Re: [time-nuts] 100 MHz decade Divider II

Hi Indeed the filtering / noise shaping aspect of these devices is what ultimately drove them off of most test benches. That was still taking place on a few benches back in the early 70’s (when I first started doing this stuff …). There were still enough of them running around that it was

[time-nuts] Lowest Power NTP Server

Hi If you are going to run the beast on batteries, and talk to it via WiFi, what’s the lowest power NTP server you can build? Timing source to keep it under a few ms would have to be included. GPS seems to be a reasonable choice. So far this seems to be the leading contender:

Re: [time-nuts] Lowest Power NTP Server

lients are likely to be a bit “time challenged” and some of them could need fairly high update rates. (sorry for the double post ….) Bob > On Dec 1, 2019, at 1:21 PM, Bob kb8tq wrote: > > Hi > > I guess one *could* claim that this: > > https://github.com/DennisSc/PPS-ntp-se

Re: [time-nuts] Lowest Power NTP Server

; > ESP8266 as a simple UDP server is 50mA * 3.3V = 0.17W. > > Tim N3QE > > On Sun, Dec 1, 2019 at 12:22 PM Bob kb8tq wrote: > >> Hi >> >> If you are going to run the beast on batteries, and talk to it via WiFi, >> what’s the lowest power >> NTP server

Re: [time-nuts] Lowest Power NTP Server

e tens of microseconds). I > think several years ago on this list, we were talking about tricking > commodity WiFi chipsets into doing these but haven't seen anything as of > late. > > Tim N3QE > > On Mon, Dec 2, 2019 at 8:02 AM Bob kb8tq wrote: > >> Hi >> &g

Re: [time-nuts] Lowest Power NTP Server

as already written some code that could be adapted? >> >> https://github.com/DennisSc/PPS-ntp-server/blob/master/README.md >> >> -David >> >> Original Message >> On Dec 1, 2019, 09:49, Bob kb8tq wrote: >> >>> Hi >&g

Re: [time-nuts] Lowest Power NTP Server

.io wrote: >>>> >>>>> I'd think one of the ESP32's would be a fine choice. They have some >>>>> good >>>> >>>>> power management options to wake up periodically to do the work, making >>>>> for >>&

Re: [time-nuts] Lowest Power NTP Server

gt; think several years ago on this list, we were talking about tricking >> commodity WiFi chipsets into doing these but haven't seen anything as of >> late. >> >> Tim N3QE >> >> On Mon, Dec 2, 2019 at 8:02 AM Bob kb8tq wrote: >> >>> Hi >>

Re: [time-nuts] Lowest Power NTP Server

g with the beacon frames or sending some special frame on the > channel?) > > -David (AD7WZ) > > > > > ‐‐‐ Original Message ‐‐‐ > On Monday, December 2, 2019 11:51 AM, Bob kb8tq wrote: > >> Hi >> >> Wired is out for this particular setup. It

Re: [time-nuts] gpsdo 10MHz steering resolution

Hi The quick version: Going straight from 10 MHz to 1.5 GHz with no spurs is a tall order if the 10 MHz comes from some sort of system. The normal answer is to put in a cleanup oscillator (often a OCXO) in the 100 MHz range. That locks through a narrow loop and takes care about as well as you

Re: [time-nuts] gpsdo 10MHz steering resolution

Hi I caught the 1KHz and took it to be per division…. oopss … (sorry about that) If the device is indeed in 50 Hz power main land, the 100 Hz spurs might make some sense as line related. If it’s in 60 Hz power land, they are coming from something else. No idea (yet) what part of the world

Re: [time-nuts] Effects on GPS antenna performance due to installation proximity of second antenna

Hi Most of what you see suggests > 10’ / 3M between GPS antennas. They seem to be concerned about a variety of things. Exactly how those concerns translates into the magic distance has always been a bit obscure. Bob > On Nov 23, 2019, at 7:07 PM, JAMES ROBBINS wrote: > > I would

Re: [time-nuts] Efratom PC-10

Hi I was about to mention that there actually are a few more steps in the “who bought who” chain :) The date codes put this back to 1992. That’s a long time in “internet years”. Portable clocks were made for a variety of markets. It’s not even clear which market this one was aimed at.

