Re: [time-nuts] Linux PPS clues?

Yes, you might need a separate dedicated chip to take in the serial input steadily. Although you may not. Many serial ports have a small buffer to prevent missed serial input when the operating system gets distracted with something other than processing serial data.

Re: [time-nuts] Thermal impact on OCXO

On 11/4/16 6:56 PM, Bob Stewart wrote: In the general case, is the impact of changing the ambient temperature around an OCXO from, say, 40C to 41C the same as changing it from 41C to 40C all else being equal? IOW, if I somehow have the same temperature ramp over the same time period in both

Re: [time-nuts] Thinking outside the box a super reference

On 11/4/16 5:27 PM, Richard (Rick) Karlquist wrote: On 11/4/2016 4:04 PM, Poul-Henning Kamp wrote: Historically resonance cavities were used so that step/avalance diode multipliers had enough power to excite them. Today we have semiconductors which work at those frequencies. A great deal

[time-nuts] Gentlemen: Synchronize Your Watches!

List Time may be relative, but physicists are a stickler for accuracy. While many of us may give a few minutes’ grace to the timepieces in our homes, one group of scientists has successfully synchronized a pair of optical clocks to within a million billionths of a second. By measuring time to

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 06:53:53PM -0500, David wrote: > On Fri, 4 Nov 2016 18:43:03 -0400, you wrote: > > >... > > > > There HAVE been attempts to deliberately jam cable distribution > >satellites... mostly the EIRPs used for distribution signal uplinks > >make this a bit difficult, but it

Re: [time-nuts] Linux PPS clues?

I suspect the multitasking aspect of the OS will give you far more jitter than one could cope with. > On Nov 4, 2016, at 22:46, Casey L. Jones wrote: > > Maybe you could use something like a serial to parallel converter chip or the > serial port input of a

Re: [time-nuts] Linux PPS clues?

Maybe you could use something like a serial to parallel converter chip or the serial port input of a microcontroller. You could feed in a constant string of zeros until an event, and then feed in a one to the stream when the event occurs. You could save the stream of ones and zeros in memory

[time-nuts] Newbie With a Z3801 Problem

I recently got in a KS24361 system to test Lady Heather with. I was having a terrible time talking to it. Lady Heather would detect it (at 19200,7,O,1 on the GPS box, 9600,8,N,1 on the non-gps box). Nothing I did would get it to accept commands. Turns out that the GPS box speaks SCPI at

Re: [time-nuts] Thermal impact on OCXO

OK, never mind.  I see the obvious.  Phase changes faster at a higher frequency than it does at a lower frequency. Bob  - AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Bob Stewart

Re: [time-nuts] Thinking outside the box a super reference

Rick on the pll DRO I agree with you for today. So is it built for 9180 and then the 12.63 is mixed with it? Or is it actually a direct PLL precisely at the frequency so not even the synthesizer is used? Regards Paul WB8TSL On Fri, Nov 4, 2016 at 9:40 PM, bownes wrote: > Not

[time-nuts] Thinking outside the box a super reference

I have a scintillator that will pick up a small piece of uranium ore from several feet away. I just checked some Rb lamps and cells and got no response. Every single fireplace that I have checked sends the scintillator off into clicking heaven. Apparently firebrick is rather hot stuff in more

[time-nuts] Thermal impact on OCXO

In the general case, is the impact of changing the ambient temperature around an OCXO from, say, 40C to 41C the same as changing it from 41C to 40C all else being equal?  IOW, if I somehow have the same temperature ramp over the same time period in both directions, will I wind up with the same

Re: [time-nuts] Newbie With a Z3801 Problem

I guess what I heard so far sounds normal on start. Just the green power led. Then it warms up and takes a long time up to 48 hours to acquire the satellites if it has no battery backup and has been off a long time. Not sure when the messages go active. Regards Paul WB8TSL On Fri, Nov 4, 2016 at

[time-nuts] Lady Heather and LeapSecond

The problems with the Z3801 (and Z3812 / KS23xxx) devices is they expect the leapsecond to occur at the end of March/June/Sept/Dec. So if the leapsecond is announced more than 3 months in advance they calculate the wrong day of the leapsecond. I suspect that they would mess up any leapsecond

