch?v=Ao653tz1kVE actually it has a special program made for analyzing crystals Greetings and 73 KJ6UHN Alex On 3/1/2021 12:32 AM, Magnus Danielson wrote: Hi, On 2021-03-01 01:23, Attila Kinali wrote: On Sun, 28 Feb 2021 18:35:57 -0500 Dan Kemppainen wrote: If any of you have any suggestions on where to find information on how to get something like this to oscillate properly, guess at correct parameters, or even measure any of the parameters I would really appreciate it. The best way would be to use a network analyzer and measure the crystals LCR parameters. Using that you can use the standard harmonic oscillator literature (Parzen, Frerking,...) to design the circuit. I seem to have misplaced my literature on how to measure crystal oscillators. But if you search for "Neubig" and "crystal measurement", you should be able to find some of the nice documents that Bernd Neubig has written on the topic. The same Neubig made a comment that your normal network analyzer isn't such a good tool, even a very good one. The reason being you need both a wide and narrow sweep to make the model values accurate enough. Most network analyzers achieve the wide sweep, few do the narrow sweep and then having that combined to fill in the LCR parameters of a suitable model, not so much. Things you learn by eating breakfast with him. Turns out that my network analyzer is good for the measurement, but not for model fitting. Neubig have been very much involved in standardizing measurements, and doing those well to characterize accurate enough those high-Q resonators have it's challenges that leads many efforts into incorrect values. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Mains Frequency
at the time I grew up in Eastern Europe -- "communist time" -- they kept he clocks using the line frequency as reference -- by counting the periods during the day and week and for longer time for equal time interval the "provided" equal number of line frequency periods, as longer the time interval was as more precise was the time. That way the clocks were relative accurate. They could do it since everything was "central governed". On 2/12/2021 9:24 AM, Lux, Jim wrote: On 2/12/21 8:23 AM, Thomas D. Erb wrote: "I would think they try to hold it over 1 day, so that mains driven clocks don't run slow or fast.? That being said, I wonder how many clocks are still being built using a synchronous motor drive? Given that all the clocks on appliances in my kitchen have drifted apart, I'll bet they use their internal microcontroller crystal as a reference." Actually I think all of my kitchen appliances use line frequency for time reference - it's so easy to count. Maybe.. you've got to condition the AC from the secondary side of the transformer and use a pin to bring it in on, which requires at least 2 or 3 passive components, and you already have a crystal for the microcontroller (thinking here of oven timers and the like, which have a numeric display). These applications are super price sensitive, and those 2 or 3 components cost money, in components, in board space, and in assembly costs. Pennies to be sure, but... And the fact that my appliances drift on the order of a minute in a month, differently. So maybe some count cycles and some have a rock. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] La Crosse Clocks -
actually you could transmit and receive on the same frequency if you take care that they have different polarization. A small transmit loop around -- vertical axis -- the building and very low power and receive the wwvb normally with the ferrite roads with horizontal axis, the transmission outside of the loop is negligible, I am running such a system for my old clocks, wwvb receiver antenna properly oriented in the attic, amplifier downstairs, the loop cca 1/2' from the ground an one LM386 "drives" the loop with low power, just you have to turn you clock's ferrite - antenna vertically. 