Re: [time-nuts] Commercial software defined radio for clock metrology

Hi Bruce, What about the BeMicroCV-A9 that Scotty Cowling has been recommending in QEX? It has a Cyclone V SoC FPGA running at 800MHz. Installments to his series have been slow coming, but I've been wondering if this could be the basis for a Timepod type of unit. Bob

Re: [time-nuts] Ublox Neo-6M time error.

Hal, thanks for reminding me of what I ran into on the LEA-6T modules. When you first power them on, they are often a second off in time. It's not until the NAV-TIMEUTC->valid field returns a set validUTC flag that the time can be counted on. But it usually doesn't take more than a minute or

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

I've given thought to stencils, but without building something to prop my hands on, I'll smear the paste. So, I place up to 10 or 15 parts at a time and use the hot-air gun. To each his own, I guess. Bob --- GFS

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

[time-nuts] OT stuffing boards: was GPS interface/prototyping board To: "Bob Stewart" <b...@evoria.net>, "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Date: Thursday, June 23, 2016, 5:27 PM Hi Around here, assuming: 1)

[time-nuts] OT stuffing boards: was GPS interface/prototyping board

One more related question before this topic dies, if you don't mind. What about the other side of building: stuffing the boards. My GPSDOs have about 120 parts per board, plus some custom work on the SMA connectors. Is there a service out there that will populate boards with SMT components

Re: [time-nuts] OCXO noise as they retrace

Thanks Bob.  That makes sense.  --- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time a

Re: [time-nuts] OCXO noise as they retrace

Hi John, That is a thought.  The 1s ADEV had been very stable across units until just now.  But, I don't know how to look at the beam current.  There is a "Monitor3" program that I can use (see link below) that can plot the Clock Servo values, as well as Zeeman Servo, Gain Servo, CBT Supplies,

[time-nuts] OCXO noise as they retrace

I've had a specific GPSDO running for some time now, and I notice that the noise at tau 1s has gotten worse as the retrace flattens out.  In this case, the  ADEV was about 3.6E-11 a month or so ago, and has now gone up to about 8.5E-11.  (Measurements performed by a 5370A against a PRS-45A Cs

Re: [time-nuts] The home time-lab

Hi Brooke, Thanks for that info.  I've got the important bits (PRS and GPSDOs) now hooked up to an APC Smart-UPS 700.  What will happen when it goes to battery power, I don't know.  I've been doing qualification testing on a new batch of GPSDOs, so I haven't had time to do any testing of power

Re: [time-nuts] The home time-lab - APC Smart UPS 700

I let an older, well-aged GPSDO warm up overnight and then I ran a test with the UPS.  Attached were the PRS*, the GPSDO, and the 5370A.  I didn't notice anything when I removed power.  I did notice about a 450ps phase spike when I plugged the UPS back in some 640 seconds later.  But that was

Re: [time-nuts] Venus838LPx-T opinions?

In timing mode, you care very much about the quantization error messages. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Gary E. Miller To: Mark Sims

Re: [time-nuts] LSEM (Leap Second Every Month)

But would it really solve your problems, Jim?  The problem is essentially that periodically, there are two different clock times that represent the same moment in time.  For telescopes, stock markets, spread spectrum, time-based encryption, etc that's a big problem.  Would it not be better to

Re: [time-nuts] Very Accurate Delta Time RF Pulse Measurements

Hi Jerome, This may or may not be of any help, but have you considered using several RTL-SDR devices running at the same time?  You'd need to use a common clock, and probably a number of other enhancements.  But, if you could pull it off, you'd have a wideband RDF type of device.  You'd

Re: [time-nuts] The home time-lab

Charles, I can't speak for Brooke, but I have to point out that each of us has different needs when it comes to powering our lab.  For myself, if I lose power, that's OK.  I'm retired selling a few GPSDOs here and there and working on some other stuff, so I don't need a 24/7 operation.  What

Re: [time-nuts] Adafruit Ultimate GPS timing message arrival times

I liked the Adafruit too when I was using it a couple of years ago, but it did have a bad habit of going walkabout.  Yeah, a lot of that was my antenna, but it's still worth mentioning. Bob - AE6RV.com GFS GPSDO list:

[time-nuts] Low cost SDR suitable for phase noise measurement?