Re: [time-nuts] Distributing GPS L1 signal to many GPS devices

Hi There are a number of MiniCircuits passive multiport splitters that show up on eBay at reasonable (< $40) sort of prices. You can get eight port versions with SMA connectors on them fairly quickly. Other connector types or higher port counts may take a bit of shopping and added cost. There

Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing

Hi I would dump the batteries. If you need backup, run a UPS or some sort of external DC setup. Batteries inside something like the 105 only seem to lead to messy problems down the road. Bob > On Oct 10, 2019, at 2:10 PM, Roy Thistle wrote: > > Hi All: > A 105B (quartz oscillator) is blowing

Re: [time-nuts] Question for my new GPSDO

Hi What is the temperature stability of the OCXO you plan to use? In the case of open windows, what is the *dynamic* temperature stability of the OCXO? What is the tuning range of the EFC on the OCXO? The wider the EFC range on the OCXO, the more the tempco of the control system impacts the

Re: [time-nuts] Question for my new GPSDO

> From: time-nuts [time-nuts-boun...@lists.febo.com] on behalf of Bob kb8tq > [kb...@n1k.org] > Sent: Tuesday, October 08, 2019 17:18 > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Question for my new GPSDO > > Hi

Re: [time-nuts] DC distribution

Hi The biggest “issue” I’ve seen with Power Poles is that after being mated for 20 to 30 years they start to loose the spring force that holds them together. Bob > On Oct 5, 2019, at 11:45 AM, John Ackermann N8UR wrote: > > One thing the PowerPole tool does is provide a little cavity for

Re: [time-nuts] DC distribution

019, at 8:11 PM, Jeremy Nichols wrote: > > For a connection that remains undisturbed for 20 to 30 years, could you get > by with no connector at all? > > > On Sat, Oct 5, 2019 at 6:03 PM Bob kb8tq wrote: > >> Hi >> >> The biggest “issue” I’ve seen

Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing

Hi Indeed, the unit seems to work fine without batteries. --- If filtering and short duration spikes are the concern, one could replace the batteries with super capacitors. One would *hope* they are a bit less likely to create problems. …… - While it is a good idea to keep OCXO’s on

Re: [time-nuts] Question for my new GPSDO

lating the EFC is also interesting. I never >> thought about that, but indeed, this is true and thus having common ground >> pins for the heater and the EFC makes "accurate" tuning more complicated ;-) >> maybe this is the reason for the old HP 10544A and 10811A having

Re: [time-nuts] Using HP5071A with dead tube along with GPS

Hi The OCXO in the 5071 is an HP10811 it was selected at the time of manufacture for good performance. As far as anybody knows that testing was for short term stability. How well it retains that performance many years later - who knows? Is the original OCXO in the device - who knows…. Other

Re: [time-nuts] Using HP5071A with dead tube along with GPS

Hi The PPS input on the 5071 does *not* set the frequency of the device. To do so would “break” the Cs ( = you use the beam to get frequency). The *only* thing the PPS input gets used for is to reset the *time* to sync with UTC. Bob > On Dec 19, 2019, at 5:56 PM, Taka Kamiya via time-nuts

Re: [time-nuts] Power supply for time source concerns

Hi Each project is a different “experience”. Some things are way more susceptible to switching noise than others. Some switchers put out way more noise than others. You would not run a linear supply on a computer. The low noise front end of a radio is going to need a quiet supply ….. There

Re: [time-nuts] Microstepper

Hi Different sort of micro stepper. The 3D printing version runs a stepping motor to improve the angular resolution. As you mention, the poles in the motor limit just how well you can do. There are dedicated chips out there these days that get down below the limits on any motor I’ve ever seen.

Re: [time-nuts] Power supply for time source concerns

Hi If you dig into the app notes on the LT304x parts after a lot of extolling the wonders and virtues, they eventually get into magnetic coupling between the “upstream” and “downstream” bypass components. Taking care of that with proper layout is possible, but non-trivial. Is milivolts of

Re: [time-nuts] Using a common power supply among few time standards

Hi Unless there is something wrong with the linear supply, it will produce heat proportional to the output load. They all have very low “parasitic” current in the control circuits. A unit with a damaged transformer or bad caps *can* indeed heat up with no load. In that case, it needs to be

Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?

