Re: [time-nuts] Linux PPS clues?

[Casey L. Jones]

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.

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Re: [time-nuts] Thermal impact on OCXO

[jimlux]

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 directions, will I wind up with the same frequency and 
phase, or will the frequency revert but at some phase difference?

most oscillators exhibit some degree of hysteresis - the mechanical 
mounting puts stresses on the crystal, if nothing else.




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

[jimlux]

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 of complexity in the 5061 went into
exciting an SRD at 90 MHz and getting a sufficient
line at 9180 MHz to put on a sideband at 9192.
I spent a lot of time trying to do this during the
5071 project and was never able to get anywhere
near the efficiency that the 5061 waveguide structure
was able to do.  It was designed by a visiting Korean
professor, so he wasn't around to mentor me.
The 10816 also used an SRD, and it was also a
struggle, although I was able to make it work.

Fortunately, we were able to replace all this with a
DRO and PLL, and that was 25 years ago.  At this time,
it is even more of a no brainer that you don't want
to knock yourself out trying to make an SRD multiplier
work.  Also, these days, it is harder than ever to
purchase good SRD's.

You can get a nice GaAs VCO that will tune 9GHz with no sweat, and the 
PLL parts to go around it. I'm not sure what the DRO market is these 
days - You can probably build a synthesizer with lower DC power with a 
DRO than using GaAs (although CMOS is getting ever better and getting up 
to that kind of range).  There are probably low cost low precision 
(unlocked) designs like LNBs that use a DRO.


But things like 10 GHz microwave motion detectors these days use VCOs, 
not DROs.


DROs are subject to microphonics and such - yes, the dominant resonance 
is the puck, but the cavity it's in affects it too, so vibration and 
temperature have effects.



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[time-nuts] Gentlemen: Synchronize Your Watches!

[Perry Sandeen via time-nuts]

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 such a fine point of accuracy, physicists could ultimately 
change the length of a second.

Scientists have managed to synchronize two optical clocks 12 km apart to within 
a quintillionth of a second. By measuring time to such a fine point of 
accuracy, physicists could ultimately change our longstanding units for how 
time is measured

World's most accurate clocks are synchronised to a quadrillionth of a second - 
and it could change how we define time

SUPER ACCURACTE CLOCKS 

Physicists in the US fired a laser beam between two buildings more than seven 
miles (12 km) apart.

At either end they used optical clocks to detect regular laser pulses every 
five nanoseconds – five billionths of a second – just like ticking of a clock.

The two clocks send the pulses to each other, with the arrival time measured at 
each clock.
The measurements were so fine that they even took the swaying of the buildings 
and air turbulence into account, to account for tiny changes which could affect 
the arrival times of the pulses.
Once the tiny differences were taken into account, the clocks could be 
synchronized to within a quadrillionth of a second.
In order to make such precise measurements, a team led by physicists at the US 
National Institutes of Standards and Technology (NIST) in Colorado fired a 
laser beam from one building to another, more than seven miles (12 km) away.
At either end they used optical clocks, which work in a similar way to 
microwave clocks, using atoms or ions which oscillate about 100,000 times 
higher than microwave frequencies, in the optical, or visible, part of the 
electromagnetic spectrum.
Using a specialized laser tool called a frequency comb, they were able to 
detect regular laser pulses every five nanoseconds – five billionths of a 
second – just like ticking of a clock.The two clocks send the pulses to each 
other, with the arrival time measured at each clock.The team’s measurements 
were so minute that they even took the swaying of the buildings and air 
turbulence into account, to account for tiny changes which could affect the 
arrival times of the pulses.
Accounting for these differences meant they could be subtracted from any 
difference in arrival times to synchronize the two to within a quadrillionth of 
a second.
Once we measure the difference of the clock times, we can speed up or slow down 
the clock at site B so that it agrees with the clock at site A to within 
femtoseconds,’ explained Laura Sinclair, a physicist at the NIST.
Writing in the journal Applied Physical Letters, the team reports the how they 
were able to maintain such a fine degree of accuracy in spite of such large 
distances.More accurately keeping would enable financial networks to use more 
precise time stamps, so handle even more transactions in shorter amounts of 
time. It would also allow GPS and other satellite-based navigation systems to 
provide even more precise location information
‘The 12 km of turbulent air results in massive distortions of the laser beams, 
yet the two clocks agree in time to 20 digits,’ said Sinclair.
The physicist added: ‘How far, in distance, can we really go?
‘If we want to someday redefine the second so that it’s based on an optical 
standard instead of a microwave standard, we’ll need to be able to link up the 
world’s best clocks and then distribute that time information.’
Earlier this year, researchers in Germany devised the method to measure 
precisely how long a second is with far more accuracy.
It could mean the definition for what a second actually is will change by an 
incomprehensibly tiny amount - just a fraction of a quadrilltionth of a second. 
 

The change will see the amount of error in estimating the length of a second 
reducing from 0.25 quadrilliionths of a second - that is 0.25 with 15 zeros in 
front of it - by a factor of ten.Reducing the amount of uncertainty in how long 
a second is means physicists will be able to make much more accurate estimates 
of how long events take.
 In context, it means such clocks would only have lost about 100 seconds since 
the universe began, 14 billion years ago.

Read more: 
http://www.dailymail.co.uk/sciencetech/article-3834518/World-s-accurate-clocks-synchronised-quadrillionth-second-change-define-time.html#ixzz4MtN7WvBJ
 

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

[David I. Emery]

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 has been done.   There are also some
> >countermeasures in place to help quickly locate and ID rogue uplinks.
> >
> >...
> 
> Captain Midnight was the first satellite incident that came to mind
> but I wonder how many others there have been.

I've heard various numbers (not all that many in NA, more in
other parts of the world) but as you may or may not know, orders of
magnitude more cases of accidental lighting up an uplink pointing at the
wrong satellite, or on the wrong transponder or polarity (or with the
polarity skew wrong) or at the wrong time.

There is a current upgrade in process to require most uplinks to
carry a DSSS spread spectrum buried carrier ID under the actual
modulation energy  with information in it that can be linked back to an
uplinker phone number and ID and location, either by directly including
that info or by an uplinker ID ESN listed in a protected non public
database kept by the satellite operators and space managers allowing them to
determine who the uplinker is (among their customers).


-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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Re: [time-nuts] Linux PPS clues?