A number of posts have appeared about Zynq SDRs on the "Shera revisited" thread.  So, I'd like to ask the more general question: Are there any low cost SDRs that are suitable for measuring phase noise when coupled with a DMTD?  I believe what I'm looking for is something with enough bits to

Re: [time-nuts] Working with SMT parts.

Hi Bob, You want to get something along the lines of ebay item 272331719376 or 262202931320.  The boom is pretty important, otherwise how do you get your boards under the microscope if they're not very small?  Some time ago, I got a Bausch & Lomb Stereo 3 with 10X oculars and a 0.5 barlow.  The

Re: [time-nuts] Low cost SDR suitable for phase noise measurement?

Hi Brooke, It looks like I've asked a question poorly, yet again.  So, let me try again.  I have this idea of combining a DMTD with an SDR.  So, said that way, it looks like what I really need is a 2-channel audio SDR.  And having said that, maybe what I'm looking for is an external USB sound

Re: [time-nuts] Safely getting the electrical length of a connected antenna feedline

Why is velocity factor an issue?  Aren't we only interested in the electrical time from one end of the coax to the other? Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Didier Juges

Re: [time-nuts] Low cost SDR suitable for phase noise measurement?

arget signal” is in the 1 to 10 Hz range. Is that correct or are you looking for something to use instead of a DMTD? Bob > On Aug 11, 2016, at 3:29 PM, Bob Stewart <b...@evoria.net> wrote: > > Hi Brooke, > It looks like I've asked a question poorly, yet again.  So, let me t

Re: [time-nuts] Low cost SDR suitable for phase noise measurement?

noise. Bob > On Aug 11, 2016, at 5:15 PM, Bob Stewart <b...@evoria.net> wrote: > > Hi Bob, > If I understand the question correctly, yes.  The DMTDs that I've encountered > so far use a zero-crossing detector and a TIC.  I wanted to build sort of a > hybrid system that

Re: [time-nuts] Low cost SDR suitable for phase noise measurement?

att...@kinali.ch> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, August 11, 2016 5:12 PM Subject: Re: [time-nuts] Low cost SDR suitable for phase noise measurement? On Thu, 11 Aug 2016 19:29:08 + (U

[time-nuts] Syncing Tom's PICDivs to 1PPS

For my next GPSDO board revision, I would like to include one of Tom's PICDiv devices to give a much better 1PPS out than the Ublox receivers are capable of.  This means that it has to be started (or slewed to be) exactly on time.  So I was wondering if anyone had experimented in controlling

Re: [time-nuts] HP5370 power supply measurements

Hi Rami, I am very interested in your 5370 power conversion.  Can you give us any more information as to the model number of the buck regulators you used and where you got them.  Did you run into any problems?  Did you make any notes or drawings? Bob 

Re: [time-nuts] GPS message jitter (was GPS for Nixie Clock)

Interestingly enough, the Ublox LEA series of timing receivers has a USB port which you can connect directly to a USB cable.  Of course you want to use an ESD device, etc. Bob  - AE6RV.com GFS GPSDO list:

Re: [time-nuts] How does sawtooth compensation work?

