Re: [time-nuts] Raw phase data of super-5065

Hi I would not find it at all surprising that any of the older Rb’s are running below 1x10^-11 / month these days ( after a good run-in). Below 1x10^-12 is pretty amazing. The FRK’s will normally hang out a bit above that point. Indeed, getting all of the pressure and temperature stuff

Re: [time-nuts] Affordable PoE 6-digit time displays?

pi-powered 3.5" TFTs > cheaply. This may work best. > > A friend also pointed me to some networked dot-matrix displays that will do > NTP from timemachinescorp, which might be a fun diversion. :); -Dave > > > -Dave > > > On Fri, Jun 15, 2018 at 12:52

Re: [time-nuts] GPS Antenna Grounding/Lightning protection.

joules of energy concentrated within the discharge > > But a proper ground system also ‘bleeds off’ the potential difference thereby > preventing discharge > > Content by Scott > Typos by Siri > > On Jun 19, 2018, at 11:19 AM, Bob kb8tq wrote: > > Hi > > 18

Re: [time-nuts] 1 pps Sync'ing

Hi On a Time Nut metaphysical note - > On Jun 25, 2018, at 10:38 AM, Tom Van Baak wrote: > > Steve, > >> I need the rising edges of both the 10 MHz and 100 MHz squarewave outputs >> to be aligned with the GPS 1 pps (UTC) to within 1 ns. > > Two comments. > > 1) If you divide 100 MHz -> 10

Re: [time-nuts] HP 5065A A1 replacement with DDS

Hi One of the things I’ve run into doing Rb’s this way is that the spurs out of the DDS are not always the same device to device. They also change a lot with small tuning changes. The result can be a very close in spur ( like << 1 Hz) that really rips up your ADEV since it passes through all

Re: [time-nuts] 1 pps Sync'ing

Hi You can indeed do this, the question is - do you *really* want to? Depending a bit on your GPS module, the 1 pps output can jump around a few nanoseconds on a second to second basis. Keeping the 100 MH edge locked implies modulating the 100 MHz by at least a few ppb at some rate faster

Re: [time-nuts] Low phase noise affordable GPSDO

Hi > On Jun 20, 2018, at 10:27 AM, Ethan Waldo wrote: > > Hello time afficionados. I've tried my best to scan through the archives to > see if this has already been answered, so apologies if I missed something > relevant. I am going to be experimenting with >10Ghz microwave frequency >

Re: [time-nuts] 10 MHz 'failover' switch?

t; thats needed is a crossing detector and relay / switch driver > > Yes there would be a momentary hit but it would work. > > Content by Scott > Typos by Siri > > On Jul 26, 2018, at 4:13 PM, Bob kb8tq wrote: > > Hi > > They are a pretty rare item. A more common approac

Re: [time-nuts] 10 MHz 'failover' switch?

Hi 90 db will not drive the ADEV nuts, but it still will be a lot worse than a normal standard will deliver, even at 120 db down, if the offset is a bit above 1 Hz you will still see it in an ADEV plot. Bob > On Jul 26, 2018, at 5:40 PM, Scott McGrath wrote: > > True but if you use a good

Re: [time-nuts] 10 MHz 'failover' switch?

Hi Isolation in a carefully managed test setup can be done (with enough money to spend). Isolation it the real world with grounds and cables running here and there is likely to be a challenge. At least that’s been the case on the few dozen of these systems I’ve designed and put into production

Re: [time-nuts] High-end GPSDO's

Hi Getting into the ~2 ns region is not as hard as it once was. The real gotcha is needing a L1/L2 receiver to do it *consistently*. If you just have L1, then you can easily get more than a couple of ns over a day due to various atmospheric effects. It’s not at all clear what sort of GPS

Re: [time-nuts] Bicentennial GOES satellite clock

Hi If GPS goes down, you then have Glonass. If Glonass goes down, you have Galileo. If all of those go down and you are in the right region, the Chinese and Japanese both have systems you could use. In terms of *system* failure, there’s a lot of redundancy out there ….. Yes, you *would* have