[bownes]

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 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 for maybe a 
> second, and then stamp the block with the time. Then you can have your main 
> CPU figure out the time of each event by knowing the bitrate and looking at 
> how many bits precede each one bit back to the beginning of the block. The 
> blocks would likely be largely zeros, and would thus compress really well if 
> you decide to not even bother converting the format of the blocks to a 
> timestamp format. The advantage of this scheme is that it could probably have 
> a sampling rate far higher than a timestamping process, without overstressing 
> even many modestly powered processors.
> 
> Another way to synchronize your samples with GPS, at the cost of some sample 
> rate, is to use a two input multiplexer at your serial input and to take 
> every odd bit of your serial stream to be a sample of the pps output of your 
> GPS and every even bit to be the state of your event trigger. That way your 
> pps and data are interleaved in your bitstream for post processing.
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Re: [time-nuts] Linux PPS clues?

[Casey L. Jones]

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 for maybe a second, and then stamp the block with the 
time. Then you can have your main CPU figure out the time of each event by 
knowing the bitrate and looking at how many bits precede each one bit back 
to the beginning of the block. The blocks would likely be largely zeros, 
and would thus compress really well if you decide to not even bother 
converting the format of the blocks to a timestamp format. The advantage 
of this scheme is that it could probably have a sampling rate far higher 
than a timestamping process, without overstressing even many modestly 
powered processors.


Another way to synchronize your samples with GPS, at the cost of some 
sample rate, is to use a two input multiplexer at your serial input and to 
take every odd bit of your serial stream to be a sample of the pps output 
of your GPS and every even bit to be the state of your event trigger. That 
way your pps and data are interleaved in your bitstream for post 
processing.

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[time-nuts] Newbie With a Z3801 Problem

[Mark Sims]

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 19200,8,N,1 and my 
detection routine sent a   at 19200,7,O,1 and looked for the SCPI> 
prompt.   The unit accepted the  and responded (Heather does not care 
about pairty on reponses) so I assumed the serial port parameters were properly 
configured,  but any real commands sent would not be recognized.

Once that was sorted out, the other problem was getting the GPS receiver 
initialized.  I could not get it to accept a position.  Also it would not 
automatically re-survey (after a week it had not done a survey).   That problem 
was that I was connected to the non-GPS box and thought it would send the 
commands over to the GPS box.  It was responding as if it had accepted the 
commands, but nope, GPS related commands are only actually processed when 
connected to the GPS box.

Lady Heather now has a terminal emulator built in... makes it easier to to 
diagnose serial port issues and play with sending various SCPI commands.  
Another issue that I had was I tried using a null-modem 25-9 pin cable on a 
Z3801A.   NULL MODEM was molded into the cable connectors.  No go.  It was 
wired a straight through cable... g... wasted a lot of time on that one.

Until you can talk to the Z3801A with a terminal program and verified your 
connection and serial port parameters,  forget about using SATSTAT and GPSCON, 
etc.  Even Lady Heather's auto-detect routine can get fooled by improper parity 
settings.

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Re: [time-nuts] Thermal impact on OCXO

[Bob Stewart]

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 
 To: Discussion of Precise Time and Frequency Measurement  
 Sent: Friday, November 4, 2016 8:56 PM
 Subject: [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 frequency and 
phase, or will the frequency revert but at some phase difference?

Bob - AE6RV
 -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info
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Re: [time-nuts] Thinking outside the box a super reference

[paul swed]

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 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 , 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, that sounds about right for an isotope with a 40 billion years
> > half-life.
> >
> > 1 to 2 months is a LNG time for photographic film.
> >
> > --
> > Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> > p...@freebsd.org | TCP/IP since RFC 956
> > FreeBSD committer   | BSD since 4.3-tahoe
> > Never attribute to malice what can adequately be explained by
> incompetence.
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
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[time-nuts] Thinking outside the box a super reference

[Mark Sims]

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 ways than 
one.  I have some uranium glazed pottery that is less active.

The guy that lived behind us when I was a kid was a geologist.  His living room 
coffee table was a chunk of yellow uranium ore about 36x36x18 inches with a 
piece of glass on top...  he had discovered a very large uranium deposit and 
kept a "souvenir" for his living room.


-

> 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
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[time-nuts] Thermal impact on OCXO

[Bob Stewart]

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 frequency and 
phase, or will the frequency revert but at some phase difference?

Bob - AE6RV
 -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info
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Re: [time-nuts] Newbie With a Z3801 Problem

[paul swed]

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 9:02 PM, n2lym  wrote:

> 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 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
>> establish communications" and "No response..." until I power down then
>> back
>> up, and it repeats the cycle.
>>
>> I don't have any real info on power supply voltages, so I don't know what
>> they should be.  On power up, it goes through the cycle of briefly
>> lighting
>> the LEDs on the main board red, ending with the green blinking one on the
>> main board at the same time cycling through the front panel LEDs and
>> ending
>> with just the power LED lit.  I can pull it apart and check for caps
>> needing
>> replacement if you think that might be a cause of this.
>>
>> Dave
>>
>> -Original Message-
>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal
>> Murray
>> Sent: Friday, November 04, 2016 6:56 PM
>> To: Discussion of precise time and frequency measurement
>> Cc: hmur...@megapathdsl.net
>> Subject: 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.
>>
>>
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
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>> ailman/listinfo/time-nuts
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[time-nuts] Lady Heather and LeapSecond

[Mark Sims]

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 not at the end of 
March/June/Sept/Dec.  I don't know if the HP53xxx devices have the same 
firmware bug...

After a couple of days after 30 Sep the Z3801A and Z3812A did not show a leap 
second was pending, so I power-cycled the Z3801A and it started showing the 
leap pending again.  I left the Z3812A running and after 3 days it started 
showing the proper leap second pending.
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Re: [time-nuts] Thinking outside the box a super reference

[bownes]

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 , 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, that sounds about right for an isotope with a 40 billion years
> half-life.
> 
> 1 to 2 months is a LNG time for photographic film.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
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Re: [time-nuts] Newbie With a Z3801 Problem

[n2lym]

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 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
establish communications" and "No response..." until I power down then 
back

up, and it repeats the cycle.

I don't have any real info on power supply voltages, so I don't know 
what
they should be.  On power up, it goes through the cycle of briefly 
lighting
the LEDs on the main board red, ending with the green blinking one on 
the
main board at the same time cycling through the front panel LEDs and 
ending
with just the power LED lit.  I can pull it apart and check for caps 
needing

replacement if you think that might be a cause of this.

Dave

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal 
Murray

Sent: Friday, November 04, 2016 6:56 PM
To: Discussion of precise time and frequency measurement
Cc: hmur...@megapathdsl.net
Subject: 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.



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[time-nuts] HP 58503A failure

[Stan]

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 it, let it rest for a minute or so, and plugged it in again, and
this time the display lit up with a string of several identical "garbage"
characters that extended only part way across the display. The rest of the
display was blank. Pushing on the front panel buttons had no effect, the
display at one point changed to a different string of meaningless characters
and, needless to say, the clock never resumed running. 

