Re: [time-nuts] FE-5680A GPS discipline board on sale now

Absolutely. There’s a standard AVR ISP header on the board and the firmware is open source - on github - so even if I didn’t do it, anyone else could. > On May 22, 2016, at 9:04 AM, GandalfG8--- via time-nuts > wrote: > > Nick, > > This looks very interesting but just

Re: [time-nuts] Maser 0.7 nsec jumps solved

As far as a remedy goes we are going to try a solid state relay that only switches on at 0V in the AC waveform. This should slow the inrush current, and hopefully the magnetic impulse. If this doesn't work, then a better model of air conditioner might have to be installed. These ones do come on

Re: [time-nuts] Building a mains frequency monitor

Guten nacht Attila, On 04/14/2016 12:24 PM, Attila Kinali wrote: God middag Magnus, On Thu, 14 Apr 2016 03:38:38 +0200 Magnus Danielson wrote: The professional equipment does it this way. It samples, filters and decimate the data. For the professional use the

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Well, if you're open to something completely different, consider using a motor-driven potentiometer that provides a trim voltage to the OCXO. Adjust the motor at long intervals, leaving it off the rest of the time. It's called sampling control. You'll need to have an analog phase comparator for 1

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

I like the little boards at: http://navspark.mybigcommerce.com/development-boards/ It's a GPS with a fully programmable 32-bit Arduino-compatible processor. $22 Crowdsourced about 3 yr ago, matured now. Various versions; you can even have Beidou :-). Don On 2016-05-22 19:45, Tom Van Baak

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

> Can a pure analog design access the sawtooth correction? My GPS > receivers send sawtooth as a digital message on a serial port. I > don't know if saw tooth correction is required to meet his spec. Hi Chris, Many GPS/1PPS receivers don't output sawtooth information and yet they work really

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Hi No, there is no purely analog way to access the sawtooth information. If you restrict yourself to “pure analog” then the PPS will be bopping around by +/- 10 to +/-20 ns each second. Put another way, you start out with 1 to 2x10^-8 at 1 second. The same thing is true at 10 KHz or at any

Re: [time-nuts] DMTD was: high rev isolation amps

Charles, On 05/12/2016 10:34 AM, Charles Steinmetz wrote: Bruce wrote: For even lower flicker noise using a mixer assembled using 2NA's as diodes is even quieter as NIST have shown. Note that mixers built with 2Ns only have lower noise than good schottky DBMs below about 200 Hz

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

bneu...@t-online.de said: > Hello Fellow time-nuts, I am looking for a simple solution to discipline my > 10 MHz reference OCXO in my private lab with an 1 PPS signal from a separate > GPS receiver. I am curious if there is a solution possible without > programming a microcontroller, as I am an

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

If you can build with small scale TTL gates you can save the need for a huge precision capacitor by storing the current EFC value in a 16-bit register/counter. This 16-bit register drives a DAC. Then you build a phase detector that can detect if the XO leads or lags the GPS. If it leads you

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

On Sun, 22 May 2016 19:41:25 +0200, Bernd Neubig wrote: > Hello Fellow time-nuts, > I am looking for a simple solution to discipline my 10 MHz reference > OCXO in my private lab with an 1 PPS signal from a separate GPS > receiver. There seems to be some TU60 D102 on *bay search for #:

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

On Sun, May 22, 2016 at 3:52 PM, Attila Kinali wrote: > Judging from the ADEV plots of the M12 receiver from TvB[1], which hit > 10^-10 (w/ sawtooth) around 200s, I'd say that 10^-10 @1000s should be > easy. Can a pure analog design access the sawtooth correction? My GPS

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

How do you measure "simple"? Do you count the chips and the passive components or do you count lines of code? Or maybe you draw a block diagram and count the blocks and the number of interconnections? If you count chips the design with the micro controller wins by a long shot But if you count

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

On Sun, 22 May 2016 19:41:25 +0200, Bernd Neubig wrote: > Hello Fellow time-nuts, > I am looking for a simple solution to discipline my 10 MHz reference > OCXO in my private lab with an 1 PPS signal from a separate GPS > receiver. > I am curious if there is a solution possible without programming

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Hoi Bernd, Is there any special reason for this endavour or are you just courious what can be done? On Sun, 22 May 2016 19:41:25 +0200 "Bernd Neubig" wrote: > I am well aware, that such a solution would have a lot of disadvantages, > as it cannot effectively compensate

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Bernd, On 05/22/2016 07:41 PM, Bernd Neubig wrote: Hello Fellow time-nuts, I am looking for a simple solution to discipline my 10 MHz reference OCXO in my private lab with an 1 PPS signal from a separate GPS receiver. I am curious if there is a solution possible without programming a

