Re: [time-nuts] Rakon HSO-14

he blank seems to have been > simple. The shapes for the electrodes seems to have been worse. > > Cheers, > Magnus > > On 02/03/2018 11:34 PM, Bob kb8tq wrote: >> Hi >> >> The “BVA” part of the name refers to the slots machined into the crystal >> blank

Re: [time-nuts] Rakon HSO-14

Hi The “BVA” part of the name refers to the slots machined into the crystal blank to manage the mounting stress on the resonator. Both the “plated on the blank” and the “electrodes off blank” versions are legit BVA approaches. Indeed the electrode off the blank version is the more expensive

Re: [time-nuts] More on SiLabs 5340

Hi There may be “tweaks” to get the noise shaping working better on the 10 MHz input. Some PLL chips have pre-multipliers for the reference to improve things…. the magic apparently works better with a fast input …(and yes, there are good reasons why) Bob > On Jan 29, 2018, at 3:38 PM, John

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi Questions are good, it’s how you figure things out. We’re talking about a “practical” timing device design. It’s not as crazy a topic as it might seem. Some basic math: You get to a million seconds at about 11.6 days. A millisecond error over that period is one ppb. If you are off 1 ppb

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi As mentioned multiple times in the archives. As you get into the single digit milliseconds, the human eye simply can’t keep up. A watch that is 1 ns off and one that is 1 ms off are both “good enough” if you are looking at it with a normal eyeball. >From a design standpoint 1 ms / day /

Re: [time-nuts] Si5340 synthesizer chip performance

Hi It would be *very* interesting to see what happens if you sync it up to a 10 MHz input …. Bob > On Jan 28, 2018, at 7:23 PM, John Ackermann N8UR wrote: > > I received the Si5340A evaluation board from Digikey on Friday and fired it > up yesterday. I used the SiLabs

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi A GPS PPS output will (most likely) be more accurate than the CSAC each time you go back to dock with the charger. A GPS module to do everything you would ever want to do is a sub $100 sort of item. You would still need a bit of hardware to “glue” things together (but not a lot) and some

Re: [time-nuts] Microsemi 3120A sold on eBay

Hi There’s a cluster of time and frequency outfits up in the Salem area. Some have been there for a *long* time indeed. The EG / Perkin Elmer Rubidium guys are one that comes to mind. MTI is a bit further north, but still in the same side of the Boston urban sprawl. Bob > On Jan 27, 2018,

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi Yes, I have set up a CPU to dump all the data from a CSAC. Everything they list in their data sheet can easily be dumped via a standard UART interface. The serial protocol works exactly the way they describe. There is no “built in clock” so no ability to dump the time and date. You can

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi “Included software” on the CSAC is a pretty short list …. There is not much past the “stuff” to set it on frequency and read out a few alarms. One thing that gets into a lot of these projects: We are Time Nuts and spec things in terms of time. This error over that period is some specific

Re: [time-nuts] Microsemi up for sale?

Hi I suspect that a lot of people are wondering who the buyer might be …. Bob > On Jan 26, 2018, at 6:27 PM, Clint Jay wrote: > > Perhaps of interest to the list > > https://www.theregister.co.uk/2018/01/25/microsemi/ > > -- > Clint. > > *No trees were harmed in the

Re: [time-nuts] Suggestion for a timing GPS receiver (Trimble / Ublox / other?)

Hi The target application is NTP with the PPS probably coming in via a RS-232 serial port. Anything that jitters less than 200 ns is probably going to look “same / same “. Bob > On Jan 26, 2018, at 6:48 PM, Bryan _ wrote: > > Thanks, forgot I have a Jupiter-T (D-120?) in

Re: [time-nuts] Suggestion for a timing GPS receiver (Trimble / Ublox / other?)

Hi Which ever you can get for the least money. Anything much over $10 is probably “over budget”. Bob > On Jan 26, 2018, at 3:57 PM, Bryan _ wrote: > > Which would be the preference as timing receiver Motorola Oncore or a Trimble > Resolution T ? > > > -=Bryan=- > >

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi One way or the other you will need some “smarts” to do aging compensation. That implies adding a CPU of some sort to the “system” you are building. There is no built in subsystem on the CSAC that will do any of this for you. You also need some sort of display for your “wrist watch”. Having

Re: [time-nuts] New OCXO claims ppb performance.