Re: [time-nuts] NIST

as a time source. I only >> need accuracy within perhaps a third of a second so manually setting a >> computer clock while listening to WWV works for me. >> >> For my own interest I'd be curious in knowing of other routine uses of the >> WWV / WWVH time signals. >>

Re: [time-nuts] NIST

Hi Ok, this is Time Nuts. We probably have a pretty good sample of those who use this and that as a source of time. We also are reasonably conscious about what we are doing. NIST’s claimed reason for running WWV (and WWVH) is to distribute accurate time and frequency. Would / does anybody on

Re: [time-nuts] 1PPS for the beginner

Hi A normal GPS module generates it’s outputs off of a free running internal clock. Generally this is a TCXO in a “timing” GPS ( = one that puts out a rational PPS). This is a bit counter intuitive, since you would *think* they phase lock the local source in the module. They don’t mainly

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

Hi > On Aug 18, 2018, at 2:25 PM, Attila Kinali wrote: > > On Thu, 16 Aug 2018 17:45:30 +0200 > Nicolas Braud-Santoni wrote: > >> The main issue I'm running into is that most timing GPS modules will >> happily give you carrier phase measurements... for their internal >> oscillator, and the

Re: [time-nuts] WWV, WWVB and Daylight Savings Time

Hi I think there are a lot of ways to come up with a “local” WWVB signal that has all the DST stuff in it (or not if you prefer …). There’s not a lot of code or development involved. Even with the current shortage of parts, there are an ocean of dirt cheap MCU’s and boards to pick between.

Re: [time-nuts] WWV, WWVB and Daylight Savings Time

Hi > On Aug 24, 2018, at 1:18 PM, Mark Sims wrote: > > Lady Heather has DST support code in it (in file heathmsc.cpp). It supports > the current standard settings for several areas (US, Europe, Australia, New > Zealand) or you can specify a custom DST rule. The code is around 200 lines >

Re: [time-nuts] WWVB Chronverter update progress

Hi You can do the 14 db deep modulation with a tristate gate and a pair of resistors. Ground the input and feed the “modulation” signal to the tristate control. Bob > On Aug 25, 2018, at 4:35 PM, paul swed wrote: > > From the earlier threads OOK modulation does not work for high end clocks

Re: [time-nuts] WWVB Chronverter update progress

ed. Getting lazy these days. >>> I have some number of tcxos from a company called vectron. Several cards >>> of each. Can't imagine how I came by those. >>> :-) Believe the lowest freq was 12 MHz. >>> Regards >>> Paul. >>> >>> >>&

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

Hi > On Aug 19, 2018, at 5:26 PM, Nicolas Braud-Santoni > wrote: > > On Sat, Aug 18, 2018 at 08:25:11PM +0200, Attila Kinali wrote: >> On Thu, 16 Aug 2018 17:45:30 +0200 >> Nicolas Braud-Santoni wrote: >> >>> The main issue I'm running into is that most timing GPS modules will >>> happily

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

Hi > On Aug 20, 2018, at 5:46 AM, Nicolas Braud-Santoni > wrote: > > On Mon, Aug 20, 2018 at 01:15:10AM +0200, Attila Kinali wrote: >> On Sun, 19 Aug 2018 23:26:03 +0200 >> Nicolas Braud-Santoni wrote: >> Yeah. u-blox isn't as nice as they used to be to small customers :-( >>> >>> Ah,

Re: [time-nuts] WWVB Chronverter update progress

Hi One of the “interesting” things about the phase modulation on WWVB is that it does not get converted to AM (and thus mess things up) in the front end filters of the typical watches and clocks. The filters also do not strip off the AM modulation sidebands of the signal. One would *guess*

Re: [time-nuts] WWVB Chronverter update progress

018 at 7:29 AM, Mike Feher wrote: > >> Simple error. It is 1.667. 73 - Mike >> >> >> >> Mike B. Feher, N4FS >> >> 89 Arnold Blvd. >> >> Howell NJ 07731 >> >> 848-245-9115 >> >> >> >> -Origin

Re: [time-nuts] WWVB Chronverter update progress

how > it'll respond to just plain amplitude keying for the time code. You might > think the WWVB BPSK chip will respond to loud and clear amplitude > modulation but I have no experience with this. Nor do I even know if a > single consumer clock was ever sold with BPSK ability. > > Tim