Hi As long as we are beating up on the poor old SC for mode issues: We have an C mode ( = the one that normally gets used in a precision oscillator) We have a B mode ( = the “thermometer” mode that gets used in some MCXO’s) Hmmm …. why did they start with B … hmmm …. Well yes indeed there

Re: [time-nuts] PCB layout question for GPSDO

Hi The TDC has a range dimensioned in ms. It has a resolution dimensioned in ps. As long as your “reference” is stable in the ~ ppm range, moving it around will not impact the calibration. Hopefully any change you make to a stabilized GPSDO will be in the < ppb range …. ( so roughly 1000X

Re: [time-nuts] What’s the BEST crystal?

Hi > On Feb 29, 2020, at 3:23 PM, Poul-Henning Kamp wrote: > > > In message <20200229210755.1abd900696f8aa85567d2...@kinali.ch>, Attila Kinali > writes: >> On Sat, 29 Feb 2020 13:44:59 -0500 > >> But, there is not much we can do about absorption/desorption. > > Actually, there are

Re: [time-nuts] What’s the BEST crystal?

Hi > On Feb 29, 2020, at 3:07 PM, Attila Kinali wrote: > > On Sat, 29 Feb 2020 13:44:59 -0500 > Bob kb8tq wrote: > >> One wonders what the result would be of doing a large blank (> 50mm) >> 2.5 MHz 5th OT using modern design, packaging and mounting techniques.

Re: [time-nuts] What’s the BEST crystal?

Hi > On Feb 29, 2020, at 2:44 PM, Poul-Henning Kamp wrote: > > > In message <2e09a559-b476-45c0-a476-7d5808a93...@n1k.org>, Bob kb8tq writes: > >> One wonders what the result would be of doing a large blank (> 50mm) 2.5 MHz >> 5th OT using moder

Re: [time-nuts] What’s the BEST crystal?

Hi More than the cut, the packaging, resonator design, mount design, and processing of the crystal (in no particular order ) are what really make this or that crystal suitable for use in a precision OCXO. You can indeed find AT cut OCXO’s that do pretty well once they warm up …. One wonders

Re: [time-nuts] Frequency standards for different tau in Allen Dev measurement

Hi Backing up a bit: If you are going to measure something like a crystal oscillator against a PPS, you need to be careful of phase slip. The oscillator may be off frequency by many ns/s. Working out what happens as it crosses a 100 ns boundary is not as easy as one might think. In addition,

Re: [time-nuts] What is the BEST crystal?

Hi It’s also the size of the 2.5 MHz 5th’s and similar parts made “way back”. They went into glass packages the size of door knobs. Packaging / design / mounting / processing has changed a lot since then. Bob > On Feb 29, 2020, at 7:41 PM, John Moran, Scawby Design > wrote: > > Wow, that

Re: [time-nuts] Synchronisation of crystal oscillators

Hi The correct answer is “that depends”. The quick answer is “probably will”. It depends on the Q of the parts (which likely is pretty low), the coupling (which will be pretty good), and the exact frequency of each unit (which is unknown). Setups like this have been known to lock up. Bob >

Re: [time-nuts] Synchronisation of crystal oscillators

Hi Well, there goes Barkhausen …. :) https://en.wikipedia.org/wiki/Barkhausen_stability_criterion Bob > On Mar 1, 2020, at 8:58 PM, Alex Pummer wrote: > > don't forget the oscillator is one amplifier with infinite gain on his

Re: [time-nuts] Newbie question about GPS

Hi > On Mar 2, 2020, at 7:14 AM, Anton Moehammad via time-nuts > wrote: > > Hi All,I hope some one can help me to find the answer.1. Let say some one can > extract the L1 carrier frequency 15xx MHz and convert it down to let say 1MHz > and put it to phase comparator and made the PLL to

Re: [time-nuts] Time-Nutters-- Adding Rubidium to a Thunderbolt...?

