Re: [time-nuts] Determination of the placement of the first pps (FE-5680A)

[beale]

Yikes, please delete that pastebin link. That was just my initial try at a FAQ. 
 A significantly updated and more current version of the FE-5680A FAQ is 
located at 
http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5860a_faq

Scott's utility seems to be able to dump the FEI unit serial number, and 
perhaps the included options.  If my guess is correct, all three of the units I 
have are equipped only with "Option 2" which is the RS-232 port.  But there are 
many possible varieties of 5680 units out there, and some of them may have the 
1 PPS behavior you mention while others do not- I have no information on that.


>  ---Original Message---
>  From: Magnus Danielson 
>  
>  Didn't see these link hit the list:
>  http://pastebin.com/S8UcnCMZ
>  http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%200_7.pdf
>  http://vk2xv.djirra.com/tech_rubidium.htm

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Re: [time-nuts] US Army Frequency Standard

[J. Forster]

Self generating, therefore selenium (or possibly silicon). There is no
bias so it's not a photoconductor. I'm sure it's called out in the -24P
manual.

-John

===

> Thank you everyone for your comments, and if I've got it right Brooke, if
> you paste this into your browser:
>
> http://www.flickr.com//photos/75ohm/sets/72157629019710615/show/
>
> you should get a quick tour and a movie!
>
> This is indeed a tuning fork driving a synchronous motor that has a
> perforated disc on its shaft. The whole unit operates as it should and the
> quality of manufacture is superb, so I'm reluctant to pull it apart  but I
> am curious as to the type of photocell it uses. It seems very small and
> the dates on many of the components suggest manufacture in the mid to late
> 1950s so what was around to do the job at that time? There is no cathode
> bias on the "voltage amplifier" that it feeds which suggests it s
> Photovoltaic rather than Photoconductive.
>
> Thanks again for your replies,
>
> John H.
>
>
> On 24 Jan 2012, at 22:34, Brooke Clarke wrote:
>
>> Hi John:
>>
>> Is there a photo of the freq std on line?
>>
>> Have Fun,
>>
>> Brooke Clarke
>> http://www.PRC68.com
>> http://www.end2partygovernment.com/Brooke4Congress.html
>>
>>
>> John Howell wrote:
>>> Thanks Bob,
>>>
>>> If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100,
>>> 120, 140, 160, 180, 190Hz.
>>>
>>> John.
>>>
>>> On 24 Jan 2012, at 22:09, Bob Camp wrote:
>>>
 Hi

 Sounds about right for calibrating / verifying vibrating reed
 frequency
 readouts.

 Bob

 -Original Message-
 From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]
 On
 Behalf Of John Howell
 Sent: Tuesday, January 24, 2012 5:00 PM
 To: Discussion of precise time and frequency measurement
 Subject: [time-nuts] US Army Frequency Standard

 Hi All,

 I recently obtained a curious Low Frequency Standard dating from the
 late
 1950s. Its output can be switched to a number of frequencies from 10
 to
 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US
 Army"
 with a type number TS-65D/FMQ-1.


 Does anyone have any information about this unit, in particular what
 it was
 used for and why the strange negative going pulse output and specific
 frequencies.

 Thanks in advance,
 John H.

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Re: [time-nuts] US Army Frequency Standard

[J. Forster]

American Time Products still exists:

http://www.powercontroldevices.com/about-us/

ATP has also been closely connected to Buliva, makers of the Accutron.

-John





> Amazing, the things that can be picked out of the noise.
>
> I have one of these frequency standards, but it belonged to the US
> Dept. of Commerce, during the period 1965 to 1970 when the DoC was
> given the weather bureau, named Environmental Science Services (ESSA).
> It was last calibrated 9-27-72, after ESSA became NOAA.
>
> The schematic on the cover of the cable box, inside the door, has
> the schematic for "Frequency Standard TS-65C/FMQ-1" The box contains
> two cables, one with a PL-259 and one with a BNC connector.
>
> The name tag says "Type 2509-2 Ser 140" made by American Time Products
> in New York, licensed under Western Electric patents. ATP made timing
> chart devices for setting the correct rate for a wrist or pocket watch.
> Google has nothing for ATP, but a search for "TS-65C/FMQ-1" has one by
> Newton Time Products, which had negative search results.
>
> My device works, 60 Hz reads 60.06, which is 0.1%, but the 10 and 20 Hz
> ranges unaccountably have no output. Abe Books has a manual for $5.
>
> Since I'm cleaning out, this mechanical marvel is yours for the cost
> of shipping 24 pounds in a 12x12x20 box from Minneapolis 55438. It goes
> on the scrap truck Thursday if no one wants old stuff, as usual.
>
> Bill Hawkins
>
>
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Re: [time-nuts] US Army Frequency Standard

[Bill Hawkins]

Amazing, the things that can be picked out of the noise.

I have one of these frequency standards, but it belonged to the US
Dept. of Commerce, during the period 1965 to 1970 when the DoC was
given the weather bureau, named Environmental Science Services (ESSA).
It was last calibrated 9-27-72, after ESSA became NOAA.

The schematic on the cover of the cable box, inside the door, has
the schematic for "Frequency Standard TS-65C/FMQ-1" The box contains
two cables, one with a PL-259 and one with a BNC connector.

The name tag says "Type 2509-2 Ser 140" made by American Time Products
in New York, licensed under Western Electric patents. ATP made timing
chart devices for setting the correct rate for a wrist or pocket watch.
Google has nothing for ATP, but a search for "TS-65C/FMQ-1" has one by
Newton Time Products, which had negative search results.

My device works, 60 Hz reads 60.06, which is 0.1%, but the 10 and 20 Hz
ranges unaccountably have no output. Abe Books has a manual for $5.

Since I'm cleaning out, this mechanical marvel is yours for the cost
of shipping 24 pounds in a 12x12x20 box from Minneapolis 55438. It goes
on the scrap truck Thursday if no one wants old stuff, as usual.

Bill Hawkins


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Re: [time-nuts] Windows app for FE5680 info dump

[paul swed]

Newell that explains that. Let me try tomorrow at the command line level.
Thanks

On Tue, Jan 24, 2012 at 9:37 PM, Scott Newell wrote:

> I've been asked for a windows version of the FE5680 info dump app, so here
> it is:
> http://n5tnl.com/time/fe-**5680a/control/fe5680_info_**win32.exe
>
> Please let me know if you have any trouble.  It's a command line program
> that's expecting a com port number as the only parameter
> ("fe5680_info_win32.exe 1" for com 1).  It'll dump the replies to all the
> commands we know of in both hex and ascii.
>
> If you try it out, please send me a copy of your results.
>
>
> thanks!
> newell  N5TNL
>
>
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Re: [time-nuts] US Army Frequency Standard

[John Howell]

Thank you everyone for your comments, and if I've got it right Brooke, if you 
paste this into your browser:   

http://www.flickr.com//photos/75ohm/sets/72157629019710615/show/

you should get a quick tour and a movie!

This is indeed a tuning fork driving a synchronous motor that has a perforated 
disc on its shaft. The whole unit operates as it should and the quality of 
manufacture is superb, so I'm reluctant to pull it apart  but I am curious as 
to the type of photocell it uses. It seems very small and the dates on many of 
the components suggest manufacture in the mid to late 1950s so what was around 
to do the job at that time? There is no cathode bias on the "voltage amplifier" 
that it feeds which suggests it s Photovoltaic rather than Photoconductive.

Thanks again for your replies,

John H.


On 24 Jan 2012, at 22:34, Brooke Clarke wrote:

> Hi John:
> 
> Is there a photo of the freq std on line?
> 
> Have Fun,
> 
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/Brooke4Congress.html
> 
> 
> John Howell wrote:
>> Thanks Bob,
>> 
>> If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100, 120, 
>> 140, 160, 180, 190Hz.
>> 
>> John.
>> 
>> On 24 Jan 2012, at 22:09, Bob Camp wrote:
>> 
>>> Hi
>>> 
>>> Sounds about right for calibrating / verifying vibrating reed frequency
>>> readouts.
>>> 
>>> Bob
>>> 
>>> -Original Message-
>>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
>>> Behalf Of John Howell
>>> Sent: Tuesday, January 24, 2012 5:00 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: [time-nuts] US Army Frequency Standard
>>> 
>>> Hi All,
>>> 
>>> I recently obtained a curious Low Frequency Standard dating from the late
>>> 1950s. Its output can be switched to a number of frequencies from 10 to
>>> 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US Army"
>>> with a type number TS-65D/FMQ-1.
>>> 
>>> 
>>> Does anyone have any information about this unit, in particular what it was
>>> used for and why the strange negative going pulse output and specific
>>> frequencies.
>>> 
>>> Thanks in advance,
>>> John H.
>>> 
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to
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Re: [time-nuts] Determination of the placement of the first pps

[Magnus Danielson]

On 01/25/2012 02:41 AM, J. L. Trantham wrote:

Darn.

I was hoping for that feature.  I still think it should be there.


Indeed. Should be in there somewhere...

Didn't see these link hit the list:
http://pastebin.com/S8UcnCMZ

http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%200_7.pdf

http://vk2xv.djirra.com/tech_rubidium.htm

Looking at the last one it says:

"NOTE: Although this unit is marked with both 10MHz and 1pps, research 
on the 'net seems to indicate that the '1pps' output has only a period 
of exactly 1 second when the frequency is set to 223 Hz (8.388608Mhz). 
According to those sources the '1pps' will have a period of 0.8388608 
seconds when the output frequency is set to 10MHz. This should be easy 
to verify. In any case I have no need for a 1pps output - I use a GPS 
module to get a 1pps signal which also has the advantage of being 
in-phase with real time seconds. "


Now... to speed-adjust the PPS phase, use the DDS and steer it 
intentionally of frequence with sufficient delta frequence for suitable 
time and you should home in pretty quickly.


Hunting some more:
http://www.qsl.net/zl1bpu/PROJ/Ruby.htm

"Without modification the units have just one output - 1pps (1 Hz). 
There is a simple modification to extract 8388.608 kHz, which is of 
course 223 Hz, and this frequency is used, through binary division, to 
generate the 1pps output. The 8388.608 kHz output is generated by a 
32-bit Direct Digital Synthesizer chip (AD9830). This output can be 
steered to any other frequency within the operating range, by 
interacting with the controlling microcontroller, with three provisos:


1. The unit has a peaked filter at the synthesizer output, and so the 
level at other frequencies varies wildly. This can be corrected with 
minor modifications.
2. When operating at any other frequency than 8388.608kHz, the 1pps 
output is of course incorrect.
3. The synthesizer operating frequency can be set to within ±5 mHz 
(milliHertz) of the requested frequency,
- but ONLY if the calculations, on which the command sent to it 
is based, correctly use 32-bit maths. "


Which is a confirmation...

http://www.leapsecond.com/museum/fei5650a/

http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:rubidium_oscillators

So, this would work for the 50,255+ MHz based FE 5680A. For 60 MHz 
variants it works a little different, but it has two MCUs sitting there, 
so some use for theme should there be.


Cheers,
Magnus

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[time-nuts] Windows app for FE5680 info dump

[Scott Newell]

I've been asked for a windows version of the FE5680 info dump app, so 
here it is:

http://n5tnl.com/time/fe-5680a/control/fe5680_info_win32.exe

Please let me know if you have any trouble.  It's a command line 
program that's expecting a com port number as the only parameter 
("fe5680_info_win32.exe 1" for com 1).  It'll dump the replies to all 
the commands we know of in both hex and ascii.


If you try it out, please send me a copy of your results.


thanks!
newell  N5TNL


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Re: [time-nuts] establishing your position w/o gps

[Jim Lux]

On 1/24/12 3:19 PM, J. Forster wrote:

Is the USNO almana/ephemeris still published in hard copy every year? That
had moon timing, etc.



You can download pieces from the Astronomical Applications website at USNO.