Re: [time-nuts] WWVB Signal Generator

Hi The gotcha is if you have neighbors two or three doors away that *also* put up one of these devices. You then have a real problem with the neighbor(s) in the middle. The wavelength is long enough that Raleigh issues won’t get you. You still have the two signals ( at slightly different

Re: [time-nuts] WWVB Chronverter update progress

HI If you are feeding “Time Nuts” gear, a fancy filter on the output of the WWVB gizmo may be an issue. Temperature impacts the value of the components and that value change impacts the phase of the signal…. Bob > On Aug 28, 2018, at 9:33 PM, paul swed wrote: > > LPF filter added 2.2mH choke

Re: [time-nuts] time-nuts Digest, Vol 168, Issue 21

Hi I think it’s just the normal summertime drop-off. Everybody is on vacation….. Bob > On Jul 23, 2018, at 12:41 PM, Dan Kemppainen wrote: > > FYI, > > I would tend to agree about the drop in traffic. Not sure if it's just a > quiet period, but there are many less messages than before in

Re: [time-nuts] WWV and legal issues

Hi This is not so much a GPS issue as a system design issue. GPSDO’s are used to “smooth over” bumps in a lot of systems out there. At the timing levels required by ATM or authentication setups, you can go a *long* time running on a GPSDO. It’s not a matter of GPS, it’s a matter of doing

[time-nuts] News

Hi Magnus … do you have some news you might want to share with the group? 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

Re: [time-nuts] NIST

Hi When infastructure GPS *does* get jammed these days that source gets tracked down a lot faster than a month or so. Anything that goes on for more than a day gets booted up pretty high pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be ….. The same sort

Re: [time-nuts] NIST

Hi Well, designing jammers on a public forum is an “interesting” thing to do….. With WWVB, you are fine with a “near field” solution. You don’t need something that propagates for miles and miles. The other thing you have in your favor is that coming up with a KW at 60 KHz is quite easy. All

Re: [time-nuts] WWV and legal issues

Hi WWVB as transmitted ( = right at the input to the antenna) is a wonderfully stable signal. As soon as that signal hits the real world things start to degrade. Propagation between transmit and receive sites is a big deal, even at 60 KHz. On top of that, there is a *lot* of manmade noise at

Re: [time-nuts] NIST

Hi > On Aug 30, 2018, at 12:58 PM, Peter Laws wrote: > > On Mon, Aug 13, 2018 at 8:52 AM Peter Laws wrote: > > >> I have yet to hear anyone make a case for retaining the HF system that >> isn't backed by nostalgia. > > Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS >

Re: [time-nuts] WWV and legal issues

a system 24 hours a day 365 days a year. Bob > On Aug 30, 2018, at 1:54 PM, Attila Kinali wrote: > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As

Re: [time-nuts] WWV and legal issues

e determined.With > eLoran you can get similar levels of accuracy as the old Austron monitors > used to prove > > Content by Scott > Typos by Siri > > On Aug 30, 2018, at 12:27 PM, Bob kb8tq wrote: > > Hi > > WWVB as transmitted ( = right at the input to t

Re: [time-nuts] Effects of Simple GPS jamming on GPSDO's ?

, at 3:41 PM, Gerhard Hoffmann wrote: > > > >> Am 31.08.2018 um 19:39 schrieb jimlux: >>> On 8/31/18 10:15 AM, Bob kb8tq wrote: >>> Hi >>> >>> Having spent a lot of my life designing GPSDO’s it’s a “that depends” sort >>> of thing.