73 KJ6UHN Alex On 12/26/2020 5:23 PM, Tom Van Baak wrote: > Transmitting on the same frequency you are receiving on seems like asking for troubles. Same frequency, but you wouldn't do both at the same time. See, you can't transmit AM WWVB until you first know what time it is. To get the time you enable the ES100 and listen to BPSK WWVB. So the ES100 receiver and Arduino transmitter are not active as the same time. One example might be to enable the ES100 for 3 minutes each hour and run the Arduino for the balance. > How far apart would the antennas have to be? Use the standard dual right angle ES100 antenna setup to receive BPSK WWVB. For transmit, you likely don't need, and legally don't want, an antenna. The Arduino is likely within a few feet of the 24h RC clock that you're trying to set. If it doesn't work first time, dangle a jumper off the GPIO pin. /tvb On 12/26/2020 1:59 PM, Hal Murray wrote: t...@leapsecond.com said: Use a ES100 board [2] to receive the real BPSK WWVB and then generate a fake AM WWVB signal for the 24h clock to receive. That way you get the enhanced reception of the new format and the wide clock selection of the Transmitting on the same frequency you are receiving on seems like asking for troubles. How far apart would the antennas have to be? How would you calculate that distance? Or what is the right question? ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] PDIP package 100 MHz decade dividers
Hi Perrier https://www.y-ic.es/datasheet/3b/74F569SC.pdf will work 73 KJ6UHN Alex On 7/11/2020 3:00 PM, Perry Sandeen via time-nuts wrote: Learned List, On previous posts I was looking for a PDIP package 100 MHz decade divider. Reading just the front of the data sheet I thought that the 74LS161 would work. Boy, was I wrong. Several members posted that 25 Mhz max was its limit. So *on the road again* (sorry Willie) I went on another search this time with the correct logic family. It turns out Arrow carries the 74HC161 for less that $1. Additionally I D/L'd the Charles Wenzel Unusual Frequency Dividers PDF and discovered a 100 MHz decade divider circuit using 1/2 of a 74HC74 in a configuration that will decade divide up to 300 MHz. I'm attaching a copy of the circuit for anyone interested. Regards, Perrier ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] low power divide by 5
There was once upon the time a very good data/application-book from Fairchild for TTL logic, they published many different modulo frequency dividers with 50% duty-cycle for the "9316" which is the functional equivalent grandfather for 74161 and therefore for the AC161 to. For frequency division, if the output is used for analog application it is preferable to have 50% duty-cycle. Alex KJ6UHN On 7/1/2020 2:03 PM, Peter McCollum wrote: When I was looking for a 100 MHz divide by 10 in a dip package I was advised by someone on the list to use the 74LS161. It's available on Ebay on ebay from several sources for reasonable prices. 74LS161 won't go that fast - 20-25 MHz is max. Pete On Wed, Jul 1, 2020 at 2:46 PM Perry Sandeen via time-nuts < time-nuts@lists.febo.com> wrote: Learned List When I was looking for a 100 MHz divide by 10 in a dip package I was advised by someone on the list to use the 74LS161. It's available on Ebay on ebay from several sources for reasonable prices. Regards, Perrier ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] OCXO and fluctuations after EFC adjustment
Taka, it was possible, to do without computer, although the computer is a very big help particularly for routine works, but it is possible not just trouble shoot but design, very complicated circuits to, and there are out there areas where computers still do not help today, Bob Peasa even cached the computer, that it is lied to him, -- look here: https://www.autodesk.com/products/eagle/blog/whats-all-this-bob-pease-stuff-anyhow/ -- but it is fun, it is still fun I am doing it for the last 60 years. I just for that OCXO thema, I cleaned up the output of the DDS with out VCO, but the principle is usable for any spectrum cleaning, I filed for patent thus could talk about it, but it would not fit into the tread. Engineering or as we spell it in German Ingenieur -ing, since the Franco-German word is derived from ingenuity, not from the engine.And yes over there we figured out how to make the "thinking machine", but we still using our own head to think. 