Hi Nick, Let's use the example of a Ublox timing receiver.  In the TIM-TP data package, there is a qErr value, which is the quantization error of the *next* PPS pulse output by the receiver.  At the next PPS, you would subtract that from the unwrapped phase measurement your GPSDO makes and

Re: [time-nuts] Allan Deviation recipe?

t <time-nuts@febo.com> Sent: Tuesday, July 19, 2016 1:42 PM Subject: Re: [time-nuts] Allan Deviation recipe? Yo All! With help from Tom Van Baak and Bob Stewart, I have 6 weeks worth of GPS Serial and PPS timing data in a nice ADEV chart.  I think. Check it out:     https://rellim.c

Re: [time-nuts] GPS for Nixie Clock

Mark, I see some LEA-6T units and some NEO-M8N units.  Has anyone done any timing tests on these since they came up last time on time-nuts?  The prices just seem to be way on the low side. Bob  - AE6RV.com GFS GPSDO list:

Re: [time-nuts] The home time-lab

/info From: Poul-Henning Kamp <p...@phk.freebsd.dk> To: Discussion of precise time and frequency measurement <time-nuts@febo.com>; Hal Murray <hmur...@megapathdsl.net> Cc: Bob Stewart <b...@evoria.net> Sent: Friday, July 8, 2016 1:52 AM Subject: Re: [time

Re: [time-nuts] The home time-lab

bro...@pacific.net> To: Bob Stewart <b...@evoria.net> Sent: Friday, July 8, 2016 1:13 PM Subject: Re: [time-nuts] The home time-lab Hi Bob: Just ordered a Sola SOLA 23-23-150-8 CONSTANT VOLTAGE TRANSFORMER 500VAon eBay for under $200 including shipping. -- Have Fun, Brooke

Re: [time-nuts] The home time-lab

/groups/GFS-GPSDOs/info From: Brooke Clarke <bro...@pacific.net> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Friday, July 8, 2016 12:18 PM Subject: Re: [time-nuts] The home time-lab Hi Bob: A re

Re: [time-nuts] The home time-lab

posted.  I certainly got my money's worth! Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Tim Shoppa <tsho...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and

Re: [time-nuts] Good GPSDO on eBay?

And when you build your own, you're still left with the issue of the oscillator.  In my experience, only about 2 out of 3 of the 34310-Ts I get from China are worth using.  If you buy them one at a time your odds aren't good.  OTOH, as your first oscillator, especially for HF use, noise and

[time-nuts] The home time-lab

I hope this isn't too far off topic, as this is having a big impact on my testing. I decided to run an A/B test on one of my GPSDOs: comparing the phase of the two 10MHz output channels.  In the middle of the night, there was a long series of 35ns pops in the phase data.  Strangely enough,

Re: [time-nuts] The home time-lab

a phase variance of only +60ps to -80ps in timelab with an "averaging window" of 0. Bob   --- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Tim Shoppa <tsho...@gmail.com> To

Re: [time-nuts] The home time-lab

oppa <tsho...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, July 7, 2016 8:16 PM Subject: Re: [time-nuts] The home time-lab 1/35ns is about 30MHz. Is there anything in your clock chai

Re: [time-nuts] The home time-lab

  --- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Hal Murray <hmur...@megapathdsl.net> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo

Re: [time-nuts] The home time-lab

: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, July 7, 2016 10:17 PM Subject: Re: [time-nuts] The home time-lab Hi Hav

Re: [time-nuts] The home time-lab

LiFePO battery and float charge the battery with an appropriately constructed linear PS... ALL but the most expensive UPSs use switch-mode power supplies... to power the load when on mains. __ Clay Autery, KY5G MONTAC Enterprises (318) 518-1389 On 7/7/2016 7:44 PM, Bob Stewart

Re: [time-nuts] The home time-lab

list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Hal Murray <hmur...@megapathdsl.net> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Cc: Hal Murray <hmur...@megapathdsl.net>; hmur...@megapathdsl.net

[time-nuts] Safely getting the electrical length of a connected antenna feedline

Earlier this year, with some help, I pulled the dish off of an old DishTV antenna on the roof and put a 5V bullet antenna on the mast.  I also pulled a new cable through by attaching it to the old one.  The problem is that I was not able to measure the new cable.  So, the question is, without