Re: [time-nuts] NIST

Hi > On Sep 1, 2018, at 3:06 AM, Magnus Danielson > wrote: > > > > On 08/31/2018 03:36 PM, Bob kb8tq wrote: >> Hi >> >> “Backbone timing” gets done by boxes buried deep in systems. Those systems >> take years >> to design. The boxes

Re: [time-nuts] Effects of Simple GPS jamming on GPSDO's ?

r more > to worry about > than keeping our watches accurately set. But what if it's another > Carrington-level > event? I'm sure we'd all like to get back to business as usual as quickly > as possible. > > Dana > > > On Fri, Aug 31, 2018 at 5:23 PM Bob kb8tq wr

Re: [time-nuts] Lots of Off Topic discussion

Hi I most certainly *have* seen an NTP server that ran off of WWVB and relayed the result to the internet. The fun part was that they had entered the “delay” number into their config file with the wrong sign on it (or there was a bug in the NTP code at that time). The result was that they were

Re: [time-nuts] NIST

s > wrote: > > On Thu, Aug 30, 2018 at 12:59 PM Bob kb8tq wrote: > >> There most certainly was a lot of “stuff” in orbit by that time. If there was >> a mass die off of satellites, you would not have to look hard to find out >> about >> it. > &

Re: [time-nuts] Lots of Off Topic discussion

e: >> On Sat, Sep 1, 2018 at 7:25 PM Bob kb8tq wrote: >> >>> I most certainly *have* seen an NTP server that ran off of WWVB and relayed >>> the result to the internet. The fun part was that they had entered the >>> “delay” >> I didn't say it COULD

Re: [time-nuts] Frequency over fiber (was WWV and legal issues)

Hi Tidal effects can be very “non linear” as you approach a coast line. Lots of change over a fairly short distance. If indeed the world decides to put in a global PTTI fiber system, all of this would get into the mix on some links. It appears that the existing technology would handle the

Re: [time-nuts] Can eloran Backup GPS?

/uploads/On-the-Uses-of-High-Accuracy-eLoran-Time-Frequency-and-Phase-2015.pdf > > I've attached a screen capture of one of the pages that compares > eloran with GPS in case anyone is interested. This is where it > appears that the 50ns is received as opposed to at the transmitter. > >

Re: [time-nuts] Can eloran Backup GPS?

-Paper.pdf > > I'm sure after a few more prefix letters are added to Loran it will work for > everyone! > > Time for a new house to flip or dead horse to flog, > > Bob Martin > > > > > > On 9/8/2018 2:44 PM, Bob kb8tq wrote: >> Hi >> The d

Re: [time-nuts] Lost GPS lock or 1PPS recently?

Hi > On Sep 8, 2018, at 1:53 PM, Scott McGrath wrote: > > This is precisely the scenario even a short GPS blackout of 1-2 weeks would > cause. Its not that GPS is not the finest time transfer system ever > devised. Its that with the loss of legacy systems we’ve lost the ability to >

Re: [time-nuts] Lost GPS lock or 1PPS recently?

Hi I believe the 50 ns is the “as transmitted” signal from the tower. The “as received” signal after going through all the various gyrations is not that good on a ~1 second basis. One of the gotchas here is that we lump “systems” into one giant bag. That’s not a good way to analyze

Re: [time-nuts] Can eloran Backup GPS?

stem mentions that the differential corrections are sent on the LDC pulse. > > To be honest, I don't know if this addresses your "gotcha". > > Best, > > Bob Martin > > On 9/8/2018 12:38 PM, Bob kb8tq wrote: >> Hi >> The gotcha is the differ

Re: [time-nuts] Can eloran Backup GPS?

Hi > On Sep 9, 2018, at 10:43 AM, jimlux wrote: > > On 9/8/18 4:52 PM, paul swed wrote: >> Hello to the group I won't quote figures here but did indeed help UrsaNav >> do testing. Hey 90 days with a HP 5071 that was a sweet deal at the cost of >> some power. >> They do send corrective data in

Re: [time-nuts] Can eloran Backup GPS?

Hi Back in the day, Loran was monitored and corrections were published. If you really were “time nutty” about using Loran, you got the correction tables (in the mail) and post processed them into your measurements. Bob > On Sep 9, 2018, at 11:34 AM, paul swed wrote: > > The correction

Re: [time-nuts] Lost GPS lock or 1PPS recently?

Hi Well, we *do* have experience with that. It was called selective availability. Indeed it might get turned back on again. It’s impact on a properly designed GPSDO - not much. It takes a bit longer to get to best stability. System time wise, it still works “good enough”. A four hour long

Re: [time-nuts] Lost GPS lock or 1PPS recently?