Or you can buy a copy of the Nautical Almanac for about $20 from a 
variety of sources.  You could also download the pdf (but printing it 
would cost you more than the $20)..


Amazon has it, for instance.

http://www.usno.navy.mil/USNO/astronomical-applications/publications/naut-almanac

will find it, but the GPO version is more expensive than the commercial 
versions..



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Re: [time-nuts] establishing your position w/o gps

[Jim Lux]

On 1/24/12 10:26 AM, Chris Albertson wrote:

have you ever tried to measure an angular distance using a hand held
instrument while standing on the deck of a moving boat in the open
ocean?  try it and you will see why they wanted a clock. You
really can't measure an arc minute reliably we should expect about 15
arc minute accuracy if you are standing on a moving ship.  A few very
skilled people could do better.

The moon moves what? about 10 degrees per day so in practical terms
you can get time to about 30 minutes.   But other sources of error
would add to that.   But still knowing even the hour is very good
that puts you in the correct time zone



you can do much better than that by looking for occultations (and they 
work with the new moon as well).  If you know what day it is, you know 
about where the moon is, and you can look up in a table which stars get 
occulted when.  Then you just watch through binoculars.


I'd say you can get within ten seconds without much trouble, assuming 
you can find the star.






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Re: [time-nuts] Determination of the placement of the first pps

[J. L. Trantham]

Darn.

I was hoping for that feature.  I still think it should be there.

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Magnus Danielson
Sent: Tuesday, January 24, 2012 1:19 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Determination of the placement of the first pps

On 01/24/2012 08:07 PM, J. L. Trantham wrote:
> Magnus,
>
> How did you 'jump' the PPS on the FE-5680A?  Is it a serial command?  How
do
> you 'sync' it to the external PPS from say a TBolt?

I was not talking about the 5680 specific. Sorry for the unclarity.

Cheers,
Magnus

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Re: [time-nuts] establishing your position w/o gps

[Jim Lux]

On 1/24/12 9:46 AM, Attila Kinali wrote:

On Tue, 24 Jan 2012 11:05:58 -0600
"Lee Mushel"  wrote:


If you're looking for a really interesting topic to read about, the
development of an accurate ship-board clock is really fascinating!   And it
wasn't done overnight!


If you have a few references on books to read, you shouldn't keep them
for yourself ;-)


Dava Sobel's book is good.

The Great Arc by John Keay also has useful information on this kind of 
thing.


the Institute of Navigation (ION) has an $50 CDROM of almost 300 
celestial navigation papers (http://www.ion.org/shopping/begin.cfm  look 
down at the bottom) Lots about timekeeping, etc. in there.


(got that one loaded on the iPad for long plane trips)

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Re: [time-nuts] establishing your position w/o gps

[Jim Lux]

On 1/24/12 9:48 AM, Chris Albertson wrote:

If you want to try your hand at position determination in the pre
radio nav days you can buy a "studen sextent"  It's a low cost plastic
instrument sells for about $60.
That's the Davis Mark 3 (which is basically a copy of a lifeboat 
sextant).  $50 from starpath.com (which also has the more expensive mark 
15, and others)


Or get a copy of "Emergency Navigation" by David Burch, and you can make 
your own instruments from materials close at hand.


All the sight reduction tables and such are available online for free 
now. (although a paper copy is nice, and fairly cheap, being a 
government publication. )


 Better ones start at $200 with $500

to $800 for a good one.   But it required much pratice and training to
outgrow the plastic instrument.I took the class.


It's not that hard to learn yourself, once you get the right conceptual 
model.  The trick is knowing how to use the sight reduction tables.  (I 
figure that if your GPS has died, so has your calculator, so you'd 
better be able to do it with pencil and paper).


I haven't gone to the extreme of calculating the trig functions by hand 
(wasn't that what Napier's wife did.. calculate log tables by hand 
during long sea voyages)


I think you could probably do some interesting 
compass/straightedge/protractor kinds of geometric constructions to do 
sight reduction as well.


Doing a fix on land, in one place, is pretty easy.  (Much easier than 
standing on the deck of a boat that is moving).  The only trick is 
having an "artificial horizon" that doesn't move.. A pan of liquid works 
nicely (molasses, thick motor oil, or corn syrup are your friends. 
Water is bad.. ripples in the least wind)


Star sights are a bit trickier, just because the stars are dimmer and 
harder to find. And seeing the horizon at night is also tough.


 I think most

anyone who wants to sail on the ocean had better take the class just
in case their GPS fails.   I know some one who had both his primary
and backup GPSes fail and he was still a week from Hawaii.   They had
to revert to the old techniques from the 1700's


And hey, you can learn while you're on the way, like Jack London did, on 
his way to Hawaii.  Read "the cruise of the snark" (Project Gutenberg)




Much of pre-GPS position determination is not about finding your
latitude and longitude.  That is a modern notion.What they did and
what sailors still do is find a "line of position".






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Re: [time-nuts] US Army Frequency Standard

[J. Forster]

Ah, thanks.

I have complained to Google about that scanning issue. IMO, it's a real
problem.

In a few years, Google may have the only extant copy of some doc.

And it will be near useless w/o the fully scanned pages. This is the third
time this has come up in the last few months.

Either they should do it correctly, or not at all.

YMMV,

-John

=


> On 01/24/2012 11:59 PM, J. Forster wrote:
>> Google:
>>
>>   "FMQ-1" Test Set
>>
>> The -24P Parts Manual w/ exploded parts ID is in many places and has a
>> drawing of the front panel. It has no schematics.
>>
>> The full manual will be -15 to -45 Depot Maintenance Manual, per
>> standard
>> Army nomenclature. The last digit will be 5, without a following P.
>
> Google has TM 11-6625-407-14 scanned.
>
> The fold-out schematic pages isn't folded out... but you get a pretty
> good idea how it works from the rest of the text.
>
> The schematics is there fractioned over the pages explaining it.
>
> Cheers,
> Magnus
>
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Re: [time-nuts] US Army Frequency Standard

[Magnus Danielson]

On 01/24/2012 11:59 PM, J. Forster wrote:

Google:

  "FMQ-1" Test Set

The -24P Parts Manual w/ exploded parts ID is in many places and has a
drawing of the front panel. It has no schematics.

The full manual will be -15 to -45 Depot Maintenance Manual, per standard
Army nomenclature. The last digit will be 5, without a following P.


Google has TM 11-6625-407-14 scanned.

The fold-out schematic pages isn't folded out... but you get a pretty 
good idea how it works from the rest of the text.


The schematics is there fractioned over the pages explaining it.

Cheers,
Magnus

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Re: [time-nuts] establishing your position w/o gps

[jmfranke]

For a rough determination; you are facing due south, or due north when the 
elevation of a celestial body stops increasing with time. The elevation is 
highest when the body is on the observer's local meridian. There are 
exceptions, for instance when observing a body below Polaris, then the body 
reaches the lowest elevation when crossing the observer's local meridian, 
but reaches its highest elevation twelve sidereal hours later.


John  WA4WDL

--





But how do you untangle longitude and time? How do you know that you are
looking exactly south (or north)?


If I understand what you are asking, it's the same problem as navigating 
a

ship without a clock.

Classic navigation with a sextant needs a clock and sightings on 3 
objects

in
the sky.  Each sighting  gives you a circle on the globe, or a line if 
you

know roughly where you are.  The lines form a triangle.  The size of the
triangle is an indication of the accuracy.  You pick the objects so the
triangle is roughly equilateral.
  http://en.wikipedia.org/wiki/Celestial_navigation
You can get time from the moon, so in theory at least, that's an answer 
to

your question.
  http://en.wikipedia.org/wiki/Lunar_distance_%28navigation%29

Years ago, when a friend was learning navigation, he was reading one of
the
old classic texts.  There was a good story about the guy off the coast of
England/Ireland who didn't trust his clock, so he did the calculations
again
assuming his clock was a bit fast and again with it slow.  That gave him 
3

parallel lines for each sighting.  Anybody recognize that story?


Longitude by Dava Sobel is a good read, especially for time-nuts.  There
is
also a version with lots of good photographs.

One of the techniques they actually considered before Harrison built good
enough clocks was to derive time from Jupiter's moons.  They knew enough
to
correct for the time shift due to speed of light delays as the
Earth-Jupiter
distance changed.  (I don't know if they knew if was due to speed of
light.)

You can synchronize two clocks if both sites can see the same event in 
the

sky,  Occultations are often used for this.

With modern technology, radio telescopes are very very good at this.   In
order to do VLBI, you need to know where the telescopes are located. 
With

a
big collection of data you can do least-squared fit type calculations to
refine the location and clock calibration.

--
These are my opinions, not necessarily my employer's.  I hate spam.




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Re: [time-nuts] establishing your position w/o gps

[Brooke Clarke]

Hi:

The basic way to find your location anywhere in the world is to use a photo 
sensor.
This is the method used on tagged fish.  The light level is logged and time stamped probably using a watch crystal.  
When the fish is caught the logger data is read out.


Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Brooke4Congress.html


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Re: [time-nuts] establishing your position w/o gps

[J. Forster]

Is the USNO almana/ephemeris still published in hard copy every year? That
had moon timing, etc.

-John

===

-John



>
>> But how do you untangle longitude and time? How do you know that you are
>> looking exactly south (or north)?
>
> If I understand what you are asking, it's the same problem as navigating a
> ship without a clock.
>
> Classic navigation with a sextant needs a clock and sightings on 3 objects
> in
> the sky.  Each sighting  gives you a circle on the globe, or a line if you
> know roughly where you are.  The lines form a triangle.  The size of the
> triangle is an indication of the accuracy.  You pick the objects so the
> triangle is roughly equilateral.
>   http://en.wikipedia.org/wiki/Celestial_navigation
> You can get time from the moon, so in theory at least, that's an answer to
> your question.
>   http://en.wikipedia.org/wiki/Lunar_distance_%28navigation%29
>
> Years ago, when a friend was learning navigation, he was reading one of
> the
> old classic texts.  There was a good story about the guy off the coast of
> England/Ireland who didn't trust his clock, so he did the calculations
> again
> assuming his clock was a bit fast and again with it slow.  That gave him 3
> parallel lines for each sighting.  Anybody recognize that story?
>
>
> Longitude by Dava Sobel is a good read, especially for time-nuts.  There
> is
> also a version with lots of good photographs.
>
> One of the techniques they actually considered before Harrison built good
> enough clocks was to derive time from Jupiter's moons.  They knew enough
> to
> correct for the time shift due to speed of light delays as the
> Earth-Jupiter
> distance changed.  (I don't know if they knew if was due to speed of
> light.)
>
> You can synchronize two clocks if both sites can see the same event in the
> sky,  Occultations are often used for this.
>
> With modern technology, radio telescopes are very very good at this.   In
> order to do VLBI, you need to know where the telescopes are located.  With
> a
> big collection of data you can do least-squared fit type calculations to
> refine the location and clock calibration.
>
> --
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> ___
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>
>



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Re: [time-nuts] US Army Frequency Standard

[Stan, W1LE]

Possibly tuning up the mechanicals of a teletype set.

Stan, W1LE


On 1/24/2012 4:59 PM, John Howell wrote:

Hi All,

I recently obtained a curious Low Frequency Standard dating from the late 1950s. Its output can be 
switched to a number of frequencies from 10 to 190Hz, derived from a tuning fork. It is marked 
"Signal Corps" and "US Army" with a type number TS-65D/FMQ-1.

Does anyone have any information about this unit, in particular what it was 
used for and why the strange negative going pulse output and specific 
frequencies.

Thanks in advance,
John H.

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Re: [time-nuts] establishing your position w/o gps

[Hal Murray]

> But how do you untangle longitude and time? How do you know that you are
> looking exactly south (or north)? 

If I understand what you are asking, it's the same problem as navigating a 
ship without a clock.

