Re: [time-nuts] CW12-TIM vs M12M and the world

[Ulrich Bangert]

Thomas,

> The sawtooth error on the Motorola M12+ is about +/- 25ns, while the 
> CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the 
> sawtooth error is not as critical with the CW12-TIM. 

The first claim

> The sawtooth error on the Motorola M12+ is about +/- 25ns

is correct but are you absolutely sure that the second claim is correct
too?

It would mean a factor >10 improvement of the CW12-TIM against the M12 which
is hardly believeable. 

Best regards
Ulrich Bangert 

> -Ursprungliche Nachricht-
> Von: time-nuts-boun...@febo.com 
> [mailto:time-nuts-boun...@febo.com] Im Auftrag von Tom Knox
> Gesendet: Mittwoch, 28. Marz 2012 20:42
> An: Time-Nuts
> Betreff: [time-nuts] CW12-TIM vs M12M and the world
> 
> 
> 
> I spoke with Navsync about some of the issues we are 
> discussing and this was their response. I just received mine 
> and will try to test it over the weekend. 1. Is CW12-TIM 
> compatible with Motorola M12 ?>>  The CW12 is designed to be 
> compatible with the M12 although there are 
> some differences.  The main hardware differences are listed 
> on page 7 of  the CW12 User Manual 
> (http://www.navsync.com/docs/cw12-tim_um.pdf).  2.  According 
> to the customer, M12 has a Sawtooth Correction Error & 
> Hanging Bridge Error? Does CW12 have a solution for these type of 
> errors? How these errors are taken care of in CW12?>>
>  The Hanging Bridge Error is a pattern seen in the sawtooth 
> error that 
> occurs as the local clock frequency changes.  The standard Motorola 
> Binary software for the CW12-TIM does not have the sawtooth 
> correction 
> field in the @@Hn command implemented, but NavSync is currently 
> developing this and it will be available in future standard releases. 
>  The sawtooth error on the Motorola M12+ is about +/- 25ns, while the 
> CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the 
> sawtooth error is not as critical with the CW12-TIM. 
> 
> Thomas Knox
> 
> 
> 
> ___
> 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.

Re: [time-nuts] Best reason

[Sanjeev Gupta]

On Thu, Mar 29, 2012 at 08:43, Hal Murray  wrote:

>
> I think of GPS as a bunch of satellites broadcasting "I'm Bob, my orbit
> parameters are XXX, my clock says YYY."  If you hear 4 of those, you have 4
> equations to work out 4 unknowns.  The unknowns are your position: X, Y, Z,
> and T.
>

But, but, but, they told you the value of Y three times.  Why don't they
say: "I'm Bob, my orbit
parameters are X,Y,Z, my clock says T."  Nothing to solve :-)

And GPS jamming would work by other people calling you with: "Hi, Hal,
ignore that guy, _I_ am the genuwine Bob".

(For those who see this in a list archive many years from now: I am NOT
serious, please).

-- 
Sanjeev Gupta, the person formerly known as Bob
+65 98551208 http://www.linkedin.com/in/ghane
___
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] Best reason

[Jim Lux]

On 3/28/12 6:41 PM, Chris Dawes wrote:

Hi All,

Thanks Jim P for the thread.

I was lurking hoping for some amazing idea that would help me explain
(in simple and interesting terms) what I do, firstly you need to know my
company is the local rep for Symmetricom in Australia.

So when asked what I do for a living, you should see the eyes glaze
over; so normally easier to just say no you first!

I thought this thread was going to be my saviour! Sadly not to be.  lol




You just need to get one of their old T-shirts that looks like a 
concert-t that says "born to sync" on it (with the winged clock).  Tell 
them you're a roadie.


(that is, don't try to explain what you *really* do...)


___
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] Pulsar Source?

[Jim Lux]

On 3/28/12 1:11 PM, Tom Knox wrote:


My thought was to rec it in space before it is degraded and perhaps rec it in 
the x-ray region. A few Geo Sync Sats doing a correction algorithm for earth 
position vs the pulsars would not be that complex.

Thomas Knox




What you're talking about is generically called the X-Nav deep space 
navigation system. googling NASA XNAV turns up a lot
"XNAV holds great potential for NASA as an enabling technology for fully 
autonomous interplanetary navigation and..."


The problem is that nobody has a small, light, X-ray detector that is 
good enough.  Invent one and people will beat a path to your door and 
fling some money at you (not billions, but certainly enough to tinker on 
X-ray detectors for the rest of your life)


___
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] Best reason

[michael batchelor]

jim77...@gmail.com said:
>So when a member of the general public says:
>Why do we need really accurate clocks?
>What is your answer?
>The alternative is inaccurate clocks, would that ever be preferable?

Wouldn't that depend on how late for work you were?
___
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] Best reason

[Michael Blazer]

Just remember, to the 'average' person (no such exists in reality), all 
technology is magic.  The TV remote is a magic wand that you wave at the 
TV and recite the proper incantation (sometimes profane).  You chant the 
spell to your smart phone and you can talk to your friend anywhere in 
the world.  Everyone knows the 'spells' to make things operate, but have 
no idea how they actually work. The math used with GPS is beyond most 
(non-technical) college graduates.
One young child was asked how TV worked and he answered 'with gas. The 
pipe (cable) bring the picture in and the electricity heats it up to 
fill the screen'.  He knew that things expand when heated and made the 
connection.  This (6 or 7 year old, if I recall) showed far more 
scientific reasoning than most of our elected officials.
Most people understand faster, slower, bigger, smaller, but 'more 
accurate' is a hard concept.  1% accuracy is bad until you realize you 
are referring 1% uncertainty (99% accuracy).  I'm currently have to 
convince management that our 6-1/2 DMM (0.01% uncertainty) can't be used 
to test the 0.1ppm DC Source that we're repairing.
My earlier comment of '1 nanosecond = 1 foot' really applies to GPS. If 
the atomic clock on the satellites are allowed to drift, even a fraction 
of a nanosecond, the accuracy of the whole system quickly degrades.  
These clocks are updated at less than 4 hour intervals to keep this from 
happening.


Mike

On 3/28/2012 7:43 PM, Hal Murray wrote:

jim77...@gmail.com said:

So when a member of the general public says:
Why do we need really accurate clocks?
What is your answer?
Personally I explain that accurate clocks enable you to pack a higher data
rate into your smart phone. They like that.
Any other thoughts?

Navigation?  It goes back to Harrison.  Dava Sobel's Longitude is good.
There is a version with nice pictures.


GPS is probably something they can appreciate.

If you have to explain why GPS needs accurate clocks, it might be simpler to
start with LORAN in 2D.  Work out a simple example and then do it again with
one of the transmitters being off by a few microseconds.

I think of GPS as a bunch of satellites broadcasting "I'm Bob, my orbit
parameters are XXX, my clock says YYY."  If you hear 4 of those, you have 4
equations to work out 4 unknowns.  The unknowns are your position: X, Y, Z,
and T.





___
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] Lucent GPS Timing Antenna question

[k4...@aol.com]

Jerry, that antenna is made by PCTEL.  See: antenna.pctel.com
Doug, K4CLE
Connected by DROID on Verizon Wireless

-Original message-
From: Jerry Mulchin 
To: time-nuts@febo.com
Sent: Sun, Mar 25, 2012 23:31:09 GMT+00:00
Subject: [time-nuts] Lucent GPS Timing Antenna question

I just picked up a Lucent KS-24019L116 GPS Timing antenna and wondered if  
anyone
here has information on the antenna. I do know that it has 40dB of gain. But  
I don't
know what the power supply voltage is suppose to be. I would assume +5VDC.  
If
any has information I would appreciate getting it if possible. My usual  
friend Google

was of no help.