> Wrt cellsites staying operational i imagine the oscillators in holdover would > probably remain sufficiently synchronized for a month or so. > > > > On Sep 6, 2018, at 4:56 PM, Bob kb8tq wrote: > > Hi > > Well, we *do* have experience with that. It was calle

Re: [time-nuts] WWVB Chronverter update progress

Hi Even when dividing from 48 MHz straight to 60 KHz, the uBlox is going to do a pulse drop / pulse add to keep things on frequency. For a wall clock that probably is not an issue. For a phase locking receiver it’s not quite as clear. The 60 KHz edge is going to hop by about 21 ns every so

Re: [time-nuts] NIST

Hi Actually it’s pretty simple to track down that sort of jammer ….. and yes, the gear to do it is out there in quantity. Bob > On Aug 30, 2018, at 6:51 PM, Scott McGrath wrote: > > As Brooke notes while low frequency jammers are possible, practicality is > another matter, All it takes

Re: [time-nuts] NIST

s by Siri > > On Aug 30, 2018, at 8:24 PM, Bob kb8tq wrote: > > Hi > > Since timing receivers are actually going to prefer high angle sats, an > antenna that rejects > close to the horizon is a pretty common thing. Enhancing that sort of > rejection doesn’t take &g

Re: [time-nuts] NIST

Hi Since timing receivers are actually going to prefer high angle sats, an antenna that rejects close to the horizon is a pretty common thing. Enhancing that sort of rejection doesn’t take a lot of effort. Bob > On Aug 30, 2018, at 7:05 PM, Gregory Maxwell wrote: > > On Thu, Aug 30, 2018

Re: [time-nuts] NIST

Hi The original “we cracked GPS” paper back in the 1980’s (that unlimitedly lead to the end of SA) used a medium sized dish ( think of the good old C-band antennas) to pick out a single sat. Bob > On Aug 30, 2018, at 9:54 PM, Brooke Clarke wrote: > > Hi Gregory: > > I wonder if anyone has

Re: [time-nuts] WWVB Signal Generator

have but I can tell you around here its >>> the phone. Not to concerned about someone putting up a wwvb replacement. >>> And I can always up the power. Chickle. >>> Regards >>> Paul >>> >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: >>

Re: [time-nuts] IQRB-1 RBXO

Hi That basic design (though maybe not this exact part) has been kicking around for at least the last ten years. Various people have popped up reselling it. There are a lot of older Rb’s that are in the <2x10^-11 range at 1 second: http://www.ke5fx.com/rb.htm

Re: [time-nuts] OOPS on my wwv legal post

Hi The whole issue of who is what goes back to some very obscure laws / rules passed quite a long time ago. It’s been a matter of debate (usually with beer involved) for quite a while. Bob > On Aug 29, 2018, at 9:24 PM, Steve Allen wrote: > > On Wed 2018-08-29T19:49:59-0400 Bob k

Re: [time-nuts] WWV and legal issues

Hi The same sort of massive solar flare that fiddles with sat systems also makes a mess of HF and VLF systems. You have a high level of correlation in the impact. That makes them a poor “backup” in this case. Bob > On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote: > > Excellent point on

Re: [time-nuts] WWV and legal issues

Hi One of the basic disconnects here seems to be the idea that radio was the “best thing” before GPS came along. In fact that’s not really how it worked. Time was traced / coordinated by hauling atomic clocks on airplanes as the “best thing” before satellite systems came along….That was true

Re: [time-nuts] Lost GPS lock or 1PPS recently?

t; > Its also fun watching executives realizing that their phone during the > exercise is a paperweight useful only in weighting down stacks of Form 213’s > > Its not for nothing that Symmetricom is building more 5071’s than HP/Agilent > ever did. > > On Sep 7, 2018, at 5:18 PM, Bo

Re: [time-nuts] Frequency over fiber (was WWV and legal issues)

Hi > On Sep 2, 2018, at 7:17 AM, Magnus Danielson > wrote: > > Hi Gerhard, > > I see that this became a separate thread. > > On 09/02/2018 01:38 AM, Gerhard Hoffmann wrote: >> >> >> Am 01.09.2018 um 20:40 schrieb Magnus Danielson: >>> One should first know that there is a lot of papers now

Re: [time-nuts] Lady Heather V6.0 and RINEX files...