 

Unplugging it and plugging it in again resulted in the same behavior,
although different "garbage" characters were displayed, including some of
the annunciators in the VFD that are just 53131A and 53132A counter
functions (+WID, -WID, GATE, etc.). I opened it up and checked the power
supplies, and they were spot on (+5 VDC, +15 VDC, and -15 VDC) with no
measurable ripple. I also checked to see if I could communicate with it
through the serial port using GPSCom (which has worked fine in the past),
but no luck. I just got "Receiver Timeout" error messages. The power LED
glows steady green, but no other LEDs light, even when the buttons are
pushed.

 

I'm not sure if a service manual or CLIP even exists, but I certainly
couldn't locate any service info whatsoever. Any ideas?

 

Thanks,

Stan

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

[Peter Reilley]

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, EB4APL wrote:
A bit OT, but regarding your Rb, some units needs to be powered thru 2 
pins, one is used only for the 10 MHz output buffer, if remember it 
correctly. Which is your model number?


Ignacio EB4APL


El 04/11/2016 a las 16:35, Peter Reilley escribió:
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 sawtooth corrected then it 
would be better

but you really need a GPS disciplined oscillator.

Not to be outdone, I brought out a rubidium oscillator that I had put 
away because
it did not appear to work properly.   It only put out a 1 PPS signal 
and nothing else.
I compared that with the GPS PPS and could get a good comparison on 
the scope.
The rubidium drifted about 40 nS over 12 hours.   So it seemed to be 
good.


With that I could adjust the OCXO's in my 5370's.   The spec for the 
HP 5370B with
a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That 
is, it should
take more than 1,000 seconds for one 10 MHz wave to shift by 360 
degrees.   That
is very hard to do using the screw adjustment in the OCXO. Even the 
slightest
movement possible will cause a frequency change greater that is 
spec'ed.   How

do cal labs do it?

My HP 5370A has a 10544 OCXO which is spec'ed for short term 
stability of
better than 1 X 10^11 for 1 second.   Even better than the 5370B! The 
adjustment
screw is much coarser and it is not possible to get any better than a 
few seconds for
one cycle phase shift of the 10 MHz OCXO against the standard. It 
seems that I can't

get even close to the spec.

These have been running for a few days.   It that enough?

Pete.



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busca de virus.

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

[Richard (Rick) Karlquist]

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 binary
property.  We used to mark CBT's "cesium device, non radioactive"
because the work "cesium" means "cesium 137 nuclear fallout"
to many people.

Reminds me of an interesting Jack Kusters story.
There was some customer who was having problems with
his atomic clocks being noisy (I don't remember exactly
the story) but the bottom line was that they determined
it was because of helium contamination.  Kusters was
called in to answer to the customer about this contamination
and how they were going to fix it.  Kusters measured the
air in the customer's plant and found that in contained
helium.  But the customer did not use helium at all in the
plant.  Kusters pointed out that that could mean only one
thing:  the plant had a radon problem, and radon breaks down
into helium.  Kusters told the customer that if they
dropped the complaint, he wouldn't have to say anything
about radon to anyone.  That was the last heard about the
helium problem.

Rick

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

[Richard (Rick) Karlquist]

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 90 MHz and getting a sufficient
line at 9180 MHz to put on a sideband at 9192.
I spent a lot of time trying to do this during the
5071 project and was never able to get anywhere
near the efficiency that the 5061 waveguide structure
was able to do.  It was designed by a visiting Korean
professor, so he wasn't around to mentor me.
The 10816 also used an SRD, and it was also a
struggle, although I was able to make it work.

Fortunately, we were able to replace all this with a
DRO and PLL, and that was 25 years ago.  At this time,
it is even more of a no brainer that you don't want
to knock yourself out trying to make an SRD multiplier
work.  Also, these days, it is harder than ever to
purchase good SRD's.

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

[Poul-Henning Kamp]

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, that sounds about right for an isotope with a 40 billion years
half-life.

1 to 2 months is a LNG time for photographic film.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Newbie With a Z3801 Problem

[Dave Hallidy]

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
establish communications" and "No response..." until I power down then back
up, and it repeats the cycle.

I don't have any real info on power supply voltages, so I don't know what
they should be.  On power up, it goes through the cycle of briefly lighting
the LEDs on the main board red, ending with the green blinking one on the
main board at the same time cycling through the front panel LEDs and ending
with just the power LED lit.  I can pull it apart and check for caps needing
replacement if you think that might be a cause of this.

Dave

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray
Sent: Friday, November 04, 2016 6:56 PM
To: Discussion of precise time and frequency measurement
Cc: hmur...@megapathdsl.net
Subject: 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?


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

[Tom Van Baak]

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. So using a digital 
divider is what almost all of us do.

What you don't want to get in the habit of doing is comparing 10 MHz (100 ns 
cycles) against 1 PPS. Why? Because it works most of the time, except when it 
doesn't. Which is to say a good GPS/1PPS is within +/-50 ns almost all the 
time, except when it isn't. So it's more robust to phase compare a GPS/1PPS 
against another 1PPS, or even 1 kHz or 10 kHz, but not 10 MHz. This drastically 
reduces to practically eliminates chances of cycle slip. It's one reason why 
the PIC divider chips (or equivalent) are so useful (www.leapsecond.com/pic).

/tvb

- Original Message - 
From: "David" 
To: "Discussion of precise time and frequency measurement" 
Sent: Friday, November 04, 2016 4:30 PM
Subject: 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 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 sawtooth corrected then it 
>>would be better
>>but you really need a GPS disciplined oscillator.
>>
>>...
>>
>>Pete.
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[David]

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 help quickly locate and ID rogue uplinks.
>
>...

Captain Midnight was the first satellite incident that came to mind
but I wonder how many others there have been.


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

[David]

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 years ago, the guy in the next cubicle got away with
>> >storing it under his desk.  He also happily smoked
>> >cigarettes all day at his desk.  Another ERA.
>
>> Rb87 has a halflife north of the age of the planet as far
>> as I recall, and the result is a beta which goes nowhere
>> far and Sr87 which is stable.
>
>87-Rb has a half life of something like 4.9e10 years — you'll be waiting
>a while for that strontium. /gp

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

[David]

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 got between me and the satellite as well

We have Dish outages a couple times a year here in Missouri do to
thunderheads.  I might have thought that was do a particular dish and
receiver but when they were both upgraded, the outages do to
thunderheads remained.
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Re: [time-nuts] Thinking outside the box a super reference

[Bruce Griffiths]

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 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, factory
>>> or home-built, dropping dramatically in price.
>>
>> You need to tune it regardless.
>
> First:  Yes, but if you pick a sensible vibration mode for your
> microwave resonance, that can be done with an screw-in endcap.