Classic navigation with a sextant needs a clock and sightings on 3 objects in 
the sky.  Each sighting  gives you a circle on the globe, or a line if you 
know roughly where you are.  The lines form a triangle.  The size of the 
triangle is an indication of the accuracy.  You pick the objects so the 
triangle is roughly equilateral.
  http://en.wikipedia.org/wiki/Celestial_navigation
You can get time from the moon, so in theory at least, that's an answer to 
your question.
  http://en.wikipedia.org/wiki/Lunar_distance_%28navigation%29

Years ago, when a friend was learning navigation, he was reading one of the 
old classic texts.  There was a good story about the guy off the coast of 
England/Ireland who didn't trust his clock, so he did the calculations again 
assuming his clock was a bit fast and again with it slow.  That gave him 3 
parallel lines for each sighting.  Anybody recognize that story?


Longitude by Dava Sobel is a good read, especially for time-nuts.  There is 
also a version with lots of good photographs.

One of the techniques they actually considered before Harrison built good 
enough clocks was to derive time from Jupiter's moons.  They knew enough to 
correct for the time shift due to speed of light delays as the Earth-Jupiter 
distance changed.  (I don't know if they knew if was due to speed of light.)

You can synchronize two clocks if both sites can see the same event in the 
sky,  Occultations are often used for this.

With modern technology, radio telescopes are very very good at this.   In 
order to do VLBI, you need to know where the telescopes are located.  With a 
big collection of data you can do least-squared fit type calculations to 
refine the location and clock calibration.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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Re: [time-nuts] US Army Frequency Standard

[J. Forster]

Google:

 "FMQ-1" Test Set

The -24P Parts Manual w/ exploded parts ID is in many places and has a
drawing of the front panel. It has no schematics.

The full manual will be -15 to -45 Depot Maintenance Manual, per standard
Army nomenclature. The last digit will be 5, without a following P.

-John





> Hi John:
>
> Is there a photo of the freq std on line?
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/Brooke4Congress.html
>
>
> John Howell wrote:
>> Thanks Bob,
>>
>> If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100,
>> 120, 140, 160, 180, 190Hz.
>>
>> John.
>>
>> On 24 Jan 2012, at 22:09, Bob Camp wrote:
>>
>>> Hi
>>>
>>> Sounds about right for calibrating / verifying vibrating reed frequency
>>> readouts.
>>>
>>> Bob
>>>
>>> -Original Message-
>>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
>>> Behalf Of John Howell
>>> Sent: Tuesday, January 24, 2012 5:00 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: [time-nuts] US Army Frequency Standard
>>>
>>> Hi All,
>>>
>>> I recently obtained a curious Low Frequency Standard dating from the
>>> late
>>> 1950s. Its output can be switched to a number of frequencies from 10 to
>>> 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US
>>> Army"
>>> with a type number TS-65D/FMQ-1.
>>>
>>>
>>> Does anyone have any information about this unit, in particular what it
>>> was
>>> used for and why the strange negative going pulse output and specific
>>> frequencies.
>>>
>>> Thanks in advance,
>>> John H.
>>>
>>> ___
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>>
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Re: [time-nuts] establishing your position w/o gps

[jmfranke]

The Lunar Distance method was not practical, but it was supported by the 
astronomers who felt that a mechanical contraption was beneath the art. Even 
Newton, who was the first head of the Longitude Board, would not consider 
the use of a mechanical clock. One argument from the astronomers was that 
astronomy could determine time but a clock could only keep time.


John  WA4WDL

--
From: "Chris Albertson" 
Sent: Tuesday, January 24, 2012 1:26 PM
To: "Discussion of precise time and frequency measurement" 


Subject: Re: [time-nuts] establishing your position w/o gps


have you ever tried to measure an angular distance using a hand held
instrument while standing on the deck of a moving boat in the open
ocean?  try it and you will see why they wanted a clock. You
really can't measure an arc minute reliably we should expect about 15
arc minute accuracy if you are standing on a moving ship.  A few very
skilled people could do better.

The moon moves what? about 10 degrees per day so in practical terms
you can get time to about 30 minutes.   But other sources of error
would add to that.   But still knowing even the hour is very good
that puts you in the correct time zone

On Tue, Jan 24, 2012 at 9:54 AM, jmfranke  wrote:

In addition to the moons of Jupiter, there was a method in direct
competition with Harrison. It was the Lunar distance method. The Lunar
distance method used the position of the Earth's moon against the zodiac 
as
a clock. The term lunar distance was used because the navigator measured 
the

angular distance from the moon to various stars to establish the moon's
position and then the time was deduced from lunar position tables.
Developing the lunar distance tables was part of the reason for 
establishing

the Royal Observatory.

John WA4WDL 




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Re: [time-nuts] US Army Frequency Standard

[Brooke Clarke]

Hi John:

Is there a photo of the freq std on line?

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Brooke4Congress.html


John Howell wrote:

Thanks Bob,

If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100, 120, 140, 
160, 180, 190Hz.

John.

On 24 Jan 2012, at 22:09, Bob Camp wrote:


Hi

Sounds about right for calibrating / verifying vibrating reed frequency
readouts.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Howell
Sent: Tuesday, January 24, 2012 5:00 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] US Army Frequency Standard

Hi All,

I recently obtained a curious Low Frequency Standard dating from the late
1950s. Its output can be switched to a number of frequencies from 10 to
190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US Army"
with a type number TS-65D/FMQ-1.


Does anyone have any information about this unit, in particular what it was
used for and why the strange negative going pulse output and specific
frequencies.

Thanks in advance,
John H.

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Re: [time-nuts] US Army Frequency Standard

[jmfranke]

If it is the instrument I remember, the tuning fork was used to generate the 
drive for a synchronous motor. The motor drove a disc with hole patterns at 
different radial positions. The frequency control moved a photo cell 
assembly to pick off the different frequencies from the disc.


John  WA4WDL

--
From: "John Howell" 
Sent: Tuesday, January 24, 2012 5:29 PM
To: "Discussion of precise time and frequency measurement" 


Subject: Re: [time-nuts] US Army Frequency Standard


Thanks Bob,

If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100, 120, 
140, 160, 180, 190Hz.


John.

On 24 Jan 2012, at 22:09, Bob Camp wrote:


Hi

Sounds about right for calibrating / verifying vibrating reed frequency
readouts.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Howell
Sent: Tuesday, January 24, 2012 5:00 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] US Army Frequency Standard

Hi All,

I recently obtained a curious Low Frequency Standard dating from the late
1950s. Its output can be switched to a number of frequencies from 10 to
190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US 
Army"

with a type number TS-65D/FMQ-1.


Does anyone have any information about this unit, in particular what it 
was

used for and why the strange negative going pulse output and specific
frequencies.

Thanks in advance,
John H.

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Re: [time-nuts] US Army Frequency Standard

[J. Forster]

It appears to be a Test Set for the FMQ-1 Radiosonde Receiveing system.
Radiosondes used audio tones to encode temperature, pressure, and humidity
as audio tones and transmitted those tones to a ground station where they
were demodulated and recorded.

Interestingly, this thing apparently used a tuning fork to run a
synchronous motor with a disk with holes punched in it to generate the
tones. I've only been able to fing the -24P manual, which is an
illustrated parts list.

I'd try either ArmyRadios Group on Yahoo or Milsurplus on QTH

Best,

-John

===


> Hi All,
>
> I recently obtained a curious Low Frequency Standard dating from the late
> 1950s. Its output can be switched to a number of frequencies from 10 to
> 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US
> Army" with a type number TS-65D/FMQ-1.
>
> Does anyone have any information about this unit, in particular what it
> was used for and why the strange negative going pulse output and specific
> frequencies.
>
> Thanks in advance,
> John H.
>
> ___
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>



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Re: [time-nuts] US Army Frequency Standard

[John Howell]

Thanks Bob,

If it helps the switched frequencies are: 0, 10, 20, 40, 60, 80, 100, 120, 140, 
160, 180, 190Hz.

John.

On 24 Jan 2012, at 22:09, Bob Camp wrote:

> Hi
> 
> Sounds about right for calibrating / verifying vibrating reed frequency
> readouts. 
> 
> Bob
> 
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of John Howell
> Sent: Tuesday, January 24, 2012 5:00 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] US Army Frequency Standard
> 
> Hi All,
> 
> I recently obtained a curious Low Frequency Standard dating from the late
> 1950s. Its output can be switched to a number of frequencies from 10 to
> 190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US Army"
> with a type number TS-65D/FMQ-1.
> 
> 
> Does anyone have any information about this unit, in particular what it was
> used for and why the strange negative going pulse output and specific
> frequencies.
> 
> Thanks in advance,
> John H.
> 
> ___
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Re: [time-nuts] US Army Frequency Standard

[Bob Camp]

Hi

Sounds about right for calibrating / verifying vibrating reed frequency
readouts. 

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Howell
Sent: Tuesday, January 24, 2012 5:00 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] US Army Frequency Standard

Hi All,

I recently obtained a curious Low Frequency Standard dating from the late
1950s. Its output can be switched to a number of frequencies from 10 to
190Hz, derived from a tuning fork. It is marked "Signal Corps" and "US Army"
with a type number TS-65D/FMQ-1.


Does anyone have any information about this unit, in particular what it was
used for and why the strange negative going pulse output and specific
frequencies.

Thanks in advance,
John H.

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[time-nuts] US Army Frequency Standard

[John Howell]

Hi All,

I recently obtained a curious Low Frequency Standard dating from the late 
1950s. Its output can be switched to a number of frequencies from 10 to 190Hz, 
derived from a tuning fork. It is marked "Signal Corps" and "US Army" with a 
type number TS-65D/FMQ-1.

Does anyone have any information about this unit, in particular what it was 
used for and why the strange negative going pulse output and specific 
frequencies.

Thanks in advance,
John H.

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Re: [time-nuts] establishing your position w/o gps

[J. Forster]

Then, as now, a knot is a unit of speed, not distance! If you counted 7
knots in a standard song, it was still speed.

-John

==


> On Tue, Jan 24, 2012 at 10:31 AM, J. Forster  wrote:
>
>> Nope. A knot is a unit of velocity, not didtance.
>>
>>  A "knot" is 1 nautical mile per hour
>>  A nautical mile is that distance, subtended at the earth's surface at
the equator, by 1 arc-minute.
>>
>> If somebody tells you the ship was going "22 knots/hour" they don't
know what they are talking about. A knot/hour is an acceleration.
>
> You are using modern terminology.   In the days when they tossed a real
log overboard and measured time by singing a song.  Issac Newton was
still 100+ years in the future and no one new calculus or what
"acceleration" was.  Most sailors could not count to 100 out load and
many could not even write their own name.I doubt they used the terms
as precisely as we do now.   History seems to only teach us about the
top tier, the Royal Navy and their educated officers and the explorers
like Cook and Magellan.   Most were not nearly at that level of
competence.  Most captains followed "cook book"  like directions and did
not understand the theory.
>
>
> Chris Albertson
> Redondo Beach, California
>
>





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Re: [time-nuts] establishing your position w/o gps

[Eric Garner]

I managed to score a Davis Mark 25 sextant off of ebay for under 100
dollars. it's taken a fairly large amount of practice but I'm able to
get my position to a bit north of a mile.

It's a fun skill to acquire, and  has lead me off in several other fun
hobby tangents.