73 KJ6UHN ex DL6QF On 4/11/2020 7:05 PM, Taka Kamiya via time-nuts wrote: I'm STILL reading this, with interest. I want to know the method of fault discovery, thought process that ensued, analysis conducted, testing process, and eventual root cause analysis. We rely too much on automated processes and computers. I want to know how engineers did more with less. Before they are forever lost, we got to document it, or better yet, pass it on to newcomers. I care more about how it was done before, not how it can be done better with this or that million dollar tool. --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Saturday, April 11, 2020, 8:59:32 PM EDT, Bob kb8tq wrote: Hi On Apr 11, 2020, at 8:10 PM, Richard (Rick) Karlquist wrote: On 4/11/2020 2:25 PM, Bob kb8tq wrote: Hi Would you *really* want to read a book about how from August of 1986 to January of 1993 AVX NPO’s had some sort of issue ( not that the issue is clearly known, just that they are flakey) and that by 1994 the parts with values below 220 pf in 0805 seemed to be fixed? Again, the task was never to *fix* a component, simply to sort out the parts that worked from the parts you didn’t want to use. The only feedback to the manufacturer was via the (lack of) purchase orders. Somehow I doubt anybody would make it past the first page …. Bob Back when before HP broke up into pieces, capacitor vendors considered it a computer company and assumed that all capacitor orders were for "computer grade" capacitors. This envisioned huge motherboards with thousands of bypass capacitors. Like monitor specs where it is OK for so many pixels to be bad, as long as 99% of the capacitors were good ... ship them. As long as the average leakage current met some spec, it didn't matter if a few of them were very leaky. The current wouldn't be noticed. Tempco and dissipation factor didn't matter. We did actually give the manufacturer feedback, but it was not accepted because we as an instrument division were not in their target market. They didn't support repurposing. It didn't matter than we were owned by HP; we were using them for the wrong end use. It's like those disclaimers that say "We do not authorize for the life support market" etc. Some vendors flat out would not sell to our division although they were fine with the computer divisions. By now, few people besides Bob are still reading this. :-) Rick N6RK Indeed over the years, our experience was that feedback on components was at best unwelcome and at worst a major waste of everybody’s time. Lots of “dialog” and very little benefit. Unless you are a precision crystal company, oscillator companies are *not* a big customer for any component outfit …. Bob ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Synchronisation of crystal oscillators
don't forget the oscillator is one amplifier with infinite gain on his own frequency 73 KJ6UHN Alex On 3/1/2020 2:46 PM, Richard (Rick) Karlquist wrote: On 3/1/2020 2:28 PM, John Moran, Scawby Design wrote: My apologies if this is slightly off-topic, but it does concern crystal oscillators. However, I then remembered Huygens's discovery that 1S pendulums mounted on the same wall, or beam, would synchronise and swing either in phase, or out of phase and sometimes one would be stopped, by the minute interactions. So, my question is - will my row of low frequency crystals 'talk' to each other and synchronise in their frequency groups as well? Remember that these crystals are long thin bars of quartz - one of the 3,600Hz crystals being 2mm square by 60mm long - so they will possibly vibrate quite vigorously compared w Injection locking requires that the oscillators be within each others 3 dB bandwidth, or at least close to that. Oscillators on different nominal frequencies are no problem (EG 3 MHz and 10 MHz). Even two "10 MHz" oscillators won't lock unless they are adjusted to close to zero beat. OTOH, if you carefully adjust a couple of HP10811's to zero beat, you will have to go to extraordinary measures to keep them from injection locking. A lot more than just running them on individual voltage regulators. Bottom line: probably not worth worrying about for your hobby project. Rick N6RK ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Quartz crystall and beyond