Indeed.

> Second:  No, I would actually not need to tune it.
>
> 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.
>
> Later people kept the resonance, because it works well with low
> power budgets in telecoms/milspec applications.
>
> But the resonanance leads to all sorts of trouble, including frequency
> pulling, temperature sensitivities etc.
>
> We're neither space nor power constrained, we'd probably be
> perfectly happy if the end result is 4U and 100W, so resonance
> is not mandatory.

Sure, but if you do have a cavity, as you was hinting at, tuning it is 
still needed for the cavity pull effect.

> Third:  A lot of the "everybody knows" about which atoms can be
> used for active vs. passive atomic standards comes from the
> state of the art electronics about 30 years ago.

Sure, but some behaviors just remains there when still using such setups.

> Using laser-pumping and modern semiconductors, it might actually
> be possible to detect the 6.8GHz photons from the Rb.
>
> They won't be coherent photons, like in a Hydrogen maser, but we
> don't need them to be, in fact that just causes the same exact
> problems as the tuned cavity anyway, as long as we can measure
> the frequency well enough.

You can avoid the cavity using sidebands of the pumping laser and all 
that, yes I know.

Active maser like the hydrogen would be possible naturally, but would 
require the resonator.

A passive direct observation would also possible, but detection will be 
harder and then you would run into S/N issues.

> (No, I havn't done the math on this, my wife has banned me from
> starting any new projects until our house is finished.)

Probably a wise thing.

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

[David]

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 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 sawtooth corrected then it 
>would be better
>but you really need a GPS disciplined oscillator.
>
>...
>
>Pete.
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[David I. Emery]

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 shares 3.7-4.2 Ghz with C band satellite) than
> at Ku band, but that is less true today...

Since folks have brought this up, a couple of more observations
are relevant.

C band has MUCH less weather absorption by normal storms...

Ku band satellite signal fades from rain in passing
thunderstorms often can and do exceed 10-12 db...

This means in practice that C band link budgets can get by with
significantly lower margin to handle rain fades...

So many Ku signals are run with big margins of excess signal so
as to reduce the number of seconds of reception lost to passing
thunderstorms  something not needed as much for C band.

Thus a C band dish sized to just work reliably will have less
margin for the noise floor to rise as the sun goes past the satellite.  
But it DOES rise for Ku dishes as well, just they may be sized to have
more margin and/or the satellite power is higher.

Some home DTH dishes don't leave much margin, others are better.

But it is not true that the sky noise temp doesn't go up a lot 
at Ku band during sun outage season or that for some dishes and some signals
this will not eat the margin up and "ku does not have sun outages".


-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[Magnus Danielson]

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, factory
or home-built, dropping dramatically in price.


You need to tune it regardless.


First:  Yes, but if you pick a sensible vibration mode for your
microwave resonance, that can be done with an screw-in endcap.


Indeed.


Second:  No, I would actually not need to tune it.

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.

Later people kept the resonance, because it works well with low
power budgets in telecoms/milspec applications.

But the resonanance leads to all sorts of trouble, including frequency
pulling, temperature sensitivities etc.

We're neither space nor power constrained, we'd probably be
perfectly happy if the end result is 4U and 100W, so resonance
is not mandatory.


Sure, but if you do have a cavity, as you was hinting at, tuning it is 
still needed for the cavity pull effect.



Third:  A lot of the "everybody knows" about which atoms can be
used for active vs. passive atomic standards comes from the
state of the art electronics about 30 years ago.


Sure, but some behaviors just remains there when still using such setups.


Using laser-pumping and modern semiconductors, it might actually
be possible to detect the 6.8GHz photons from the Rb.

They won't be coherent photons, like in a Hydrogen maser, but we
don't need them to be, in fact that just causes the same exact
problems as the tuned cavity anyway, as long as we can measure
the frequency well enough.


You can avoid the cavity using sidebands of the pumping laser and all 
that, yes I know.


Active maser like the hydrogen would be possible naturally, but would 
require the resonator.


A passive direct observation would also possible, but detection will be 
harder and then you would run into S/N issues.



(No, I havn't done the math on this, my wife has banned me from
starting any new projects until our house is finished.)


Probably a wise thing.

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

[Hal Murray]

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?


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

[Magnus Danielson]

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 beam, scattering from a colloidal suspension of Titanium dioxide is very 
effective.There are no macroscopic moving parts.Brownian motion of the 
colloidal partticels suffices.
Bruce

On Saturday, 5 November 2016 11:28 AM, Magnus Danielson 
 wrote:


 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 his desk.  He also happily smoked
cigarettes all day at his desk.  Another ERA.


Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.


With a half-life of 49.2 Gigayears compared to universe life around 13.8
Gigayears and the beta-decay within both glas and metal enclosure, I'm
not overly concerned. For all practical purposes it is essentially stable.


He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.

Just for the heck of it, I'd go laser instead of the old UHF lamp.


The 780 nm laserdiodes isn't all that hard to get, in fact I've got some
lying around. Depolarizing needed with a quarter-wave needed not to get
a Stark-pull.


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.


You need to tune it regardless.

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

[Poul-Henning Kamp]

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.
>
>You need to tune it regardless.

First:  Yes, but if you pick a sensible vibration mode for your
microwave resonance, that can be done with an screw-in endcap.

Second:  No, I would actually not need to tune it.

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.

Later people kept the resonance, because it works well with low
power budgets in telecoms/milspec applications.

But the resonanance leads to all sorts of trouble, including frequency
pulling, temperature sensitivities etc.

We're neither space nor power constrained, we'd probably be
perfectly happy if the end result is 4U and 100W, so resonance
is not mandatory.

Third:  A lot of the "everybody knows" about which atoms can be
used for active vs. passive atomic standards comes from the
state of the art electronics about 30 years ago.

Using laser-pumping and modern semiconductors, it might actually
be possible to detect the 6.8GHz photons from the Rb.

They won't be coherent photons, like in a Hydrogen maser, but we
don't need them to be, in fact that just causes the same exact
problems as the tuned cavity anyway, as long as we can measure
the frequency well enough.

(No, I havn't done the math on this, my wife has banned me from
starting any new projects until our house is finished.)

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[David I. Emery]

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. 
> 
> Right.  But I think that's because the sun is lining up with the satellite 
> rather than the ionosphere is getting trashed and messing up propagation.

BOTH can be issues.   Faraday rotation can reduce polarization 
isolation in geomagnetic storms... worse at high latitudes... and also
geomagnetic storms can cause antenna pointing issues for satellites...



