Re: [time-nuts] HP5061B High Ion Current/Tubes Out of Cesium

Hi > On Apr 7, 2017, at 4:33 PM, Poul-Henning Kamp wrote: > > > In message >

Re: [time-nuts] The ultraAtomic clock for home

Hi > On Apr 7, 2017, at 1:16 PM, John Ackermann N8UR wrote: > > Is there any way to derive carrier phase from these chips? Or to get raw > modulation data that might make it usable as the front end to one of PaulS's > de-PSKers? Unless it shows up on one of the test points on

Re: [time-nuts] The ultraAtomic clock for home

Hi Since it’s a magnetic stepper motor, how about a magnetic (coil) sensor? Based on past data, anything past 1us is massive overkill. A mag sensor with a ~100 KHz bandwidth should be a do-able sort of thing. A couple dozen turns of wire around a suitable ferrite rod might be enough. Bob >

Re: [time-nuts] CSAC vs NAC1

Hi If you set them both on the table, the CSAC’s I’ve seen are just slightly smaller than the NAC’s. It’s not by much. I never bothered to see if the mechanical specs on the parts reflected this or not. Bob > On Apr 6, 2017, at 10:41 PM, jimlux wrote: > > On 4/6/17

Re: [time-nuts] The ultraAtomic clock for home

Hi I’m sure it would have happily corrected for summer time in Europe two weeks later …. Provided (of course) it got the switch codes from DCF77 to tell it when to do so. My guess is that the tiny little watch antenna isn’t very good picking up time code from the other side of the Atlantic :)

Re: [time-nuts] CSAC vs NAC1

Hi Yes the numbers are correct, the NAC pulls roughly 10X the power of a CSAC. Bob > On Apr 6, 2017, at 8:11 PM, paul swed wrote: > > Jim am I reading the casc power consumption correctly? .12 and .14 W. > Thats 10X lower. > Any idea on the $$ > Regards > Paul > WB8TSL >

Re: [time-nuts] Looking for Gen Rad 1101A oscillator/parts

<p...@petelancashire.com> wrote: > > I took a gamble at a swap meet a few years ago $5 but did not have time etc > to look inside get home no rock but nice wooden box :-) > > On Thu, Apr 6, 2017 at 2:21 PM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >>

Re: [time-nuts] Looking for Gen Rad 1101A oscillator/parts

Hi Does your unit have the 1190 100 Kc quartz bar still in it? If so does the mount appear to be intact? At this late date, replacing that resonator is not going to be easy. Bob > On Apr 6, 2017, at 3:58 PM, jmfra...@cox.net wrote: > > I am trying to restore a clunker General Radio 1101A

Re: [time-nuts] Line Frequeny Stablity

verage very close to 60.000 Hz. They saw I had an interest > and offered me one of their toys. The only thing it doesn't do is connect > to my PC so I can monitor it long-term. I suppose if I were clever with > network stuff there'd be a way to tap into its data stream. > > Jeremy,

Re: [time-nuts] Line Frequeny Stablity

Hi Back in high school, one of the radio club members figured out that the “clock adjustment” took place locally between 4:30 and 5:00 PM. Needless to say, pretty much everybody spent the next week listening to WWV and watching the clock’s second hand go out of sync with the beeps. This was

Re: [time-nuts] The ultraAtomic clock for home

Hi > On Apr 5, 2017, at 9:00 AM, Jim Harman <j99har...@gmail.com> wrote: > > On Wed, Apr 5, 2017 at 7:30 AM, Bob kb8tq <kb...@n1k.org> wrote: > >> I’m still a bit unclear on how many people will set up a wall of clocks >> running >> on a dozen or

Re: [time-nuts] The ultraAtomic clock for home

Hi The Lacrosse wall clocks I’m using now are hybrid analog / digital displays. You get the time analog and the date off the digital display. For whatever reason, that model is now history. Bob > On Apr 5, 2017, at 11:30 AM, Richard (Rick) Karlquist > wrote: > >

Re: [time-nuts] Spirent STR4500 GPS simulator

Hi > On Apr 5, 2017, at 1:36 PM, Magnus Danielson > wrote: > > Hi Phil, > > I just wanted to chime in an make a note that the STR4500 seems to have USB > connection rather than serial. The manual mentions installing a driver. I > wonder if the USB port is

Re: [time-nuts] Spirent STR4500 GPS simulator

Hi Just to clarify a bit: These gizmos fall into two broad categories: 1) The single sat simulators like the GSS6100 that show up cheap. 2) The full constellation simulators that show up for a bit more money. The single sat stuff is simple to run from a serial port and limited in function.