Hi So backing up a bit: What are you trying to do? GPS signals by their nature are noisy short term. They get better the longer you stretch out the observation time. If you are running a single band / uncorrected GPS ( = most GPSDO’s and most GPS modules) you will hit a bunch of issues

[time-nuts] uBlox F9T

Hi For any out playing with the F9T, there is a new version of the manuals out. They also have an update to the “ROM boot loader" code. I have yet to work out if you can do a field upgrade on that part of it. My guess is “not so much”. Still no stock at any of the “usual” US distributors.

Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?

Hi Ok, so just to run the math: 5 MHz / 2.9 = 1.724 MHz If the Q at the fundamental is 500K (a wild guess) then 1.724 MHz / 500,000 = 3.4 Hz In a world where a synthesized sweeper *might* be stepping in 10Hz steps, that’s an easy one to miss. Bob > On Feb 26, 2020, at 11:40 PM, Bernd

Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?

Hi > On Feb 28, 2020, at 9:33 AM, jimlux wrote: > > On 2/28/20 2:34 AM, Attila Kinali wrote: >> On Thu, 27 Feb 2020 08:45:16 -0800 >> "Richard (Rick) Karlquist" wrote: >>> OTOH, you could build a simple Colpitts >>> oscillator and see where it oscillates. >>> That's what they did back in the

Re: [time-nuts] Yukon to make Daylight Saving Time permanent after final time change Sunday

Hi I suspect that DST is a decision you can make at the provincial / territorial level and that time zones are a federal level sort of thing …… Bob > On Mar 5, 2020, at 4:13 PM, Adrian Godwin wrote: > > Would it be too pedantic to say they're ending DST but changing > their timezone ? > >

Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?

Hi A, but did you then whip up a batch of ammonium bifluoride to clean them up after playing with the grinding compound? :) They figured that part out part way through WWII. The lack proper post grind etch just about had all the radios out there out of service. Bob > On Feb 27, 2020,

Re: [time-nuts] Are there SC-crystals out there in the wild that are not Overtone?

Hi The crystal industry in the US went from a couple of outfits (mostly in PA) making < a hundred a month in the 1930’s, to a massive bunch of outfits during WWII. Most were turning out a couple hundred an hour. Much of that collapsed when the war ended and the demand went away. A few

Re: [time-nuts] Symmetricom 023-63008-07 5MHz Crystal Oscillators

Hi One interesting thing to do with good / cheap OCXO’s: If you multiply an OCXO from 5 to 10 MHz, noise goes up by 6 db. If you mix two independent 5 MHz OCXO’s to get 10 MHz, phase noise goes up by 3 db. The same thing happens with ADEV, multiply has no impact. Mixing *should* only get you

Re: [time-nuts] Digital Pots, wiper noise and fine tweaking oscillators

Hi > On Jan 27, 2020, at 1:32 PM, Charles Steinmetz wrote: > > Bob wrote: > >> Digital pots have *lots* of issues. A high quality wire wound pot likely >> will be significantly >> more stable and lower noise than your typical digital unit. In addition the >> 10 or 20 turn wire >> wound will

Re: [time-nuts] digital pots Part 2

Hi The advantage a wire wound pot has is that all the wire is (nearly) the same temperature coefficient. This ~$15 Bourns part: https://www.digikey.com/product-detail/en/bourns-inc/3590S-2-103L/3590S-2-103L-ND/1088586

Re: [time-nuts] Ublox timepulse

Hi I suspect that even with setting the timepulse to 60 seconds and aligning it, you still will be routinely parsing the serial just to be sure “all is well”. There are always random things that come along and mess this or that up ….. Bob > On Feb 4, 2020, at 10:11 AM, Tim Shoppa wrote: > >

Re: [time-nuts] PCB layout question for GPSDO

Hi > On Jan 30, 2020, at 3:20 PM, Tobias Pluess wrote: > > Hi guys > I have almost finished the layout for my new GPSDO having a TDC. I have > attached a screenshot of the PCB layout, for which I have some questions. > > First I will explain a bit what is on the board. > The connector X2