Re: [time-nuts] Safely getting the electrical length of a connected antenna feedline

probably be in a new thread.  I'd be happy to link to a schematic if wanted. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@e

Re: [time-nuts] Safely getting the electrical length of a connected antenna feedline

<bob91...@yahoo.com> To: Bob Stewart <b...@evoria.net>; Discussion of Precise Time and Frequency Measurement <time-nuts@febo.com>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Monday, August 8, 2016 2:18 PM Subject: Re: [time-nuts] Safel

Re: [time-nuts] GPS antenna selection - lightning

Hi Bill, A lot of us are hams.  The ARRL handbook has a section on grounds, including the need for bonding additional grounds to the power line ground.  A loop of heavy gauge wire around the house that has periodic 8' ground rods is seen as a good thing as long as it's bonded to the power line

[time-nuts] The Nature of Noise

With my recent Cs problems, I've been wondering about the subject of noise generation and measurement.  Specifically, my question is this:  Let's say that I have 3 disciplined oscillators: A, B, and C.  So, I use the same 5370 to create a 1000 second ADEV and discover that the 1s noise value

Re: [time-nuts] The Nature of Noise

the term 3-cornered hat bandied about, but I didn't really grock it until now. Bob  --- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@e

Re: [time-nuts] OCXO noise as they retrace

iable. Bob   --- GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Attila Kinali <att...@kinali.ch> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com>

[time-nuts] Holdover

It's been pointed out to me that I didn't understand the function of the 1PPS of a time standard.  I confess that somehow I had confused the term to be timing standard; which would be an entirely different thing.  But, this is time-nuts, so I should have realized... Anyway, is there a standard,

Re: [time-nuts] Holdover

o: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Tuesday, August 16, 2016 3:46 PM Subject: Re: [time-nuts] Holdover On Tue, 16 Aug 2016 04:35:40 + (UTC) Bob Stewart <b...@evoria.net> wrote: > It's be

Re: [time-nuts] Holdover

w my unit works as a frequency standard. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Attila Kinali <att...@kinali.ch> To: Bob Stewart <b...@evoria.net> Cc: Discussion of Prec

Re: [time-nuts] What interrupts aging?

Hi John, My experience, which is far from scientific, is that any disturbance to the Trimbles I use is like a slap in the face.  It can be just a momentary power loss or a large change in the EFC.  After either of these events, it goes into some period of retrace before it settles back down. 

Re: [time-nuts] Power Problems Lucent KS-24361, L101 & L102

To add in some small manner to what Bob Camp said: IIRC, the input is polarity protected by a diode or two.  I think the input to the brick is floated; i.e. neither of the two power leads is connected to ground.  The brick can be disassembled, if you're careful.  The components, except for the

Re: [time-nuts] Sub-ps delay line

Since you need a set-and-forget type of solution, could you use a wide trace on your board and laser etch/mill it to set your delay, similar to the way film resistors are trimmed?  IOW, add length by turning the wide trace into a zig-zag. Bob 

Re: [time-nuts] distribution amp question + hp 59309A

Walter said: "Also on an unrelated topic, I found an HP 59309A HPIB clock on a forgotten shelf  and looked at it, and was surprised to see such a poor primary time standard oscillator inside, just a 1Mhz crystal using a cmos buffer oscillator. It can accept an external standard, but it did feel

Re: [time-nuts] Timelab question

.  I've pretty much given up on it. Bob  From: John Miles <j...@miles.io> To: 'Bob Stewart' <b...@evoria.net>; 'Discussion of precise time and frequency measurement' <time-nuts@febo.com> Sent: Tuesday, February 21, 2017 3:56 PM Subject: RE: [time-nuts] Timelab questi

[time-nuts] Timelab question

Is there a way to change the escape key in Timelab so that it doesn't default to "yes"?  I love Timelab, but this is driving me nuts.  I hit the escape key and it asks me if I really want to exit.  No, I don't!  So, I hit the escape key and yes, it does exit. Bob