Re: [time-nuts] Thinking outside the box a super reference

Not to mention there is not so sensitive film, sensitive film and really sensitive film. Good old orthographic film took minutes in bright light. > On Nov 4, 2016, at 20:24, Poul-Henning Kamp wrote: > > > In message

Re: [time-nuts] Newbie With a Z3801 Problem

Have you tried a loop back connection, short pins 2 and 3 and a terminal program? You may have to disable hardware handshaking in hardware manager for that USB device or possibly a baud rate problem. Mike On Fri, Nov 04, 2016 at 08:23 PM, Dave Hallidy wrote: Hal- I took your suggestion

[time-nuts] HP 58503A failure

I have had an HP 58503A GPSDO with the Option 001 display running continuously for over ten years without a problem-that is, until today. When I looked at it this morning, the display was showing a valid time, but it was frozen and not advancing. Pushing on the buttons had no effect. I unplugged

Re: [time-nuts] Man with too many clocks.

It is a FE-5680B. It is my understanding that these were made in many variations of features but that what features were present or absent could not be known from the model numbers of other external identifying information. This one has the 1 PPS apparently. Pete. On 11/4/2016 1:07 PM,

Re: [time-nuts] Thinking outside the box a super reference

On 11/4/2016 5:24 PM, Poul-Henning Kamp wrote: Yes, that sounds about right for an isotope with a 40 billion years half-life. The problem with the half life number is that the cylinder still was marked "radioactive" complex with the radiation symbol. Radioactivity (for legal purposes) is a

Re: [time-nuts] Thinking outside the box a super reference

On 11/4/2016 4:04 PM, Poul-Henning Kamp wrote: Historically resonance cavities were used so that step/avalance diode multipliers had enough power to excite them. Today we have semiconductors which work at those frequencies. A great deal of complexity in the 5061 went into exciting an SRD at

Re: [time-nuts] Thinking outside the box a super reference

In message , David writes: >Various online sources say that natural rubidium is radioactive enough >to fog photographic film in 1 to 2 months but that is also the case >with unprocessed uranium ore so I would not worry about it at all. Yes,

Re: [time-nuts] Newbie With a Z3801 Problem

Hal- I took your suggestion and sure enough, I can see on the scope that it puts out a string on power up. I'm sure that's why SatStat gives me a "Communications established- please wait" then "Checking echo". But then it all seems to fall apart, because after that, it drops back to "Trying to

Re: [time-nuts] Man with too many clocks.

Hi David, Your solution is fine. Most time interval counters can only make 10 or 100 or at most 1000 measurements per second, so what you did is exactly the right thing. When using a divider + TIC nothing is lost and everything is gained. Even 'scopes cannot retrace 1000's of times a second.

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, 4 Nov 2016 18:43:03 -0400, you wrote: >... > > There HAVE been attempts to deliberately jam cable distribution >satellites... mostly the EIRPs used for distribution signal uplinks >make this a bit difficult, but it has been done. There are also some >countermeasures in place to

Re: [time-nuts] Thinking outside the box a super reference

On Fri, 04 Nov 2016 14:39:54 -0700, you wrote: >On Fri, Nov 4, 2016, at 02:27 PM, Poul-Henning Kamp wrote: >> >> In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard >> (Rick) Karlquist" w >> rites: >> >Also, one of the Rb isotopes is slightly radioactive. >> >35

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, 4 Nov 2016 18:23:16 -0400, you wrote: >I no longer have DISH but I did have it a year ago and the outage >happened every year like clockwork , they even sent me a notice that I >could expect a sun outage and I did.. I also experienced outages every >time a thunderhead at 30,+ feet

Re: [time-nuts] Thinking outside the box a super reference

The N resonance discussedd in:http://walsworth.physics.harvard.edu/publications/2005_Smallwood_HUBAThesis.pdf May be a better bet than traditional CPT. Bruce On Saturday, 5 November 2016 12:17 PM, Magnus Danielson wrote: Poul-Henning, On 11/05/2016 12:04

Re: [time-nuts] Man with too many clocks.