Hi The “ppb” number in this case is the temperature performance. Indeed, that is “pretty close” to the temperature performance of the CSAC. Aging is rated at 50 ppb / year. That’s a bit further out than what a typical CSAC will do. In either case, if you let the beast run for a year, it is

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi The CSAC (like any vapor cell standard) has a drift (aging) process. That’s just the way it works. It is at a *much* lower rate than a crystal oscillator, but it is the same sort of idea. It is one of their basic differences from a Cesium beam tube. Can you “estimate” aging in advance?

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi > On Jan 25, 2018, at 5:47 PM, Ronald Held wrote: > > Nigel; > Will read the PDF carefully. > Ronald > > > "if it runs for years (or even months)" sounds like an informed comment:-) > > When searching for some data recently I came across a report which >

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

Hi You can mod toaster ovens, they work ok, EEVB has *lots* of info on that. When you buy your PCB you can get solder stencils at the same time. Bought as a package they are in the $10 or so range. Without buying the boards with them, I’m sure the price goes up a bit. The metal ones are a bit

Re: [time-nuts] CSAC Project(was CSAC purchase)

018, at 3:42 PM, jimlux <jim...@earthlink.net> wrote: > > On 1/25/18 11:20 AM, Bob kb8tq wrote: >> Hi >> One of the unique features of underwater timing is that the sea bottom >> temperature >> (once you get well away from a coastline) is *very* stable. In some

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi Just to be clear, the current data sheet has the temperature range back to -10 to +70C. They most certainly had a major headache on their hands for several years straightening things out. I have not seen any complaints about the “new” (post rework) version of the part. Bob > On Jan 25,

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi One of the unique features of underwater timing is that the sea bottom temperature (once you get well away from a coastline) is *very* stable. In some deployments, the “random” nature of ambient temperature that we fight all the time in the rest of the world, simply is not present. The

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

Hi > On Jan 25, 2018, at 2:02 PM, wb6bnq wrote: > > Hi John, > > After looking at the data sheet, it seems way more involved then just making > a carrier board for it. Besides the power supply requirements, various > design selections would dictate different circuit layouts

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi > On Jan 25, 2018, at 12:39 PM, gandalfg8--- via time-nuts > wrote: > > > > Hi > > The CSAC spec sheet calls out an aging rate of 0.9 ppb per month as > “typical”. There is also a temperature spec of 0.4 ppb. If both are correct > for your sample (*and* aging is

Re: [time-nuts] CSAC Project(was CSAC purchase)

Hi The CSAC spec sheet calls out an aging rate of 0.9 ppb per month as “typical”. There is also a temperature spec of 0.4 ppb. If both are correct for your sample (*and* aging is linear ) you would be out by roughly 10 ppb per year. There also is a voltage stability spec that might be impacted

Re: [time-nuts] RE CSAC Project(was CSAC purchase)

Hi The original RbXO was not a whole lot bigger than the Rb. The CSAC is a *lot* smaller than the Rb’s of that era. The TCXO’s and OCXO’s today are a lot smaller as well. I’d bet you could do it in < 2X the volume of the CSAC with a pretty good OCXO and < 1.2X the volume with a precision TCXO.

Re: [time-nuts] Suggestion for a timing GPS receiver (Trimble / Ublox /other?)

Hi The T software does support locked position. If your antenna location is so bad that this is of any use …. move the antenna. I can get full coverage with a modern uBlox from a chair in the family room. A bit more information: If you are in an “urban canyon” (or maybe a real canyon) then

Re: [time-nuts] CSAC purchase

Hi I’m guessing there was a question to me that somehow got lost in the world of ones and zeros …. My comment was in terms of temperature stability. The CSAC has a temp stability specification of +/-4x10^-10 over -10 to +70C. There are TCXO’s that will get below 5x10^-9 over that range and

Re: [time-nuts] CSAC purchase

Hi For something portable, the good old RBXO approach might well be worth considering. Bob > On Jan 22, 2018, at 3:05 PM, Ronald Held wrote: > > Magnus: > I wanted one since they were announced in 2005, AFAIR. Incorporated > into a watch was my first choice, but that

Re: [time-nuts] Suggestion for a timing GPS receiver (Trimble / Ublox / other?)

Hi It is doubtful that the pc board has an RS-232 to TTL converter onboard. The module it’s self “talks” TTL levels rather than RS-232 levels. RS-232 to TTL adapters are dirt cheap and easy to find on eBay. Make sure you get one that has control lines along with the basic RX and TX functions.