Hi > On Jul 2, 2018, at 6:49 PM, Michael Baker wrote: > > Time Nutters-- > > Mark Sims said of the latest release of Lady Heather: > >> There are several cosmetic tweaks. > > A major new feature is the ability to write RINEX files for receivers that > can output satellite RAW

Re: [time-nuts] Need Advice on Trimble 22020 Antenna

Hi Trimble has been making GPS for a *long* time. Your antenna dates back a ways. You see them for $50 to $100 if you do some careful shopping. They have about 50 db of front end gain and need 12V for power. They are pretty broadband compared to a timing antenna with built in filtering. All of

Re: [time-nuts] 10 MHz -> 16 MHz

Hi If (as originally specified) noise and jitter are not a big deal - there are a lot of chips out there like the ICS570. They are designed to do weird ratio frequency conversions so 10 to 12 or 10 to 16 are trivial for them. The Clockblock board was one way to get it all put together. Bob

Re: [time-nuts] GPSDO uncertainties

Hi The question becomes very much, what confidence level are you after? Is 99% good enough? Are you after 99.%? Obviously the stability gets worse as you crank on more nines. Next layer to the onion is - how long have things been running and under what conditions are they running? A few

Re: [time-nuts] RF isolation amplifier question

Hi What you have there is known as a cascade buffer amplifier. The common base stage combined with the common emitter has some well known issues at high frequencies ( like UHF / microwave). That’s the tradeoff for having really good isolation at HF and usually at VHF. Put a sniffer loop near

Re: [time-nuts] Question about the PLL of Trimble Thunderbold

Hi The Thunderbolt actually is not a real good solution if you want to synchronize to something other than GPS. It depends on direct phase data from its internal GPS chip set to do the GPSDO magic. A board that has a PPS signal between the GPS and “PLL” probably is a better way to go. Even

Re: [time-nuts] cable delay variation (was: Question about the PLL of Trimble Thunderbold)

Hi > On Oct 29, 2018, at 3:42 PM, Attila Kinali wrote: > > On Mon, 29 Oct 2018 12:03:25 -0700 > Hal Murray wrote: > >> If I go looking for good cables, do they specify temperature coefficient? I >> don't remember ever seeing it when scanning specs, but I probably wasn't >> looking for it

Re: [time-nuts] Question about the PLL of Trimble Thunderbold

ways. There is no single “right” solution. Yes, there are a *lot* of assumptions and more than a few simplifications above. Lots of fun !! Bob > On Oct 29, 2018, at 2:38 AM, Ferran Valdés wrote: > > > > Thanks everybody for your answers. > > > >

Re: [time-nuts] Helium and MEMS oscillators don;t mix well

Hi A lot of Radon and *really* poor ventilation…. There are a lot of ways for He to show up. In normal use, issue is hanging on to it. It tends to run away from its source very quickly. Maintaining a measurable concentration in something like a normal room …. not very easy at all. Bob >

Re: [time-nuts] MEMS oscillators

Hi More than sketchy, it sounds a bit crazy. MEMS are not a lot different than any IC in that you can get packaging issues. Put them in a high pressure “bomb” test and you will see the same issues that you do on any IC. The gotcha is that an IC is die coated and a MEMS oscillator likely is

Re: [time-nuts] Question about the PLL of Trimble Thunderbold

hunderbolt, and the Time Interval circuit > could show the difference in between this signal and the feedback of the VCO. > > > > > > @ Bob kb8tq > > > > The aim of this project has no commercial purposes and the project itself is > to develop the algo

Re: [time-nuts] Still looking for a schematic drawing for Oscilloquartz 8600-3 (945.860.011.03 S/N 422)

it. >> Simply a suggestion. Especially since you have it open. >> Regards >> Paul >> WB8TSL >> >> On Thu, Oct 25, 2018 at 2:15 PM Bob kb8tq wrote: >> >>> Hi >>> >>> Even with an “account”, most oscillator companies will not su