Re: [time-nuts] TTimelab question

Hi John, I have to agree with you about enclosures.  They make the difference between a DIY unit and a nice commercial unit, but they are very expensive.  The enclosures I use are about $20 each from Mouser.  But the end panels are another $20 each: milled front and back.  So, that's $60 per

Re: [time-nuts] Timelab question

From: Andrew Rodland <and...@cleverdomain.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Friday, February 24, 2017 12:18 AM Subject: Re: [time-nuts] Timelab question On Tue, Feb 21, 2017 at 5:26

Re: [time-nuts] Timelab question

John, I apologize.  I was mistaken in my question.  Under wine it behaves poorly, but that's to be expected.  Under XP in a Virtual box, it works as you say.  The same in a real Win 10 box.  The problem is actually that I was expecting the "No" box to be checked, and to require the user to

Re: [time-nuts] advice

there; whether it's time or something else. Bob Stewart (Not a physicist)  From: Rhoderick Beery <rjbe...@gmail.com> To: time-nuts@febo.com Sent: Tuesday, February 21, 2017 11:13 AM Subject: [time-nuts] advice Greetings Time-Nuts! I'm a physics theorist interested in perf

Re: [time-nuts] Vintage Frequency Measurement

In fact, I used a similar method for adjusting the AOR DDS-2A synthesizer on my Collins rig.  I tune an AM radio to WWV.  And I tun the DDS-2A / Collins to the same signal only using SSB.  Then when WWV is sending the tone modulated signal, I tune the DDS-2A calibration control to eliminate the

Re: [time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

I used KICAD for my GPSDO.  I've never used Eagle, so I don't know what differences there are.  I had used ExpressPCB, so it did take some getting used to.  Even at my early entry-level stage, a number of components supplied with the program were unusable.  This was mainly due to the size of

Re: [time-nuts] Subject: Re: Working with SMT parts (Bob Albert)

The stuff I use is Chipquik SMD291AX.  The first syringe of it I bought was from Mouser and was 15 grams.  That was back in 2014.  The second syringe I got was SMD291AX10, which is 35 grams.  It's dated 3/15/16, so you can see how long solder paste will last if you take reasonable car of it.  I

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

Hi Tim, If I understand your post correctly, you're using a frequency counter to measure the accuracy of your GPSDO.  Assuming there's nothing wrong with the GPSDO, what you're actually doing is measuring the frequency accuracy of your counters.  Unless you have something that is known to be

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

OTOH, how many time-nuts have any interest in paying for a power supply that's up to time-nuts standards?  It's really not easy to bring a small product to market at a small price.  Even if you completely discount the personal effort of design, construction, and marketing, there's the issue of

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

Charles, said: "So the answer is to bring crap to market because nobody will pay for something that actually does the job?" I don't mean to cause offense, but is everything you don't like crap?  The reality is that whatever the market will bear is what determines what comes to market.  If you

Re: [time-nuts] A new take on the all-hardware GPSDO concept

Nick said: "Jim Miller's 10 kHz GPSDO that’s been referenced here has either solved this problem, or the 10 kHz output of the Jupiter is substantially better than the Venus’ 10 MHz output, or the design doesn’t give the results time-nuts expect from a GPSDO. Which of those applies?" Hi Nick,

Re: [time-nuts] Measure GPSDO stability with minimum resources?

.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Jim Harman <j99har...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Wednesday, October 5, 2016 9:14 PM Subject: R

Re: [time-nuts] Measure GPSDO stability with minimum resources?

something for aging rate. Bob - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Jim Harman <j99har...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time a

Re: [time-nuts] ADC sample voting algorithm?

Hi Nick, Are you applying sawtooth correction to your phase measurement?  If not, are you merely seeing a hanging bridge that dissolves into at a normal sort of tick-tock movement? Bob From: Nick Sayer via time-nuts To: Discussion of precise time and frequency

Re: [time-nuts] ADC sample voting algorithm?