Re: [time-nuts] CSAC purchase

Hi The “compelling case” for the CSAC is the combination of low power and long term stability. You can get OCXO’s that run less power. A TCXO that uses less power is trivial. Temperature stability wise, there are TCXO’s that get pretty close (= factor of 10) to overlapping with the CSAC.

Re: [time-nuts] Time interval measurement vs dual mixer method

Hi What level of stability are you trying to measure? What sort of offset frequency are you running? What kind (phase noise / spurs / adev) offset oscillator are you using? What sort of limiter are you running with what sort of pre filtering? We have run around on a lot of generalities. You

Re: [time-nuts] Time interval measurement vs dual mixer method

Hi The quality of the offset signal source matters in a DMTD system. If you are using a “noisy” source you will have trouble with the data. You also will have trouble if the offset signal is correlated in some way to one of the DUT signals. Bob > On Jan 20, 2018, at 3:43 AM, tim...@timeok.it

Re: [time-nuts] minimalist sine to square

in the IC protection diodes can degrade the timing jitter > substantially (tens of picosec for HCMOS). > > Bruce >> On 20 January 2018 at 14:34 Bob kb8tq <kb...@n1k.org> wrote: >> >> >> Hi >> >> Unless you really beat on the thing for days on e

Re: [time-nuts] minimalist sine to square

e used it should all fit on a DIP compatible daughter board. > > Bruce >> On 20 January 2018 at 12:37 Bob kb8tq <kb...@n1k.org> wrote: >> >> >> Bob >> >> With a 1V p-p sort of output, a simple matching network will get you into >> the 4 t

Re: [time-nuts] minimalist sine to square

Bob With a 1V p-p sort of output, a simple matching network will get you into the 4 to 6V p-p range. Drive that into a 5V compatible CMOS gate and move on …. If you have a super hot output, put a 3 db pad on it. Bob > On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: >

Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.

Hi The antenna has a measured / documented pattern (amplitude and more importantly phase). If you have it pointed in a known direction, that information can be used when post processing carrier phase information. If you are trying to get to mm / picosecond levels on an multi hour L1/L2

Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.

Hi Since this *is* an L1 / L2 antenna, there are a lot of things you might be doing with it. If indeed dual frequency GPS is part of the intended use, the survey oriented gear will be slightly happier if the “right” corner faces north. It only really counts in that sort of L1 / L2 data

Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.

Hi It is very much a 12V antenna. It also is a “50 db gain” antenna as well. Most of the timing gear is looking for 20 to 30 db less gain than that in an antenna. The good news is that you can run a really big splitter after one to drive lots of stuff. The bad news is that you may still need

Re: [time-nuts] MTI-Milliren OCXO Issue

Hi They always had a pretty lean operation and some unique approaches as part of their business plan. That said, they do seem to be a going concern. Bob > On Jan 19, 2018, at 3:54 AM, John C. Westmoreland, P.E. > wrote: > > Hello All, > > Just wondering -

Re: [time-nuts] Tbolt 1pps

Hi Back a number of years ago I did a number of them. The results vary a bit between units and depending on the quality of the antenna. No idea if I can dig that data back up again or not. Bob > On Jan 17, 2018, at 9:57 AM, ew via time-nuts wrote: > > Has any one done a

Re: [time-nuts] Time interval measurement vs dual mixer method

Hi If the time offset gets to the point that it bothers the measurement, you likely are running to low a difference frequency. It is quite possible (though not easy) to get low parts in 10^-13 running an offset of 8 or 9 Hz at 10 MHz. If you are running very precise signals, then line

Re: [time-nuts] Time interval measurement vs dual mixer method

Hi You have to measure two different outputs to do what you describe. The PPS measurements are limited to > 1 x10^-10 with most counters at tau = 1 second and 2x10^-11 with some exotic models. The mixer based stuff can get around three orders of magnitude past that at the same tau. Since a

Re: [time-nuts] Identify RFTGM-II-XO Part

Hi I would second Paul’s input. Is the unit actually working at the moment? Some of the circuits in these gizmos *do* run pretty hot in normal operation. If there is a problem with that device, before I paid $67 for the replacement part (or anything close to that) I probably would convert it

Re: [time-nuts] Antenna Supply voltage

Hi The normal TBolt supplies 5V to the antenna. There *are* some 3.3V only antennas out there. You could blow one up with a TBolt. There are also survey oriented receivers (and antennas) that work at 12V. Most 5V (but not all) antennas will fry if hooked to a 12V receiver. Current wise, you

Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??