My simple solution to this was to divide the 1 PPS signal down so the jitter from the uncorrected GPS was a smaller part. Of course then each measurement takes proportionally longer. On Fri, 4 Nov 2016 11:35:59 -0400, you wrote: >I gave up on trying to use the GPS 1 PPS signal to calibrate the

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 06:19:13PM -0400, David I. Emery wrote: > Solar outages are not greatly worse on C band. > > It WAS true that EIRPs at C band were kept lower at one time (to > protect the now mostly completely abandoned terrestrial C band microwave > telephone network which

Re: [time-nuts] Thinking outside the box a super reference

Poul-Henning, On 11/05/2016 12:04 AM, Poul-Henning Kamp wrote: In message <59dc074a-3a09-6315-29d4-6877c3bf7...@rubidium.dyndns.org>, Magnus Danielson write s: With respect to precision machining, that space has changed a lot over the last five years, with precision CNC machines,

Re: [time-nuts] Newbie With a Z3801 Problem

I would put a scope on the TX line from the Z3801A and power cycle it. I'm pretty sure it prints out the version string on power up. Have you checked the power supplies? Or looked for old electrolytics? -- These are my opinions. I hate spam.

Re: [time-nuts] Thinking outside the box a super reference

Hej Bruce, Ah yes, that's it. Sorry for the bad wording. Cheers, Magnus On 11/04/2016 11:41 PM, Bruce Griffiths wrote: Hej Magnus A quarter waveplate doesn't depolarise, it can however convert a linearly polarised beam to a circularly polarised one.If you really need to depolarise a laser

Re: [time-nuts] Thinking outside the box a super reference

In message <59dc074a-3a09-6315-29d4-6877c3bf7...@rubidium.dyndns.org>, Magnus Danielson write s: >> With respect to precision machining, that space has changed a lot >> over the last five years, with precision CNC machines, factory >> or home-built, dropping dramatically in price. >

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 03:19:20PM -0700, Hal Murray wrote: > > petervince1...@gmail.com said: > > Sorry Don, I beg to differ. The effects are often not noticeable in these > > days of digital television, but the noise-floor can definitely be seen to > > rise dramatically on a spectrum analyser.

Re: [time-nuts] Satellite TV messed up, how is GPS time

On 11/4/2016 6:04 PM, Peter Vince wrote: Sorry Don, I beg to differ. The effects are often not noticeable in these days of digital television, but the noise-floor can definitely be seen to rise dramatically on a spectrum analyser. Regards (ex BBC TV, London) On 4 November 2016 at

Re: [time-nuts] Thinking outside the box a super reference

Hej Magnus A quarter waveplate doesn't depolarise, it can however convert a linearly polarised beam to a circularly polarised one.If you really need to depolarise a laser beam, scattering from a colloidal suspension of Titanium dioxide is very effective.There are no macroscopic moving

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 09:58:50PM +, Mark Sims wrote: > I was a local electronics parts store this afternoon and they were > saying some of the satellite TV internet infrastructure was being > DDoS'd... ah, the subtle wonders of a few hundred thousand hacked TV > cameras yammering down your

Re: [time-nuts] Satellite TV messed up, how is GPS time

petervince1...@gmail.com said: > Sorry Don, I beg to differ. The effects are often not noticeable in these > days of digital television, but the noise-floor can definitely be seen to > rise dramatically on a spectrum analyser. Right. But I think that's because the sun is lining up with the

Re: [time-nuts] Thinking outside the box a super reference

Hi, On 11/04/2016 10:27 PM, Poul-Henning Kamp wrote: In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard (Rick) Karlquist" w rites: Also, one of the Rb isotopes is slightly radioactive. 35 years ago, the guy in the next cubicle got away with storing it under

Re: [time-nuts] Satellite TV messed up, how is GPS time

Peter... The rise in the noise floor on Ku was not sufficient to cause programming outage. When I was running the satellite receive system in Miami, we never had problems with Ku downlinks during the twice yearly sun outage. My customers in the news department got very upset when their

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 06:11:48PM -0400, David I. Emery wrote: > > The solar outage season (a loss of signal for about 10 minutes > max when the sun is directly behind the satellite as seen from the dish) > runs from very late Sept (deep south) to about Oct 15 or so (Canada). Try

Re: [time-nuts] Satellite TV messed up, how is GPS time

On 11/4/2016 2:51 PM, Don Murray via time-nuts wrote: DirecTV and DishNetwork are on Ku-Band platforms. Ku-Band is not affected by sun outage. Don W4WJ The backhaul on C band might be affected. Rick ___ time-nuts mailing list -- time-nuts@febo.com