Re: [time-nuts] Spirent STR4500 GPS simulator

Hi To the extent that the device runs like a 4100 or a 6100, it does not need any software to support it. The same may be true of the 6300. They all run from a drop dead simple serial command set. On the 6100 you fire up a terminal program at 38.4 K baud 8N1 and type away. All of the features

Re: [time-nuts] Sinlge ADC multi-band receiver

Hi Galileo E5 is a bit of a strange case. It’s really E5a and E5b. You can either grab it all as one giant signal or as two separate signals. You may (or may not) care about the data on E5a or b depending on what you are trying to do. Getting the entire very wide signal likely has some

Re: [time-nuts] The ultraAtomic clock for home

PM, Richard (Rick) Karlquist <rich...@karlquist.com> > wrote: > > > > On 4/4/2017 3:19 PM, Bob kb8tq wrote: >> Hi >> >> Based on their web site, the model you saw is the one and only version that >> does the new modulation. One very useful feature is

Re: [time-nuts] The ultraAtomic clock for home

Hi Based on their web site, the model you saw is the one and only version that does the new modulation. One very useful feature is the ability to set it to any time zone world wide. I guess I missed the note on the WWVB coverage area expanding to cover the entire planet …..:) Bob > On Apr 4,

Re: [time-nuts] TU30 jump second

Hi > On Apr 4, 2017, at 10:01 AM, Bo Hansen wrote: > > Hi all > > The data can be a bit hard to read in an email. So I will give it another try. > > PC-time | Diff. | GPS-time | Diff. > ... > 011606.005 | 0.992 | 011604 |1 > 011607.013 | 1.008 | 011605 |1 > 011608.005 |

Re: [time-nuts] TU30 jump second

Hi Welcome to the ever growing list of people with buggy GPS modules. One thing that makes this stuff tough to track down is the firmware. A lot of these parts went out with various revs of the standard firmware. Some of them went out with specific customized versions of the firmware. Since

Re: [time-nuts] HP-59309A Clock counts only seconds

Hi A lot of the early IC’s were packaged in the era of “learning by doing”. The net result is that some of them do indeed have process related packaging “use by dates”. On top of that the early IC processes were not as fully worked out as the more modern ones. Things like metallization

Re: [time-nuts] TAPR TICC boxed (input protection)

Hi One interesting “feature” of leakage specs: They often reflect the measurement limit rather than the actual device performance. If they are guaranteed by test, the limit may be orders of magnitude above the actual performance. That’s on top of the likely “rated at max temperature” part

Re: [time-nuts] TAPR TICC boxed

Hi If need it, indeed coming up with individual delays is a bit of a pain. One of the most basic decisions is to establish a reference plane. More or less - the signal at “this point” is zero. Everything else is going to be off by nanoseconds from that point (with meter long cables involved).

Re: [time-nuts] TAPR TICC boxed

Hi There are low(fish) leakage / low capacitance / high speed transient suppressor diodes out there. The aren’t going to do anything good in a 1 megohm environment. They are quite useful in lower impedance circuits. Bob > On Apr 1, 2017, at 1:49 AM, Scott Stobbe

Re: [time-nuts] GPS first LO need to be locked?

Hi There are a lot of GPS chips that do an I/Q mix down to a low IF. It’s then (re) sampled from there. The “LO” in this case would down convert to the low IF …. Bob > On Mar 31, 2017, at 6:08 PM, Magnus Danielson > wrote: > > God natt Attila, > > On

Re: [time-nuts] GPS first LO need to be locked?

Hi > On Mar 30, 2017, at 7:05 PM, jimlux wrote: > > On 3/30/17 10:32 AM, Bob Camp wrote: >> Hi >> >> There is a limited tracking range for Doppler. You would need to stay inside >> that. >> > > Doppler is pretty big when the spacecraft is coming or going at the

Re: [time-nuts] TAPR Oncore M12+ kit

Hi At least from a quick read of the TAPR page it’s not real clear if the GPS modules are M12+T or just M12+ boards. I believe that if they don’t have the T on the end, they don’t have sawtooth / PPS (?). Bob > On Mar 30, 2017, at 2:11 AM, Mike Cook wrote: > > I would