Thanks
Jerry


___
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.

Re: [time-nuts] Loran Signals

[paul swed]

Good to hear that someone responds and it looks like you have an email
address that works. This confirms the thread I sent earlier today about the
emission delay. Its actually not dual rated. It also confirms the reason
that the master and x delay were exactly identical in signal strength.
Something that never happened in the real chains.
How do you contact them by email?
Further when and if they get the go ahead you just have to wonder what the
rcvr cost will be.
Somehow I might guess not in the ole time-nut range.
Thanks
Paul
WB8TSL

On Wed, Mar 28, 2012 at 9:57 PM, Stan, W1LE  wrote:

> Rich, Thanks for the update.
>
> I suspect the GRI rates are part of a receiver's firmware look up table,
> which led me astray.
>
> Stan, W1LE   Cape Cod
>
>
>
> On 3/28/2012 9:52 PM, Rich and Marcia Putz wrote:
>
>> Hi all;
>> I exchanged an email with a gentleman from UrsaNav and he indicated that
>> transmissions were eminating(sic) from Wilwood NJ and that they were dual
>> rated to look like Dana and Seneca. This explains why the signals level are
>> much lower than they were here in Indiana then when Dana was on the air.
>> And as the article stated he also mentioned different modulation schemes
>> that may not be able to be locked to by conventional receivers,ie. FS-700s&
>>  2100Fs. UrsaNav does offer their SDR receivers that will recover the
>> appropriate timing information, we shall see where this leads.
>>
>> Regards;
>> Rich
>> __**_
>> 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.
>
___
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] Loran Signals

[Stan, W1LE]

Rich, Thanks for the update.

I suspect the GRI rates are part of a receiver's firmware look up table, 
which led me astray.


Stan, W1LE   Cape Cod


On 3/28/2012 9:52 PM, Rich and Marcia Putz wrote:

Hi all;
I exchanged an email with a gentleman from UrsaNav and he indicated that 
transmissions were eminating(sic) from Wilwood NJ and that they were dual rated to 
look like Dana and Seneca. This explains why the signals level are much lower than 
they were here in Indiana then when Dana was on the air. And as the article stated 
he also mentioned different modulation schemes that may not be able to be locked to 
by conventional receivers,ie. FS-700s&  2100Fs. UrsaNav does offer their SDR 
receivers that will recover the appropriate timing information, we shall see where 
this leads.
Regards;
Rich
___
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.

[time-nuts] Loran Signals

[Rich and Marcia Putz]

Hi all;
I exchanged an email with a gentleman from UrsaNav and he indicated that 
transmissions were eminating(sic) from Wilwood NJ and that they were dual rated 
to look like Dana and Seneca. This explains why the signals level are much 
lower than they were here in Indiana then when Dana was on the air. And as the 
article stated he also mentioned different modulation schemes that may not be 
able to be locked to by conventional receivers,ie. FS-700s & 2100Fs. UrsaNav 
does offer their SDR receivers that will recover the appropriate timing 
information, we shall see where this leads.
Regards;
Rich
___
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] Best reason

[Randall Prentice]

People can all relate to their cellphones.

Just tell them that the cellphones all yell at each other but not at the same 
time so as long as you know when to listen you can hear the other end.  :-)

Regards
Randall
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Chris Dawes
Sent: Thursday, 29 March 2012 2:41 p.m.
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Best reason

Hi All,

Thanks Jim P for the thread.  

I was lurking hoping for some amazing idea that would help me explain (in 
simple and interesting terms) what I do, firstly you need to know my company is 
the local rep for Symmetricom in Australia.

So when asked what I do for a living, you should see the eyes glaze over; so 
normally easier to just say no you first!

I thought this thread was going to be my saviour! Sadly not to be.  lol



Chris


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Chris Stake
Sent: Thursday, 29 March 2012 12:31 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Best reason

jim77...@gmail.com said:
So when a member of the general public says:
Why do we need really accurate clocks?
What is your answer?
The alternative is inaccurate clocks, would that ever be preferable?


___
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.

___
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] Best reason

[Chris Dawes]

Hi All,

Thanks Jim P for the thread.  

I was lurking hoping for some amazing idea that would help me explain
(in simple and interesting terms) what I do, firstly you need to know my
company is the local rep for Symmetricom in Australia.

So when asked what I do for a living, you should see the eyes glaze
over; so normally easier to just say no you first!

I thought this thread was going to be my saviour! Sadly not to be.  lol



Chris


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Stake
Sent: Thursday, 29 March 2012 12:31 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Best reason

jim77...@gmail.com said:
So when a member of the general public says:
Why do we need really accurate clocks?
What is your answer?
The alternative is inaccurate clocks, would that ever be preferable?


___
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.

Re: [time-nuts] Best reason

[Chris Stake]

jim77...@gmail.com said:
So when a member of the general public says:
Why do we need really accurate clocks?
What is your answer?
The alternative is inaccurate clocks, would that ever be preferable?


___
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] Best reason

[Hal Murray]

jim77...@gmail.com said:
> So when a member of the general public says:
> Why do we need really accurate clocks?
> What is your answer?
> Personally I explain that accurate clocks enable you to pack a higher data
> rate into your smart phone. They like that.

> Any other thoughts?

Navigation?  It goes back to Harrison.  Dava Sobel's Longitude is good.  
There is a version with nice pictures.


GPS is probably something they can appreciate.

If you have to explain why GPS needs accurate clocks, it might be simpler to 
start with LORAN in 2D.  Work out a simple example and then do it again with 
one of the transmitters being off by a few microseconds.

I think of GPS as a bunch of satellites broadcasting "I'm Bob, my orbit 
parameters are XXX, my clock says YYY."  If you hear 4 of those, you have 4 
equations to work out 4 unknowns.  The unknowns are your position: X, Y, Z, 
and T.



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




___
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] ntpdc -c kern explanation

[Hal Murray]

> Can someone give me a lay mans explanation of each of the lines of output
> from my ntpdc -c kern command please? 

You will probably get better answers to NTP specific questions on the NTP 
mailing list:
  http://lists.ntp.org/listinfo/questions
It's gatewayed (both directions) to usenet:comp.protocols.time.ntp


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




___
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] Pulsar Source?

[Jim Palfreyman]

Folks, I'm currently writing my thesis on pulsars, but I need to spend time
on it rather than here. :-) But since a lot of this discussion is right at
the front of my brain, here's a summary.

Some pulsars "glitch" or speed up. The Vela pulsar (PSR J0835-4510) does
this (this is the pulsar I've been studying) and yes these type of pulsars
are bad clocks. A jump of its pulse rate of the order of 10^-6 s/s randomly
every few years is not good. It does nearly settle back to its original
rate after a few months.

The nature of these glitches (in Vela at least) is not well understood, but
three theories have been put forward:

   - An orbiting planet - but this has been discarded due to their
   irregularity.
   - Star quakes caused by a separation of the crust on the surface of the
   neutron star from its super-fluid interior. (Not very popular any more)
   - The effects of tiny micro vortices in the internal super-fluid. (If
   you can understand this paper - good luck to you!)

Now faster pulsars, in particular millisecond pulsars (~700 Hz from memory
is the fastest) are quite good clocks and they do rival atomic clocks. The
hunt is on to find as many of these as they can, well spread across the
sky, so they can look at the effects of gravitational waves on the beams of
these super accurate clocks. This is one proposed method to detect
gravitational waves.

The main problem I see from the original suggestion is that most pulsars
are quite faint and you need a very decent telescope to see individual
pulses. Vela is very bright, and the 26m telescope I used can only just see
the average pulse. I'm studying bright pulses and we can see those easily.

So to dedicate a massive radio telescope (or two) pointing at a millisecond
pulsar just so we can re-transmit it, is probably not sensible. However,
studies of these remarkable pulsars is ongoing.