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Hi Of course it’s possible, you simply need enough high quality film capacitors to make up the control loop integrator. You probably also would use a pile of the same capacitors to slow down the PPS jitter a bit before it went into the loop. The setup process would probably involve a bunch of

Re: [time-nuts] HP5065A environmental sensitivities

On 5/22/16 10:25 AM, Bob Camp wrote: Hi In 40 years of getting phone calls, the one that never seems to go away starts out with: “We … errr… measured the temperature rise in our box and need to adjust the upper end temperature on your part”. Or, as a designer using an OCXO part, you have

Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

Among Simple , analog, 1PPS you'll have to pick two of the three. The miller GPSDO needs 10KHz it's simple and analog. http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm The IK0OTG is simple, uses 1PPS and is digital

Re: [time-nuts] HP5065A environmental sensitivities

In message <5741e08b.9080...@rubidium.dyndns.org>, Magnus Danielson writes: >The negative voltage switcher of A15 board should be replaced with a >suitable switcher, and some of the DC/DC switcher modules is built with >isolation, so it should allow for mounting two in parallel such

[time-nuts] Simple solution for disciplining OCXO with 1 PPS

Hello Fellow time-nuts, I am looking for a simple solution to discipline my 10 MHz reference OCXO in my private lab with an 1 PPS signal from a separate GPS receiver. I am curious if there is a solution possible without programming a microcontroller, as I am an old-fashioned "analogue" guy ;) I

Re: [time-nuts] FE-5680A GPS discipline board on sale now

Nick, This looks very interesting but just wondering, will there be an option for end users to reprogram the board themselves just in case there does turn out to be any bugs in the software, and if so would you be making updates available? Regards Nigel GM8PZR

Re: [time-nuts] HP5065A environmental sensitivities

In message <02878e59-0bae-4220-8a86-5e59f0ca5...@n1k.org>, Bob Camp writes: >'We ... errr... measured the temperature rise in our box and need to adjust >the upper end temperature on your part'. yeah, I know that story: http://phk.freebsd.dk/hotsun/ That's the CPU/fan cover

Re: [time-nuts] Allan

Magnus I have to say I actually did not think Dr. Allen was still alive. Just kind of amazing. I bet that did make your eyes pop out. Regards Paul. On Sun, May 22, 2016 at 11:16 AM, Magnus Danielson < mag...@rubidium.dyndns.org> wrote: > Paul, > > Indeed. Just wanted to share the joy. > >

Re: [time-nuts] HP5065A environmental sensitivities

Hi In 40 years of getting phone calls, the one that never seems to go away starts out with: “We … errr… measured the temperature rise in our box and need to adjust the upper end temperature on your part”. The really interesting part is that you can get multiple calls that go the same way

[time-nuts] HP5065A environmental sensitivities

Angus, The HP 5065A has a fairly open path from atmosphere to the cells as far a barometric pressure is concerned. Response is rapid to a change. The mechanism is "oil-canning" of the windows on the ends of the cell. Depends on diameter of the cell, thickness of the windows, and stiffness of

Re: [time-nuts] HP5065A environmental sensitivities

Hi Bob, On 05/22/2016 05:21 PM, Bob Camp wrote: Hi On May 22, 2016, at 10:49 AM, Attila Kinali wrote: Hoi Poul-Henning, On Fri, 20 May 2016 09:52:39 + "Poul-Henning Kamp" wrote: Temperature effects are by far the largest effects we have to deal

Re: [time-nuts] Get together at IMS?

Agreed! See you on Wed at 5.00pm at Booth 714 (Dynamic Engineers) -Ursprüngliche Nachricht- Von: time-nuts [mailto:time-nuts-boun...@febo.com] Im Auftrag von Mark Kahrs Gesendet: Sonntag, 22. Mai 2016 16:41 An: Discussion of precise time and frequency measurement

Re: [time-nuts] FE-5680A GPS discipline board on sale now

On Fri, 20 May 2016 07:03:10 -0700 Nick Sayer via time-nuts wrote: > > The discharge resistor of the integrator (R13) is with 10M way too high. > > The PCB resistance is usually in the same order of magnitude. Ie with > > a resistance that high, the actual resistance highly

Re: [time-nuts] Allan

Paul, Indeed. Just wanted to share the joy. Cheers, Magnus On 05/22/2016 04:14 PM, paul swed wrote: Magnus it seems you do have things to do and what better motivator! Regards Paul WB8TSL On Sat, May 21, 2016 at 8:52 PM, Magnus Danielson < mag...@rubidium.dyndns.org> wrote: Fellow