-Eric

On Tue, Jan 24, 2012 at 10:13 AM, Bob Camp  wrote:
> Hi
>
> If you spend some time on the auction sites you can find some fairly good
> (though not brand name) sextants on the cheap.
>
> Bob
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of Chris Albertson
> Sent: Tuesday, January 24, 2012 12:48 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] establishing your position w/o gps
>
> If you want to try your hand at position determination in the pre
> radio nav days you can buy a "studen sextent"  It's a low cost plastic
> instrument sells for about $60.  Better ones start at $200 with $500
> to $800 for a good one.   But it required much pratice and training to
> outgrow the plastic instrument.    I took the class.    I think most
> anyone who wants to sail on the ocean had better take the class just
> in case their GPS fails.   I know some one who had both his primary
> and backup GPSes fail and he was still a week from Hawaii.   They had
> to revert to the old techniques from the 1700's
>
> Much of pre-GPS position determination is not about finding your
> latitude and longitude.  That is a modern notion.    What they did and
> what sailors still do is find a "line of position".  That means "I am
> some place on this line but I don't know where on the line"  There are
> many ways to do this and they would work every method and find several
> lines.   If they could see land they could shoot a compass bearing and
> draw a reciprocal bearing and know they were on that line.  They would
> know the ship's heading and could estimate drift and know course over
> ground was parallel to that.  They could always find a latitude line.
>  Then if they did this right some of these lines would roughly
> intersect and they would know the position without need to know
> longitude.   There were other methods to find lines that required an
> estimate of your speed and without clocks they resorted to chants and
> songs (jo ho, jo ho,...)  As long as you sing the old pirate song at
> the same tempo every time you have a decent clock.  Then you measure
> distance by tossing a big chunk of lumber overboard with a measured
> rope tied to it.  The captains hated doing math by hand so they
> calibrated the rope by tieing knots at intervals so the natural unit
> was one arc minute at the equator and called it a "knot".
>
> My buddy who was headed to hawaii put both GPSes in the oven in the
> galley and after three days was able to get one of them to work a few
> minutes  a couple times a day.  That was enough.  But he said he was
> within maybe 15 miles of where he thought he was
>
> Basically your estimated course line intersected with a line of
> latitude gives you longitude.
>
>
>
>
>
>
> On Tue, Jan 24, 2012 at 8:50 AM, Azelio Boriani
>  wrote:
>> Yes, the first real push was the Longitude Act (1714) and the Harrison's
>> clocks.
>>
>> On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
>> wrote:
>>
>>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>>> > On Tue, 24 Jan 2012 11:04:08 +
>>> > "Poul-Henning Kamp"  wrote:
>>> >
>>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
>>> Kinali w
>>> >> rites:
>>> >>
>>> >> >All this talk about telling the time using stars or the sun made me
>>> wonder
>>> >> >how did people tell what position their telescopes had back in the
> days
>>> >> >before GPS?
>>>
>>> Sailingships and trade was what pushed this.   At the time of Columbus
>>> he was able to know his latitude within a few 10s of miles but even
>>> after returning to Europe he did no know how far around the world he
>>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.    The
>>> problem was that on one had a clock that should keep time well enough.
>>>  They used hour glasses on board ship for short duration time keeping
>>> but those were of no use on a longer ocean crossing.
>>>
>>> Later they discovered the idea of common view of the moons of Jupiter
>>> and they could measure the time from local noon some even on Jupitor
>>> while a person back home did the same thing.  Later when he got back
>>> home they compare notes and then know the difference in longitude.
>>>  Good ocean going clocks were still centuries away.    But in the
>>> 1500's they could only know the location after the fact when they
>>> returned
>>>
>>> --
>>>
>>> Chris Albertson
>>> Redondo Beach, California
>>>
>>> ___
>>> 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.

Re: [time-nuts] Looking for Harris/Qbit amplifers

[Don Latham]

also see: http://rfbay.com
Don
Peter Gottlieb
>  I have a bunch of those *somewhere* but finding them would be an issue.
>
> Recently I bought some really nice amp blocks made by Miteq so you may
> want to search for those on feebay.  There's also Minicircuits, they
> have some pretty reasonably priced units.  Interestingly, I found a
> couple of cases where feebay sellers were asking *more* for Minicircuits
> parts than Minicircuits wanted on their site!
>
> Peter
>
>
>
> On 01/24/12, John Ackermann N8UR wrote:
>
> Several years ago eBay offered some nice amplifier blocks that went up
> to 500 MHz with about 10dB gain and 25dBm maximum output.
>
> The part number on the unit is Harris 0130-211013, but they were sold as
> "Qbit 512".
>
> I got a couple back then, and would now like to find two or three more
> to use in a project. Of course, the eBay source is long gone. There's
> not much in the way of Google hits other than the page I put up with
> some test results.
>
> Anyone have any of these squirreled away, or know where any might be
> found?
>
> Thanks,
>
> John
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
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> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
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>


-- 
"Neither the voice of authority nor the weight of reason and argument
are as significant as experiment, for thence comes quiet to the mind."
R. Bacon
"If you don't know what it is, don't poke it."
Ghost in the Shell


Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com



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Re: [time-nuts] Determination of the placement of the first pps

[Magnus Danielson]

On 01/24/2012 08:07 PM, J. L. Trantham wrote:

Magnus,

How did you 'jump' the PPS on the FE-5680A?  Is it a serial command?  How do
you 'sync' it to the external PPS from say a TBolt?


I was not talking about the 5680 specific. Sorry for the unclarity.

Cheers,
Magnus

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Re: [time-nuts] Looking for Harris/Qbit amplifers

[Bruce Griffiths]

ed breya wrote:
Yes, those are handy amplifier modules - I always save any that I find 
in surplus RF gear. You can easily replicate the functions with modern 
gain blocks, or your own circuit using discrete parts, if you don't 
need the "drop-in" hermetic package style.


The ones with about 10 dB gain are single stage shunt feedback 
amplifiers. Besides simplicity, the big advantage of store-bought ones 
is that they are exactly specified, while home-made ones are not, so 
it depends on the application.


The larger TO-8 cans usually have built-in coupling caps, while the 
TO-5 types often do not. Quite a few manufacturers got into the VHF 
amplifier module business through the 70s and 80s, but I don't know 
who is still left making those old hermetic can styles. There are lots 
of makers and models of newer types in plastic packages


Here are some that used to make hermetic styles - they all had more or 
less equivalent models available:


Amplifonix
Anzac
Avantek
Motorola (TO-5 MWA series only)
NEC
Qbit (merged w/ Amplifonix?)
Teledyne
Watkins-Johnson

I would look at Minicircuit Labs for modern amplifier blocks, maybe 
including hermetic - but those will be spendy brand new, regardless of 
the source.


Ed

Spectrum microwave  inherited 
 the Qbit line.


Bruce

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Re: [time-nuts] establishing your position w/o gps

[Chris Albertson]

On Tue, Jan 24, 2012 at 10:31 AM, J. Forster  wrote:

> Nope. A knot is a unit of velocity, not didtance.
>
>  A "knot" is 1 nautical mile per hour
>  A nautical mile is that distance, subtended at the earth's surface at
> the equator, by 1 arc-minute.
>
> If somebody tells you the ship was going "22 knots/hour" they don't know
> what they are talking about. A knot/hour is an acceleration.

You are using modern terminology.   In the days when they tossed a
real log overboard and measured time by singing a song.  Issac Newton
was still 100+ years in the future and no one new calculus or what
"acceleration" was.  Most sailors could not count to 100 out load and
many could not even write their own name.I doubt they used the
terms as precisely as we do now.   History seems to only teach us
about the top tier, the Royal Navy and their educated officers and the
explorers like Cook and Magellan.   Most were not nearly at that level
of competence.  Most captains followed "cook book"  like directions
and did not understand the theory.


Chris Albertson
Redondo Beach, California

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Re: [time-nuts] Determination of the placement of the first pps

[J. L. Trantham]

Magnus,

How did you 'jump' the PPS on the FE-5680A?  Is it a serial command?  How do
you 'sync' it to the external PPS from say a TBolt?

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Magnus Danielson
Sent: Tuesday, January 24, 2012 12:51 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Determination of the placement of the first pps

On 01/24/2012 12:42 PM, J. L. Trantham wrote:
> Thanks Chris.
>
> It seems such a logical feature to have, I would think it would have 
> been included perhaps by a serial command.  My old CS clocks have this 
> feature though I have never taken the time to sync them.

"Jumping" the PPS into about the right phase is done within a second and is
well worth the effort. I use this myself and it works well.

Forcing "sync" on atomic clocks is badly needed. The frequency steering
range is small so frequency limit sideways would take ages.

Cheers,
Magnus

> Joe
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] 
> On Behalf Of Chris Albertson
> Sent: Tuesday, January 24, 2012 12:34 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Determination of the placement of the first 
> pps
>
>
> On Mon, Jan 23, 2012 at 5:50 PM, J. L. Trantham  wrote:
>> Is this, in any way, related to the fact the Earth has a Moon?
>>
>>   is there a way to
>> 'sync' the 1 PPS output of an FE-5680A to an external signal, such as 
>> a GPS receiver or TBolt?  I would think that might be possible given 
>> their original purpose.
>
> The 1PPS is not in the units specs.  It is just by luck that it works.
>However we could adjust the phase of the 1PPS by running the unit 
> fast or slow for some period of time and then going back to exact 
> 10MHz.  But that method could take a LONG time, like tens of thousands
> of seconds.Better I think to test the phase and if it is "off" by
> more than say, 0.01 second to just power the unit off and restart and
> see what luck gives you.   I bet 100 power cycles is faster than
> moving the phase by 0.5 seconds.
>
> Maybe the answer is to wire up a few decade divers and divide the 
> 10MHz to 1pps yourself.  Thenyou can let a known good PPS reset your 
> counters and get the phase correct instantly
>
>
>
>
>
>


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[time-nuts] Looking for Harris/Qbit amplifers

[ed breya]

Yes, those are handy amplifier modules - I always save any that I 
find in surplus RF gear. You can easily replicate the functions with 
modern gain blocks, or your own circuit using discrete parts, if you 
don't need the "drop-in" hermetic package style.


The ones with about 10 dB gain are single stage shunt feedback 
amplifiers. Besides simplicity, the big advantage of store-bought 
ones is that they are exactly specified, while home-made ones are 
not, so it depends on the application.


The larger TO-8 cans usually have built-in coupling caps, while the 
TO-5 types often do not. Quite a few manufacturers got into the VHF 
amplifier module business through the 70s and 80s, but I don't know 
who is still left making those old hermetic can styles. There are 
lots of makers and models of newer types in plastic packages


Here are some that used to make hermetic styles - they all had more 
or less equivalent models available:


Amplifonix
Anzac
Avantek
Motorola (TO-5 MWA series only)
NEC
Qbit (merged w/ Amplifonix?)
Teledyne
Watkins-Johnson

I would look at Minicircuit Labs for modern amplifier blocks, maybe 
including hermetic - but those will be spendy brand new, regardless 
of the source.


Ed






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[time-nuts] Solar storms

[Magnus Danielson]

Fellow time-nuts,

Solar storms, don't expect large problems with GPSes, but do look 
towards closest magnetic pole for some spectacular aurora :)


Cheers,
Magnus

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Re: [time-nuts] Determination of the placement of the first pps

[Magnus Danielson]

On 01/24/2012 12:42 PM, J. L. Trantham wrote:

Thanks Chris.

It seems such a logical feature to have, I would think it would have been
included perhaps by a serial command.  My old CS clocks have this feature
though I have never taken the time to sync them.


"Jumping" the PPS into about the right phase is done within a second and 
is well worth the effort. I use this myself and it works well.


Forcing "sync" on atomic clocks is badly needed. The frequency steering 
range is small so frequency limit sideways would take ages.


Cheers,
Magnus


Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: Tuesday, January 24, 2012 12:34 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Determination of the placement of the first pps


On Mon, Jan 23, 2012 at 5:50 PM, J. L. Trantham  wrote:

Is this, in any way, related to the fact the Earth has a Moon?

  is there a way to
'sync' the 1 PPS output of an FE-5680A to an external signal, such as
a GPS receiver or TBolt?  I would think that might be possible given
their original purpose.


The 1PPS is not in the units specs.  It is just by luck that it works.
   However we could adjust the phase of the 1PPS by running the unit fast or
slow for some period of time and then going back to exact 10MHz.  But that
method could take a LONG time, like tens of thousands
of seconds.Better I think to test the phase and if it is "off" by
more than say, 0.01 second to just power the unit off and restart and
see what luck gives you.   I bet 100 power cycles is faster than
moving the phase by 0.5 seconds.