Jim



On 29 March 2012 10:20, Hal Murray  wrote:

>
> > All that is of course correct. But ultimately the pulsars are a better
> > source, I see it as an application question, could it be utilized?
> Perhaps
> > building an algorithm and basing corrections on multiple pulsars x-ray
> > pulses like a GPS constellation for the next generation of conventional
> GPS.
>
> I think modern atomic clocks are better than Pulsars.
>
> Unfortunately, I don't have a good reference handy.  I think the theorists
> have several ideas for why the period of Pulsars change.
>
>
> --
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> ___
> 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.

Re: [time-nuts] Pulsar Source?

[Michael Blazer]

Ultimately all pulsars slow down.  Pulsars are rotating neutron stars.  
We see the pulse whenever the beam from one of the poles points in our 
direction. A pulsar emits a massive amount of energy and there is drag 
from the rotating magnetic field in its stellar environment. There is 
also matter falling onto the neutron star and the crust can flex and 
shift (star quakes).  All these lead to variations in the period.


Mike

On 3/28/2012 6:20 PM, Hal Murray wrote:

All that is of course correct. But ultimately the pulsars are a better
source, I see it as an application question, could it be utilized? Perhaps
building an algorithm and basing corrections on multiple pulsars x-ray
pulses like a GPS constellation for the next generation of conventional GPS.

I think modern atomic clocks are better than Pulsars.

Unfortunately, I don't have a good reference handy.  I think the theorists
have several ideas for why the period of Pulsars change.




___
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] Pulsar Source?

[Hal Murray]

> All that is of course correct. But ultimately the pulsars are a better
> source, I see it as an application question, could it be utilized? Perhaps
> building an algorithm and basing corrections on multiple pulsars x-ray
> pulses like a GPS constellation for the next generation of conventional GPS.

I think modern atomic clocks are better than Pulsars.

Unfortunately, I don't have a good reference handy.  I think the theorists 
have several ideas for why the period of Pulsars change.


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




___
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] Best reason

[Michael Blazer]

1 nanosecond = 1 foot, do you know where you are?

Remember, wherever you go, there you are.  Buckaroo Banzai


On 3/28/2012 3:28 AM, Jim Palfreyman wrote:

So when a member of the general public says:

Why do we need really accurate clocks?

What is your answer?

Personally I explain that accurate clocks enable you to pack a higher data
rate into your smart phone. They like that.

Any other thoughts?

Jim
___
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.

Re: [time-nuts] Pulsar Source?

[J. Forster]

I don't know about pulsars other than The Crab.

If you are contemplating using a pulsar, you also have a load of orbital
mechanics corrections to consider. It is highly unlikely the pulsar is not
moving with respect to the earth, in several prettx complex ways.

-John



> That cuts to the heart of my question, are starquakes common to all
> pulsars? It seem long ago Pulsars were discounted as a viable terrestrial
> freq standard. But my thought was doing this in space away from the noise
> and atmospheric concerns on earth.
>
> Thomas Knox
>
>
>
>> Date: Wed, 28 Mar 2012 16:09:59 -0400
>> From: paulsw...@gmail.com
>> To: j...@quikus.com; time-nuts@febo.com
>> Subject: Re: [time-nuts] Pulsar Source?
>>
>> I have enough trouble with wwvb :-)
>> Going to skip this project
>>
>> On Wed, Mar 28, 2012 at 4:02 PM, J. Forster  wrote:
>>
>> > Pulsars use for high accuracy timing was discarded in about the
>> > 1960s-1970s. There are sudden pulsar rate changes, related to
>> starquakes
>> > as I remember. Counselman et al did the expeeriment.
>> >
>> > Also, there are very few microwave photons per pulse. It takes a lot
>> of
>> > correlation to get anything, even with as big a dish as Aricebo.
>> >
>> > -John
>> >
>> > 
>> >
>> >
>> >
>> > > If I recall correctly,
>> > >
>> > > In one of my trips to the NRAO in Greenbank, WV they were, at one
>> time,
>> > > using a
>> > > dedicated 60ft dish to track a pulsar to compare it against their
>> local
>> > > H-Maser.
>> > > (It was interesting to see the Maser as it looked like a "homebrew"
>> > > version.  I
>> > > saw no manufacturer's name on it.)
>> > >
>> > > It would come down to what value of S/N do you want or need to make
>> your
>> > > own
>> > > measurment.
>> > >
>> > > -Brian, WA1ZMS
>> > >
>> > >
>> > >
>> > >
>> > > - Original Message 
>> > > From: David McGaw 
>> > > To: Discussion of precise time and frequency measurement
>> > > 
>> > > Sent: Wed, March 28, 2012 3:16:03 PM
>> > > Subject: Re: [time-nuts] Pulsar Source?
>> > >
>> > > What would it take (how big a dish) to receive a pulsar directly,
>> such
>> > > as the millisecond one in the Crab Nebula?  DBTV, TVRO?
>> > >
>> > > David
>> > >
>> > > On 3/28/12 2:29 PM, Tom Knox wrote:
>> > >> If pulsars are natures best clocks, I wonder how practical it would
>> be
>> > >> to use
>> > >>satellites to receive and rebroadcast a highly accurate timing
>> signal
>> > >> based on
>> > >>their signals?
>> > >>
>> > >> Thomas Knox
>> > >>
>> > >>
>> > >>
>> > >> ___
>> > >> 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.
>> > >
>> > >
>> > > ___
>> > > 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.
>> >
>> ___
>> 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.
>
>



___
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] Pulsar Source?

[Tom Knox]

That cuts to the heart of my question, are starquakes common to all pulsars? It 
seem long ago Pulsars were discounted as a viable terrestrial freq standard. 
But my thought was doing this in space away from the noise and atmospheric 
concerns on earth.  

Thomas Knox



> Date: Wed, 28 Mar 2012 16:09:59 -0400
> From: paulsw...@gmail.com
> To: j...@quikus.com; time-nuts@febo.com
> Subject: Re: [time-nuts] Pulsar Source?
> 
> I have enough trouble with wwvb :-)
> Going to skip this project
> 
> On Wed, Mar 28, 2012 at 4:02 PM, J. Forster  wrote:
> 
> > Pulsars use for high accuracy timing was discarded in about the
> > 1960s-1970s. There are sudden pulsar rate changes, related to starquakes
> > as I remember. Counselman et al did the expeeriment.
> >
> > Also, there are very few microwave photons per pulse. It takes a lot of
> > correlation to get anything, even with as big a dish as Aricebo.
> >
> > -John
> >
> > 
> >
> >
> >
> > > If I recall correctly,
> > >
> > > In one of my trips to the NRAO in Greenbank, WV they were, at one time,
> > > using a
> > > dedicated 60ft dish to track a pulsar to compare it against their local
> > > H-Maser.
> > > (It was interesting to see the Maser as it looked like a "homebrew"
> > > version.  I
> > > saw no manufacturer's name on it.)
> > >
> > > It would come down to what value of S/N do you want or need to make your
> > > own
> > > measurment.
> > >
> > > -Brian, WA1ZMS
> > >
> > >
> > >
> > >
> > > - Original Message 
> > > From: David McGaw 
> > > To: Discussion of precise time and frequency measurement
> > > 
> > > Sent: Wed, March 28, 2012 3:16:03 PM
> > > Subject: Re: [time-nuts] Pulsar Source?
> > >
> > > What would it take (how big a dish) to receive a pulsar directly, such
> > > as the millisecond one in the Crab Nebula?  DBTV, TVRO?
> > >
> > > David
> > >
> > > On 3/28/12 2:29 PM, Tom Knox wrote:
> > >> If pulsars are natures best clocks, I wonder how practical it would be
> > >> to use
> > >>satellites to receive and rebroadcast a highly accurate timing signal
> > >> based on
> > >>their signals?
> > >>
> > >> Thomas Knox
> > >>
> > >>
> > >>
> > >> ___
> > >> 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.
> > >
> > >
> > > ___
> > > 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.
> >
> ___
> 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.

Re: [time-nuts] Pulsar Source?