Re: [time-nuts] TAPR Oncore M12+ kit

Hi That’s a very good price for what it is !! Bob > On Mar 27, 2017, at 9:31 AM, Gregory Beat wrote: > > The TAPR offering is a "partial kit" from the Synergy's SynPaQ/E product. > Here is that data sheet: >

Re: [time-nuts] Single ended or differential input to TDC chip

Hi Eventually you will want multiple inputs to any chip like this. The more I/o the more crosstalk. Properly done, differential inputs will reduce your crosstalk quite a bit. You might as well debug that part of it now. Bob > On Mar 27, 2017, at 9:05 AM, Attila Kinali

Re: [time-nuts] Time Dilation tinkering

Hi The outer can is at best only “sort of” sealed. Bob > On Mar 22, 2017, at 10:58 AM, jimlux wrote: > > On 3/22/17 4:28 AM, Bob Camp wrote: >> Hi >> >> In this case, the vacuum might work against you. You change the pressure >> outside >> the package and you get a

Re: [time-nuts] PLL Digital Loop Filter

Hi > On Mar 22, 2017, at 7:50 AM, Attila Kinali wrote: > > On Tue, 21 Mar 2017 21:45:24 -0400 > Bob Camp wrote: > >> 1) You need a way to digitize the phase input with adequate resolution. If >> you have a 1 second period and want 1 ns, you need a way to

Re: [time-nuts] PLL performance?

Hi As others have pointed out, a control loop at 100 seconds is more a gain spec than an R/C time constant spec. The real issue is that you should have an integrator on the loop and that *is* an R/C sort of thing. It’s also likely to have a much longer time constant than the magic number for

Re: [time-nuts] ADEV query Timelab and TICC

Hi It’s a pretty good bet that the “upper” trace has a noise pop in it. One of the wonderful things about ADEV is that a single noise event can impact the whole curve. That is a bit non-intuitive. It is indeed how the math works and how the testing comes out in the real world. Bob > On Mar

Re: [time-nuts] hm H Maser

Hi Masers pop up in good (as in new or almost so) condition in the $30 to $70K range from time to time. You *do* need to be a bit lucky, but compared to a decade long development process … not very lucky. The biggest issue with Masers is that there isn’t much of a market. They simply are to

Re: [time-nuts] hm H Maser

Hi > On Jan 10, 2017, at 5:26 PM, Bob Stewart wrote: > > This may be a dumb question, but how much of an H Maser's advantage over a Cs > Standard, for us mere mortal time-nuts, is down to the output oscillator it > uses, rather than the reference source (H MASER or Cs beam)?

Re: [time-nuts] σ vs s in ADEV

Hi > On Jan 10, 2017, at 1:22 PM, Magnus Danielson <mag...@rubidium.dyndns.org> > wrote: > > Hi Bob, > > On 01/10/2017 12:20 AM, Bob kb8tq wrote: >> Hi >> >>> On Jan 9, 2017, at 5:09 PM, Jeremy Nichols <jn6...@gmail.com> wrote: >>>

Re: [time-nuts] Survey plot as art.

Hi > On Jan 9, 2017, at 6:06 PM, Jay Grizzard wrote: > > Does anyone know of any schematics for amplified GPS splitters floating > around out there? I looked a while back and couldn't find anything. I use a > 58536A right now, but it's big and I hate having to

Re: [time-nuts] σ vs s in ADEV

Bob > > Jeremy > > > On Mon, Jan 9, 2017 at 2:00 PM Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> >> >>> On Jan 9, 2017, at 4:49 PM, Magnus Danielson <mag...@rubidium.dyndns.org> >> wrote: >> >>>

Re: [time-nuts] σ vs s in ADEV

Hi > On Jan 9, 2017, at 4:49 PM, Magnus Danielson > wrote: > > Scott, > > On 01/09/2017 07:41 PM, Scott Stobbe wrote: >> I could be wrong here, but it is my understanding that Allan's pioneering >> work was in response to finding a statistic which is convergent to

Re: [time-nuts] FE-5650A option 58 tuning word for 10 MHz output

Hi In most Rb’s (including the FE 56xx’s) the DDS is mixed with a fixed microwave frequency signal. The DDS only has to make up “part” of the total offset. You get roughly a three orders of magnitude improvement because of this. Rick has gone into all the gory details of why it gets done this

Re: [time-nuts] Why are PPS pulses so narrow? (was: 53132A triggering)

e wrong edge. > > Peter > > > >> On 16 September 2016 at 23:55, Bob kb8tq <kb...@n1k.org> wrote: >> >> Hi >> >> Most PPS signals these days are very low duty cycle. If you AC couple > t

Re: [time-nuts] 53132A triggering

Hi Most PPS signals these days are very low duty cycle. If you AC couple them, you can easily be triggering on the wrong edge. With the narrow pulse it may not be very obvious. Bob > On Sep 16, 2016, at 5:46 PM, Charles Steinmetz wrote: > > Bob wrote: > >> Set it

Re: [time-nuts] HP-105B Battery Replacement?