Re: [time-nuts] Still looking for a schematic drawing for Oscilloquartz 8600-3 (945.860.011.03 S/N 422)

Hi Even with an “account”, most oscillator companies will not supply internal details on their product. That’s in part to protect their IP. It also reflects the complexity of tracing back to exactly what doc’s apply to an older unit. The normal drill is for you to send it back and they take a

Re: [time-nuts] OCXO Board

Hi Well if this turns into a major enterprise …. do a second board with a different set of footprints. Probably better to see if this one will fly first ….. Bob > On Oct 26, 2018, at 4:19 PM, ewkehren via time-nuts > wrote: > > I have added OSA 8663 was not easy no more Please

Re: [time-nuts] OCXO Board

Hi I think what is needed is somebody to stand up and say “ok, I’ll handle all the ordering and shipping stuff”. No, that somebody is not me …. sorry about that. There are a *lot* more board designs than just this one floating around. This could turn into a fairly complex little enterprise.

Re: [time-nuts] Racal Dana 9478 frequency distribution system with option 04B high stability oven (5x10^-10/day aging rate).

Hi One would *guess* that the PLL bandwidth in the 9578 is wider than what you see in a typical GPSDO. As long as they don’t both line up at the same point, noise and phase peaking should not be a big deal. Depending on how clean your GPSDO is, the 9578 might clean things up a bit. For

Re: [time-nuts] Datum PRS-50 ionizer voltage supply

Hi Just as a guess, it would be rare for a “heated wire” type of thing to have much over a 10:1 ratio between hot and cold. Most have ratios that are less. (think of a light bulb …) If you suspect the ionizer, I’d suggest working out just what it’s resistance is. If it’s down below 0.1 ohms

Re: [time-nuts] Helium and MEMS oscillators don;t mix well

Hi As much fun as this is, once it moves over to wireless charging as the likely issue ….. that’s getting pretty far from TimeNuts main focus….. Bob > On Nov 1, 2018, at 5:08 PM, David Witten wrote: > > Ok, one last try: > > From AuntMinnie.com, free but subscrip[tion-based newslettter for

Re: [time-nuts] Helium and MEMS oscillators don;t mix well

Hi Now, getting back to the original issue. MEMS oscillators of some types have really tiny structures in them. They mount them as close to being in “free space” as they can. The idea is no different than a crystal. A properly shape lump running in free space has higher Q. Higher Q is normally

Re: [time-nuts] Helium and MEMS oscillators don;t mix well

Hi If you take an IC package up to fairly high pressure for a few hours (and it’s defective) you can pretty well fill it with helium and have it well above 1 ATM internal pressure. It will then leak out (maybe over a few years) until it gets back down to one atmosphere internally. In some

Re: [time-nuts] hp 10544A and 10811A ovenized oscillators

Hi The change is suspiciously close to the electrical tuning range of a typical HP OCXO. The answer may be a failure of the bias on the EFC line ….. Bob > On Nov 2, 2018, at 2:51 PM, Walter Shawlee 2 wrote: > > I have several of these as the -010 high stability timebase options > in my

Re: [time-nuts] Question about the PLL of Trimble Thunderbold

” level, the NRE may be a bit above the few thousand level. Also expect to supply a full spec requirement when you go shopping …. Bob > On Oct 29, 2018, at 2:38 AM, Ferran Valdés wrote: > > > > Thanks everybody for your answers. > > > > @ Bob kb8tq > >

Re: [time-nuts] hp 10544A and 10811A ovenized oscillators

Hi A failed ( = cold) oven on either a normal OCXO should give you a “tens of ppm” sort of frequency error. At 10 MHz that would be over 100 Hz. Fractions of a ppm are less likely to be oven issues. Bob > On Nov 5, 2018, at 1:01 PM, Dr. Frank wrote: > > Walter, > > did you check on both

Re: [time-nuts] Need recommendation for GPS antenna for Oncore GPS module

Hi Appears to be an Italian clone of the generic timing antenna. That is only a guess and it could easily be something very different …. Since it’s a part made for Erickson by somebody else, you would need their part number to properly track it down. If it’s a custom part, even that might