[Tom Knox]

My thought was to rec it in space before it is degraded and perhaps rec it in 
the x-ray region. A few Geo Sync Sats doing a correction algorithm for earth 
position vs the pulsars would not be that complex.

Thomas Knox



> From: albertson.ch...@gmail.com
> Date: Wed, 28 Mar 2012 12:51:20 -0700
> To: n1...@alum.dartmouth.org; time-nuts@febo.com
> Subject: Re: [time-nuts] Pulsar Source?
> 
> On Wed, Mar 28, 2012 at 12:16 PM, David McGaw  
> wrote:
> > What would it take (how big a dish) to receive a pulsar directly, such as
> > the millisecond one in the Crab Nebula?  DBTV, TVRO?
> 
> Amateurs have observed it using Yagi type antenna.  You'd need at
> least a pair of them spaced out on an east-west line.  It is within
> the realm of a reasonable project for a person working at home
> 
> 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.

Re: [time-nuts] Pulsar Source?

[paul swed]

I have enough trouble with wwvb :-)
Going to skip this project

On Wed, Mar 28, 2012 at 4:02 PM, J. Forster  wrote:

> Pulsars use for high accuracy timing was discarded in about the
> 1960s-1970s. There are sudden pulsar rate changes, related to starquakes
> as I remember. Counselman et al did the expeeriment.
>
> Also, there are very few microwave photons per pulse. It takes a lot of
> correlation to get anything, even with as big a dish as Aricebo.
>
> -John
>
> 
>
>
>
> > If I recall correctly,
> >
> > In one of my trips to the NRAO in Greenbank, WV they were, at one time,
> > using a
> > dedicated 60ft dish to track a pulsar to compare it against their local
> > H-Maser.
> > (It was interesting to see the Maser as it looked like a "homebrew"
> > version.  I
> > saw no manufacturer's name on it.)
> >
> > It would come down to what value of S/N do you want or need to make your
> > own
> > measurment.
> >
> > -Brian, WA1ZMS
> >
> >
> >
> >
> > - Original Message 
> > From: David McGaw 
> > To: Discussion of precise time and frequency measurement
> > 
> > Sent: Wed, March 28, 2012 3:16:03 PM
> > Subject: Re: [time-nuts] Pulsar Source?
> >
> > What would it take (how big a dish) to receive a pulsar directly, such
> > as the millisecond one in the Crab Nebula?  DBTV, TVRO?
> >
> > David
> >
> > On 3/28/12 2:29 PM, Tom Knox wrote:
> >> If pulsars are natures best clocks, I wonder how practical it would be
> >> to use
> >>satellites to receive and rebroadcast a highly accurate timing signal
> >> based on
> >>their signals?
> >>
> >> Thomas Knox
> >>
> >>
> >>
> >> ___
> >> 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.
> >
> >
> > ___
> > 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.
>
___
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] Pulsar Source?

[J. Forster]

Pulsars use for high accuracy timing was discarded in about the
1960s-1970s. There are sudden pulsar rate changes, related to starquakes
as I remember. Counselman et al did the expeeriment.

Also, there are very few microwave photons per pulse. It takes a lot of
correlation to get anything, even with as big a dish as Aricebo.

-John





> If I recall correctly,
>
> In one of my trips to the NRAO in Greenbank, WV they were, at one time,
> using a
> dedicated 60ft dish to track a pulsar to compare it against their local
> H-Maser.
> (It was interesting to see the Maser as it looked like a "homebrew"
> version.  I
> saw no manufacturer's name on it.)
>
> It would come down to what value of S/N do you want or need to make your
> own
> measurment.
>
> -Brian, WA1ZMS
>
>
>
>
> - Original Message 
> From: David McGaw 
> To: Discussion of precise time and frequency measurement
> 
> Sent: Wed, March 28, 2012 3:16:03 PM
> Subject: Re: [time-nuts] Pulsar Source?
>
> What would it take (how big a dish) to receive a pulsar directly, such
> as the millisecond one in the Crab Nebula?  DBTV, TVRO?
>
> David
>
> On 3/28/12 2:29 PM, Tom Knox wrote:
>> If pulsars are natures best clocks, I wonder how practical it would be
>> to use
>>satellites to receive and rebroadcast a highly accurate timing signal
>> based on
>>their signals?
>>
>> Thomas Knox
>>
>>
>>
>> ___
>> 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.
>
>
> ___
> 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.

Re: [time-nuts] Pulsar Source?

[Tom Knox]

Hi Chris;
All that is of course correct. But ultimately the pulsars are a better source, 
I see it as an application question, could it be utilized? Perhaps building an 
algorithm and basing corrections on multiple pulsars x-ray pulses like a GPS 
constellation for the next generation of conventional GPS. 
Thomas Knox



> From: albertson.ch...@gmail.com
> Date: Wed, 28 Mar 2012 12:13:24 -0700
> To: time-nuts@febo.com
> Subject: Re: [time-nuts] Pulsar Source?
> 
> On Wed, Mar 28, 2012 at 11:29 AM, Tom Knox  wrote:
> >
> > If pulsars are natures best clocks, I wonder how practical it would be to 
> > use satellites to receive and rebroadcast a highly accurate timing signal 
> > based on their signals?
> 
> The problem is in the rebroadcasting which will have the same problems
> as GPS.  One needs to know the exact location of the satellite
> transmitter and there is the problem if the patch through the
> atmosphere effecting the signal in non-predictable ways.   The
> solutions to these problem apply to GPS as well.
> 
> There is also the problem of Doppler shift between Earth and the
> pulsar.  For that reason you need to look at many of them and try and
> back all the shifts out to get a kind of average reference frame.  A
> bet of processing is involved.   You can't simply re-transmit the
> signal from one of them.
> 
> 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.

Re: [time-nuts] Pulsar Source?

[Chris Albertson]

On Wed, Mar 28, 2012 at 12:16 PM, David McGaw  wrote:
> What would it take (how big a dish) to receive a pulsar directly, such as
> the millisecond one in the Crab Nebula?  DBTV, TVRO?

Amateurs have observed it using Yagi type antenna.  You'd need at
least a pair of them spaced out on an east-west line.  It is within
the realm of a reasonable project for a person working at home

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] Pulsar Source?

[Brian Justin]

If I recall correctly,

In one of my trips to the NRAO in Greenbank, WV they were, at one time, using a 
dedicated 60ft dish to track a pulsar to compare it against their local H-Maser.
(It was interesting to see the Maser as it looked like a "homebrew" version.  I 
saw no manufacturer's name on it.)

It would come down to what value of S/N do you want or need to make your own 
measurment.

-Brian, WA1ZMS




- Original Message 
From: David McGaw 
To: Discussion of precise time and frequency measurement 
Sent: Wed, March 28, 2012 3:16:03 PM
Subject: Re: [time-nuts] Pulsar Source?

What would it take (how big a dish) to receive a pulsar directly, such 
as the millisecond one in the Crab Nebula?  DBTV, TVRO?

David

On 3/28/12 2:29 PM, Tom Knox wrote:
> If pulsars are natures best clocks, I wonder how practical it would be to use 
>satellites to receive and rebroadcast a highly accurate timing signal based on 
>their signals?
>
> Thomas Knox
>
>
>   
> ___
> 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.


___
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] Best reason

[michael batchelor]

Antonio I8IOV wrote:
>I wrote:

>>Well the best reason is that by our social convention it makes people 

>comfortable. 
>>
>>But that reason does have much logic behind it. 

>One month ago a 38-year old wristwatch resurfaced from a junk box and I 
>decided to return to it at least temporarily. It drifts some 30 seconds per 
>day, but sincerely I don't feel any particular discomfort with it.

Obviously I meant to say that it "doesn't" have much logic, not that
it "does" have much logic. 

Clearly for tens of thousands of years we had no more precision than 
daily sunrise for timekeeping, so the world won't vanish if we don't 
have accurate clocks. 