-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[Artek Manuals]

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 21:51, Don Murray via time-nuts 
wrote:


DirecTV and DishNetwork are on Ku-Band platforms.
Ku-Band is not affected by sun outage.

Don
W4WJ


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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 got between me and the satellite as well



--
Dave
manu...@artekmanuals.com
www.ArtekManuals.com
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Re: [time-nuts] Thinking outside the box a super reference

[Bruce Griffiths]

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 parts.Brownian motion of the 
colloidal partticels suffices.
Bruce 

On Saturday, 5 November 2016 11:28 AM, Magnus Danielson 
 wrote:
 

 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 his desk.  He also happily smoked
>> cigarettes all day at his desk.  Another ERA.
>
> Rb87 has a halflife north of the age of the planet as far
> as I recall, and the result is a beta which goes nowhere
> far and Sr87 which is stable.

With a half-life of 49.2 Gigayears compared to universe life around 13.8 
Gigayears and the beta-decay within both glas and metal enclosure, I'm 
not overly concerned. For all practical purposes it is essentially stable.

> He got a lot more ionizing radiation from his cigaretess than he
> ever got from the Rb87.
>
> Just for the heck of it, I'd go laser instead of the old UHF lamp.

The 780 nm laserdiodes isn't all that hard to get, in fact I've got some 
lying around. Depolarizing needed with a quarter-wave needed not to get 
a Stark-pull.

> 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.

You need to tune it regardless.

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

[David I. Emery]

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 pipe at the same time.

Interesting but probably not that likely.

At least DirecTV is fully capable of doing most things without
any Internet connection at all... maybe not Pay per view or special
stuff like the Sunday Ticket authorizations and data feed (or obviously
video on demand) ... but most everything else

There ARE lots of feeds of local stations to the uplink
facilities via leased fiber circuits, but I don't think a lot of those
are competing for bandwidth on the open Internet but are closed circuit
switched networks.   There is talk of using VPNs over the Internet but I
think such issues as DDOS attacks have mostly kept that from happening
just yet.

Most of the cable channels reach the uplink facility via C band
dishes from the cable signal distributions that feed other head ends... 

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 help quickly locate and ID rogue uplinks.

Because the US military and government is a heavy user of 
commercial satellite capacity, they maintain monitoring facilities that
keep constant watch for intruders... as do the satellite control
facilities responsible for the operation of the birds.


-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[Hal Murray]

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 satellite 
rather than the ionosphere is getting trashed and messing up propagation.
 

-- 
These are my opinions.  I hate spam.



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

[Magnus Danielson]

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 his desk.  He also happily smoked
cigarettes all day at his desk.  Another ERA.


Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.


With a half-life of 49.2 Gigayears compared to universe life around 13.8 
Gigayears and the beta-decay within both glas and metal enclosure, I'm 
not overly concerned. For all practical purposes it is essentially stable.



He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.

Just for the heck of it, I'd go laser instead of the old UHF lamp.


The 780 nm laserdiodes isn't all that hard to get, in fact I've got some 
lying around. Depolarizing needed with a quarter-wave needed not to get 
a Stark-pull.



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.


You need to tune it regardless.

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

[Don Murray via time-nuts]

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
C-Band feeds went into the dumper.
 
They didn't understand why some of the satellite feeds (Ku),
including DirecTV and Dish, were not affected.
 
Don
W4WJ

 
 
In a message dated 11/4/2016 5:04:53 P.M. Central Daylight Time,  
petervince1...@gmail.com writes:

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   
wrote:

DirecTV  and DishNetwork are on Ku-Band platforms.
Ku-Band is not affected by sun  outage.

Don
W4WJ






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

[David I. Emery]

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 




-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[Richard (Rick) Karlquist]

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
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[time-nuts] Newbie With a Z3801 Problem

[Dave Hallidy]

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 help here, maybe a new suggestion or two.  I'll
tell you what I've tried.

 

When I used it before, I used it with an old Fujitsu laptop running (I
think) Windows 98SE.  I had modified the Z3801's port for RS-232 and it
worked fine for several years.

 

When I got it out the other day, I used the same cable that I had made for
it before (basically a null modem, crossing RXD and TXD).  I loaded SatStat
and tried to run it, but it wouldn't communicate with the receiver.  The
current computer is a Win 7 laptop with a Prolific USB to Serial converter,
but I also tried several XP computers, with the same result.

 

I've confirmed that I'm using the correct com port and I've gotten to the
point of even putting a scope on the RS-232 output and input on the
receiver.  I see requests to connect coming into the Z3801, but no response
of any kind- the 232 line just stays low.  I backed up to the serial driver
chip on the 3801's main board (an LT1180 RS-232 driver/receiver) and the
receiver is passing the request on to the processor, but the driver is not
changing state.  So apparently, the processor on the board doesn't recognize
the command SatStat is sending to it.

 

I've tried the recommended baud rate of 19200,7, O,1 but also just about all
other combinations- thinking maybe the old Fujitsu wasn't capable of 19200
and I might have changed the baud rate.  But all to no avail, and frankly, I
wonder if the 19200,7O,1 configuration isn't hard-coded into the Z3801 and
can't be changed.

 

I've made sure my com port setting on the computers' device managers
correspond to the settings I'm using in SatStat, so the setting should allow
the two to talk to each other.

 

I've had it on for numerous long periods and it hasn't achieved GPS lock,
but I assume that's because it's not in survey mode and I was in a different
location last time I used it.  It goes into holdover after a period of time.

 

Has anyone else experienced this and if so, were you able to overcome it
successfully?  RS-422 isn't really an option and as I said, it used to work
fine via RS-232.

 

Thanks in advance for any assistance- I've become quite interested in
precision time and would like to get this thing running again.

 

73

Dave K2DH

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

[Dave Hallidy]

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 [mailto:k2...@frontier.com] 
Sent: Friday, November 04, 2016 5:48 PM
To: 'time-nuts@febo.com'
Subject: 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 help here, maybe a new suggestion or two.  I'll
tell you what I've tried.

 

When I used it before, I used it with an old Fujitsu laptop running (I
think) Windows 98SE.  I had modified the Z3801's port for RS-232 and it
worked fine for several years.

 

When I got it out the other day, I used the same cable that I had made for
it before (basically a null modem, crossing RXD and TXD).  I loaded SatStat
and tried to run it, but it wouldn't communicate with the receiver.  The
current computer is a Win 7 laptop with a Prolific USB to Serial converter,
but I also tried several XP computers, with the same result.