IMPROVING THE FREQUENCY STABILITY OF MICROWAVE OSCILLATORS BY UTILIZING THE TEMPERATURE COMPENSATED DIFFERENCE FREQUENCY OF A DUAL-MODE SAPPHIRE LOADED CAVITY RESONATOR https://images.search.yahoo.com/yhs/search;_ylt=AwrUiqr58Fpe2kYAigIPxQt.;_ylu=X3oDMTByNWU4cGh1BGNvbG8DZ3ExBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=poseidon+scientific+whispering+gallery+oscillators&fr=yhs-dcola-001&hspart=dcola&hsimp=yhs-001#id=0&iurl=https%3A%2F%2Fwww.researchgate.net%2Fprofile%2FMichael_Tobar%2Fpublication%2F242255140%2Ffigure%2Ffig1%2FAS%3A669508037509121%401536634563175%2FThe-frequency-of-the-WGE-11-0-0-mode-and-the-difference-between-the-WGE-11-0-0-and-WGH_Q320.jpg&action=click 73 KJ6UHN Alex On 2/29/2020 2:57 PM, Richard (Rick) Karlquist wrote: On 2/29/2020 1:58 PM, Attila Kinali wrote: Different concept. Quartz oscillators are mechanical resonators. Cryogenic sapphire oscillators are electro-magnetic resonators. The problem with those is, that they are large and need liquid He for cooling. Not only is He expensive, but it also needs a cryostat that will mechanically shake the CSO. But they get down to a few parts in 10^-15 between 1s and ~1000s, I've even seen papers with a few parts in 10^-16 in the same range(e.g. [1]) . There have been attempts to get them to liquid nitrogen temperatures [2]. But they only got down to 1e-13 (i.e. where good crystal oscillators are). And not much happend since, beside an attempt to get them working at room temperature [3] Agilent (now Keysight) attempted for years to put a whispering gallery oscillator in an instrument. It wasn't cyrogenic. They actually heated/cooled it to lock it to a 10811. The real thing that stymied them was microphonics. I retired in 2014 and don't know whatever became of this effort. The two biggest experts on WGO's went with Agilent during the Keysight spinoff, which might have finally killed it completely. A cryogenic WGO would face the same microphonic issues. Rick N6RK ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] decimation versus decimation
in original -- Latin -- it means; take every tenth 73 KJ6UHN Alex On 2/25/2020 7:15 AM, Bob kb8tq via time-nuts wrote: Hi In the common vernacular “decimation” does indeed mean “just throw the rest away”. You can find papers where that *is* what’s being done with samples and that term is used. Downsample also means “just throw them away”…… Bob On Feb 25, 2020, at 9:55 AM, Dana Whitlow via time-nuts wrote: I'm confused: I seem to see multiple (at least double) meanings for the term 'decimation'. One meaning is simply: "take every nth sample and discard the others without regard to possible aliasing". The other meaning is: "take every nth sample, but first prefilter as appropriate to (sensibly) eliminate aliasing". Which is it? And if the answer is "both", then shouldn't we all be very careful to explicitly specify which meaning applies to the situation at hand whenever we use the term "decimation"? Thanks, DanaK8YUM ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO
I got my German edition of T+S [16] for $120.- shipped to California,
but don't be surprised some of the medicament's made in Europe costing
50 times more here.
73
KJ6UHN
Alex
On 1/19/2020 5:30 PM, Charles Steinmetz wrote:
Gerhard wrote:
The idea was just to measure 1/f noise on my AF and RF transistors
in a circuit inspired by that in Art Of Electronics V3.
Good book. Must have.
Absolutely right. But most electronics amateurs don't seem to want to
spend the money for what is arguably the most important tool available
to improve their understanding. In my view, Chapter 8 alone ("Noise")
is worth the price all by itself ($80 at Amazon).
Speaking of price, I see Springer has a newish English edition of
Tietze & Schenk for over $900!! I like my 1991 English edition just
fine, but for >$900 I expect it to actually build prototypes of the
circuits it shows!! [Generally speaking, H&H is a better learning
resource, IMO. To call T&S a "cookbook" is an unwarranted put-down,
but it is organized more or less along those lines though with much
additional explanation. I see it more as a reference and refresher
for those who already know the material ("I seem to recall seeing a
circuit that would do what I need...") rather than getting students up
the hump of the learning curve in the first instance.]
For anyone who doesn't know yet, the long-awaited Horowitz & Hill "X
Chapters" is on pre-order now at Amazon ($54), expected to ship around
the end of January:
I have seen some of it, and as I expected, it is another must-have.