I myself have a few mechanical watches, and I no longer wear a wrist 
watch since I seem to be surrounded by clocks all the time. Every 
computer screen in my sight has the TOD in the corner. My cell phone has
the TOD. There's a clock on the wall in almost every room I walk in at 
work and at home. 

But our social convention has changed over time, and now we expect 
to know the time precision closer than sunrise/sunset can tell us. 

Personally, +/- a minute or two is good enough for most everything I
do in my life. But frequency is important to me. 

Michael / KA7ZNZ
___
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] Best reason

[Mike S]

On 3/28/2012 1:42 PM, David McGaw wrote:

I never have
considered quartz watches to be better unless they can be adjusted,
which most cannot.


Most decent ones can be. I've got some Citizens and Seikos, which have a 
small trimmer cap you can adjust. There's usually a test point nearby 
with a easy to figure out frequency output you can look at with a good 
counter (I think I've seen both 100 Hz and 32768 Hz outputs).



___
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] FE-5680A x-rays

[Rich]

I have received several requests stemming from the original posting a few
days ago to include a TIFF format in addition to the RAW and PSD format used
in Photoshop. My goal was to trace the 1pps and lock circuit so I did not go
for smooth grayscale in the printed 8x11 pictures I pasted on my shop wall. 

They are now in the Data directory. The TIFF images have been properly
rotated so you are looking from the backplate to the top when stitching.

At the link below are about 30 real-time X-ray images were done in
transmission

In the attached file the two directories in "Data" are one: image format in
raw (need to be flipped and rotated as needed) in two: in the psd Photoshop
format and three: in the TIFF format.

Best resolution will be in the RAW format.

Two other files, in the top level, are for guidance in positioning them on
the chart and a look at the final assembly result (at much lower
resolution).

*
Of note (while I was doing this) is a posting here by Jose Camara that also
did a wonderful stitching job of the individual photos at high res.
Thanks for the nice job Jose.
*

The images are now available at: http://download.muanalysis.com/FE-5680A.zip

Have fun.

Rich



___
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] Pulsar Source?

[David McGaw]

What would it take (how big a dish) to receive a pulsar directly, such 
as the millisecond one in the Crab Nebula?  DBTV, TVRO?


David

On 3/28/12 2:29 PM, Tom Knox wrote:

If pulsars are natures best clocks, I wonder how practical it would be to use 
satellites to receive and rebroadcast a highly accurate timing signal based on 
their signals?

Thomas Knox



___
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.

Re: [time-nuts] Pulsar Source?

[Chris Albertson]

On Wed, Mar 28, 2012 at 11:29 AM, Tom Knox  wrote:
>
> If pulsars are natures best clocks, I wonder how practical it would be to use 
> satellites to receive and rebroadcast a highly accurate timing signal based 
> on their signals?

The problem is in the rebroadcasting which will have the same problems
as GPS.  One needs to know the exact location of the satellite
transmitter and there is the problem if the patch through the
atmosphere effecting the signal in non-predictable ways.   The
solutions to these problem apply to GPS as well.

There is also the problem of Doppler shift between Earth and the
pulsar.  For that reason you need to look at many of them and try and
back all the shifts out to get a kind of average reference frame.  A
bet of processing is involved.   You can't simply re-transmit the
signal from one of them.

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] FE5680A x-rays

[Rich]

Nice job. I downloaded them for reference.

The original composite was done while repairing my defective 1pps unit and
thus I just printed sheets from the original x-rays as needed and eventually
decided completing the whole thing with scotch tape. You are right about the
down conversion. The composite posted as the example was just a picture of
the shop wall with my small camera. That is why I posted the original RAW
photos. Actually I hope to have the individual TIFF properly oriented on the
web link in a few hours (not quite the res you have as I only have a
freeware program to do that)

The only reason I did this was to trace the 1pps and lock circuit (turned
out the 74act240 was the guilty party).

Having lost sight of our objective we will redouble efforts.. I'll post
a note when the TIFFs are up.

Cheers

Richard


___
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] CW12-TIM vs M12M and the world

[Tom Knox]

I spoke with Navsync about some of the issues we are discussing and this was 
their response. I just received mine and will try to test it over the weekend.
1. Is CW12-TIM compatible with Motorola M12 ?>>
 The CW12 is designed to be compatible with the M12 although there are 
some differences.  The main hardware differences are listed on page 7 of
 the CW12 User Manual (http://www.navsync.com/docs/cw12-tim_um.pdf).  2.
 According to the customer, M12 has a Sawtooth Correction Error & 
Hanging Bridge Error? Does CW12 have a solution for these type of 
errors? How these errors are taken care of in CW12?>>
 The Hanging Bridge Error is a pattern seen in the sawtooth error that 
occurs as the local clock frequency changes.  The standard Motorola 
Binary software for the CW12-TIM does not have the sawtooth correction 
field in the @@Hn command implemented, but NavSync is currently 
developing this and it will be available in future standard releases. 
 The sawtooth error on the Motorola M12+ is about +/- 25ns, while the 
CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the 
sawtooth error is not as critical with the CW12-TIM. 

Thomas Knox


  
___
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] Pulsar Source?

[Tom Knox]

If pulsars are natures best clocks, I wonder how practical it would be to use 
satellites to receive and rebroadcast a highly accurate timing signal based on 
their signals?

Thomas Knox


  
___
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] Best reason

[Chris Albertson]

Two good reasons:

(1) Many uses in science and engineering.  Mostly indirectly, you need
a good frequency standard to calibrate some instrument so you can
measure something.  Thinks like distance, current, capacitance are
based on time if you follow the chain long enough.As frequencies
get lower you starting thinking of period and so now you need to know
the time.There are many practical reasons but most are many levels
indirect.

(2) it is a fun hobby, like building a model ship inside a glass
bottle it is useless but that is the point of hobbies.

___
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] Best reason

[David McGaw]

Mechanical wristwatches are capable of good precision.  I have an 
inexpensive 40-year old Caravelle (Bulova) that with reasonable 
adjustment can still keep to a few seconds per day.  I never have 
considered quartz watches to be better unless they can be adjusted, 
which most cannot.


David

On 3/28/12 1:08 PM, iov...@inwind.it wrote:

batchelo...@yahoo.com  wrote


Well the best reason is that by our social convention it makes people

comfortable.

But that reason does have much logic behind it.

One month ago a 38-year old wristwatch resurfaced from a junk box and I
decided to return to it at least temporarily. It drifts some 30 seconds per
day, but sincerely I don't feel any particular discomfort with it.
Antonio I8IOV

___
time-nuts mailing list --time-nuts@febo.com
To unsubscribe, go tohttps://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.

Re: [time-nuts] pc loran c program

[paul swed]

:-) cause it is wildwood

On Wed, Mar 28, 2012 at 12:11 PM, Stan, W1LE  wrote:

> Thanks for the pointer.
>
> The DF6NM Grabber shows the active GRIs:
>
> http://www.alice-dsl.net/**df6nm/LoranView/LoranGrabber.**htm
>
> Interesting he calls 89700 as Wildwood vice Dana or Seneca.
>
> Stan, W1LE
>
>
>
>
>
> On 3/28/2012 11:45 AM, ALAN MELIA wrote:
>
>> Peter Martinez G3PLX wrote some software which I think used GPS 1pps sync
>> to receive Canadian eastern stations in the UK and monitor variations in
>> time of arrival.I dont know that it produces "IDs" I belive that was
>> derived from the GRIs.I think )Peter named the technique "clicklock"
>> and several others added embellishments. I used one of these for measuring
>> Loran-C sidebands as heard way up on 136kHz (an amateur radio band in
>> Europe and the rest of the World) Peter lost interest in this and moved on,
>> but copies may still be floating around o the web.
>>
>> Markus Vester DF6NM runs a site that observes and records Loran
>> transmissions worldwide. I dont have the URL in this PC but a google of his
>> name and call + loran should yield something. I believe Markus's program is
>> feely available for amateur use.
>>
>> Alan
>> G3NYK
>>
>>
>> --- On Wed, 28/3/12, Stan, W1LE  wrote:
>>
>>  From: Stan, W1LE
>>> Subject: Re: [time-nuts] pc loran c program
>>> To: "Discussion of precise time and frequency measurement"<
>>> time-nuts@febo.**com >
>>> Date: Wednesday, 28 March, 2012, 15:45
>>>
>>> A google search shows:
>>>
>>> http://www.coaa.co.uk/**ndbfinder.htm
>>>
>>> I will try it later this evening when I get back home...
>>>
>>> Stan, W1LE   Cape Cod
>>>
>>>
>>>
>>> On 3/28/2012 8:53 AM, paul swed wrote:
>>>
 Never heard of one.
 Generally its a hardware decode


 On Wed, Mar 28, 2012 at 7:17 AM, Bill Riches>>> >wrote:

  Are there any pc programs that can decode Loran C
>
 id's?
>>>
 73,
>
> Bill, WA2DVU
> Cape May, NJH
>
>
>
>>> __**_
>>> 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.
>>
>>
>
> __**_
> 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.