Hi Depending on the noise floor of the phase detector (which probably is not super duper), even the noise *inside* the PLL bandwidth may not be all that great. Bob > On Jan 8, 2018, at 2:23 PM, Bruce Griffiths > wrote: > > Yes, but the PN noise (outside the PLL

Re: [time-nuts] Reference input on HP counters

Hi > On Jan 7, 2018, at 12:55 PM, Jerry Hancock wrote: > > As far as lazy, I will check my equipment. > > When the others that replied using the term “lock” or “locked”, what do you > mean by that? That for instance, the external reference is multiplied up > directly to

Re: [time-nuts] AM vs PM noise of signal sources

Hi > On Jan 7, 2018, at 12:26 PM, jimlux wrote: > > On 1/7/18 8:05 AM, Arnold Tibus wrote: >> Am 07.01.2018 um 16:33 schrieb jimlux: >>> On 1/6/18 6:12 PM, Dana Whitlow wrote: One point about oscillator design I've not yet seen mentioned is this: the limiter

Re: [time-nuts] Reference input on HP counters

Hi > On Jan 7, 2018, at 10:21 AM, Jerry Hancock wrote: > > I’m being a little lazy as I can check the schematics, but in the general > case, do HP counters, frequency generators, etc, switch to the external > reference when one is available or discipline the internal

Re: [time-nuts] AM vs PM noise of signal sources

ndns.org >> wrote: > >> >> >> On 01/06/2018 10:31 PM, Joseph Gwinn wrote: >>>> -- >>>> >>>> Message: 2 >>>> Date: Sat, 6 Jan 2018 09:19:31 -0500 >>>> From: Bob kb8tq <kb...@n1k.org> >>>> To: Discuss

Re: [time-nuts] AM vs PM noise of signal sources

;> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms >> issue except, of course, for things happening within the AGC loop's >> bandwidth. >> Is anybody reading this aware of what the truth really is? >> >> Dana >> >> >> O

Re: [time-nuts] AM vs PM noise of signal sources

Hi > On Jan 6, 2018, at 4:31 PM, Joseph Gwinn <joegw...@comcast.net> wrote: > >> -- >> >> Message: 2 >> Date: Sat, 6 Jan 2018 09:19:31 -0500 >> From: Bob kb8tq <kb...@n1k.org> >> To: Discussion of precise time

Re: [time-nuts] AM vs PM noise of signal sources

ated, not how a > physical design actually works. > > The modified Leeson model starts to approach the actual design. > > Cheers, > Magnus > > On 01/06/2018 03:19 PM, Bob kb8tq wrote: >> Hi >> >> The key point missing is the fact that any real oscil

Re: [time-nuts] AM vs PM noise of signal sources

Hi The key point missing is the fact that any real oscillator must have a limiter in the loop. Otherwise it will “create one” by going over the max output of this or that amplifier. To the degree that the limiter has issues (limits poorly) you will get AM noise. On a practical basis, loop Q

Re: [time-nuts] AM vs PM noise of signal sources

low <k8yumdoo...@gmail.com> wrote: > > But what I'm wondering, because this is important to the discussion, is the > tone at a frequency encompassed on both sides by the noise band? Or > is the tone outside the noise band? > > Dana > > > On Fri, Jan 5, 2018 at 1:35

Re: [time-nuts] AM vs PM noise of signal sources

Whitlow <k8yumdoo...@gmail.com> wrote: > > Is this an audio tone, summed with audio noise whose spectrum surrounds > that of the tone? > > Dana > > > On Fri, Jan 5, 2018 at 9:56 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >>

Re: [time-nuts] AM vs PM noise of signal sources

Hi If I pass both a sine wave tone and a pile of audio noise through a perfectly linear circuit, I get no AM or PM noise sidebands on the signal. The only way they combine is if the circuit is non-linear. There are a lot of ways to model this non-linearity. The “old school” approach is with a

Re: [time-nuts] Trimble Thunderbolt Power Cable Needed

Hi Your typical junk PC has a number of the connectors you need in it The wire gauge is normally “good enough” to allow them to be dropped right into the job of powering a TBolt. PC’s are only one of many devices that use the same stuff …. check your junk box. Bob > On Jan 4, 2018, at 11:09

Re: [time-nuts] Anyone have a working HP-113AR/BR Clock?