Hi They are very common when you look at server UPS or larger units. There are literally hundreds of models to pick between. Prices are from roughly $400 up to a few hundred thousand dollars per unit. Bob > On Sep 15, 2016, at 6:13 PM, Jeremy Nichols wrote: > > Since I

Re: [time-nuts] Z3801A gps week rollover

Hi The rollover is in the GPS module firmware. If you dig into it, they didn't quite update the firmware once every 3 months, but almost that often. Each manufacturer latched onto various versions as they sailed by. None of them had a validation process that could keep up with 4 releases a

Re: [time-nuts] Tbolt issues

Hi The problem is that ADEV is not really the best tool for measuring / modeling narrow band noise. There are other measures that are better. None of them really give you a direct connection to a band limited noise process. Without a model for the process, coming up with a max limit is just

Re: [time-nuts] Tbolt issues

Hi Since the measurement in the frequency domain is a "peak" measure, you need to convert both to frequency error and to an absolute max. If you *do* care about the one second per day (or 10 days) as some do, that is a different factor than one second out of two minutes. Since the noise is

Re: [time-nuts] Tbolt issues

Hi Just to be a bit more clear: This is *not* something unique to the Tbolt. It shows up on all GPSDO's. There have been a lot of posts with data plots showing this on lots of GPSDO's. The issue is more basic than a goof in a control loop setting. To some extent it is a problem on all

Re: [time-nuts] Tbolt issues

Hi The GPSDO might have an ADEV of 1 ppt at 1 sec and that rises to 30 ppt at 100 sec. It also might not, but let's use those numbers. ADEV is a standard deviation. You can get an idea of the magnitude of the change reading to reading from it. It does not give you a sign for that change. In

Re: [time-nuts] Tbolt issues

Hi The gotcha in your approach is that you are using more than one sample out of the system to get frequency. Thus you are measuring over a time period. To get instantaneous frequency you need to base it on a single sample. There are some other restrictions (infinite bandwidth being the big

Re: [time-nuts] Tbolt issues

Hi Unfortunately if you read a typical text on FM modulation, "instantaneous frequency" comes up pretty fast. In that context it has a valid meaning. Once out of context, it gets you in trouble. That point is never made when the term is introduced. Bob > On Sep 1, 2016, at 8:51 PM, Charles

Re: [time-nuts] Tbolt issues

Hi Frequency is a "change over time". If delta time is zero it is undefined. As you observe it in shorter time periods, the accuracy / stability gets worse. Since the error bars expand there isn't much of a limit as you go shorter. They are not quite the same thing, but they are related. Bob

Re: [time-nuts] Anybody want a Thunderbolt power supply?

Hi The easy answer for a couple dozen Tbolts is a +15 V high current linear supply and a low power -15 V linear. Wire them to regulators mounted on chunks of perf board. Bob > On Sep 1, 2016, at 12:24 AM, DaveH wrote: > > Someone could come out with a circuit

Re: [time-nuts] Anybody want a Thunderbolt power supply?

Hi It is not that hard to do. Use a linear rather than a switching approach. Run the +12 and +5 supplies off of LT1764 regulators. The -12 is very low current, run it off of a low noise op amp. There are lots of toroidal line transformers that will drive something like this. Bob > On Aug

Re: [time-nuts] Anybody want a Thunderbolt power supply?