Re: [time-nuts] Yahoo group not receiving emal

[J. Forster]

???  This is not a Yahoo Group.

-John


> Hi,
> I have been a member of the group for a long time yahoo is not sending
> email.
> Thank You
> ___
> 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.

[time-nuts] LORAN C another item figured out station location...

[paul swed]

Several comments and now a press release. That UsraNav is working out of NJ
One of the time-nuts has been saying for several weeks they were using the
NJ site.
Yet the signals indicated Dana and Seneca as the sources.
However that actually could not be
The signal levels between the master and slave were always exactly the same.

Under LORAN C the system supported dual GRI emissions for system economy.
I suggest that under this testing they are doing dual delay emissions.
Very very easy to do and in fact I think the modulators had that capability
built in.

So in fact the only station on the air is the NJ location and using a GRI
of 89700.

Additional comments.
The systems up and down all over the place so catching it on long enough to
allow austrons and FR700 to arrive at accuracy is unlikely to happen. All
reasonable. Just not useful for a time-nut.

Reagrds
Paul
WB8TSL
___
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] Yahoo group not receiving emal

[CORNACCHIA]

Hi,
I have been a member of the group for a long time yahoo is not sending email.
Thank You
___
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] SimpleLink CC44000 GPS Development Kit

[Bob Camp]

Hi

"100 ns nominal accuracy" on the PPS. Sounds like a positioning part rather
than timing. 
The good timing receivers all have some firmware mods to improve the PPS
accuracy. More or less, they favor time over navigation in the way they
process the raw data. They also let you do needed stuff like position hold. 

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David Armstrong
Sent: Wednesday, March 28, 2012 12:58 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] SimpleLink CC44000 GPS Development Kit

It appears that TI has entered the GPS market.  I don't know if this would
make a good start on a GPSDO or not?  Comments?

https://estore.ti.com/SimpleLink-CC44000-GPS-Development-Kit-P2945C159.aspx



___
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.

Re: [time-nuts] Best reason

[iov...@inwind.it]

batchelo...@yahoo.com wrote

>Well the best reason is that by our social convention it makes people 
comfortable. 
>
>But that reason does have much logic behind it. 

One month ago a 38-year old wristwatch resurfaced from a junk box and I 
decided to return to it at least temporarily. It drifts some 30 seconds per 
day, but sincerely I don't feel any particular discomfort with it.
Antonio I8IOV

___
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] Best reason

[J. Forster]

There are good technical reasons for having very accurate standards of
time interval, but IMO, far fewer reasons for ns or even ms accuracy in
time of day.

Most everyday things, except possibly eBay and some financial
transactions, really don't have to happen exactly on the dot.

As to having very accurate time, widely distributed, and then measuring
time interval by subtraction, that is fraught with perils. Would you use a
the difference between a pair of mile long platinum-iridium rods to
measure the thickness of a sheet of paper?

YMMV,

-John






> Well the best reason is that by our social convention it makes people
> comfortable.
>
> But that reason does have much logic behind it.
> ___
> 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.

[time-nuts] SimpleLink CC44000 GPS Development Kit

[David Armstrong]

It appears that TI has entered the GPS market.  I don't know if this would make 
a good start on a GPSDO or not?  Comments?

https://estore.ti.com/SimpleLink-CC44000-GPS-Development-Kit-P2945C159.aspx



___
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] ntpdc -c kern explanation

[Ron Hahn (EI2JP)]

Colleagues,

Can someone give me a lay mans explanation of each of the lines of
output from my ntpdc -c kern command please?

[root@tock /usr/local/etc]# ntpdc -c kern
pll offset:   8e-07 s
pll frequency:-2.289 ppm
maximum error:0.006736 s
estimated error:  1e-06 s
status:   2107  pll ppsfreq ppstime ppssignal nano
pll time constant:4
precision:1e-09 s
frequency tolerance:  496 ppm
pps frequency:-2.289 ppm
pps stability:0.011 ppm
pps jitter:   1.564e-06 s
calibration interval: 256 s
calibration cycles:   1646
jitter exceeded:  345
stability exceeded:   1
calibration errors:   1
[root@tock /usr/local/etc]#

Thanks!

Ron

-- 
Ron Hahn, EI2JP
Rosslare Strand,
County Wexford, Ireland

___
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] Best reason

[Michael Batchelor]

Well the best reason is that by our social convention it makes people 
comfortable. 

But that reason does have much logic behind it. 
___
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] pc loran c program

[Stan, W1LE]

Thanks for the pointer.

The DF6NM Grabber shows the active GRIs:

http://www.alice-dsl.net/df6nm/LoranView/LoranGrabber.htm

Interesting he calls 89700 as Wildwood vice Dana or Seneca.

Stan, W1LE




On 3/28/2012 11:45 AM, ALAN MELIA wrote:

Peter Martinez G3PLX wrote some software which I think used GPS 1pps sync to receive Canadian 
eastern stations in the UK and monitor variations in time of arrival.I dont know that it 
produces "IDs" I belive that was derived from the GRIs.I think )Peter named the 
technique "clicklock" and several others added embellishments. I used one of these for 
measuring Loran-C sidebands as heard way up on 136kHz (an amateur radio band in Europe and the rest 
of the World) Peter lost interest in this and moved on, but copies may still be floating around o 
the web.

Markus Vester DF6NM runs a site that observes and records Loran transmissions 
worldwide. I dont have the URL in this PC but a google of his name and call + 
loran should yield something. I believe Markus's program is feely available for 
amateur use.

Alan
G3NYK


--- On Wed, 28/3/12, Stan, W1LE  wrote:


From: Stan, W1LE
Subject: Re: [time-nuts] pc loran c program
To: "Discussion of precise time and frequency measurement"
Date: Wednesday, 28 March, 2012, 15:45

A google search shows:

http://www.coaa.co.uk/ndbfinder.htm

I will try it later this evening when I get back home...

Stan, W1LE   Cape Cod



On 3/28/2012 8:53 AM, paul swed wrote:

Never heard of one.
Generally its a hardware decode


On Wed, Mar 28, 2012 at 7:17 AM, Bill Richeswrote:


Are there any pc programs that can decode Loran C

id's?

73,

Bill, WA2DVU
Cape May, NJH




___
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.




___
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] pc loran c program

[ALAN MELIA]

Hi Paul yes it can be a bit of a fiddleone of the Brit Columbia stations 
maybe VE7SL did a friendly "front end" for it and one of Murray Greenman's 
collegues produced another for phase tracking VLF stations amongst other 
application, I think.