Hi I would second the previous comment on the 113. Every time I have seen one it has been a really noisy device. Certainly *not* what you would want in anything described as a “quiet lab”. Since it’s full of gears (like a Teletype) proper lubrication and cleaning are going to be part of the

Re: [time-nuts] AM vs PM noise of signal sources

Hi Just as with PM noise, AM noise is a “that depends” sort of thing. The first dependency is on your test gear. If the AM noise was well below the PM noise, would you be able to measure it? Equally, if you are doing something like a diode detector - can it measure AM below XXX dbc? If the

Re: [time-nuts] Stable32 now available

Hi If the code also *is* part of the deal (or becomes part of the deal) I would suggest that there are a series of papers in the “to be written” category about how it does what it does. I have no idea what the code looks like so this is in no way a knock. It’s a big program with a lot of

Re: [time-nuts] Regarding the improved integrator A9 in the 5065A...

Hi The 70 or 100K resistors are in there because they are a dirt cheap way to isolate the RF on the diode from the DC control signal. If by some strange error, the diode actually *has* leakage near its ratings, they could be an issue. Real world diodes don’t ever seem to have measurable

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

Hi With these little OCXO’s you likely will move them 0.1 ppb simply walking past the bench. If they have a total of 0.25 ppm of trim, a 25 turn pot will get you 1 ppb per turn. Setting these pots to 1/10 turn is not all that crazy. Yes, there are a bunch of assumptions made there and your

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

Hi The nice thing is that the footprint on the Pulse Puppy is pretty generic. There are a lot of OCXO’s on eBay that will fit the pattern on the board. When you get into the more exotic parts, the footprints (and functions) don’t tend to be as standardized. The small package OCXO’s will

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

Hi The other issue with putting in an amp is noise. You really do not want to feed a bunch of added “stuff” into the FM modulation port on the oscillator. You get some thermal noise from the pot, so it is never zero. How close you need to get to zero - who knows? When the part was tested to see

Re: [time-nuts] New product: the TAPR "PulsePuppy"

Hi There’s a lot of debate out there about that. When used as a variable resistor (two terminal device) there is no doubt that a sereis resistor can help. When used as a voltage divider (three terminal device) the claim by the pot manufacturing OCXO companies is that you are better with no

Re: [time-nuts] New product: the TAPR "PulsePuppy"

Hi Looks neat !!! It is a pretty good bet that everything you see in the ADEV plot is a function of the specific OCXO you put on the board. Put another way, the. board’s ADEV is way better than the ADEV of the OCXO. It’s a very safe bet that everything past 2 seconds or is the OCXO. Bob >

Re: [time-nuts] Down-conversion to IF and sampling

Hi What is the Time Nut goal here? Are we after the carrier frequency or after the modulation on the signal? Bob > On Dec 23, 2017, at 10:46 AM, Stephan Sandenbergh > wrote: > > Oops, I noted a sign error in the previous diagram. The attached seems > better... > > On

Re: [time-nuts] Down-conversion to IF and sampling

Hi Assuming you are trying to extract timing from the signal (time ticks on WWVB), the downconversion really does not matter. The ADC samples are what will “tag” your time data. If you are trying to extract frequency from the signal (you are after the center frequency of WWVB) then both the

Re: [time-nuts] External cooling fans - source

Hi Yes, this *is* a bit off topic. Sorry about that … I’m sure it’ll never / ever happen again :) …. ummm …. today …. The voltage that supply feeds are set to is as much a public relations issue as a technical one. People would routinely complain “the lights are to dim”. Voltage gets bumped

Re: [time-nuts] Recently acquired 53132A

uld not find anything. > Hopefully still a good $100 investment. > > > > On Mon, Dec 18, 2017 at 11:43 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> The 53132 is the older version of the 53230 counter. It’s been out of >> production >> and past

Re: [time-nuts] Recently acquired 53132A

Hi The 53132 is the older version of the 53230 counter. It’s been out of production and past "end of life" support for quite a while now. It’s main issue measurement wise is a group of issues that make it less sensitive (lower resolution) than one might think right at 10 MHz and to a lesser