Re: [time-nuts] HP5065A environmental sensitivities

Hi > On May 22, 2016, at 10:49 AM, Attila Kinali wrote: > > Hoi Poul-Henning, > > On Fri, 20 May 2016 09:52:39 + > "Poul-Henning Kamp" wrote: > >>> Temperature effects are by far the largest effects we have to deal with. >> >> Which is why you'd be

Re: [time-nuts] HP5065A environmental sensitivities

In message <20160522164909.9fbc6cc820403cc70904e...@kinali.ch>, Attila Kinali writes: >Hoi Poul-Henning, > >On Fri, 20 May 2016 09:52:39 + >"Poul-Henning Kamp" wrote: > >> >Temperature effects are by far the largest effects we have to deal with. >> >> Which is

Re: [time-nuts] HP5065A environmental sensitivities

Hoi Poul-Henning, On Fri, 20 May 2016 09:52:39 + "Poul-Henning Kamp" wrote: > >Temperature effects are by far the largest effects we have to deal with. > > Which is why you'd be much better of with 20 sensors at 16 bits, > than a single sensor at 24 bits. Does the

Re: [time-nuts] Get together at IMS?

I think this makes it real easy, let's meet at Bernd's booth at 5 p.m. on Wednesday. Bring friends. On Sat, May 21, 2016 at 3:46 AM, Bernd Neubig wrote: > I will attend the IMS from Tuesday through Thursday noon time. Most time I > will be at booth 714 (Dynamic

Re: [time-nuts] Maser 0.7 nsec jumps solved

Interesting math: Hydrogen maser frequency standards use the 1420 MHz line. Period of 1420MHz is 0.7 ns. It's not so clear to me that the maser itself is being disrupted, it seems more likely the external noise is inducing an extra count or causing a count to be slipped. A different Australian

Re: [time-nuts] Allan

Magnus it seems you do have things to do and what better motivator! Regards Paul WB8TSL On Sat, May 21, 2016 at 8:52 PM, Magnus Danielson < mag...@rubidium.dyndns.org> wrote: > Fellow time-nuts, > > Last week I was at the IFCS conference in New Orleans. There was also Dr. > David W. Allan who

Re: [time-nuts] Maser 0.7 nsec jumps solved

Hi Jim, Thanks much for the update. I can see how this was a pain to track down. For those that don't remember the issue, the archive starts here: https://www.febo.com/pipermail/time-nuts/2015-December/094904.html And note that 1 / 0.704 ns = 1420 MHz, the frequency of a H-maser. So it's either

Re: [time-nuts] Maser 0.7 nsec jumps solved

Hi That’s a pretty good example for the “why you don’t do your timescale based on a single brand of gear / single setup” file. Thanks for sharing!! Bob > On May 21, 2016, at 9:58 PM, Jim Palfreyman wrote: > > Hi all, > > Awhile back I posted about some mysterious 0.7

Re: [time-nuts] Maser 0.7 nsec jumps solved

Jim, On 05/22/2016 03:58 AM, Jim Palfreyman wrote: Hi all, Awhile back I posted about some mysterious 0.7 ns jumps in three different masers (of the same brand) at three different locations around Australia. Well we think we've found the problem. All three locations also have in-room air

Re: [time-nuts] GPS on Science Friday, Marconi Prize

Col. /Professor Parkinson definitely deserves the prize, pushing GPS was not the best career move but he had a vision and we have to thank him for his commitment. Attached a picture of one of his visit with his boss at TI. A peace of trivia because of my security clearance I had to brief the

Re: [time-nuts] HP5065A environmental sensitivities

I know Corby is working on it and he will share his results. I think he is right now on vacation that is most likely why he is not commenting. Bert Kehren In a message dated 5/21/2016 10:02:59 P.M. Eastern Daylight Time, mag...@rubidium.dyndns.org writes: Hej Poul-Henning, On 05/20/2016

Re: [time-nuts] US PNT Advisory Board

In message <5740fc6e.9030...@rubidium.dyndns.org>, Magnus Danielson writes: >I see that the slide material is now up there: >http://www.gps.gov/governance/advisory/meetings/2016-05/ Good thing Edward Tufte didn't attend, he would have had a meltdown :-) -- Poul-Henning Kamp |

Re: [time-nuts] FE-5680A GPS discipline board on sale now

All the more reason to just observe the log and manually select the value to burn in, IMHO. If you happen to see that the discipline is alternating between adjacent values, then you can "de-dither" by adding back the two lost resolution bits and selecting the correct low-bits by interpolation.