Re: [time-nuts] Cesium Mechanical Chronometer

Hi If the idea is to generate a rate card and keep it up to date ….. I think that can be done with just the GPS. The CSAC really does not add a lot that I can see to that case. Of course I may have (yet again) missed something …. == The very standard / “old school” approach for this is a

Re: [time-nuts] Cesium Mechanical Chronometer

c field on the > balance wheel. > > On Sat, Feb 1, 2020 at 3:06 PM Bob kb8tq wrote: >> >> Hi >> >> If the idea is to generate a rate card and keep it up to date ….. I think >> that >> can be done with just the GPS. The CSAC really does not add a lot tha

Re: [time-nuts] questions about oscilloquartz 10MHz module

Hi Backing off a bit: The 10811 in your Z3801 has an outer heater to allow it to operate at -40C. The “stock” 10811 will run out of oven power before it gets that cold. The outer oven does nothing other than allowing operation at very cold temperatures. It cuts out (or should do so) before the

Re: [time-nuts] time-nuts Digest, Vol 186, Issue 41 Double Oven

They are also restricted in some countries it seems. > > -Andre > > > -- > > Message: 1 > Date: Thu, 30 Jan 2020 12:29:56 -0500 > From: Bob kb8tq > To: Discussion of precise time and frequency m

Re: [time-nuts] Thunderbolt power requirements

Hi The better you regulate the 12V, the better the TBolt will function. The OCXO will be very unhappy outside a +/- 0.5V region. It really wants something well regulated (like at the couple of millivolts level). Depending on exactly what era OCXO your TBolt has in it and how well it is still

Re: [time-nuts] Thunderbolt power requirements

Hi > On Jan 31, 2020, at 2:16 PM, Brian Lloyd wrote: > > On Fri, Jan 31, 2020 at 12:17 PM Bob kb8tq wrote: > >> Hi >> >> The better you regulate the 12V, the better the TBolt will function. >> The OCXO will be very unhappy outside a +/- 0.5V regio

Re: [time-nuts] questions about oscilloquartz 10MHz module

…. Bob > On Feb 2, 2020, at 1:03 PM, Attila Kinali wrote: > > On Sat, 1 Feb 2020 21:08:42 -0500 > Bob kb8tq wrote: > >> are representative, the 8663’s don’t quite get to that level. The typical >> spec unit is at 1 to 4 ppb over 0 to 70. That’s >> reasonable per

Re: [time-nuts] GPS location inaccuracies from a cell phone

Hi Cell phone GPS is very much a “that depends” sort of thing. In some cases, the raw data comes to the phone, but the location processing takes place “in the cloud” somewhere. Loose cell coverage with this sort of device and you also loose location. This sort of processing does allow “tower

Re: [time-nuts] Cesium Mechanical Chronometer

Hi There’s not a lot of “room” inside the typical Hamilton chronometer. Simply getting an electronic drive gizmo inside (and wires out) would be a major task. Having it work properly with the drive coming and going ….wow …. The detent setup is a very fiddly bit in these devices. My *guess*

Re: [time-nuts] Cesium Mechanical Chronometer

Hi > On Jan 30, 2020, at 1:31 PM, jimlux wrote: > > On 1/30/20 9:29 AM, Bob kb8tq wrote: >> Hi >> There’s not a lot of “room” inside the typical Hamilton chronometer. Simply >> getting >> an electronic drive gizmo inside (and wires out) would be a major tas

Re: [time-nuts] questions about oscilloquartz 10MHz module

Hi Regardless of it being a double or single oven, it’s a good bet that it did once and still does meet the original temperature specification with some margin. The open question is - what was that spec? Bob > On Feb 3, 2020, at 3:58 PM, gandalfg8--- via time-nuts > wrote: > > Ah, > I now

Re: [time-nuts] questions about oscilloquartz 10MHz module

Hi The bigger issue is: Was the “ST” version done as a low cost approach that just happened to be in the 8663 footprint? If so, the only way to know what it does / what it is would be to find the elusive spec sheet. Bob > On Feb 2, 2020, at 5:47 PM, Magnus Danielson wrote: > > Hi Nigel, >