Best regards,
Charles
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Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO
the only problem with that CMOS freq. multiplying circuit's that the threshold of the inputs has a thermal noise component = jitter [phase noise] 73 KJ6UHN Alex On 1/19/2020 11:31 AM, Mark Haun wrote: Hi Jim, On Sun, 19 Jan 2020 10:35:42 -0800 jimlux wrote: On 1/19/20 9:29 AM, Mark Haun wrote: On Sun, 19 Jan 2020 09:37:39 -0500 Bob kb8tq wrote: Is your intended application tolerant of spurs at 16 and 32 MHz? If not, do they need to be in the 90 dB down vicinity (= the SFDR of the ADC) ? I guess you mean stray coupling between the oscillator, clock conditioning circuitry and the analog inputs? (Spurs on the ADC clock input shouldn't matter as long as the zero crossings are clean and jitter is low.) Not exactly. The sampler of the ADC is essentially a mixer, so if the clock has other signals on it, even at low levels, they can mix with input signals and show up in band. I had a SDR receiver with a 49.244 MHz ADC clock that was contaminated by the 66MHz processor clock (at a very, very low level), and I saw mixing products when the input to the ADC was a clean sine wave at 112.5 MHz. Analog Devices even has an app note on this. https://e2echina.ti.com/cfs-file/__key/telligent-evolution-components-attachments/13-109-00-00-00-00-93-58/Impact-of-sampling_2D00_clock-spurs-on-ADC-performance.pdf Hmmm, so in my case, other residual odd-order harmonics of the 16 MHz input clock which make it through the multiplier will become non-harmonic spurs of the desired 80 MHz, and therefore a potential problem unless filtered out. The analog amplifier scheme will therefore require decent bandpass filtering, mainly against 16, 48, and 112 MHz. One advantage of the Wenzel CMOS-based multiplier is that the threshold behavior of the last inverter [mostly?] gets rid of everything but the selected harmonic. I'm still trying to understand the phase-noise pros/cons of that design using, say, a pair of NC7SZ04 (UHS family) gates, versus a discrete transistor amplifier tuned at 80 MHz, like the common-base design quoted in the original post. Regards, Mark ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Norton amplifiers
there was one "zwischen basis-Schaltung" which has good noise properties basically the basis and the emitter of a bipolar transistor is connected to the two ends of a transformer's secondary winding , a tap on said winding is grounded. Ulrich Rohde may could tell more about it, I have seen articles written by him on that subject long time ego, perhaps in German. 73 KJ6UHN Alex On 1/13/2020 9:27 AM, Jeffrey Pawlan wrote: Many years ago I did a study of Norton amplifiers and optimized for IP3 using non-linear circuit simulation tools. I published a two part article in RF Design Magazine which covered the amplifier itself as well as the non-linear model for the BJT. My use for the Norton amplifier did not require high isolation so I spent little tile on that aspect. I am friends with the co-inventor of the original and the author of the subsequent patents. His name is Allen Podell. The webpage you included speculated that the reverse isolation degradation at high frequencies was owing to the layout or the transformer. Although those are contributors, the simulation showed high frequencies had poorer s12 so it is expected. If high isolation is what you need, then as written on this list, there are ICs which can provide this much better than a single stage amplifier. They do suffer from more residual noise however. Jeffrey Pawlan ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] 15 to 10 MHz
Hi Perrier, I would like to see that circuit -- divide by 1.5 -- also, thank you in advance Alex 73 KJ6UHN On 9/19/2019 5:03 AM, B Riches via time-nuts wrote: Hi Perrier, I would appreciate the circuit. Thank you. 73, Bill, WA2DVUCape May On Wednesday, September 18, 2019, 10:11:02 PM EDT, Perry Sandeen via time-nuts wrote: Yo Bubba Dudes!, I sent David a divide by 1.5 circuit diagram. If it would be of interest to any please send me an email off list and I'd be glad to email to you. Regards, Perrier ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Aerial coax downlead placement
well, you have a point, the coax cable if it is ideal it will work as somebody described earlier in that treed, but unfortunately life is real, and therefore despite that the E and H field is mostly "inside of the cable", but due to the cables loss particularly because braid has resistance there will be a voltage between the two end of the cable's shield. And that is related to a "mess" called transfer-impedance, and about that you could find really interesting explanations like that: https://spira-emi.com/references/pdf/tf4_cables_cntrs_hoeft.pdf and thathttps://www.araconfiber.com/what-is-transfer-impedance/ and much more, because that transfer impedance is a big headache for people who are sending signals trough coax cables, and above a certain