 

I've confirmed that I'm using the correct com port and I've gotten to the
point of even putting a scope on the RS-232 output and input on the
receiver.  I see requests to connect coming into the Z3801, but no response
of any kind- the 232 line just stays low.  I backed up to the serial driver
chip on the 3801's main board (an LT1180 RS-232 driver/receiver) and the
receiver is passing the request on to the processor, but the driver is not
changing state.  So apparently, the processor on the board doesn't recognize
the command SatStat is sending to it.

 

I've tried the recommended baud rate of 19200,7, O,1 but also just about all
other combinations- thinking maybe the old Fujitsu wasn't capable of 19200
and I might have changed the baud rate.  But all to no avail, and frankly, I
wonder if the 19200,7O,1 configuration isn't hard-coded into the Z3801 and
can't be changed.

 

I've made sure my com port setting on the computers' device managers
correspond to the settings I'm using in SatStat, so the setting should allow
the two to talk to each other.

 

I've had it on for numerous long periods and it hasn't achieved GPS lock,
but I assume that's because it's not in survey mode and I was in a different
location last time I used it.  It goes into holdover after a period of time.

 

Has anyone else experienced this and if so, were you able to overcome it
successfully?  RS-422 isn't really an option and as I said, it used to work
fine via RS-232.

 

Thanks in advance for any assistance- I've become quite interested in
precision time and would like to get this thing running again.

 

73

Dave K2DH

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

[David I. Emery]

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 transmissions.   

In fact the solar flux is measured at 10 Ghz...

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 shares 3.7-4.2 Ghz with C band satellite) than
at Ku band, but that is less true today...



-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[David I. Emery]

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 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).

Around here in Boston the max is either the 9th or 10th of October
depending on which satellite you are talking about.   Both DirecTV and
dish use more than one orbital location so there are outages of DIFFERENT
channels at different times during the outage seasons in spring and fall.
This of course somewhat depends on the level of service you have, such
as whether you get the entire HD package or International channels or
your local TV stations, and what market area you are located in.

Some outage happens for a window of maybe 4-6 days centered on
the max... but because of the cliff effect with FEC corrected digital
modulations that means that reception will be close to perfect until the
S/N gets just a little worse and then it fails completely - this may
almost not be noticeable except when the sun is right behind the
satellite.



-- 
  Dave Emery N1PRE/AE, d...@dieconsulting.com  DIE Consulting, Weston, Mass 
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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

[Gian-Paolo Musumeci]

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
> >storing it under his desk.  He also happily smoked
> >cigarettes all day at his desk.  Another ERA.
> Rb87 has a halflife north of the age of the planet as far
> as I recall, and the result is a beta which goes nowhere
> far and Sr87 which is stable.

87-Rb has a half life of something like 4.9e10 years — you'll be waiting
a while for that strontium. /gp
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Re: [time-nuts] Thinking outside the box a super reference

[Bruce Griffiths]

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 with
> >storing it under his desk.  He also happily smoked
> >cigarettes all day at his desk.  Another ERA.
> 
> Rb87 has a halflife north of the age of the planet as far
> as I recall, and the result is a beta which goes nowhere
> far and Sr87 which is stable.
> 
> He got a lot more ionizing radiation from his cigaretess than he
> ever got from the Rb87.
> 
> Just for the heck of it, I'd go laser instead of the old UHF lamp.
> 
> 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.
Yes, the laser technique is doable even if one has to build an ECDL.
What would be nice would be a scheme that allows the same Rb filled bulb 
to be used to both lock the laser to the right wavelength and to detect 
that the microwave signal is also locked to the Rb microwave transition.

Bruce
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Re: [time-nuts] Lady Heather and LeapSecond

[Hal Murray]

> 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 I added (ages ago) to handle the leap second getting 
announced more than a month early?


-- 
These are my opinions.  I hate spam.



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

[Peter Vince]

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 
wrote:

> DirecTV and DishNetwork are on Ku-Band platforms.
> Ku-Band is not affected by sun outage.
>
> Don
> W4WJ
>
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[Peter Vince]

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  wrote:

> U with respect to direct TV is it the noramal two time per year sun
> outage its about the right time.
> Regards
> Paul.
>
>
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[time-nuts] Satellite TV messed up, how is GPS time

[Mark Sims]

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

[Don Murray via time-nuts]

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 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 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  writes:
> >
> > 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 I wonder how  GPS is doing.
> >
> > Thanks for any  comments.
>  >
> > Bill  Hawkins
> >
> >  ___
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> >
> >  ___
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> mailman/listinfo/time-nuts
> >  and follow the instructions there.
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[time-nuts] Lady Heather and LeapSecond

[Mark Sims]

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 differently.  Instead 
of dragging around variables for 
year,month,day,hours,minutes,seconds,fractions-of-second, it now keeps time in 
double precision Julian date variables (for gps, utc, local, and astronomical 
times).  When those are converted to hours/minutes/seconds for display the 
23:59:60 was coming out 00:00:00 .  I had to implement a special flag that says 
to show it as 23:59:60  ...  hopefully that all works...  it did when my Z3801A 
did a false leap-second at the end of September.

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

[Poul-Henning Kamp]

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 his desk.  Another ERA.

Rb87 has a halflife north of the age of the planet as far
as I recall, and the result is a beta which goes nowhere
far and Sr87 which is stable.

He got a lot more ionizing radiation from his cigaretess than he
ever got from the Rb87.

Just for the heck of it, I'd go laser instead of the old UHF lamp.

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.


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[paul swed]

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 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 writes:
> >
> > 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 I wonder how GPS is doing.
> >
> > Thanks for any  comments.
> >
> > Bill  Hawkins
> >
> > ___
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> > and follow the  instructions there.
> >
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[Norm n3ykf]

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 writes:
>
> 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 I wonder how GPS is doing.
>
> Thanks for any  comments.
>
> Bill  Hawkins
>
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Re: [time-nuts] Man with too many clocks.

[Wes]

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 matter, how does temperature
effect the typical mechanical capacitor?  Does anybody play fancy tricks to
cancel out the mechanical motions?  (like the mercury pendulum - as the
pendulum rod expands the mercury expands in the other direction to keep the
CG the same)

The variable tuning capacitor in one of the military "frequency meters" (I 
forget which one, BC221 leaps to mind) had a small disk on an adjustment screw 
that worked against a bi-metallic strip "diving board" to make a temperature 
sensitive trimmer capacitor.  I suspect, however, that it functioned more to 
compensate the inductor than the variable capacitor that was very robust.


Before synthesizers, I built a VFO for a homemade receiver using one of these 
cannibalized from a freq meter.


Wes Stewart, N7WS
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Re: [time-nuts] Satellite TV messed up, how is GPS time

[Don Murray via time-nuts]

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.