2016 6:57 PM Subject: Re: [time-nuts] ADC sample voting algorithm? > On Oct 5, 2016, at 4:52 PM, Bob Stewart <b...@evoria.net> wrote: > > Hi Nick, > > Are you applying sawtooth correction to your phase measurement? Yes, these are post-correction observations. I have som

Re: [time-nuts] Inexpensive Alternative to a 5120A

Hi Randal, I've got a bad cold, so I can only hope this response is rational. To begin with, you need some sort of Time Interval Counter (TIC), as well as some way to get the measurements from it into your computer.  Once you get that, then you get a free copy of John Miles' indispensable

Re: [time-nuts] Measure GPSDO stability with minimum resources?

, but a multiple of 24 may bias it toward environmental conditions at startup, so perhaps 64 hours would b e better. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Stewart <b...@evoria.

Re: [time-nuts] Inexpensive Alternative to a 5120A

-Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Friday, 07 October, 2016 12:43 To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Subject: Re: [time-nuts] Inexpensive Alternative to a 5120A Here's the one

Re: [time-nuts] Inexpensive Alternative to a 5120A

e I was looking for in order to really use the Timelab software. Thanks again for the help, all you time-nuts, as I seem to be ready to take the next step...     -Randal R.         (at CubeCentral) -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewa

Re: [time-nuts] Measure GPSDO stability with minimum resources?

 - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Tim Shoppa <tsho...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: T

Re: [time-nuts] Measure GPSDO stability with minimum resources?

said: "The somewhat amazing holdover estimates on the HP units are one example of this problem. It does not take much testing to quickly realize that they are far more often wrong than right on a unit that has been on power for less than a few weeks." Thank you Bob.  These two sentences clear

[time-nuts] Measure GPSDO stability with minimum resources?

For my GPSDO, I need to calculate the OCXO aging for holdover projection purposes as well as get some figure of merit for the recent past of the OCXO stability.  The latter is so that I can determine that the PLL has (or soon will have) a good lock.  I'm developing on a dfPIC33FJ128MC802, and

Re: [time-nuts] TimeLab

Hi Bob, Is it actually possible to address two devices on one GPIB adapter with Timelab?  I admit to not reading the documentation carefully, but I've not been able to do this directly.  The only way I could think of doing it was to use some software to send the data to a file and then use

Re: [time-nuts] TimeLab

AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Sunday, October 9, 2016 11:50 AM Subject: Re

Re: [time-nuts] TimeLab

The problem with two counters is that they will never read exactly the same.  What would be better is if the TICs were able to steer the first incoming signal to start and the next to stop, and then apply a sign based on where the first pulse came from.  Of course, then you have the problem of

Re: [time-nuts] TimeLab

Don't forget the possibility of saving the data to a file and pre-processing the file before sending it to Timelab. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Magnus Danielson

Re: [time-nuts] Holdover

GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Magnus Danielson <mag...@rubidium.se> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Cc: mag...@rubidium.se Sent: Wednesday, August 17, 2016 1:05 AM

Re: [time-nuts] Holdover

Albertson <albertson.ch...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Tuesday, August 16, 2016 7:59 PM Subject: Re: [time-nuts] Holdover What to do during and right after holdover depends on the reas

Re: [time-nuts] Holdover

: time-nuts@febo.com Cc: mag...@rubidium.se Sent: Tuesday, August 16, 2016 6:49 PM Subject: Re: [time-nuts] Holdover Bob, On 08/16/2016 11:31 PM, Bob Stewart wrote: > Hi Attila, > In my unit, which is a frequency standard, I chose to tell the receiver to > stop sending 1PPS pulses whe

Re: [time-nuts] Measuring phase with an HP 3456A?

re in any case. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Albert <bob91...@yahoo.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com>; Bob Stewart <b...@evoria.net> Sent: Saturday, Octob

Re: [time-nuts] Measuring phase with an HP 3456A?