Re: [time-nuts] Using a common power supply among few time standards

Hi Well, I’m sitting here plotting the stability of some eBay “frequency standards”. The one thing I *can* measure is just when the power cords get bumped. As long as you can hold sub mili-volt sorts of stability on the supplies “as delivered” it pretty much does not matter how you get

Re: [time-nuts] Using a common power supply among few time standards

Hi As you have already noted, things do die from time to time. Fuses are a good idea, along with protection diodes. Still, none of it is 100%. The more heat / temperature you have in a part, the quicker it is likely to fail. One often overlooked failure mode is loosing one supply on a +/-12V

Re: [time-nuts] Using a common power supply among few time standards

Hi DC/DC converters can indeed be filtered. If you do it wrong, things will get pretty crazy. In general, you need at least an L/C filter and may need an R/L/C design. Things like ESR on the caps and SRF on the inductors do indeed matter. Both common mode and differential mode filtering may

Re: [time-nuts] Using a common power supply among few time standards

Hi Grab your DVM and take a look at the voltage on the input caps on one of those supplies as compared to the output voltage. With light loads (which is how most use them …) the voltage ratio is pretty high. As a result, the efficiency is not as good as it could be. The Acopian versions that

Re: [time-nuts] Symmetricom 023-63008-07 5MHz Crystal Oscillators

Hi If you do try it, double balanced mixers seem like the way to go. Two 5’s into one mixer gives you 10, a low level spur at 5 and some crud at DC. Duplicate that with another mixer and you have a second 10. Maybe go into a low Q filter to clean it up a little. Since you have loss in the

Re: [time-nuts] Digital Pots

> Dana > > > On Tue, Feb 4, 2020 at 7:42 AM Bob kb8tq wrote: > >> Hi >> >> The great thing about a wire wound pot is that as a voltage divider, it has >> a very low temperature coefficient. The problem with adding resistors is >> that the

Re: [time-nuts] Digital Pots

Hi The great thing about a wire wound pot is that as a voltage divider, it has a very low temperature coefficient. The problem with adding resistors is that their temperature coefficient will not match that of the winding material on the pot. The “value” of the wire wound is lost in this case.

Re: [time-nuts] GPSDO that isn't GPS locked for large time scales?

Hi More or less what the seller is doing is a simple FLL. It appears he does not have an integrator on it so it will hit an ADEV floor and never get any better than that. Bob > On Feb 4, 2020, at 7:23 PM, AC0XU (Jim) wrote: > > Time Nuts- > > I recently purchased (Ebay) a GPSDO from an

Re: [time-nuts] Digital Pots, wiper noise and fine tweaking oscillators

Hi Digital pots have *lots* of issues. A high quality wire wound pot likely will be significantly more stable and lower noise than your typical digital unit. In addition the 10 or 20 turn wire wound will have far more “steps” than a digital pot. One advantage that a digital pot has is small

Re: [time-nuts] Frequency standards for different tau in Allen Dev measurement

Hi For most good standards, all a frequency counter is measuring at a 1 second gate is the floor of the counter: A typical counter might have a 100 ps rms sort of “gate error” at 1 second. That means that the best it actually can do is 100 ppt = 1x10^-10. A good oscillator will have an RMS

Re: [time-nuts] Frequency standards for different tau in Allen Dev measurement

Hi The primer talks a lot about “averaging” of the samples. If you dig deep into the various papers on doing AVAR for frequency / time standards … you want to decimate / downsample the data rather than average. There are a *lot* of papers that make this distinction less than totally clear.

Re: [time-nuts] Tbolt and LOCK indicator - is it there?

Hi Not as far as anybody knows. Pretty much all GPSDO’s are targeted at being buried deep in an OEM system. There is no access to things like LED’s in that case. All monitoring is done by the serial / I2C / SPI / USB / Ethernet / whatever port. People have done cute little micro + display

Re: [time-nuts] DAC for OCXO disciplining

ow have a counter-acting -6 dB/Oct. > > I was amazed that it was this simple to move energy to where it makes > less damage. Turns out that FPGA logic wise, it's at the same cost as PWM. > > Now, there is other relatively simple ways of doing the same that I > would consider.