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 I wonder how GPS is doing.

Thanks for any  comments.

Bill  Hawkins

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

[Hal Murray]

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 the typical mechanical capacitor?  Does anybody play fancy tricks to 
cancel out the mechanical motions?  (like the mercury pendulum - as the 
pendulum rod expands the mercury expands in the other direction to keep the 
CG the same)

-- 
These are my opinions.  I hate spam.



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

[Pete Stephenson]

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 says we have unusual solar activity.
>
> I no longer have GPS time receivers, so I wonder how GPS is doing.

GPS timekeeping seems to be working fine here in Switzerland.

My situation here today was coincidentally similar to yours: a local
failure with some cableco equipment left me without TV or internet for a
few hours, so the GPS receivers were the only things keeping my network in
sync. No need for holdover, fortunately.

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

[Bill Hawkins]

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 I wonder how GPS is doing.

Thanks for any comments.

Bill Hawkins

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

[Scott Stobbe]

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 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 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 sawtooth corrected then it
> would be better
> > but you really need a GPS disciplined oscillator.
> >
> > Not to be outdone, I brought out a rubidium oscillator that I had put
> away because
> > it did not appear to work properly.   It only put out a 1 PPS signal and
> nothing else.
> > I compared that with the GPS PPS and could get a good comparison on the
> scope.
> > The rubidium drifted about 40 nS over 12 hours.   So it seemed to be
> good.
> >
> > With that I could adjust the OCXO's in my 5370's.   The spec for the HP
> 5370B with
> > a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That
> is, it should
> > take more than 1,000 seconds for one 10 MHz wave to shift by 360
> degrees.   That
> > is very hard to do using the screw adjustment in the OCXO.   Even the
> slightest
> > movement possible will cause a frequency change greater that is
> spec'ed.   How
> > do cal labs do it?
> >
> > My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of
> > better than 1 X 10^11 for 1 second.   Even better than the 5370B! The
> adjustment
> > screw is much coarser and it is not possible to get any better than a
> few seconds for
> > one cycle phase shift of the 10 MHz OCXO against the standard.   It
> seems that I can't
> > get even close to the spec.
> >
> > These have been running for a few days.   It that enough?
> >
> > Pete.
> >
> >
> >
> > On 11/3/2016 8:20 AM, Peter Reilley wrote:
> >> I am the proverbial man with too many clocks and I don't know what time
> it is.
> >> To correct this situation I have decided to calibrate everything.
> >>
> >> I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO
> option.   I also
> >> have some TCXO modules.   I figured that I would calibrate them against
> my Trimble
> >> Resolution T GPS receiver.
> >>
> >> I put the 1 PPS signal in one channel of my scope and one of the 10 MHz
> TCXO
> >> signals in the other channel and look at the phase relationship. The
> TCXO's are
> >> already close enough that I should not be out by more than a fraction
> of a waveform.
> >> I understand that I have to deal with the 1 PPS without sawtooth
> correction.
> >>
> >> I expected to see the 10 MHz signal bounce around but not move more
> than 1/2
> >> of a wave length.   Instead I see the 10 MHz waveform appear steady for
> a few seconds
> >> then jump a significant portion of the wave.   The jump is too much to
> be confident
> >> that I have not slipped one cycle.
> >>
> >> Can I do what I am trying to do or am I missing something?
> >>
> >> Pete.
> >>
> >> ___
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> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >
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Re: [time-nuts] Man with too many clocks.

[Bob Camp]

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 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 sawtooth corrected then it would be 
> better
> but you really need a GPS disciplined oscillator.
> 
> Not to be outdone, I brought out a rubidium oscillator that I had put away 
> because
> it did not appear to work properly.   It only put out a 1 PPS signal and 
> nothing else.
> I compared that with the GPS PPS and could get a good comparison on the scope.
> The rubidium drifted about 40 nS over 12 hours.   So it seemed to be good.
> 
> With that I could adjust the OCXO's in my 5370's.   The spec for the HP 5370B 
> with
> a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That is, it 
> should
> take more than 1,000 seconds for one 10 MHz wave to shift by 360 degrees.   
> That
> is very hard to do using the screw adjustment in the OCXO.   Even the 
> slightest
> movement possible will cause a frequency change greater that is spec'ed.   How
> do cal labs do it?
> 
> My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of
> better than 1 X 10^11 for 1 second.   Even better than the 5370B! The 
> adjustment
> screw is much coarser and it is not possible to get any better than a few 
> seconds for
> one cycle phase shift of the 10 MHz OCXO against the standard.   It seems 
> that I can't
> get even close to the spec.
> 
> These have been running for a few days.   It that enough?
> 
> Pete.
> 
> 
> 
> On 11/3/2016 8:20 AM, Peter Reilley wrote:
>> I am the proverbial man with too many clocks and I don't know what time it 
>> is.
>> To correct this situation I have decided to calibrate everything.
>> 
>> I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO option.   I 
>> also
>> have some TCXO modules.   I figured that I would calibrate them against my 
>> Trimble
>> Resolution T GPS receiver.
>> 
>> I put the 1 PPS signal in one channel of my scope and one of the 10 MHz TCXO
>> signals in the other channel and look at the phase relationship. The TCXO's 
>> are
>> already close enough that I should not be out by more than a fraction of a 
>> waveform.
>> I understand that I have to deal with the 1 PPS without sawtooth correction.
>> 
>> I expected to see the 10 MHz signal bounce around but not move more than 1/2
>> of a wave length.   Instead I see the 10 MHz waveform appear steady for a 
>> few seconds
>> then jump a significant portion of the wave.   The jump is too much to be 
>> confident
>> that I have not slipped one cycle.
>> 
>> Can I do what I am trying to do or am I missing something?
>> 
>> Pete.
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> 
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Re: [time-nuts] Man with too many clocks.

[Peter Reilley]

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 sawtooth corrected then it 
would be better

but you really need a GPS disciplined oscillator.

Not to be outdone, I brought out a rubidium oscillator that I had put 
away because
it did not appear to work properly.   It only put out a 1 PPS signal and 
nothing else.
I compared that with the GPS PPS and could get a good comparison on the 
scope.

The rubidium drifted about 40 nS over 12 hours.   So it seemed to be good.

With that I could adjust the OCXO's in my 5370's.   The spec for the HP 
5370B with
a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That 
is, it should
take more than 1,000 seconds for one 10 MHz wave to shift by 360 
degrees.   That
is very hard to do using the screw adjustment in the OCXO.   Even the 
slightest
movement possible will cause a frequency change greater that is 
spec'ed.   How

do cal labs do it?