Alan

--- On Wed, 28/3/12, paul swed  wrote:

> From: paul swed 
> Subject: Re: [time-nuts] pc loran c program
> To: "Discussion of precise time and frequency measurement" 
> 
> Date: Wednesday, 28 March, 2012, 16:59
> Boy I never really had clicloc ever
> working correctly and set it aside.
> 
> On Wed, Mar 28, 2012 at 11:45 AM, ALAN MELIA wrote:
> 
> > Peter Martinez G3PLX wrote some software which I think
> used GPS 1pps sync
> > to receive Canadian eastern stations in the UK and
> monitor variations in
> > time of arrival.I dont know that it produces "IDs"
> I belive that was
> > derived from the GRIs.I think )Peter named the
> technique "clicklock"
> > and several others added embellishments. I used one of
> these for measuring
> > Loran-C sidebands as heard way up on 136kHz (an amateur
> radio band in
> > Europe and the rest of the World) Peter lost interest
> in this and moved on,
> > but copies may still be floating around o the web.
> >
> > Markus Vester DF6NM runs a site that observes and
> records Loran
> > transmissions worldwide. I dont have the URL in this PC
> but a google of his
> > name and call + loran should yield something. I believe
> Markus's program is
> > feely available for amateur use.
> >
> > Alan
> > G3NYK
> >
> >
> > --- On Wed, 28/3/12, Stan, W1LE 
> wrote:
> >
> > > From: Stan, W1LE 
> > > Subject: Re: [time-nuts] pc loran c program
> > > To: "Discussion of precise time and frequency
> measurement" <
> > time-nuts@febo.com>
> > > Date: Wednesday, 28 March, 2012, 15:45
> > >
> > > A google search shows:
> > >
> > > http://www.coaa.co.uk/ndbfinder.htm
> > >
> > > I will try it later this evening when I get back
> home...
> > >
> > > Stan, W1LE   Cape Cod
> > >
> > >
> > >
> > > On 3/28/2012 8:53 AM, paul swed wrote:
> > > > Never heard of one.
> > > > Generally its a hardware decode
> > > >
> > > >
> > > > On Wed, Mar 28, 2012 at 7:17 AM, Bill
> Riches > >wrote:
> > > >
> > > >> Are there any pc programs that can decode
> Loran C
> > > id's?
> > > >>
> > > >> 73,
> > > >>
> > > >> Bill, WA2DVU
> > > >> Cape May, NJH
> > > >>
> > > >>
> > >
> > >
> > > ___
> > > 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.
> >
> ___
> 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.

Re: [time-nuts] pc loran c program

[paul swed]

Boy I never really had clicloc ever working correctly and set it aside.

On Wed, Mar 28, 2012 at 11:45 AM, ALAN MELIA wrote:

> Peter Martinez G3PLX wrote some software which I think used GPS 1pps sync
> to receive Canadian eastern stations in the UK and monitor variations in
> time of arrival.I dont know that it produces "IDs" I belive that was
> derived from the GRIs.I think )Peter named the technique "clicklock"
> and several others added embellishments. I used one of these for measuring
> Loran-C sidebands as heard way up on 136kHz (an amateur radio band in
> Europe and the rest of the World) Peter lost interest in this and moved on,
> but copies may still be floating around o the web.
>
> Markus Vester DF6NM runs a site that observes and records Loran
> transmissions worldwide. I dont have the URL in this PC but a google of his
> name and call + loran should yield something. I believe Markus's program is
> feely available for amateur use.
>
> Alan
> G3NYK
>
>
> --- On Wed, 28/3/12, Stan, W1LE  wrote:
>
> > From: Stan, W1LE 
> > Subject: Re: [time-nuts] pc loran c program
> > To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> > Date: Wednesday, 28 March, 2012, 15:45
> >
> > A google search shows:
> >
> > http://www.coaa.co.uk/ndbfinder.htm
> >
> > I will try it later this evening when I get back home...
> >
> > Stan, W1LE   Cape Cod
> >
> >
> >
> > On 3/28/2012 8:53 AM, paul swed wrote:
> > > Never heard of one.
> > > Generally its a hardware decode
> > >
> > >
> > > On Wed, Mar 28, 2012 at 7:17 AM, Bill Riches >wrote:
> > >
> > >> Are there any pc programs that can decode Loran C
> > id's?
> > >>
> > >> 73,
> > >>
> > >> Bill, WA2DVU
> > >> Cape May, NJH
> > >>
> > >>
> >
> >
> > ___
> > 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.
>
___
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] pc loran c program

[ALAN MELIA]

Peter Martinez G3PLX wrote some software which I think used GPS 1pps sync to 
receive Canadian eastern stations in the UK and monitor variations in time of 
arrival.I dont know that it produces "IDs" I belive that was derived from 
the GRIs.I think )Peter named the technique "clicklock" and several others 
added embellishments. I used one of these for measuring Loran-C sidebands as 
heard way up on 136kHz (an amateur radio band in Europe and the rest of the 
World) Peter lost interest in this and moved on, but copies may still be 
floating around o the web.

Markus Vester DF6NM runs a site that observes and records Loran transmissions 
worldwide. I dont have the URL in this PC but a google of his name and call + 
loran should yield something. I believe Markus's program is feely available for 
amateur use.

Alan
G3NYK
 

--- On Wed, 28/3/12, Stan, W1LE  wrote:

> From: Stan, W1LE 
> Subject: Re: [time-nuts] pc loran c program
> To: "Discussion of precise time and frequency measurement" 
> 
> Date: Wednesday, 28 March, 2012, 15:45
> 
> A google search shows:
> 
> http://www.coaa.co.uk/ndbfinder.htm
> 
> I will try it later this evening when I get back home...
> 
> Stan, W1LE   Cape Cod
> 
> 
> 
> On 3/28/2012 8:53 AM, paul swed wrote:
> > Never heard of one.
> > Generally its a hardware decode
> >
> >
> > On Wed, Mar 28, 2012 at 7:17 AM, Bill Richeswrote:
> >
> >> Are there any pc programs that can decode Loran C
> id's?
> >>
> >> 73,
> >>
> >> Bill, WA2DVU
> >> Cape May, NJH
> >>
> >>
> 
> 
> ___
> 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.

Re: [time-nuts] pc loran c program

[paul swed]

Well that is a interesting program.
Look forward to what you find out Stan

On Wed, Mar 28, 2012 at 10:45 AM, Stan, W1LE  wrote:

>
> A google search shows:
>
> http://www.coaa.co.uk/**ndbfinder.htm
>
> I will try it later this evening when I get back home...
>
> Stan, W1LE   Cape Cod
>
>
>
> On 3/28/2012 8:53 AM, paul swed wrote:
>
>> Never heard of one.
>> Generally its a hardware decode
>>
>>
>> On Wed, Mar 28, 2012 at 7:17 AM, Bill Riches> >wrote:
>>
>>  Are there any pc programs that can decode Loran C id's?
>>>
>>> 73,
>>>
>>> Bill, WA2DVU
>>> Cape May, NJH
>>>
>>>
>>>
>
> __**_
> 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.

[time-nuts] LORAN on at 1100 est

[paul swed]

___
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] pc loran c program

[Stan, W1LE]

A google search shows:

http://www.coaa.co.uk/ndbfinder.htm

I will try it later this evening when I get back home...

Stan, W1LE   Cape Cod



On 3/28/2012 8:53 AM, paul swed wrote:

Never heard of one.
Generally its a hardware decode


On Wed, Mar 28, 2012 at 7:17 AM, Bill Richeswrote:


Are there any pc programs that can decode Loran C id's?

73,

Bill, WA2DVU
Cape May, NJH





___
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] Best reason

[Jim Lux]

On 3/28/12 1:28 AM, Jim Palfreyman wrote:

So when a member of the general public says:

Why do we need really accurate clocks?



Not necessarily at "time-nuts" performance, but here's some clock and 
clock distribution applications


There are a lot of systems out there that timestamp something going in, 
and somewhere else, it gets timestamped going out, and the difference 
determines how much you pay.