Maybe the answer is to wire up a few decade divers and divide the 10MHz to
1pps yourself.  Thenyou can let a known good PPS reset your counters and get
the phase correct instantly









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[time-nuts] establishing your position w/o gps by radio

[Doug Millar]

Hi, 

   Here's a little experiment I did while on last summer's Eclipse trip near 
Tahiti on a ship.  I brought along my Sony short wave receiver and a Sony loop 
antenna. I went out on the deck and did a null and recorded the bearing to WWV, 
WWVH and JJY. I was able to read the null to within better than 5deg. I was 
hoping to hear a local LFMF broadcast station in the island group, but didn't 
get that far. That would have given me a better LOP (line of position) It 
wasn't extremely accurate but fun. 

    Another time I was sailing to San Clemente Is off of San Diego and about 
midway my friend wanted to know how far we had sailed. I took out his pelorus 
(hand held compass) and a small AM radio and did a null bearing from KNX and 
KSDO which were at about right angles to each other. I later estimated I was 
well within a mile of our true position. 
 Doug

 



 


 From: Bob Camp 
To: 'Discussion of precise time and frequency measurement'  
Sent: Tuesday, January 24, 2012 10:13 AM
Subject: Re: [time-nuts] establishing your position w/o gps
 
Hi

If you spend some time on the auction sites you can find some fairly good
(though not brand name) sextants on the cheap.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: Tuesday, January 24, 2012 12:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] establishing your position w/o gps

If you want to try your hand at position determination in the pre
radio nav days you can buy a "studen sextent"  It's a low cost plastic
instrument sells for about $60.  Better ones start at $200 with $500
to $800 for a good one.   But it required much pratice and training to
outgrow the plastic instrument.    I took the class.    I think most
anyone who wants to sail on the ocean had better take the class just
in case their GPS fails.   I know some one who had both his primary
and backup GPSes fail and he was still a week from Hawaii.   They had
to revert to the old techniques from the 1700's

Much of pre-GPS position determination is not about finding your
latitude and longitude.  That is a modern notion.    What they did and
what sailors still do is find a "line of position".  That means "I am
some place on this line but I don't know where on the line"  There are
many ways to do this and they would work every method and find several
lines.   If they could see land they could shoot a compass bearing and
draw a reciprocal bearing and know they were on that line.  They would
know the ship's heading and could estimate drift and know course over
ground was parallel to that.  They could always find a latitude line.
Then if they did this right some of these lines would roughly
intersect and they would know the position without need to know
longitude.   There were other methods to find lines that required an
estimate of your speed and without clocks they resorted to chants and
songs (jo ho, jo ho,...)  As long as you sing the old pirate song at
the same tempo every time you have a decent clock.  Then you measure
distance by tossing a big chunk of lumber overboard with a measured
rope tied to it.  The captains hated doing math by hand so they
calibrated the rope by tieing knots at intervals so the natural unit
was one arc minute at the equator and called it a "knot".

My buddy who was headed to hawaii put both GPSes in the oven in the
galley and after three days was able to get one of them to work a few
minutes  a couple times a day.  That was enough.  But he said he was
within maybe 15 miles of where he thought he was

Basically your estimated course line intersected with a line of
latitude gives you longitude.






On Tue, Jan 24, 2012 at 8:50 AM, Azelio Boriani
 wrote:
> Yes, the first real push was the Longitude Act (1714) and the Harrison's
> clocks.
>
> On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
> wrote:
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>> > On Tue, 24 Jan 2012 11:04:08 +
>> > "Poul-Henning Kamp"  wrote:
>> >
>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
>> Kinali w
>> >> rites:
>> >>
>> >> >All this talk about telling the time using stars or the sun made me
>> wonder
>> >> >how did people tell what position their telescopes had back in the
days
>> >> >before GPS?
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.    The
>> problem was that on one had a clock that should keep time well enough.
>>  They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure t

Re: [time-nuts] establishing your position w/o gps

[J. Forster]

[snip]
Then you measure
> distance by tossing a big chunk of lumber overboard with a measured
> rope tied to it.  The captains hated doing math by hand so they
> calibrated the rope by tieing knots at intervals so the natural unit
> was one arc minute at the equator and called it a "knot".

Nope. A knot is a unit of velocity, not didtance.

  A "knot" is 1 nautical mile per hour
  A nautical mile is that distance, subtended at the earth's surface at
the equator, by 1 arc-minute.

If somebody tells you the ship was going "22 knots/hour" they don't know
what they are talking about. A knot/hour is an acceleration.

I've only seen knots/hour used correctly once, in an inertial guidance
system, for cross-track acceleration.

> My buddy who was headed to hawaii put both GPSes in the oven in the
> galley and after three days was able to get one of them to work a few
> minutes  a couple times a day.  That was enough.  But he said he was
> within maybe 15 miles of where he thought he was
>
> Basically your estimated course line intersected with a line of
> latitude gives you longitude.


-John




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Re: [time-nuts] Looking for Harris/Qbit amplifers

[Peter Gottlieb]

 I have a bunch of those *somewhere* but finding them would be an issue.

Recently I bought some really nice amp blocks made by Miteq so you may want to 
search for those on feebay.  There's also Minicircuits, they have some pretty 
reasonably priced units.  Interestingly, I found a couple of cases where feebay 
sellers were asking *more* for Minicircuits parts than Minicircuits wanted on 
their site!

Peter

 
 
On 01/24/12, John Ackermann N8UR wrote:
 
Several years ago eBay offered some nice amplifier blocks that went up 
to 500 MHz with about 10dB gain and 25dBm maximum output.

The part number on the unit is Harris 0130-211013, but they were sold as 
"Qbit 512".

I got a couple back then, and would now like to find two or three more 
to use in a project. Of course, the eBay source is long gone. There's 
not much in the way of Google hits other than the page I put up with 
some test results.

Anyone have any of these squirreled away, or know where any might be found?

Thanks,

John

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Re: [time-nuts] establishing your position w/o gps

[Chris Albertson]

have you ever tried to measure an angular distance using a hand held
instrument while standing on the deck of a moving boat in the open
ocean?  try it and you will see why they wanted a clock. You
really can't measure an arc minute reliably we should expect about 15
arc minute accuracy if you are standing on a moving ship.  A few very
skilled people could do better.

The moon moves what? about 10 degrees per day so in practical terms
you can get time to about 30 minutes.   But other sources of error
would add to that.   But still knowing even the hour is very good
that puts you in the correct time zone

On Tue, Jan 24, 2012 at 9:54 AM, jmfranke  wrote:
> In addition to the moons of Jupiter, there was a method in direct
> competition with Harrison. It was the Lunar distance method. The Lunar
> distance method used the position of the Earth's moon against the zodiac as
> a clock. The term lunar distance was used because the navigator measured the
> angular distance from the moon to various stars to establish the moon's
> position and then the time was deduced from lunar position tables.
> Developing the lunar distance tables was part of the reason for establishing
> the Royal Observatory.
>
> John  WA4WDL
>
> --
> From: "Chris Albertson" 
> Sent: Tuesday, January 24, 2012 11:36 AM
>
> To: "Discussion of precise time and frequency measurement"
> 
> Subject: Re: [time-nuts] establishing your position w/o gps
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>>>
>>> On Tue, 24 Jan 2012 11:04:08 +
>>> "Poul-Henning Kamp"  wrote:
>>>
 In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
 Kinali w
 rites:

 >All this talk about telling the time using stars or the sun made me
 > >wonder
 >how did people tell what position their telescopes had back in the days
 >before GPS?
>>
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.    The
>> problem was that on one had a clock that should keep time well enough.
>> They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure the time from local noon some even on Jupitor
>> while a person back home did the same thing.  Later when he got back
>> home they compare notes and then know the difference in longitude.
>> Good ocean going clocks were still centuries away.    But in the
>> 1500's they could only know the location after the fact when they
>> returned
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
>>
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>> and follow the instructions there.
>>
>
>
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-- 

Chris Albertson
Redondo Beach, California

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Re: [time-nuts] Looking for Harris/Qbit amplifers

[J. Forster]

If you are looking for RF hardware, you might join the TestEquipTrader
Yahoo Group and post your request there.

-John

=



> Several years ago eBay offered some nice amplifier blocks that went up
> to 500 MHz with about 10dB gain and 25dBm maximum output.
>
> The part number on the unit is Harris 0130-211013, but they were sold as
> "Qbit 512".
>
> I got a couple back then, and would now like to find two or three more
> to use in a project.  Of course, the eBay source is long gone.  There's
> not much in the way of Google hits other than the page I put up with
> some test results.
>
> Anyone have any of these squirreled away, or know where any might be
> found?
>
> Thanks,
>
> John
>
> ___
> 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] establishing your position w/o gps

[Bob Camp]

Hi

If you spend some time on the auction sites you can find some fairly good
(though not brand name) sextants on the cheap.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: Tuesday, January 24, 2012 12:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] establishing your position w/o gps

If you want to try your hand at position determination in the pre
radio nav days you can buy a "studen sextent"  It's a low cost plastic
instrument sells for about $60.  Better ones start at $200 with $500
to $800 for a good one.   But it required much pratice and training to
outgrow the plastic instrument.I took the class.I think most
anyone who wants to sail on the ocean had better take the class just
in case their GPS fails.   I know some one who had both his primary
and backup GPSes fail and he was still a week from Hawaii.   They had
to revert to the old techniques from the 1700's

Much of pre-GPS position determination is not about finding your
latitude and longitude.  That is a modern notion.What they did and
what sailors still do is find a "line of position".  That means "I am
some place on this line but I don't know where on the line"  There are
many ways to do this and they would work every method and find several
lines.   If they could see land they could shoot a compass bearing and
draw a reciprocal bearing and know they were on that line.  They would
know the ship's heading and could estimate drift and know course over
ground was parallel to that.  They could always find a latitude line.
 Then if they did this right some of these lines would roughly
intersect and they would know the position without need to know
longitude.   There were other methods to find lines that required an
estimate of your speed and without clocks they resorted to chants and
songs (jo ho, jo ho,...)  As long as you sing the old pirate song at
the same tempo every time you have a decent clock.  Then you measure
distance by tossing a big chunk of lumber overboard with a measured
rope tied to it.  The captains hated doing math by hand so they
calibrated the rope by tieing knots at intervals so the natural unit
was one arc minute at the equator and called it a "knot".

My buddy who was headed to hawaii put both GPSes in the oven in the
galley and after three days was able to get one of them to work a few
minutes  a couple times a day.  That was enough.  But he said he was
within maybe 15 miles of where he thought he was

Basically your estimated course line intersected with a line of
latitude gives you longitude.






On Tue, Jan 24, 2012 at 8:50 AM, Azelio Boriani
 wrote:
> Yes, the first real push was the Longitude Act (1714) and the Harrison's
> clocks.
>
> On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
> wrote:
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>> > On Tue, 24 Jan 2012 11:04:08 +
>> > "Poul-Henning Kamp"  wrote:
>> >
>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
>> Kinali w
>> >> rites:
>> >>
>> >> >All this talk about telling the time using stars or the sun made me
>> wonder
>> >> >how did people tell what position their telescopes had back in the
days
>> >> >before GPS?
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.    The
>> problem was that on one had a clock that should keep time well enough.
>>  They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure the time from local noon some even on Jupitor
>> while a person back home did the same thing.  Later when he got back
>> home they compare notes and then know the difference in longitude.
>>  Good ocean going clocks were still centuries away.    But in the
>> 1500's they could only know the location after the fact when they
>> returned
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
>>
>> ___
>> 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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> and follow the instructions there.



-- 

Chris Albertson
Redondo Beach, California

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[time-nuts] Looking for Harris/Qbit amplifers

[John Ackermann N8UR]

Several years ago eBay offered some nice amplifier blocks that went up 
to 500 MHz with about 10dB gain and 25dBm maximum output.