Re: [time-nuts] Cannot Command RFTGm-II-Rb / RFTGm-II-XO

Hi If you go back a ways in the archives, there is a *lot* of information about how to run these beasts. There also are links to the software and command sets for the devices. Bob > On Dec 17, 2017, at 5:01 PM, Patrick Murphy wrote: > > I have recently acquired a used

Re: [time-nuts] ergodicity vs 1/f

Hi > On Dec 17, 2017, at 6:50 PM, Magnus Danielson > wrote: > > Hi, > > On 12/17/2017 03:09 PM, Mattia Rizzi wrote: >>> you demand ergodicity, you cannot have 1/f. You can have only one or the >> other. Not both. And if you choose ergodicity, you will not

Re: [time-nuts] accurate 60 hz reference chips/ckts

events. >> The observation period is 486 hours. >> >> >> >> >> On 2017-12-14 23:13, Jim Harman wrote: >>> On Thu, Dec 14, 2017 at 10:53 PM, Bob kb8tq <kb...@n1k.org> wrote: >>> >>>> >>>> >>>>

Re: [time-nuts] accurate 60 hz reference chips/ckts

Hi My guess is that the “best design” would likely do a sample at some specific time of day. Just when would depend a bit on your local grid and how it is fed and loaded. There are definitely “it’s 6 PM and everybody just got home” issues with power line phase. Next question wold be how long

Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

Hi I’m having a little trouble spotting the 9836 in AD’s current lineup of DDS chips. The stuff below is thus a bit generic. My guess is that you will have a hard time finding a canned solution. There are a bunch of registers on your typical DDS part. The what to stuff where tends to be

Re: [time-nuts] End of Range Oscilloquartz 8600-3

Hi I would bet that the design changed a bit since 1983. That is a “long time ago” in terms of OCXO design. Since we are picking up this stuff surplus or pulling it out of older gear, who knows what era this or that example might come from. Bob > On Dec 12, 2017, at 12:32 PM, Ed Palmer

Re: [time-nuts] End of Range Oscilloquartz 8600-3

Hi One of the basic issues with a quartz resonator is that it is sensitive to barometric pressure. Some are more sensitive than others, but there always is some effect. Various techniques get used to isolate the resonator. Solder sealing (or welding) the package closed is one of them. The

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

Hi Just as there are Time Nuts, there are Tide Nuts (I suppose it’s capitalized …). There is a a lot of data out there on just what sort of solid tides one might see at this or that point. Bob > On Dec 10, 2017, at 7:29 AM, Azelio Boriani wrote: > > Is that a

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

Hi If the frequency sensitivity is 1x10^-13 / G you don’t need a lot of precision in your measurement of G. The same issues apply to things like magnetic field and the rest. Bob > On Dec 9, 2017, at 4:02 PM, Chris Caudle wrote: > > On Sat, December 9, 2017 2:39 pm,

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

Hi I suspect that at the practical level, you define standard atmospheric pressure, standard gravity, standard magnetic field ….. and on down the list. At some point “sea level” becomes a redundant expression. Bob > On Dec 9, 2017, at 2:14 PM, Mark Sims wrote: > > In

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

Hi If you dig back into the various papers on the subject (and the proceedings that log the post paper questions) the issue of “can we trust the implementation?” does indeed come up. It’s come up for at least the last 50 years that I’m aware of. The basic argument runs that for fundamental

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi It might be, if it is then an upper turn in the 80C range is not all that crazy. Bob > On Dec 8, 2017, at 4:24 PM, Angus wrote: > > > That near the end of the temperature range the direction could also > give a good indication - assuming that there is only one

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

) with the fine > frequency adjust turned to maximum. I'm a rank amateur at this but the > circuit diagram looks like a series-resonant (Pierce) oscillator. Looks > like I need to replace one of the capacitors inside the oven with a smaller > value. > > > On Fri, Dec 8, 2017

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi One basic question - Is the frequency high or low? Assuming it’s an SC and on the lower turn, frequency low is possible with an off temperature oven. Frequency high is unlikely unless it’s *way* off temperature. How far off turn gives you how much delta F depends on the inflection

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

y related to the quartz, or other components? >> >> Happy-Merry; >> >> Thomas Knox >> >> >> >> >> From: time-nuts <time-nuts-boun...@febo.com> on behalf of Bob kb8tq >> <kb...@n1k.org> >&g