6 8:33 PM Subject: Re: [time-nuts] Measuring phase with an HP 3456A? On 10/1/2016 5:13 PM, Bob Stewart wrote: > Hi Bob Albert, > >  Completely eliminate the use of the term "DMTD".  I didn't post that. Actually you did in your first post.     "I've been spending a s

Re: [time-nuts] Measuring phase with an HP 3456A?

'm running a holdover/recovery test on the code and hardware changes to get a reliable 1PPS from my GPSDO, so there is some very slow movement over the range of 0 to 100ns. Bob From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and

[time-nuts] Measuring phase with an HP 3456A?

I've been spending a small amount of my time looking into making a sort of hybrid DMTD with a pair of DBMs up front feeding the stereo input to a sound card.  So, I got the 100KHz LPF back from Oshpark and hooked it up to my scope for verification - an obvious step.  Then I hooked it up to my

Re: [time-nuts] Measuring phase with an HP 3456A?

From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Saturday, October 1, 2016 6:24 PM Subject: Re: [time-nuts] Measuring phase with an HP 3456A? HI DMTD = Dual Mixer Time Dif

[time-nuts] Aging and Thermal Correction in Holdover

I'm working on the Aging and Thermal Correction algorithms in my GPSDO.  At this point, it's pretty simple: For aging, every X seconds I either increment or decrement the DAC value by 1 as determined by the unit's performance history.  For thermal, every X seconds (user settable) I check to see

Re: [time-nuts] Temp/Humidity control systems?

Hi John, Have you looked into walk-in humidors to see if there are any ideas there that you could use?  Yeah, those use high levels of humidity, but there might be something in common with your needs. Bob  - AE6RV.com GFS GPSDO

Re: [time-nuts] Aging and Thermal Correction in Holdover

From: Attila Kinali <att...@kinali.ch> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thursday, October 27, 2016 1:45 PM Subject: Re: [time-nuts] Aging and Thermal Correction in Holdover On Thu, 27 Oct 2016 16:13:06 +0000 (UTC) Bo

Re: [time-nuts] theoretical Allan Variance question

Perfect?  I can't tell you that.  But I can tell you that the 1s ADEV that I can measure is limited to the stability of the reference oscillator, and to the resolution and stability of the measuring device.  For example, I have an HP 5370A TIC.  It's good to about +/- 20ps.  So, that's the

Re: [time-nuts] Opening an Isotemp OCXO

>From experience, I can tell you that you can't always depend on the seller >when it comes to how to feed your new OCXO.  For instance, the seller of the >Trimble 65256 insisted that it took 12V.  So, that's what I used, and all the >magic smoke came tumbling out. Bob   From: Peter

Re: [time-nuts] Thermal impact on OCXO

/GFS-GPSDOs/info From: Scott Stobbe <scott.j.sto...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Monday, November 7, 2016 2:48 PM Subject: Re: [time-nuts] Thermal impact on OCXO Another n

Re: [time-nuts] Thermal impact on OCXO

/groups/GFS-GPSDOs/info From: Scott Stobbe <scott.j.sto...@gmail.com> To: Bob Camp <kb...@n1k.org> Cc: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Monday, November 7, 2016 9:34 AM Subject: Re: [time-nuts

Re: [time-nuts] Thermal impact on OCXO

divider; which is a 15K/16K divider. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Camp <kb...@n1k.org> To: Bob Stewart <b...@evoria.net> Cc: Discussion of Precise Time a

Re: [time-nuts] Thermal impact on OCXO

there. Bob - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Scott Stobbe <scott.j.sto...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measuremen

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

I'd like to comment on the idea of measuring the width of the pulse.  My experience with creating the 1PPS from an interrupt is that it's fairly straightforward how to do the set interrupt:  The interrupt happens, you execute one, maybe two instructions to raise the output pin, and you leave

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