The part number on the unit is Harris 0130-211013, but they were sold as 
"Qbit 512".


I got a couple back then, and would now like to find two or three more 
to use in a project.  Of course, the eBay source is long gone.  There's 
not much in the way of Google hits other than the page I put up with 
some test results.


Anyone have any of these squirreled away, or know where any might be found?

Thanks,

John

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Re: [time-nuts] GPIB programming 'íb' style

[shalimr9]

You are welcome to use my time-nut wiki, it's at
http://www.ko4bb.com/dokuwiki/doku.php
It is open, no need to register

Didier KO4BB

Sent from my BlackBerry Wireless thingy while I do other things...

-Original Message-
From: "Poul-Henning Kamp" 
Sender: time-nuts-boun...@febo.com
Date: Mon, 23 Jan 2012 22:15:20 
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] GPIB programming 'íb' style

In message <041401ccda19$21917480$64b45d80$@pop.net>, "John Miles" writes:

>> For porlogix I'll take a look at the timelab source,

We really need a tine-nuts wiki to record stuff like this...

-- 
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] GPIB programming 'íb' style

[shalimr9]

John,

Is there a way to make a dll or an ocx out of the gpibport.cpp so that I could 
use it from within visual basic?

Didier

Sent from my BlackBerry Wireless thingy while I do other things...

-Original Message-
From: "John Miles" 
Sender: time-nuts-boun...@febo.com
Date: Mon, 23 Jan 2012 13:51:15 
To: 'Discussion of precise time and frequency measurement'
Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] GPIB programming 'íb' style

> So for NI488.2 it is clear, I will go finding the
> new stuff in their site... I hope to find ;-)
> It would be great if they have produced some
> table with the old and the new calls. I'll dig.
> 
> For porlogix I'll take a look at the timelab source,
> good idea. At the moment I don't own one
> and was in my concerns if I could actually write
> code for it not too differently from what I already know...
> Before I get one ;-)
> 
> Thanks, that was exactly the starter info I was looking.

Note that you can just copy gpibport.cpp into your project to get support
for all three -- NI488.2, Prologix GPIB, and Prologix LAN -- with the same
API.  That way you wouldn't need to look at the NI488.2 documentation at
all, except to add support for functions that aren't abstracted by gpibport.


GPIBPORT::set_connection_properties() will take an identifier string like
"GPIB0" for NI hardware, "COM3" for Prologix GPIB-USB, "192.168.100.1" for
Prologix GPIB-LAN, or "COM1:baud=9600 parity=N data=8 stop=1" for generic
RS-232 support without Prologix markup.   

Some counters like the SR 620 can use any of the four interface types, since
they have standard GPIB ports and also allow GPIB-style control through
their serial ports, so that module needed to be able to enumerate all of the
possible connection types and handle them polymorphically, so to speak.
The source file drivers\GPIB_TIC\GPIB_TIC.cpp is probably the best example
to look at if you want to use the gpibport API.  The only real
hardware-dependent stuff is in ACQ_CONTEXT::select_port(), where it builds
the selection list of interfaces and ports found on the user's system.

-- john



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Re: [time-nuts] establishing your position w/o gps

[jmfranke]

In addition to the moons of Jupiter, there was a method in direct 
competition with Harrison. It was the Lunar distance method. The Lunar 
distance method used the position of the Earth's moon against the zodiac as 
a clock. The term lunar distance was used because the navigator measured the 
angular distance from the moon to various stars to establish the moon's 
position and then the time was deduced from lunar position tables. 
Developing the lunar distance tables was part of the reason for establishing 
the Royal Observatory.


John  WA4WDL

--
From: "Chris Albertson" 
Sent: Tuesday, January 24, 2012 11:36 AM
To: "Discussion of precise time and frequency measurement" 


Subject: Re: [time-nuts] establishing your position w/o gps


On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:

On Tue, 24 Jan 2012 11:04:08 +
"Poul-Henning Kamp"  wrote:

In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila 
Kinali w

rites:

>All this talk about telling the time using stars or the sun made me 
>wonder

>how did people tell what position their telescopes had back in the days
>before GPS?


Sailingships and trade was what pushed this.   At the time of Columbus
he was able to know his latitude within a few 10s of miles but even
after returning to Europe he did no know how far around the world he
had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.The
problem was that on one had a clock that should keep time well enough.
They used hour glasses on board ship for short duration time keeping
but those were of no use on a longer ocean crossing.

Later they discovered the idea of common view of the moons of Jupiter
and they could measure the time from local noon some even on Jupitor
while a person back home did the same thing.  Later when he got back
home they compare notes and then know the difference in longitude.
Good ocean going clocks were still centuries away.But in the
1500's they could only know the location after the fact when they
returned

--

Chris Albertson
Redondo Beach, California

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and follow the instructions there.




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Re: [time-nuts] establishing your position w/o gps

[Chris Albertson]

If you want to try your hand at position determination in the pre
radio nav days you can buy a "studen sextent"  It's a low cost plastic
instrument sells for about $60.  Better ones start at $200 with $500
to $800 for a good one.   But it required much pratice and training to
outgrow the plastic instrument.I took the class.I think most
anyone who wants to sail on the ocean had better take the class just
in case their GPS fails.   I know some one who had both his primary
and backup GPSes fail and he was still a week from Hawaii.   They had
to revert to the old techniques from the 1700's

Much of pre-GPS position determination is not about finding your
latitude and longitude.  That is a modern notion.What they did and
what sailors still do is find a "line of position".  That means "I am
some place on this line but I don't know where on the line"  There are
many ways to do this and they would work every method and find several
lines.   If they could see land they could shoot a compass bearing and
draw a reciprocal bearing and know they were on that line.  They would
know the ship's heading and could estimate drift and know course over
ground was parallel to that.  They could always find a latitude line.
 Then if they did this right some of these lines would roughly
intersect and they would know the position without need to know
longitude.   There were other methods to find lines that required an
estimate of your speed and without clocks they resorted to chants and
songs (jo ho, jo ho,...)  As long as you sing the old pirate song at
the same tempo every time you have a decent clock.  Then you measure
distance by tossing a big chunk of lumber overboard with a measured
rope tied to it.  The captains hated doing math by hand so they
calibrated the rope by tieing knots at intervals so the natural unit
was one arc minute at the equator and called it a "knot".

My buddy who was headed to hawaii put both GPSes in the oven in the
galley and after three days was able to get one of them to work a few
minutes  a couple times a day.  That was enough.  But he said he was
within maybe 15 miles of where he thought he was

Basically your estimated course line intersected with a line of
latitude gives you longitude.






On Tue, Jan 24, 2012 at 8:50 AM, Azelio Boriani
 wrote:
> Yes, the first real push was the Longitude Act (1714) and the Harrison's
> clocks.
>
> On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
> wrote:
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>> > On Tue, 24 Jan 2012 11:04:08 +
>> > "Poul-Henning Kamp"  wrote:
>> >
>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
>> Kinali w
>> >> rites:
>> >>
>> >> >All this talk about telling the time using stars or the sun made me
>> wonder
>> >> >how did people tell what position their telescopes had back in the days
>> >> >before GPS?
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.    The
>> problem was that on one had a clock that should keep time well enough.
>>  They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure the time from local noon some even on Jupitor
>> while a person back home did the same thing.  Later when he got back
>> home they compare notes and then know the difference in longitude.
>>  Good ocean going clocks were still centuries away.    But in the
>> 1500's they could only know the location after the fact when they
>> returned
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
>>
>> ___
>> 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.
>>
> ___
> 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.



-- 

Chris Albertson
Redondo Beach, California

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Re: [time-nuts] establishing your position w/o gps

[Attila Kinali]

On Tue, 24 Jan 2012 11:05:58 -0600
"Lee Mushel"  wrote:

> If you're looking for a really interesting topic to read about, the 
> development of an accurate ship-board clock is really fascinating!   And it 
> wasn't done overnight!

If you have a few references on books to read, you shouldn't keep them
for yourself ;-)

Attila Kinali
-- 
Why does it take years to find the answers to
the questions one should have asked long ago?

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[time-nuts] [Fwd: RE: [Microscope] Re: HR2000 Retuning]

[J. Forster]

 Original Message 
Subject: RE: [Microscope] Re: [time-nuts] HR2000 Retuning
From:"Randall Buck" 
Date:Tue, January 24, 2012 8:35 am
To:  microsc...@yahoogroups.com
--


Possible sources for Hg vapor calibration:

1)  The Penray lamp (a small tube ~ 2" long) with its special ballast is the
standard Hg line calibration source.

2) Ordinary CFL ("spring style" lamps) will give a few HG lines against a
continuum of phosphorescence.  I haven't tried it but it should probably be
sufficient.  Note the relative position of the lines and their wavelengths
before moving the grating.

3) T-5 , miniature 6" or 8" fluorescent lamps are available without an
internal phosphor coating.  These are used in germicidal fixtures and (with
a filter) for geological prospecting.

4) You might be able to find a "germicidal" lamp with a standard light bulb
(Edison thread) base -- the clear glass envelope is a small sphere about 1
1/2 " dia.

5) Backyard pond water sterilizers use an Hg vapor lamp.  I think these
should not be operated for long out of cooling water.


IMPORTANT NOTE:  All HG lamps are capable of emitting potentially dangerous
levels of ultra violet light.  The Penray and germicidal lamps demand
particular caution since they are designed to emit the 254nm Hg line and
even 185nm line -- both wavelengths are in the UVC band.  Shielding, using
aluminum foil with a pinhole for calibration, and UV protection goggles are
essential.  Electric arc welding goggles MAY be appropriate (check first) ,
gas welding goggles are NOT appropriate.

Randall






-Original Message-
From: microsc...@yahoogroups.com [mailto:microsc...@yahoogroups.com]On
Behalf Of J. Forster
Sent: Monday, January 23, 2012 5:34 PM
To: n...@verizon.net; Discussion of precise time and frequency
measurement
Cc: microsc...@yahoogroups.com
Subject: [Microscope] Re: [time-nuts] HR2000 Retuning


That about covers it. One note, this preoceedure will move the wavelength
range the unit scans, but will not alter it. To cover a wider chunk of
spectrum, the grating will have to be changed the one with fewer or more
lp/mm.

Also you can look for light leaks by shining a flashlight at the unit
while watching the display,. A light leak will raise the noise floor
across the spectrum.

-John

=


> My extreme curiosity eventually led me to acquire a couple ofHR2000
> spectrometers from Roland.  He still has several left, and if you ever
> want to
> have the chance to grab one of these, I recommend you act fast.
>
> The units he has were from a medical diagnostic device and have a grating
> which
> gives about 200 nm of range.  The internal sensor is specified to operate
> over
> the range of 200 to 1100 nm.  My units were adjusted to work over the
> range of
> about 467 to 671 nm.  Should you need it, Ocean Optics will gladly (for
> IIRC
> around $500) put a different grating in, or for somewhat less, change the
> range
> of the existing grating.
>
> I needed to be able to cover the wavelength of a Blu-ray laser at around
> 405 nm
> so decided to attempt a recalibration.  I was able to download the manual
> as
> well as their OOIBase32 software which talks to the spectrometer over USB.
>  I
> got a couple of USB adapters so I could plug the units directly into the
> computer's standard ports.
>
> On the side of the unit you will notice a circular slotted pattern with a
> center
> screw slot and two screws 180 degrees apart on the circle.  Those outer
> screws
> have lockwashers and each had a dab of glue.  From the manual it was clear
> that
> this is the holder of the grating.  I loosened the outer screws, and while
> the
> spectrometer's input fiber was pointed at the 405 nm laser spot, I slowly
> turned
> the center slot with a screwdriver.  It didn't take much turning (CCW)
> before I
> saw a strong response peak.  I moved it to sufficiently within the range
> and
> tightened the two outer screws.
>
> Now I turned to Appendix A in the HR2000 manual.  I had to locate a Hg
> lamp (I
> was able to find an antique scientific unit on feebay) as you will need
> several
> strong spectral lines within your range for the cal procedure.  I actually
> cheated slightly from the procedure, I made an educated guesstimate of the
> short
> wavelength being seen and loaded that into the unit with the USBprogrammer
> utility.  That made it a little easier for me to identify the Hg lines.
>
> Read the procedure all the way through and understand it before trying it.
>  Less
> hair pulled out that way.  I followed the instructions, did the linear
> regression as they specified in Excel (yes, an old version will work just
> fine),
> and loaded the correction factors into the unit's EEPROM (again, using
> USBprogrammer).
>
> I then plugged both my units in at the same time, and if you get
> SprectaSuite
> from Roland (he usually

Re: [time-nuts] establishing your position w/o gps

[David]

I think James Burke discussed these clocks in one of his documentary
series.  Besides not using a pendulum, they were temperature
compensated by using materials with opposite temperature coefficients
of expansion and then gimbaled for use on a rolling and pitching ship.