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi 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) ? Bob > On Jan 18, 2020, at 7:33 PM, Mark Haun wrote: > > Hi time nuts, > > I'm looking for a 5x frequency multiplication scheme to let me use a

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 19, 2020, at 7:48 PM, Magnus Danielson wrote: > > Hi Gerhard, > > On 2020-01-20 00:03, Gerhard Hoffmann wrote: >> >> Am 19.01.20 um 22:20 schrieb Magnus Danielson: >>> Hi Mark, >>> >>> On 2020-01-19 18:19, Mark Haun wrote: >>> >>> I've read that I should avoid high-Q tuned

Re: [time-nuts] Microstepper

Hi The closer the beat note / spur / crud is to carrier, the bigger its effect on things like ADEV and other timing issues. Indeed 97 KHz is pretty far out compared to most of what people worry about. It is also quite far compared to the PLL bandwidth of just about anything you normally would

Re: [time-nuts] time-nuts Digest, Vol 186, Issue 19

Hi Backing off a bit, there are a *lot* of different OCXO’s out there. Some will hold a few ppb for months in terms of aging. Others will age that much in a day. Some will be good to < 0.01 ppb due to room temp changes. Others will move fractions of a ppm. On top of that, some OCXO’s have

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi Pretty much everybody who wants to sell you a PLL chip also has free simulation software to give you some idea what that chip does. None of them are perfect. They all take a bit of time to get used to. Some of them (Analog Devices stuff) will deal with noise. You can get a pretty good feel

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 21, 2020, at 8:21 PM, Magnus Danielson wrote: > > Hi, > > On 2020-01-22 01:05, Mark Haun wrote: >> On Wed, 22 Jan 2020 00:30:12 +0100 >> Magnus Danielson wrote: What are the adverse consequences of using large divisors in the loop, as would be required for my odd OCXO

Re: [time-nuts] Phase Detectors/Mixers for DMTD and PN measurements

Hi > On Jan 16, 2020, at 10:51 AM, Attila Kinali wrote: > > On Thu, 12 Dec 2019 06:53:41 +0100 > Gerhard Hoffmann wrote: > >> It seems the mixer noise cannot be ignored. >> >> I wonder then why nobody takes the mixer to cross correlation land, >> and maybe even the driver amplifier. > >

Re: [time-nuts] thunerbolt, 2 problems

Hi There are no schematics for the TBolt. This is pretty typical of modern devices from a number of outfits. From doing a bit of basic circuit tracing, most of the “stuff” heads into or comes out of the FPGA or MCU. Once you get past the basic interface chip you probably are looking at an

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 3:12 PM, jimlux wrote: > > On 1/20/20 11:44 AM, Bob kb8tq wrote: >> Hi >>> On Jan 20, 2020, at 2:38 PM, jimlux wrote: >>> >>> On 1/20/20 10:01 AM, Mark Haun wrote: >>> >>>> A fair question... in fact I w

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 2:38 PM, jimlux wrote: > > On 1/20/20 10:01 AM, Mark Haun wrote: > >> A fair question... in fact I was initially planning to use the ABLNO + >> a PLL. The OCXOs I found, however, are CTS VFOV405's with phase noise >> claimed to be just as good as the ABLNO or CVHD

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 2:57 PM, Mark Haun wrote: > > On Mon, 20 Jan 2020 14:22:41 -0500 > Bob kb8tq wrote: >> On Jan 20, 2020, at 1:36 PM, Mark Haun wrote: >>> The VFOV405 datasheet lists typical phase noise for 10- and 100-MHz >>> units. (Mine ar

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 1:01 PM, Mark Haun wrote: > > Hi Attila, > > On Mon, 20 Jan 2020 14:29:15 +0100 > Attila Kinali wrote: >> On Mon, 20 Jan 2020 11:13:46 +0100 >> Attila Kinali wrote: >> >>> With those constraints, and reading the discussion, I wonder why >>> don't consider a VCXO+PLL

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

:50 PM, Mark Haun wrote: > > On Mon, 20 Jan 2020 15:25:00 -0500 > Bob kb8tq wrote: >> On Jan 20, 2020, at 2:57 PM, Mark Haun wrote: >>> Agree except you were starting from the VFOV numbers for the 100-MHz >>> version. If you use their numbers for the 10-MHz ve