[time-nuts] Newbie With a Z3801 Problem

Hi all- Dave K2DH here. I'm new to the group as of today. I have an old HP Z3801A that I've had for years and which has been packed away for several years. It worked when I put it away, but now, although it seems to come up correctly, I have no serial comms with it. I'm looking for a little

Re: [time-nuts] Newbie With a Z3801 Problem

I should add to this- On power up of the receiver, the SatStat window does say "Communications established- please wait." Then "Checking echo" Then it goes into the repetitive "Trying to establish communications" and "No response." every 3.5 seconds or so. Dave _ From: Dave Hallidy

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 05:51:35PM -0400, Don Murray via time-nuts wrote: > DirecTV and DishNetwork are on Ku-Band platforms. > Ku-Band is not affected by sun outage. I beg to differ !!! The sun is still plenty energetic enough at 10-12 Ghz to override weak satellite

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, Nov 04, 2016 at 04:52:25PM -0400, paul swed wrote: > U with respect to direct TV is it the noramal two time per year sun > outage its about the right time. > Regards > Paul. Nope way off... The solar outage season (a loss of signal for about 10 minutes max when

Re: [time-nuts] Thinking outside the box a super reference

On Fri, Nov 4, 2016, at 02:27 PM, Poul-Henning Kamp wrote: > > In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard > (Rick) Karlquist" w > rites: > >Also, one of the Rb isotopes is slightly radioactive. > >35 years ago, the guy in the next cubicle got away with >

Re: [time-nuts] Thinking outside the box a super reference

On Friday, November 04, 2016 09:27:59 PM Poul-Henning Kamp wrote: > > In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard > (Rick) Karlquist" w > rites: > >Also, one of the Rb isotopes is slightly radioactive. > >35 years ago, the guy in the next cubicle got away

Re: [time-nuts] Lady Heather and LeapSecond

> it did when my Z3801A did a false leap-second at the end of September. Was there a similar problem/opportunity at the end of Oct? Should we watch at the end of Nov (last chance for a while)? What did the Z3801A do? Was the bug in the Z3801A or in an ancient version of ntpd without the fix

Re: [time-nuts] Satellite TV messed up, how is GPS time

Sorry Don, I beg to differ. The effects are often not noticeable in these days of digital television, but the noise-floor can definitely be seen to rise dramatically on a spectrum analyser. Regards (ex BBC TV, London) On 4 November 2016 at 21:51, Don Murray via time-nuts

Re: [time-nuts] Satellite TV messed up, how is GPS time

I don't think so Paul. That happens about the 12th of October in London (51.5° North), a few days later at higher latitudes, and a few days earlier at lower latitudes. Cairo, for instance, on about 30° North, was around the 5th of October. Peter On 4 November 2016 at 20:52, paul swed

[time-nuts] Satellite TV messed up, how is GPS time

I was a local electronics parts store this afternoon and they were saying some of the satellite TV internet infrastructure was being DDoS'd... ah, the subtle wonders of a few hundred thousand hacked TV cameras yammering down your pipe at the same time.

Re: [time-nuts] Satellite TV messed up, how is GPS time

DirecTV and DishNetwork are on Ku-Band platforms. Ku-Band is not affected by sun outage. Don W4WJ In a message dated 11/4/2016 3:52:33 P.M. Central Daylight Time, paulsw...@gmail.com writes: U with respect to direct TV is it the noramal two time per year sun outage its about the

[time-nuts] Lady Heather and LeapSecond

Yes, and it will also automatically do a screen dump to the file "leap_sec.gif" That all assume that the GPS device reports a leap second as 23:59:60. Some devices duplicate 23:59:59 or 00:00:00 I have also seen one say 00:00:60 The next version of Lady Heather internally handles time

Re: [time-nuts] Thinking outside the box a super reference

In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard (Rick) Karlquist" w rites: >Also, one of the Rb isotopes is slightly radioactive. >35 years ago, the guy in the next cubicle got away with >storing it under his desk. He also happily smoked >cigarettes all day at

Re: [time-nuts] Satellite TV messed up, how is GPS time

U with respect to direct TV is it the noramal two time per year sun outage its about the right time. Regards Paul. On Fri, Nov 4, 2016 at 4:47 PM, Norm n3ykf wrote: > Tmobile clock on cell off. Garmin fenix3 watch is correct. > > On Fri, Nov 4, 2016 at 4:19 PM, Don

Re: [time-nuts] Satellite TV messed up, how is GPS time

Tmobile clock on cell off. Garmin fenix3 watch is correct. On Fri, Nov 4, 2016 at 4:19 PM, Don Murray via time-nuts wrote: > No problems here with FOX on Dish, Ch 205 > > Don > W4WJ > > > > In a message dated 11/4/2016 1:45:21 P.M. Central Daylight Time, > bill.i...@pobox.com

Re: [time-nuts] Man with too many clocks.