Oddly enough, the phase locked loop came significantly earlier when a
clock maker used it to regulate pendulum clocks overnight to quickly
calibrate a new clock to a reference clock.

On Tue, 24 Jan 2012 17:50:54 +0100, Azelio Boriani
 wrote:

>Yes, the first real push was the Longitude Act (1714) and the Harrison's
>clocks.
>
>On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
>wrote:
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>> > On Tue, 24 Jan 2012 11:04:08 +
>> > "Poul-Henning Kamp"  wrote:
>> >
>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
>> Kinali w
>> >> rites:
>> >>
>> >> >All this talk about telling the time using stars or the sun made me
>> wonder
>> >> >how did people tell what position their telescopes had back in the days
>> >> >before GPS?
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.The
>> problem was that on one had a clock that should keep time well enough.
>>  They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure the time from local noon some even on Jupitor
>> while a person back home did the same thing.  Later when he got back
>> home they compare notes and then know the difference in longitude.
>>  Good ocean going clocks were still centuries away.But in the
>> 1500's they could only know the location after the fact when they
>> returned

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Re: [time-nuts] historical photos and info about Hafele-Keating

[Lester Veenstra]

And another name to add to the flying clock chaperones is Paul Wheeler
(USCG/USNO)  
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA496085



Lester B Veenstra  MØYCM K1YCM
les...@veenstras.com
m0...@veenstras.com
k1...@veenstras.com
 

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-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: Tuesday, January 24, 2012 7:51 AM
To: Noneayour Bsnes
Cc: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] historical photos and info about Hafele-Keating

Hi Ben,

Thanks for the note. I had planned to meet Richard Keating when
I flew out to the east coast to present the results of my Mt Rainier
relativity experiment in 2005 but sadly he pass away just months
before the conference. Carroll Alley was there so I got to meet
him, which was a treat.

You can add links to both Dr. Alley's papers and to Dr. Vessot's
papers (gravity probe A). IIRC, they are all online. If not I have
copies here I can send you.

Here's a nice photo of a similar flying clock:
http://leapsecond.com/history/Flying-Clock.htm
The clock is a hp 5060A (H&K used 5061A). The gentleman in
the foreground with his back to the camera is Len Cutler.

Given my particular interest in all this, over the years I've had
contact with a number of people involved with the development
of cesium and other atomic clocks or various traveling clock
experiments. A number of them are still alive.

Some other articles related to synchronizing clocks in the flying
clock years are:

A New Performance of the "Flying Clock" Experiment
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1964-07.pdf

Correlating Time from Europe to Asia with Flying Clocks
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1965-04.pdf

World-Wide Time Synchronization, 1966
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1966-08.pdf

'Flying Clock' Comparisons Extended to East Europe, Africa and Australia
http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1967-12.pdf

I'll contact you more off-line about this. Meanwhile, thanks for
your posting.

/tvb
www.LeapSecond.com


- Original Message - 
From: "Noneayour Bsnes" 
To: 
Sent: Monday, January 23, 2012 8:46 PM
Subject: [time-nuts] historical photos and info about Hafele-Keating


I teach physics, and I love the Hafele-Keating experiment as a way
to introduce relativity. Because the experiment has a lot of charisma, 
it's cool to be able to show students photos of the men and the
clocks aboard the plane. The general relativity text by Hartle had
a photo that he claimed was of Hafele and Keating boarding a plane,
but it turns out that that was a mistake. Some actual photos from
the experiment have been available online for a while, but they were
low resolution. I've obtained and scanned copies of these at higher
resolution and posted them here:
http://www.lightandmatter.com/article/hafele_keating.html

The copyright status of these photos varies, and in some cases is 
difficult to determine. I've given what information I had on the
web page. I'm in the U.S., where we have a pretty good fair use 
exception to copyright, and for the photos that are copyrighted,
I think I have an excellent fair-use claim.

I would be grateful to anyone who could e-mail me with any of the
following:

-any biographical information about Hafele or Keating, and contact
information if they are still living

-related historical photos that are in the public domain and of high
educational or historical interest

-information about the copyright of the photo that appeared in
Popular Mechanics

Is anyone on this list old enough to have been involved in
relativistic atomic clock experiments from that era?

Regards,

Ben Crowell



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Re: [time-nuts] establishing your position w/o gps

[Azelio Boriani]

I've read the book by Dava Sobel "Longitude"... not technical but
interesting for me.

On Tue, Jan 24, 2012 at 6:05 PM, Lee Mushel  wrote:

> If you're looking for a really interesting topic to read about, the
> development of an accurate ship-board clock is really fascinating!   And it
> wasn't done overnight!
>
> Lee  K9WRU
> - Original Message - From: "Chris Albertson" <
> albertson.ch...@gmail.com>
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Tuesday, January 24, 2012 10:36 AM
> Subject: Re: [time-nuts] establishing your position w/o gps
>
>
>
>  On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>>
>>> On Tue, 24 Jan 2012 11:04:08 +
>>> "Poul-Henning Kamp"  wrote:
>>>
>>>  In message 
>>> <20120124115848.**312d60bd4fccce4f3e71c136@**kinali.ch<20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>>,
 Attila Kinali w
 rites:

 >All this talk about telling the time using stars or the sun made me
 >wonder
 >how did people tell what position their telescopes had back in the days
 >before GPS?

>>>
>> Sailingships and trade was what pushed this.
>>
>
>
>
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Re: [time-nuts] establishing your position w/o gps

[Lee Mushel]

If you're looking for a really interesting topic to read about, the 
development of an accurate ship-board clock is really fascinating!   And it 
wasn't done overnight!


Lee  K9WRU
- Original Message - 
From: "Chris Albertson" 
To: "Discussion of precise time and frequency measurement" 


Sent: Tuesday, January 24, 2012 10:36 AM
Subject: Re: [time-nuts] establishing your position w/o gps



On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:

On Tue, 24 Jan 2012 11:04:08 +
"Poul-Henning Kamp"  wrote:

In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila 
Kinali w

rites:

>All this talk about telling the time using stars or the sun made me 
>wonder

>how did people tell what position their telescopes had back in the days
>before GPS?


Sailingships and trade was what pushed this. 




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Re: [time-nuts] establishing your position w/o gps

[Azelio Boriani]

Maybe the Longitude Act was issued also because of the disaster occured in
1707 due to a navigation error: the Royal Navy fleet lost 4 of its 15 ships.

On Tue, Jan 24, 2012 at 5:50 PM, Azelio Boriani wrote:

> Yes, the first real push was the Longitude Act (1714) and the Harrison's
> clocks.
>
>
> On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson <
> albertson.ch...@gmail.com> wrote:
>
>> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
>> > On Tue, 24 Jan 2012 11:04:08 +
>> > "Poul-Henning Kamp"  wrote:
>> >
>> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>,
>> Attila Kinali w
>> >> rites:
>> >>
>> >> >All this talk about telling the time using stars or the sun made me
>> wonder
>> >> >how did people tell what position their telescopes had back in the
>> days
>> >> >before GPS?
>>
>> Sailingships and trade was what pushed this.   At the time of Columbus
>> he was able to know his latitude within a few 10s of miles but even
>> after returning to Europe he did no know how far around the world he
>> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.The
>> problem was that on one had a clock that should keep time well enough.
>>  They used hour glasses on board ship for short duration time keeping
>> but those were of no use on a longer ocean crossing.
>>
>> Later they discovered the idea of common view of the moons of Jupiter
>> and they could measure the time from local noon some even on Jupitor
>> while a person back home did the same thing.  Later when he got back
>> home they compare notes and then know the difference in longitude.
>>  Good ocean going clocks were still centuries away.But in the
>> 1500's they could only know the location after the fact when they
>> returned
>>
>> --
>>
>> Chris Albertson
>> Redondo Beach, California
>>
>> ___
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>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
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Re: [time-nuts] establishing your position w/o gps

[Azelio Boriani]

Yes, the first real push was the Longitude Act (1714) and the Harrison's
clocks.

On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson
wrote:

> On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
> > On Tue, 24 Jan 2012 11:04:08 +
> > "Poul-Henning Kamp"  wrote:
> >
> >> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila
> Kinali w
> >> rites:
> >>
> >> >All this talk about telling the time using stars or the sun made me
> wonder
> >> >how did people tell what position their telescopes had back in the days
> >> >before GPS?
>
> Sailingships and trade was what pushed this.   At the time of Columbus
> he was able to know his latitude within a few 10s of miles but even
> after returning to Europe he did no know how far around the world he
> had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.The
> problem was that on one had a clock that should keep time well enough.
>  They used hour glasses on board ship for short duration time keeping
> but those were of no use on a longer ocean crossing.
>
> Later they discovered the idea of common view of the moons of Jupiter
> and they could measure the time from local noon some even on Jupitor
> while a person back home did the same thing.  Later when he got back
> home they compare notes and then know the difference in longitude.
>  Good ocean going clocks were still centuries away.But in the
> 1500's they could only know the location after the fact when they
> returned
>
> --
>
> Chris Albertson
> Redondo Beach, California
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
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Re: [time-nuts] establishing your position w/o gps

[Chris Albertson]

On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali  wrote:
> On Tue, 24 Jan 2012 11:04:08 +
> "Poul-Henning Kamp"  wrote:
>
>> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila 
>> Kinali w
>> rites:
>>
>> >All this talk about telling the time using stars or the sun made me wonder
>> >how did people tell what position their telescopes had back in the days
>> >before GPS?

Sailingships and trade was what pushed this.   At the time of Columbus
he was able to know his latitude within a few 10s of miles but even
after returning to Europe he did no know how far around the world he
had sailed.  Was it 1/3rd or 2/3rds?  They had no way to know.The
problem was that on one had a clock that should keep time well enough.
 They used hour glasses on board ship for short duration time keeping
but those were of no use on a longer ocean crossing.

Later they discovered the idea of common view of the moons of Jupiter
and they could measure the time from local noon some even on Jupitor
while a person back home did the same thing.  Later when he got back
home they compare notes and then know the difference in longitude.
 Good ocean going clocks were still centuries away.But in the
1500's they could only know the location after the fact when they
returned

-- 

Chris Albertson
Redondo Beach, California

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[time-nuts] Shipping Cost Correction for Spectrometers

[J. Forster]

Hi,

I heard from Roland that the specs are costing more to ship than expected.
He has had to raise his price a bit to:

1 Spec  $115
2 Specs $220

Again, please contact Roland off-list at:  roland.guil...@yahoo.com


-John

===





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Re: [time-nuts] establishing your position w/o gps

[Poul-Henning Kamp]

In message <20120124121642.4a8ad1def54bc32cca928...@kinali.ch>, Attila Kinali w
rites:
>On Tue, 24 Jan 2012 11:04:08 +

>But how do you untangle longitude and time? How do you know that you
>are looking exactly south (or north)?