frequencies the coaxial cable is not a "such a good thing" any more. Just one very malicious note, that works reversible too: if you would inject a signal to that braid's two ends, the signal would show up like is it's source would be serial with the generator which is driving "legally" the cable in "coaxial" mode. I know it is very nasty but it is true, I found it out myself also some sixty-five years ego, and a whole world of ideal system just collapsed at the front of me... KJ6UHN Alex On 7/5/2019 10:47 AM, Peter Vince wrote: On Fri, 5 Jul 2019 at 18:01, WigglePig wrote: If there are currents in the braid to upset then your antenna system is not working as you might believe. I was working on the simplistic assumption that for a current to flow, there must be a complete circuit, so the current flows down the centre conductor, and must come back up the braid. But I gather that unlike DC, RF is "black magic", and only flows on the inside of the braid - if all the impedances match. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Z3801 Power Supply Schematic
Hi Richard, may I ask you to send to me that Schematic? thank you in advance 73 KJ6UHN Alex On 4/24/2019 7:46 AM, RICHARD GOLDING via time-nuts wrote: Many thanks to those who took the trouble to send me schematics of the Z3801a PSU. I'm pleased to report that, using, the schematic, I was able to trace and fix the fault and that GPS lock led is glowing again. The problem was a faulty regulator IC (U2 LM317) that had decided to produce 1.8V instead of 2.5V, which resulted in the PSU thinking that the input supply voltage was out of range. It does seem a very complicated circuit for what could be straightforward voltage window comparator. i.e. 24R's, 8 Diodes, 3 regulators, a comparator and logic IC + a handful of Mosfets! Thanks again for those that helped. 73 Richard, G3VZG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] multimeter
yes he is wright, particularly your bird will grew out before the reading settles to zero at zero DC current measurement condition, I contacted Fluke they promised to send a special box for sending the instrument to them, it was in 2017, but the box did not arrived yet, One would expect a bit better service for one instrument which costs $400.- 73 KJ6UHN Alex On 3/23/2019 1:51 PM, Poul-Henning Kamp wrote: In message , Jim Palfreyman writes: Could I have some recommendations? I'll caution against the Fluke 287: It takes forever to start and it eats batteries faster than is comfortable. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Synthesized Signal Generator query
that is a relative low noise synthesizer Programmed Test Sources PTS 160 Frequency Synthesizer 73 Alex On 3/7/2019 11:04 AM, Richard (Rick) Karlquist wrote: On 3/7/2019 8:56 AM, Didier Juges wrote: The king of low close-in noise are the HP8662 (990MHz) and HP8663 (2GHz?) by about 20dB at 1kHz compared to the 8644A Didier KO4BB When I worked at Agilent, my lab had a half dozen HP8662's and some 63's. They were not useful for any kind of high performance clock requirement, unless we divided them down with, for example, a Centellax (now Microchip) divide by 8 to 511 eval board. That was SOP in those days. If you just want 100 MHz, there are inexpensive 100 MHz VCXO's (about $25 at D/K or Mouser) that will blow the doors off of an HP signal generator. You can phase lock them to a 10 MHz OCXO if necessary. Besides 100 MHz, there are various other frequencies available. See Crystek and Abracon, etc. These VCXO's put out CMOS logic signals, so you have to convert sine to square. Rick N6RK ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.
I do not know, if the brake down voltage decreases if the electrolyte capacitor is used well bellow the original rated voltage, but I know from experience, that if you cautiously and slowly increase the voltage across the capacitor it will work at higher than the rated voltage, but with reduced capacitance. Alex On 2/24/2019 7:08 PM, Dana Whitlow wrote: I remember often reading that if you run a 'lyt at a voltage much reduced from its rating, the oxide layer would get thinner over time so that in the end, the effective rating of the capacitor was about what you had been running it at. This would seem to imply that purposely overrating a 'lyt is pretty pointless. Any comments on this notion? Dana On Sun, Feb 24, 2019 at 7:01 PM Gerhard Hoffmann wrote: Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist: yet they got a pass and became SOP. The R&D lab manager at Santa Clara Division famously said "no customer chooses HP products because they have great power supplies." G.. My HP16500C has a defective PS and my 4274A RLC bridge had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke! I re-caped the bridge, it took me a day on the DIgikey site to find replacements. I had to use substantially larger voltages to make them fit mechanically. But that is a good thing. cheers, Gerhard ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] OCXO PLL gains?