Hi The fact is that commercial linear supplies are still out there for pretty cheap prices. The price of a usable switcher is a very small fraction of the price of a Tbolt. Noise on the switcher is a big deal. Not everybody seems to care about low phase noise on the 10 MHz. Switcher frequency

Re: [time-nuts] 3D printed sundial displays the time digitally [Youtube Link]

Hi It has been kicking around for about a year. It is a real bear to print. Bob > On Aug 26, 2016, at 12:09 PM, Oz-in-DFW wrote: > > Got this in today's EDN email. Pretty clever, displays time as decimal > digits in 20 minutes increments. > >

Re: [time-nuts] Optical link connects atomic clocks over 1400 km of fibre

Hi There is also the minor issue of putting the (very thick) layers on in a spiral around the "core". You put one layer on clockwise and the next counter clockwise. Since the materials are quite springy, controlling the whole process through heat treating is a real chore. Bob > On Aug 25,

Re: [time-nuts] Optical link connects atomic clocks over 1400 km of fibre

Hi I would not rule out line noise into the electronic side of things. Bob > On Aug 23, 2016, at 7:06 PM, Magnus Danielson > wrote: > > Don't over-interpret the 50 Hz aspect, I don't remember those details from > 4.5 months back or so, as I already indicated. I

Re: [time-nuts] DIY VNA design

Hi If you really want to work out the delays through all of this GPS "stuff" ahead of the RF -> PPS conversion, a VNA is about the only good way to do it. Bob > On Aug 21, 2016, at 6:59 PM, Dr. David Kirkby (Kirkby Microwave Ltd) > wrote: > >> On 21 Aug 2016

Re: [time-nuts] DIY VNA design

Hi One option in the "1 GHz and down" range is to team up a surplus HP S-Parameter test set with your own electronics. That way you let HP do all of the fancy directional coupler stuff and relays. They don't sell well on the auction sites. The result is that a bit of time making lowball offers

Re: [time-nuts] Expected 10 MHz offset from a GPSDO?

Hi At the most basic level, ADEV is a standard deviation. When people read an instrument they usually want a "max error" sort of number. ADEV operates on delta between readings so a simple "three sigma" mental math conversion is not all you need. It *is* the right measure. It can take a bit of

Re: [time-nuts] Expected 10 MHz offset from a GPSDO?

Hi If your time base is doing < 5 ppb per year, that is an unusual 10811. I suspect it does not spend a lot of time powered off. Bob Sent from my iPad > On Aug 19, 2016, at 10:10 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> Ok let's toss some numbers into the

Re: [time-nuts] Expected 10 MHz offset from a GPSDO?

Hi I do not know of any commercial GPSDO's that do not have a holdover feature. There are a lot of variables. With a large package OCXO and a couple days operation, the numbers I gave should be good 90 to 99% of the time.(99 seconds out of 100). If the unit has such a poor antenna location

Re: [time-nuts] Expected 10 MHz offset from a GPSDO?

Hi Ok let's toss some numbers into the mix. The counter time base one day after calibration is in the 0.5 to 1.5 ppb range. The LPRO ten years after it left the factory is in the 0.5 to 1.5 ppb range. The GPSDO when running properly should be in the 0.005 to 0.02 ppb range at one second. One

Re: [time-nuts] GPSDO - probably a stupid question.

Hi You can update the EFC a billion times a second. Update rate and bandwidth are not the same thing. If you want good ADEV, the loop better not have a bandwidth greater than 0.01 Hz. GPS ADEV is pretty awful at 1 and 10 seconds. It is starts to be good past a few thousand seconds. Yes, older

Re: [time-nuts] Nortel Trimble NTBW50AA GPSTM 10MHz Oscillator GPSDO

Hi On Jul 5, 2015, at 1:52 AM, skipp Isaham via time-nuts time-nuts@febo.com wrote: re: Nortel Trimble NTBW50AA GPSTM 10MHz Oscillator GPSDO Hello to the Group, An admitted late arrival to the group here. My initial time system launch revolved around using a Trimble Thunderbolt.

Re: [time-nuts] PCI-E Serial Card For Windows NTP?

Hi I have had no problem with a variety of PIC serial cards. I’ve got a few from maybe six different outfits. They run up to at least 115.2K baud. The multi port versions will do that on all ports at one time. They are far more dependable than their USB counterparts. I’ve run them under XP,

Re: [time-nuts] magnetic electronic components

Hi The problem with coils (inductors) is that they are indeed on the “other side” of the physics / electrical engineering divide. They are not unique in this way. Most components are dealt with to a “equivalent model” level and then abandoned in engineering. You have two choices: 1) Read

Re: [time-nuts] potential source for cheap copy of labview

Hi It is interesting as you go through the various student and home versions, just how hard it is to figure out what you are (and are not) buying in each case. One example would be the inclusion (or not) of GPIB capability. One would *assume* it’s in there and fully functional. At lest for me

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