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

s to another tuning diode for coarse? Or a pot on pot >> arrangement. >> That sounds ugly. >> Regards >> Paul >> WB8TSL >> >> On Fri, Dec 8, 2017 at 10:17 AM, Bob kb8tq <kb...@n1k.org> wrote: >> >>> Hi >>> >>> It

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

4:52 PM, paul swed wrote: >> I took a quick look at the spec sheet. >> It appears coarse adjustment is an option M and would actually be a pot. >> That speaks to another tuning diode for coarse? Or a pot on pot arrangement. >> That sounds ugly. >> Regards >> Paul >> WB8T

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

ick look at the spec sheet. >>> It appears coarse adjustment is an option M and would actually be a pot. >>> That speaks to another tuning diode for coarse? Or a pot on pot >>> arrangement. >>> That sounds ugly. >>> Regards >>> Paul >>> WB8TS

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi It is quite possible that nothing is actually broken and that the crystal has simply drifted outside the tuning range. It should be pretty easy to spot the coarse tuning device once the package is open. I would bet you will find a selected capacitor across the coarse tune or in series

Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

Hi If you happen to pick 5 or 10 MHz as your target frequency, all sorts of interesting things come into play. The first is that any 5 or 10 MHz local standard distribution may well get into your receiver. That can create all sorts of odd effects as the signal fades. Next is that you aren’t

Re: [time-nuts] Trimble thunderbolt accuracy expectations

Hi I agree that your TBolt likely had some sort of issue. That probably needs to be tracked down independent of any other “quest”. First recommendation would be to run the filter tune stuff in LH. Accuracy, stability, and repeatability are all different things. They do bump into each other

Re: [time-nuts] Propagation delay within analog radio, (Radio Shack Timecube) and an SDR, at HF

Hi A lot depends on just how this or that was implemented. The bottom line is still that ionosphere issues will give you a “couple of milliseconds” sort of ill defined variation. If your RF chain is below 10 MS (which it likely is) is a bigger delay, but not a bigger variation. Bob > On

Re: [time-nuts] Rubidium freq standard - temperature

Hi Back a while ago EG decided they needed a new name. The connection of the company name to various pieces of history was believed to be an issue. Back then they were actively buying up various companies. When they bought Perkin Elmer, they decided to use that name for the new company. I used

Re: [time-nuts] Trimble Mini-T Timing Glitches

ore it gets ripped to shreds. > Leo > > From: Bob kb8tq <kb...@n1k.org> >> GPS extracts time and location by locking on to various codes in the >> transmissions. > One of them happens to run at about a 1 KHz clock rate. A slip on that part > of the > proce

Re: [time-nuts] Trimble Mini-T Timing Glitches

Hi GPS extracts time and location by locking on to various codes in the transmissions. One of them happens to run at about a 1 KHz clock rate. A slip on that part of the process gives you a (modulo) 1 ms clock jump. Certain types of interference may “help” the receiver make these sorts of

Re: [time-nuts] Performance verification for time counters

:10 PM, Attila Kinali <att...@kinali.ch> wrote: > > On Thu, 30 Nov 2017 09:39:59 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >> That last decade ( 0.01 Hz period to 0.001 Hz) > > What puzzles me here is, the reason why someone would care > about sub-1Hz fr

Re: [time-nuts] ergodicity vs 1/f

Hi > On Nov 30, 2017, at 11:10 AM, Magnus Danielson > wrote: > > > > On 11/30/2017 03:40 PM, Attila Kinali wrote: >> On Thu, 30 Nov 2017 12:44:13 +0100 >> Mattia Rizzi wrote: >>> Let me emphasize your sentence: "you will have a

Re: [time-nuts] Performance verification for time counters

frequency and the nonsense db fraction in it …. Bob > On Nov 30, 2017, at 3:29 AM, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote: > > > In message <42a2f881-1631-402c-8ed6-2c863f6fe...@n1k.org>, Bob kb8tq writes: > >>>> Needless to say *demonstrati

Re: [time-nuts] Performance verification for time counters

mlux <jim...@earthlink.net> wrote: >> >>> On 11/29/17 5:53 PM, Bob kb8tq wrote: >>> HI >>>> On Nov 29, 2017, at 8:41 PM, jimlux <jim...@earthlink.net> wrote: >>>> >>>> On 11/29/17 3:41 PM, Bob kb8tq wrote: >>>>>

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