Hi Anders look that https://www.analog.com/media/ru/training-seminars/tutorials/MT-086.pdf 73 KJ6UHN Alex On 2/1/2019 10:11 AM, Anders Wallin wrote: Hi all, is there are rule-of-thumb or simple paper/presentation of how to choose PLL-gains? I have a phase-detector that gives out a slope of roughly 1 V/rad, followed by an op-amp circuit with proportional, integral, and double-integral gains summed into one voltage [0, 3.3V] on the tune-pine of the OCXO ( +/- 0.6 ppm pull-range, from datasheet). So far it locks with only P-gain, but the phase-noise (and ADEV) shows a 'bump' somewhere between 10 and 100 Hz offset from the carrier. I tried the integrator with a time-constant of 1/16Hz using R 100k C 100n, but it wouldn't lock. The thinking was to put the integrator time-constant about where the free-running ADEV turns upwards from a 1/tau slope. So far I didn't enable the double-integrator - not sure if it's worth the trouble or not.. thanks, Anders ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] new WWVB BPSK dev board
There is a problem with most pre-amplifiers and also particularly with anything up font of the sampling; to get good data the amplitude of the sampled signal has to have relative high levels, comparable to microphone output level -- up to 50mV -- if one wanted to use the sound cart input. Additionally to that the sound card has it's internal amplifier before the A to D converter. Unfortunately the "vicinity" of the 60kHz is not a quite area, but it is full with noise of house hold and industrial origin. I spent substantial time to investigate that noises and I found many unsuspected sources. I may own household I have on tooth cleaning jet for every day use, which was replaced recently wit a new one since the previous one was more than fifteen years old and started to show old age problems. The new unit looking from the outside was very similar to the old one except that the old had one AC motor the new one has a DC motor with a switching mode power supply, which is with the motor's commutator generating RF noise up to the TV bands disturbing the reception and of course generating enough interference to overload any sound card with pre -amplifier. I am very curious how did they get that device -- the water jet-- trough the FCC test or did not ever border to do it? But that water jet is not alone, just look your own computer's including it's power supply. You no not need any very sophisticated instrument just some old spectrum analyzer, which is running on it's own without any computer connection, and you will what is out there, sweep so between 35kHz to 100kHz use one coils as antenna with a diameter of 2' to 3' and at least thirty turns. With that set up you will be able to see WWVB to. If you turn the coil's axis perpendicular to the direction from your position to Forth Collins in Colorado, you will see the --AM also-- modulated WWVB at 60kHz. These illegal carriers with very large amplitude are able to overload the input of the sound card's -- or any other --A to D converter. The old WWVB receivers for the at the time just AM modulated signal used to use crystal filter for good reason, which is not usable any more since the frequency spreading of the phase modulation will not fit into the crystal filter's band width, and the settling time of the filter's output will cause one additional AM modulation. By using some selection and very linear amplification I was able to get did I get a 120mVp_p signal from WWVB and compared it's phase stability to the phase of one other 60kHz signal derived from a GPS receiver with one u-blox board. If there is interest I could describe how did I do it. 73 KJ6UHN Alex On 12/4/2018 8:09 PM, David G. McGaw wrote: Actually, an RTL-SDR can because there is direct access to the ADC available by soldering to internal pads: www.rtl-sdr.com/rtl-sdr-direct-sampling-mode/ That will give you 8-bit, 14.4Msps. But as has also been said, a good sound card sampling 24 bits at 192kHz can be used. David N1HAC On 12/4/18 6:54 PM, Poul-Henning Kamp wrote: In message <2e7cf0ff-4094-2750-4874-96dfe2efe...@earthlink.net>, jimlux writes: I'm going to bet that the 8 bit RTL-SDR isn't going to work on 60kHz. I don't know about the RTL-SDR, but 8 bits will get you quite far with slow moving time signals like WWVB because you can average for minutes if you want - provided you feed the ADC a good stable clock. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] new WWVB BPSK dev board