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 1:36 PM, Mark Haun wrote: > > On Mon, 20 Jan 2020 13:13:00 -0500 > Bob kb8tq wrote: >> On Jan 20, 2020, at 1:01 PM, Mark Haun wrote: >>> A fair question... in fact I was initially planning to use the >>> ABLNO + a PLL. The OCXOs

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 20, 2020, at 5:16 PM, jimlux wrote: > > On 1/20/20 1:57 PM, Attila Kinali wrote: > >> And then there ia third way, which is IMHO even better: >> Your application is an SDR system, i.e. you already need some >> signal processing for the system to work. Why not extend this >> to use

Re: [time-nuts] Simple GPSDO Multiple Outputs - buffered line driver options?

Hi What are you driving? Most “normal” gear is pretty happy with a fairly wide range of input levels. Obviously things like termination and long lengths of coax can get into the act. For 4 outputs, a passive splitter with 6 db of loss should do just fine. You have only taken the output

Re: [time-nuts] Simple GPSDO Multiple Outputs - buffered line driver options?

ut reading on all counters matched exactly. They > are 75 ohms but it didn't matter in my use case. You can change/adjust > internal resisters if you are concerned. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >On Tuesday, Janua

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

Hi > On Jan 21, 2020, at 1:41 PM, Mark Haun wrote: > > Hi Attila, > > On Tue, 21 Jan 2020 15:08:16 +0100 > Attila Kinali wrote: >> On Tue, 21 Jan 2020 01:15:45 +0100 >> Attila Kinali wrote: >>> You don't need a high performance ADC for the reference as you are >>> dealing with a narrow

Re: [time-nuts] Simple GPSDO Multiple Outputs - buffered line driver options?

a MDA-3V at the hobbyist bench level, any issues that > one needs to be concerned about. A few modification projects online, but none > really comment on any issues or performance. > > -=Bryan=- > > > From: time-nuts on behalf of Bob kb8tq >

Re: [time-nuts] Simple GPSDO Multiple Outputs - buffered line driver options?

the issue. > > Thanks a-bunch! > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >On Tuesday, January 21, 2020, 4:27:26 PM EST, Bob kb8tq > wrote: > > Hi > > If all you are doing is driving a 5335 and running at 1 second gate times, >

Re: [time-nuts] DAC for OCXO disciplining

Hi Put another way - this is sort of why sigma delta was invented. The whole “move the energy” thing was very much core to the invention. These days, even some pretty cheap micro’s have sigma delta hardware on them. So far I have yet to find one with quite the “right stuff” on it to do a DAC.

Re: [time-nuts] PLL suggestions

Hi A low phase noise VCXO is going to be up in the vicinity of $20. An MCU that will do the loading stuff is in the << $1 range. BOM wise, the MCU is round off error. Code wise, the firmware is “high school project” level stuff. Bob > On Jan 2, 2020, at 9:26 AM, Dan Kemppainen wrote: > >

Re: [time-nuts] PC Time Servers

Hi Ok, so now we have the question of “what’s good enough?”. Is 10’s of ms adequate to get the job done? Would 100’s of us make a noticeable impact on performance? If so a local GPS based time source could provide that level of improvement. Cost wise the impact is not massive. Indeed this is

Re: [time-nuts] PLL suggestions

Hi The gotcha with a 6 pin package is that it is unlikely to have a (4 pin) SPI interface. Pretty much every PLL chip in the universe is SPI. Bob > On Dec 31, 2019, at 8:14 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> The most common answer is to hook up a cheap micro to shoot the

Re: [time-nuts] PLL suggestions

Hi ... SOIC-8 is an 8 pin rather than a 6 pin package :) Bob > On Jan 1, 2020, at 8:54 AM, Graham / KE9H wrote: > > On Tue, Dec 31, 2019 at 9:38 PM Bob kb8tq wrote: > >> Hi >> >> The gotcha with a 6 pin package is that it is unlikely to have a (4 pin) &g

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