Parking lots are a good example. You need to have all the timeclocks 
synchronized, so that people are charged the right amount


Automated speeding ticket generators on tollways compare timestamps of 
passage through the toll station with measured distance to determine 
average speed.



===

What's interesting is that a lot of things inherently depend on ppm 
kinds of timing accuracy that you wouldn't expect.. 10ppm is 1 second 
per day drift, and most inexpensive quartz oscillators aren't that good. 
 50-100 ppm is more typical.  While  1 second isn't a big deal, but 30 
seconds over a month might be, and 5 minutes in a month is a problem 
(you'd hate it if your DVR started recording your program 30 seconds 
after it started)



___
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] Best reason

[Poul-Henning Kamp]

In message <20120328113122.5c868800...@ip-64-139-1-69.sjc.megapath.net>, Hal Mu
rray writes:

>> "Because accurate clocks is the central technology that makes GPS, mobile
>> phones and the internet work." 
>
>What part of the internet depends upon accurate clocks?

SONET at the bottom and eBay endings at the top and a lot of stuff
in the middle.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] ANN: UK GPS Jamming update

[David J Taylor]

I have received the following notice 
___


NOTIFICATION OF GPS JAMMING EXERCISES SCOTLAND, NORTH AND WEST COASTS, 
16-26th APRIL 2012


Dates: Between 16 to 26 April 2012 inclusive.
Times:  Intermittent for 1hr slots between 0800BST  and 2130BST.
Location of MULTIPLE jammers:

A.The Little Minch and North Minch northwards from Waternish Point 
57-36N 006-38W to Stoer Head  58-14N 005-24W, including Sound of Raasay 
and Inner Sound.


B.Within 35 miles of Faraid Head 58-36N 004-46W.

Frequency: A 24 MHz band centred around 1176.45 MHz (GPS L5), 1227.60MHz 
(GPS L2) and 1575.42MHz (GPS L1).


Contact Details: In an emergency any vessel may request an abatement of 
jamming via VHF through Emergency cease jam via the CG, the Jamming 
Station (call sign: Loch Ewe / Cape Wrath GPS Jamming), or by telephone to 
Joint Warrior Duty Controller 01436 674321 ext. 4372.


It is stressed that, as in previous exercises, Safety of Life operations 
will at all times take precedence over exercise activities.




___
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] Best reason

[Azelio Boriani]

Usually (and unfortunately) governments tend to gather more money from tax
rather than giving up something (Italy docet).

On Wed, Mar 28, 2012 at 11:39 AM, Attila Kinali  wrote:

> On Wed, 28 Mar 2012 19:28:20 +1100
> Jim Palfreyman  wrote:
>
> > Why do we need really accurate clocks?
>
> Accurate clocks are expensive. The more money the US war machine
> spends for accurate clocks, the less money they have to build weapons.
>
>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
>
> ___
> 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.

Re: [time-nuts] Best reason

[Jim Lux]

On 3/28/12 1:28 AM, Jim Palfreyman wrote:

So when a member of the general public says:

Why do we need really accurate clocks?

What is your answer?

Personally I explain that accurate clocks enable you to pack a higher data
rate into your smart phone. They like that.


But I don't know that it's actually true.  The phone application has to 
tolerate temperature swings, and the modulation needs to be suitable for 
a multipath environment, but timing isn't as important.


Some degree of timing is needed for time difference of arrival kinds of 
position finding for E-911, although these days, I think more of that is 
assisted GPS, and in any case, the timing requirement to get 100 
meter-ish precision isn't all that tight.


Any other thoughts?


Precision navigation. Not just GPS in your car, but things like:
pesticide, fertilizer, and seed application
better grading for roads and construction
repeat pass interferometric radar  (allows much better remote sensing 
from airborne platforms, which is cheaper than stomping through the 
bushes and weeds)

disaster management
aircraft routing and landing




Jim
___
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.

Re: [time-nuts] pc loran c program

[paul swed]

Never heard of one.
Generally its a hardware decode


On Wed, Mar 28, 2012 at 7:17 AM, Bill Riches wrote:

> Are there any pc programs that can decode Loran C id's?
>
> 73,
>
> Bill, WA2DVU
> Cape May, NJH
>
>
>
> ___
> 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.

Re: [time-nuts] FE5680A x-rays

[Jose Camara]

Rich:

Thanks for your work, nice images.
One problem I see in the composite image is that it seems you opened
the raw files in the wrong mode, and what was 12-bit raw was reduced to only
4 bits (16 gray levels).
I reopened all from the raw (in 16-vit mac order), combined them
with soft blending and created much nicer composites. There were some
compromises done in blending adjacent images with tall components, due to
perspective, but overall traces can be followed.

I don't know if this list has a repository, or what's the accepted
practice on sharing files here, so for now they are available on Google Docs
(double zipped so GD doesn't screw up the images):


https://docs.google.com/open?id=0B18H4W8aZSP8SVhuLUl0RG1UdnFpUlJ1WHdmeF94Zw

There are four images, full size and quarter size, jpeg and tiff.

It would be nice if it was added to other FE5680A repositories. I
cannot guarantee it will stay long on that Google Docs account.

Jose


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rich
Sent: Monday, March 26, 2012 9:56 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] FE5680A x-rays

Photoshop works with both the RAW and the PSD format.
There are several free programs that will convert them in jpg with some loss
of resolution. 

If the format is a problem to people I'll see if I can convert them to jpg
but they won't be as sharp and you will loose some contrast control. The RAW
pix look almost all black in Photoshop until you use the "autolevel"
function.


___
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.

[time-nuts] pc loran c program

[Bill Riches]

Are there any pc programs that can decode Loran C id's?

73,

Bill, WA2DVU
Cape May, NJH



___
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] Best reason

[Hal Murray]

>Why do we need really accurate clocks?

Time or frequency?


p...@phk.freebsd.dk said:
> "Because accurate clocks is the central technology that makes GPS, mobile
> phones and the internet work." 

What part of the internet depends upon accurate clocks?

Ethernet, for example, requires roughly similar frequencies but doesn't care 
at all about time.


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




___
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] Best reason

[Poul-Henning Kamp]

In message 
, Jim Palfreyman writes:
>So when a member of the general public says:
>
>Why do we need really accurate clocks?
>
>What is your answer?

"Because accurate clocks is the central technology that makes
GPS, mobile phones and the internet work."


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Best reason

[Attila Kinali]

On Wed, 28 Mar 2012 19:28:20 +1100
Jim Palfreyman  wrote:

> Why do we need really accurate clocks?

Accurate clocks are expensive. The more money the US war machine
spends for accurate clocks, the less money they have to build weapons.

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

___
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] Best reason

[Jim Palfreyman]

So when a member of the general public says:

Why do we need really accurate clocks?

What is your answer?

Personally I explain that accurate clocks enable you to pack a higher data
rate into your smart phone. They like that.

Any other thoughts?

Jim
___
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] More Racal 9462 OCXO

[Larry McDavid]

The same seller, ABC Electronics, has just listed six more Racal 9462 
ocxo (Option 04E) as eBay Item 330709090416 as single-piece Buy-It-Now. 
The previous lot sold quickly. Despite the description, I believe these 
are really 10 MHz output because of the frequency doubler board seen on 
the end of the ocxo can in the offering picture; I can't guarantee that 
but I think that is the case. I don't need another of these so I have 
not bought any myself.


I believe this seller offered previously a large lot of non-working 
Racal 1992 counters that did not sell. These ocxo are likely removed 
from that lot to recover their value.


If you have a Racal 1991, 1992, 1999 or similar counter with Option 04A, 
04C or 04T, the 9462 provided as Option 04E is vastly superior; so far 
as I know, only the 9462 has both COARSE and FINE frequency adjustment 
screws.


Again, I don't know this seller and I'm only reporting the listing.

--
Best wishes,

Larry McDavid W6FUB
Anaheim, CA  (20 miles southeast of Los Angeles, near Disneyland)

___
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.