On 11/4/2016 12:34 PM, Hal Murray wrote: kb...@n1k.org said: The only practical way to set the 10811 or 10544 is with a >= 10 turn pot on the EFC. I never have worked out just why there are so many instruments that don’t have a pot on the EFC. How would temperature effect that? For that

Re: [time-nuts] Satellite TV messed up, how is GPS time

No problems here with FOX on Dish, Ch 205 Don W4WJ In a message dated 11/4/2016 1:45:21 P.M. Central Daylight Time, bill.i...@pobox.com writes: Satellite TV (Dish, Direct, etc) has been having trouble for 10 hours or so, sometimes losing some channels and occasionally all of them.

Re: [time-nuts] Man with too many clocks.

kb...@n1k.org said: > The only practical way to set the 10811 or 10544 is with a >= 10 turn pot on > the EFC. I never have worked out just why there are so many instruments that > don’t have a pot on the EFC. How would temperature effect that? For that matter, how does temperature effect

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Nov 4, 2016 19:45, "Bill Hawkins" wrote: > > Satellite TV (Dish, Direct, etc) has been having trouble for 10 hours or > so, sometimes losing some channels and occasionally all of them. > > Fox News is consistently down, so it could have a human cause, but Space > Weather

[time-nuts] Satellite TV messed up, how is GPS time

Satellite TV (Dish, Direct, etc) has been having trouble for 10 hours or so, sometimes losing some channels and occasionally all of them. Fox News is consistently down, so it could have a human cause, but Space Weather says we have unusual solar activity. I no longer have GPS time receivers, so

Re: [time-nuts] Man with too many clocks.

I'm not sure if there is a reason counters don't let you digitally calibrate beyond that, the 10 MHz ref out on the rear panel would still be out of cal. On Fri, Nov 4, 2016 at 1:48 PM, Bob Camp wrote: > Hi > > The only practical way to set the 10811 or 10544 is with a >= 10 turn

Re: [time-nuts] Man with too many clocks.

Hi The only practical way to set the 10811 or 10544 is with a >= 10 turn pot on the EFC. I never have worked out just why there are so many instruments that don’t have a pot on the EFC. Bob > On Nov 4, 2016, at 11:35 AM, Peter Reilley wrote: > > I gave up on trying

Re: [time-nuts] Man with too many clocks.

I gave up on trying to use the GPS 1 PPS signal to calibrate the 10 MHz OCXO's that I have. The reason that others have pointed out is that the uncorrected 1 PPS signal from the GPS is has just a little too much a jitter to use it for calibration with your eye using a scope. If it were

Re: [time-nuts] Thinking outside the box a super reference

Hi You are indeed effectively either doing a startup or contracting with somebody already in the business. In a lot of ways, contracting this out might be the easier approach. The trick there will be having enough business to make it attractive to them. Bob > On Nov 4, 2016, at 11:21 AM,

Re: [time-nuts] Thinking outside the box a super reference

You will also share the same challenges as Touchstone semi did, no one wanted to stick their neck out to design in a little startup. On Thu, Nov 3, 2016 at 7:49 PM, Bob Camp wrote: > Hi > > Not many people have had exposure to Rb’s or Cs standards actually being > built. That

Re: [time-nuts] Software availability for Trimble module boxed with two serial ports

I have Version 2.01.0 - appears tp be a beta from 2013. I don’t know if it’s the best though. > Le 4 nov. 2016 à 02:56, Giuseppe Marullo a écrit : > > Mike, > > thank you. > > Found several versions on the net, which one is the "best" version to try? > > TIA. > >

Re: [time-nuts] Thinking outside the box a super reference

On Thu, 3 Nov 2016 23:52:00 + (UTC) Bruce Griffiths wrote: > Attached graph indicates ADEV achieved with a 25mm double resonance Rb vapour > cell  > Performance appears somewhat better than HP5065A (even Corby's souped up > version). > The thesis (by  Thejesh N.