North/South can be done by timing (widely spaced in inclination)
stellar transits relative to each other.

-- 
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] Determination of the placement of the first pps

[J. L. Trantham]

Thanks.

As I was re-reading the postings, I noted additional information in an
earlier post that pretty much answered the question though the term
'barycenter' is new to me.

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Jim Lux
Sent: Tuesday, January 24, 2012 12:06 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Determination of the placement of the first pps


On 1/23/12 5:50 PM, J. L. Trantham wrote:
> Is this, in any way, related to the fact the Earth has a Moon?
>
> Ideally, the Earth rotates around the Sun and the Moon rotates around 
> the Earth.  However, is it better described as the 'center of mass' of 
> the Earth/Moon

barycenter is the term

  rotates around the Sun?  Not to mention all those other
> confounding variables such as other planets and moons?

Well, yes.. there are fairly sophisticated numerical integration 
programs that figure all this stuff out, if you're interested.

>

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Re: [time-nuts] Determination of the placement of the first pps

[J. L. Trantham]

Thanks Chris.

It seems such a logical feature to have, I would think it would have been
included perhaps by a serial command.  My old CS clocks have this feature
though I have never taken the time to sync them.

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: Tuesday, January 24, 2012 12:34 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Determination of the placement of the first pps


On Mon, Jan 23, 2012 at 5:50 PM, J. L. Trantham  wrote:
> Is this, in any way, related to the fact the Earth has a Moon?
>
>  is there a way to
> 'sync' the 1 PPS output of an FE-5680A to an external signal, such as 
> a GPS receiver or TBolt?  I would think that might be possible given 
> their original purpose.

The 1PPS is not in the units specs.  It is just by luck that it works.
  However we could adjust the phase of the 1PPS by running the unit fast or
slow for some period of time and then going back to exact 10MHz.  But that
method could take a LONG time, like tens of thousands
of seconds.Better I think to test the phase and if it is "off" by
more than say, 0.01 second to just power the unit off and restart and
see what luck gives you.   I bet 100 power cycles is faster than
moving the phase by 0.5 seconds.

Maybe the answer is to wire up a few decade divers and divide the 10MHz to
1pps yourself.  Thenyou can let a known good PPS reset your counters and get
the phase correct instantly






-- 

Chris Albertson
Redondo Beach, California

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Re: [time-nuts] establishing your position w/o gps

[Attila Kinali]

On Tue, 24 Jan 2012 11:04:08 +
"Poul-Henning Kamp"  wrote:

> In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila Kinali 
> w
> rites:
> 
> >All this talk about telling the time using stars or the sun made me wonder
> >how did people tell what position their telescopes had back in the days
> >before GPS?
> 
> Back then the stars were the coordinate system and the position of
> the telescope the unknown, so you did it by observing stars with
> documented coordinates with your new telescope and then you set
> your clock and calculated your lattitude accordingly.
> 
> Remember: back then longitude and time were as single convolved coordinate.

That's what i'm aiming at. Yes, the lattitude can be calculated
using angle measurements relative to a known horizontal plane (mercury
mirror) or a vertical line (plumb bob). Still not easy to get below
an arc minute, but doable. 

But how do you untangle longitude and time? How do you know that you
are looking exactly south (or north)?

Attila Kinali

-- 
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin

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Re: [time-nuts] establishing your position w/o gps

[Poul-Henning Kamp]

In message <20120124115848.312d60bd4fccce4f3e71c...@kinali.ch>, Attila Kinali w
rites:

>All this talk about telling the time using stars or the sun made me wonder
>how did people tell what position their telescopes had back in the days
>before GPS?

Back then the stars were the coordinate system and the position of
the telescope the unknown, so you did it by observing stars with
documented coordinates with your new telescope and then you set
your clock and calculated your lattitude accordingly.

Remember: back then longitude and time were as single convolved coordinate.

-- 
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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[time-nuts] establishing your position w/o gps

[Attila Kinali]

Moin,

All this talk about telling the time using stars or the sun made me wonder
how did people tell what position their telescopes had back in the days
before GPS? I know that most countries established a coordinate system
in the last 100-200 years. But astronomy has been around much longer and
had the need for precise timing and postioning.

So, how did the gentlemen back in the good old days tell what time it was,
where they were and where they were looking? How was the first global
geodetic system established?

Wikipedia has a few interesting articles, but not much about how it
is actually done.

Attila Kinali

-- 
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin

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Re: [time-nuts] Thunderbolt GPS TimeKeeper

[David J Taylor]

Ok, about half of the Windows servers have 0.5 millisecond offsets and
some have 3 millisecond offsets.   I still call that "millisecond
level".That is very different from "microsecond level".  To me the
terms "milli level", "nano level" and so on mean "round to the nearest
three orders of magnitude."   It is a VERY course level of rounding
even more so than"rough order of magnitude" type rounding.   So I
think "micro second level" means not "within one uSec but "you are
using uSec as your units when you tell people the number"

For most casual users even 100mS is better than they need.   No one
notices if you are 100mS late for a meeting.

Chris Albertson
Redondo Beach, California


Thanks, Chris.

 http://www.satsignal.eu/mrtg/performance_ntp.php

The graphs may be confusing at first glance.  To overcome the limitation 
of MRTG of only plotting positive numbers, I needed to add a fixed amount 
to the reported offset so that it becomes a positive value.  I chose the 
offset and scaling values so that a server keeping perfect time would be a 
line right down the centre of the graph.  The offset reported by NTP is 
the deviation from that centre-line.  The left axis annotation states this 
offset.


FreeBSD PC Pixie shows deviations around 10 microseconds from nominal, 
mostly caused by the heating switching on.


Windows XP PC Feenix shows maximum deviations of around 200 microseconds.

Windows-7/32 PC Stamsund shows maximum deviations which are likely under 
50 microseconds.


The scale on the graphs for PCs Alta and Bacchus does not allow the 
deviations to be estimated accurately (as they were not originally 
intended as stratum-1 servers), but the deviation may well be under 0.3 
ms.


A couple of these PCs have speaking clocks (software) running, and 
multiple speakers speaking at differing times is rather distracting.  They 
are also monitoring a satellite data broadcast, where event times are 
compared across PCs, and across Europe, and having logs time stamped 
reasonably accurately can help.  Other folk are using PCs to measure the 
propagation delay of radio signals where, I understand, millisecond 
accuracy is the level talked about.


Colloquially, I might say: FreeBSD tens of microseconds, Windows hundreds 
of microseconds or perhaps Windows tenths of milliseconds.


Cheers,
David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk 



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Re: [time-nuts] historical photos and info about Hafele-Keating

[WB6BNQ]

Hi Ben,

Surprised to see you found the list.  I am a friend of your father.

I was around back when those experiments were done.  Alas, I was only involved,
as many others were, in standing on the ground keeping it from moving while they
got to fly overhead.

73BillWB6BNQ


Noneayour Bsnes wrote:

> I teach physics, and I love the Hafele-Keating experiment as a way
> to introduce relativity. Because the experiment has a lot of charisma,
> it's cool to be able to show students photos of the men and the
> clocks aboard the plane. The general relativity text by Hartle had
> a photo that he claimed was of Hafele and Keating boarding a plane,
> but it turns out that that was a mistake. Some actual photos from
> the experiment have been available online for a while, but they were
> low resolution. I've obtained and scanned copies of these at higher
> resolution and posted them here:
> http://www.lightandmatter.com/article/hafele_keating.html
>
> The copyright status of these photos varies, and in some cases is
> difficult to determine. I've given what information I had on the
> web page. I'm in the U.S., where we have a pretty good fair use
> exception to copyright, and for the photos that are copyrighted,
> I think I have an excellent fair-use claim.
>
> I would be grateful to anyone who could e-mail me with any of the
> following:
>
> -any biographical information about Hafele or Keating, and contact
>  information if they are still living
>
> -related historical photos that are in the public domain and of high
>  educational or historical interest
>
> -information about the copyright of the photo that appeared in
>  Popular Mechanics
>
> Is anyone on this list old enough to have been involved in
> relativistic atomic clock experiments from that era?
>
> Regards,
>
> Ben Crowell
>
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Re: [time-nuts] Thunderbolt GPS TimeKeeper

[Chris Albertson]

On Tue, Jan 24, 2012 at 12:23 AM, David J Taylor
 wrote:
>> So back to time.   If the goal is keeping good time then it is best
>> not to use Microsoft Windows.  There are good technical reasons having
>> to do with the way MS Win. keeps and adjusts time.  The bottom line is
>> that you will never be able to do better then about the millisecond
>> level even with a directly attached GPS.
>
>
> I agree that Windows is not the best OS for timekeeping, but with a directly
> attached GPS/PPS device I consistently see better than the millisecond level
> with Windows.  Please see:


Ok, about half of the Windows servers have 0.5 millisecond offsets and
some have 3 millisecond offsets.   I still call that "millisecond
level".That is very different from "microsecond level".  To me the
terms "milli level", "nano level" and so on mean "round to the nearest
three orders of magnitude."   It is a VERY course level of rounding
even more so than"rough order of magnitude" type rounding.   So I
think "micro second level" means not "within one uSec but "you are
using uSec as your units when you tell people the number"

For most casual users even 100mS is better than they need.   No one
notices if you are 100mS late for a meeting.

Chris Albertson
Redondo Beach, California

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Re: [time-nuts] Thunderbolt GPS TimeKeeper

[David J Taylor]

So back to time.   If the goal is keeping good time then it is best
not to use Microsoft Windows.  There are good technical reasons having
to do with the way MS Win. keeps and adjusts time.  The bottom line is
that you will never be able to do better then about the millisecond
level even with a directly attached GPS.


I agree that Windows is not the best OS for timekeeping, but with a 
directly attached GPS/PPS device I consistently see better than the 
millisecond level with Windows.  Please see:


 http://www.satsignal.eu/mrtg/performance_ntp.php

PCs Feenix (XP), Stamsund (Win-7/32), Alta (Win-7/64) and Bacchus (Win 
2000) demonstrate this.  All are connected to either GPS 18, GPS18x, or 
Sure GPS devices.  There is also interpolation code available allowing you 
to read time more precisely than 1 ms.


 http://www.lochan.org/2005/keith-cl/useful/win32time.html


Using another OS, BSD or
Linux you can do almost three orders of magnitude better.  (Three
orders is huge.)  The OS and software is free and all you need is any
computer that has a physical serial port, not USB but a real DB9
connector.  This is a good use for a 10 year old notebook PC.  (The
computational load is trivial so even a 486 class computer is OK)

If you run BSD or a newer Linux then Pin-1 on the DB9 can be used for
time interval measurement at almost 1 uSec precision.   You can use
this for many things, NTP being just one of them.   If you have
multiple DB9 type serial ports then you can time tag multiple channels
to about a uSec or two. (certainly 3E-6 level)

Then if the Windows PCs need correct time they could use the server
running on the old BSD based notebook PC.  Zero added cost assuming
you can find and old computer.  Then you also have a tool that can
time tag any pulse at the uSec level.


Chris Albertson
Redondo Beach, California


My own experience suggests that you need rather more than a PC running a 
good timekeeping OS - such as FreeBSD.  Take a look at PC Pixie:


 http://www.satsignal.eu/mrtg/performance_ntp.php

This is an Intel Atom box running FreeBSD 8.0, and yet in an open domestic 
environment there are reported excursions of approaching 10 microseconds 
when the heating is switched on in the morning.  So put that PC in some 
sort of thermally-controlled enclosure if you want better than the 10 
microsecond level.  The GPS puck is outside, by the way, unaffected by the 
heating switch-on.


Comparing PCs Pixie and Feenix suggests that the FreeBSD system is only 
two orders of magnitude better than Windows - still a great improvement, 
of course!


Cheers,
David 



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Re: [time-nuts] hijacking threads

[David J Taylor]

.. at least the original post was about time/frequency rather than mail 
programs and headers ..


David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk 



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