My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of
better than 1 X 10^11 for 1 second.   Even better than the 5370B! The 
adjustment
screw is much coarser and it is not possible to get any better than a 
few seconds for
one cycle phase shift of the 10 MHz OCXO against the standard.   It 
seems that I can't

get even close to the spec.

These have been running for a few days.   It that enough?

Pete.



On 11/3/2016 8:20 AM, Peter Reilley wrote:
I am the proverbial man with too many clocks and I don't know what 
time it is.

To correct this situation I have decided to calibrate everything.

I have a HP 5370B, a HP 6370A, and a HP 5328A all with the TCXO 
option.   I also
have some TCXO modules.   I figured that I would calibrate them 
against my Trimble

Resolution T GPS receiver.

I put the 1 PPS signal in one channel of my scope and one of the 10 
MHz TCXO
signals in the other channel and look at the phase relationship. The 
TCXO's are
already close enough that I should not be out by more than a fraction 
of a waveform.
I understand that I have to deal with the 1 PPS without sawtooth 
correction.


I expected to see the 10 MHz signal bounce around but not move more 
than 1/2
of a wave length.   Instead I see the 10 MHz waveform appear steady 
for a few seconds
then jump a significant portion of the wave.   The jump is too much to 
be confident

that I have not slipped one cycle.

Can I do what I am trying to do or am I missing something?

Pete.

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

[Bob Camp]

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, Scott Stobbe  wrote:
> 
> 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 leaves a major gap in who you can call when you run into a
>> problem.
>> 
>> Until you have tried to build one it’s not at all clear just how much
>> “missing information” there
>> is in all those papers. It’s very much like the semiconductor business.
>> Lots of
>> information is published. There are indeed lots of gaps. At some point you
>> must
>> build tooling and get it all working.
>> 
>> Again, we are talking about a device that is at least as good as a 5065
>> and not
>> something that just barely works. If you *could* build something better
>> than a 5065
>> for a thousand or two dollars, it would be on the market today.
>> 
>> Bob
>> 
>>> On Nov 3, 2016, at 6:34 PM, Attila Kinali  wrote:
>>> 
>>> On Thu, 3 Nov 2016 16:54:24 -0400
>>> Bob Camp  wrote:
>>> 
 If you look at a modern CPU as “just a handful of sand and some stuff”,
>> it seems
 pretty easy to build one in the kitchen after an hour or two of setup.
>> When you dig
 into the nasty details the line costs rapidly spiral off into the
>> stratosphere. Atomic
 standards are not quite as complex, but there still is more than just a
>> little custom
 equipment involved. $1M sounds a bit on the low side of what it might
>> take.
>>> 
>>> 
>>> Not necessarily. There is a large corpus of knowledge available on
>>> how to build vapor cells standards and what is a good idea and what
>>> isn't. Most of it is documented in papers of the PTTI, EFTF and IFCS.
>>> The former two are freely available (for PTTI until 2010, but that
>>> should be good enough). Getting access to those papers behind a
>>> paywall, you only need to know someone with access to a university.
>>> (not for PTTI post 2010 though, ION has quite anal access rules)
>>> 
>>> Additionally, the people in the time and frequeny community are very
>>> open to discussion and exchange of knowledge. You can almost always
>>> just walk up to someone and ask questions with a high chance of getting
>>> not only answers but help in how to proceede.
>>> 
>>> Tapping into this knowhow would avoid the need to try out the whole
>>> solution space and concentrate on the few parts that are unkown or
>>> not well enough understood and optimize those. And by doing so safe
>>> a lot of money.
>>> 
>>>  Attila Kinali
>>> 
>>> --
>>> Malek's Law:
>>>   Any simple idea will be worded in the most complicated way.
>>> ___
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Re: [time-nuts] Thinking outside the box a super reference

[Scott Stobbe]

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 leaves a major gap in who you can call when you run into a
> problem.
>
> Until you have tried to build one it’s not at all clear just how much
> “missing information” there
> is in all those papers. It’s very much like the semiconductor business.
> Lots of
> information is published. There are indeed lots of gaps. At some point you
> must
> build tooling and get it all working.
>
> Again, we are talking about a device that is at least as good as a 5065
> and not
> something that just barely works. If you *could* build something better
> than a 5065
> for a thousand or two dollars, it would be on the market today.
>
> Bob
>
> > On Nov 3, 2016, at 6:34 PM, Attila Kinali  wrote:
> >
> > On Thu, 3 Nov 2016 16:54:24 -0400
> > Bob Camp  wrote:
> >
> >> If you look at a modern CPU as “just a handful of sand and some stuff”,
> it seems
> >> pretty easy to build one in the kitchen after an hour or two of setup.
> When you dig
> >> into the nasty details the line costs rapidly spiral off into the
> stratosphere. Atomic
> >> standards are not quite as complex, but there still is more than just a
> little custom
> >> equipment involved. $1M sounds a bit on the low side of what it might
> take.
> >
> >
> > Not necessarily. There is a large corpus of knowledge available on
> > how to build vapor cells standards and what is a good idea and what
> > isn't. Most of it is documented in papers of the PTTI, EFTF and IFCS.
> > The former two are freely available (for PTTI until 2010, but that
> > should be good enough). Getting access to those papers behind a
> > paywall, you only need to know someone with access to a university.
> > (not for PTTI post 2010 though, ION has quite anal access rules)
> >
> > Additionally, the people in the time and frequeny community are very
> > open to discussion and exchange of knowledge. You can almost always
> > just walk up to someone and ask questions with a high chance of getting
> > not only answers but help in how to proceede.
> >
> > Tapping into this knowhow would avoid the need to try out the whole
> > solution space and concentrate on the few parts that are unkown or
> > not well enough understood and optimize those. And by doing so safe
> > a lot of money.
> >
> >   Attila Kinali
> >
> > --
> > Malek's Law:
> >Any simple idea will be worded in the most complicated way.
> > ___
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Re: [time-nuts] Software availability for Trimble module boxed with two serial ports

[Mike Cook]

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.
> 
> Giuseppe Marullo
> 
> IW2JWW - JN45RQ
> 
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"The power of accurate observation is commonly called cynicism by those who 
have not got it. »
George Bernard Shaw

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

[Attila Kinali]

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. Bandi) on this double resonance Rubidium vapour 
> cell in a Magnetron style cavity was completed at the University of Neuchatel.

The dissertation in question is:
"Double-Resonance Studies on Compact, High-performance Rubidium Cell
Frequency Standards, bay Thejesh Bandi, 2013
https://doc.rero.ch/record/32317/files/2318.pdf


Attila Kinali
-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
 -- Miss Matheson, The Diamond Age, Neil Stephenson
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