that address is incorrect: Website: www.EversetClocks.com Alex On 12/3/2018 6:20 PM, Paul Bicknell wrote: Hi All There is a 60 Khz frequency standard operating in the UK So do the two signals interfere with each other? Paul -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Tom Van Baak Sent: 04 December 2018 02:12 To: Discussion of precise time and frequency measurement Subject: [time-nuts] new WWVB BPSK dev board At long last, a complete WWVB 60 kHz BPSK dev board is available: https://universal-solder.ca/product/everset-es100-cob-wwvb-60khz-bpsk-receiv er-kit-with-2-antennas/ Note it includes the antenna(s). Also has links to documentation. It would be very nice if a bunch of time nuts around the country played with these and reported results. Prior to this, the only device that you could buy which used the enhanced WWVB format was the La Crosse 404-1235UA-SS UltrAtomic clock. It was not developer friendly, so a dev board with the Everset ES100 chip is good news. The maker / hacker / Arduino crowd may enjoy a fresh source of accurate time; something independent of GPS or NTP. Some technical postings about reception quality, acquisition speed, and timing precision would be most welcome. /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.8048 / Virus Database: 4793/15883 - Release Date: 08/14/18 Internal Virus Database is out of date. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] 10 MHz -> 16 MHz
and what wold happen if you divide the 10MHz by 10 -- with any simple counter chip -- and injection lock a 16MHz crystal oscillator with that 1MHz, since the jitter is not critical of course it does not hurt if you make the 1MHz pulses narrow, you could use the micro-controller's own oscillator circuit, plus that counter [freq divider chip ] it is simple and cheap enough? 73 KJ6UHN Alex On 9/30/2018 7:54 AM, jimlux wrote: On 9/29/18 8:57 PM, Tom Van Baak wrote: What's a clever, simple, reliable (pick 2 of 3) way to get 16 MHz out of 10 MHz? Low phase noise isn't a big requirement and jitter doesn't need to be sub-nanosecond. The main requirement is perfect cycle count accuracy. This is for driving a 16 MHz microcontroller from a 10 MHz Rb/Cs/GPSDO. 10 MHz input is likely sine; 16 MHz output is 3v3 or 5v CMOS. Thanks, /tvb cycle counts over what interval? 5 and 8 cycles respectively? or over, say, 1 second? Multiply by 8 divide by 5 seems a bit tricky (although any number of off the shelf DDS will do it at fairly high power dissipation) You might be able to injection lock an 80MHz oscillator by coupling the 10 MHz in on the Vcc or output. Then a divide by 5 down to 16. If the requirement is over 1 second, then you can play a game with counting the first half of the second, and adjusting in the second by dropping/adding cycles to make it come out right. THat sounds pretty icky. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] wwvb antenna transmission Well harder then I might think.
by making a loop around the territory, on which you would like to receive the signal, inside of that loop you will have a very decent reception without using to high transmit power a 100' x 200' area could be covered with 100mW, since the wave length of the used low frequencies is multiple of the length of the loop length , therefore the current in the loop is constant along the loop. The polarization will be changed, the magnetic component will be vertical -- the original wwb field had horizontal magnetic, therefor the ferrite loop stick of the clock -- which is now horizontal -- shall be turned vertical. The described loop will not provide any substantial field outside the loop, and it will not interfere with the original wwb horizontal magnetic component transmission. The field outside of the loop diminishes very fast therefore it does not constitutes any problem with the surrounding area. I designed signal transmission system, which is working for the last thirty something years. 73 Alexander Pummer On 9/6/2018 6:05 PM, Dana Whitlow wrote: Paul, You really don't want to be building an antenna that radiates energy, which is a far-field concept. In your case, at 30 ft range, you're so far inside the near field that all the antenna articles in the world won't help, since they address radiating into the far field. That's what WWVB needs to do, but not you. I think what you want to do is use a loop that is no larger than your house, preferably smaller, and push enough power into it to achieve your range goal (but not any further). Dana On Thu, Sep 6, 2018 at 6:21 PM paul swed wrote: Working on the wwvb simulator and it works really well. On to the last piece. Transmission over maybe 30 ft. Ever notice everyone that makes a simulator has the clock on top? Well thats because its pretty hard to get a 60 KHz signal actually out. Even though I know loopsticks are not great transmit antennas that was the first attempt. Hey what they say is true, Bad. Next will be the loose wire over the distance. More likely a spare phone wire pair that runs all over the house. Just some humor. I have found a ton of online articles on vlf antennas and such. Heck seems like its time to read them. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. --- This email has been checked for viruses by AVG. https://www.avg.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