Re: [time-nuts] 53230A TIC and TimeLab

Hi Probably also worth mentioning: For short tau, you are probably measuring the ADEV of the counter noise floor rather than the ADEV of the GPSDO. Yes, there are noisy GPSDO’s out there but most of what you run into is not in that category. Bob > On Oct 4, 2018, at 8:42 AM, Ole Petter

Re: [time-nuts] WWV and legal issues

ng. Then it was just more arithmetic again. Several of the oscillators > had such low drift rates that all I needed was one daily phase reading from > the VLF phase tracking receiver (Tracor 599Js) at those sites to know the > frequency of the Sulzers there. > > ... Martin

Re: [time-nuts] Effects of Simple GPS jamming on GPSDO's ?

Hi Having spent a lot of my life designing GPSDO’s it’s a “that depends” sort of thing. For a simple noise jammer, yes, they pretty much all will go into holdover. When the jammer goes away, they come out of holdover. There are a few older units that may not do quite as well with various

Re: [time-nuts] Effects of Simple GPS jamming on GPSDO's ?

Hi Most of them are doing CW signal detection and notch filtering. There are a number of ways for “birdies” to show up in any environment, jamming or no jamming. Some of the details of who’s doing what and how well are under NDA. None of it is 100% effective, it’s just a way to get another 10,

Re: [time-nuts] Possible End of Daylight Savings Time in Europe?

Hi Here in the US, we have been creeping along getting rid of daylight time. At the rate we have been changing the magic dates, I’d bet we have it gone in a few hundred years :) Bob > On Aug 31, 2018, at 8:57 AM, John Franke wrote: > > See: >

Re: [time-nuts] NIST

Hi It’s back in the FCS archives. I don’t think it’s one of the ones you can hit without going through a paywall. It was a fun paper to attend. The chatter in the room was “interesting” to say the least. Bob > On Aug 31, 2018, at 1:07 PM, Brooke Clarke wrote: > > Hi Bob: > > Do you have

Re: [time-nuts] WWV and legal issues

s task... > > > On Aug 31, 2018, at 11:37 AM, Tom Holmes wrote: > > Uh, folks...Would the apparently still on hiatus TVB approve of this on-going > Urinary Olympiad? Just asking. And hoping post this won’t start another one. > > Tom Holmes, N8ZM > > -----Origin

Re: [time-nuts] Frequency over fiber (was WWV and legal issues)

variation in the fiber's delay across an active > fault line? The fiber could only break at the fault line, lay down > more fiber than needed, to compensate the movement, and the delay > doesn't change. > On Sun, Sep 2, 2018 at 4:51 PM Bob kb8tq wrote: >> >> Hi >> >>

Re: [time-nuts] Efratom Oscillators

Hi The Efratom units looked like the “two generations back” Vectron devices. They are roughly a 1.3” cube. Efratom sold the line of parts to Vectron back in the 1990’s. Bob > On Sep 21, 2018, at 12:32 PM, ed breya wrote: > > Do they look anything like this? > >

Re: [time-nuts] question about multi-way measurement

Hi There also are a lot of papers going back a ways by Jim Barnes and David Alan (sometimes together and sometimes separately) related to multiple clocks driving a single “estimate” of what time it actually is. Bob > On Dec 27, 2018, at 2:34 PM, Steve Allen wrote: > > On Wed

Re: [time-nuts] More ES100 WWVB Measurements

a building or parking > garage? > > Wayne > > On Mon, Dec 31, 2018 at 5:29 PM Bob kb8tq wrote: > >> Hi >> >> If you are fairly deep inside a building, GPS isn’t going to get there. >> WWVB likely >> will make it to an internal location. >> &g

Re: [time-nuts] More ES100 WWVB Measurements

Hi If you are fairly deep inside a building, GPS isn’t going to get there. WWVB likely will make it to an internal location. If you are convinced that WWVB is un-jamable and that GPS is easily jammed, WWVB would be more robust. That’s about it. Bob > On Dec 31, 2018, at 7:56 PM, Wayne

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