The sock problem has a simple, and obvious, solution.

When you buy socks, buy a several year supply, all identical. When you no
longer have more than 1 pair, buy a new batch.

QED.

-John

=============

Hi

Socks? Obviously an un-needed item ...

Bob

On Nov 12, 2010, at 3:52 PM, J. Forster wrote:

IMO, a GPS and Rb is less needed than socks, but then I have cold feet. :)

-John

=============

I want a mini-RFID with a hand-held remote (or an iPhone app), so that
I could stick an RFID on (say) my car keys and then
click on the little button for "find car keys"

Surgically attaching that remote might be a problem, though.

Regards
Marshall

On Nov 12, 2010, at 5:39 PM, J. Forster wrote:

Hi

Your time nuts priorities obviously need to be re-calibrated...

GPS's and Rb's (both plural) are definitely on the list ahead of socks.

Bob

On Nov 12, 2010, at 5:39 PM, J. Forster wrote:

Maybe...  if you put them on the floor under the desk and put your feet on
them.

-John

==============

http://www.keyringer.com/

-John

==================

On 13/11/2010, J. Forster jfor@quik.com wrote:

But what if you loose all the left or right foot socks (Murphy's Law
applies here), you'll end up buying more when just half of them are
lost.

Steve

--
Steve Rooke - ZL3TUV & G8KVD
The only reason for time is so that everything doesn't happen at once.

• Einstein

Socks, not gloves. AFAIK, socks are not handed.

-John

=============

Not ususally, anyway; my daughter has some with toes that are.  Maybe high-end socks?

-Dave
----- Original Message -----
From: "J. Forster" jfor@quik.com
To: "Steve Rooke" sar10538@gmail.com
Cc: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 3:52:06 PM
Subject: Re: [time-nuts] OT loosing things

Socks, not gloves. AFAIK, socks are not handed.

-John

=============

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Well, how often do you loose your daughters socks? -

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of d.seiter@comcast.net
Sent: Friday, November 12, 2010 7:10 PM
To: jfor@quik.com; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT loosing things

Not ususally, anyway; my daughter has some with toes that are.  Maybe high-end socks?

-Dave
----- Original Message -----
From: "J. Forster" jfor@quik.com
To: "Steve Rooke" sar10538@gmail.com
Cc: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 3:52:06 PM
Subject: Re: [time-nuts] OT loosing things

Socks, not gloves. AFAIK, socks are not handed.

-John

=============

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LOL-  They don't get lost, it's mine that vanish and turn up randomly.

Dave
----- Original Message -----
From: "Mike Feher" mfeher@eozinc.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 4:35:54 PM
Subject: Re: [time-nuts] OT loosing things

Well, how often do you loose your daughters socks? -

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of d.seiter@comcast.net
Sent: Friday, November 12, 2010 7:10 PM
To: jfor@quik.com; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT loosing things

Not ususally, anyway; my daughter has some with toes that are.  Maybe high-end socks?

-Dave
----- Original Message -----
From: "J. Forster" jfor@quik.com
To: "Steve Rooke" sar10538@gmail.com
Cc: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 3:52:06 PM
Subject: Re: [time-nuts] OT loosing things

Socks, not gloves. AFAIK, socks are not handed.

-John

=============

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Well, you know, one never knows. Thought maybe you liked them :). - Mike

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of d.seiter@comcast.net
Sent: Friday, November 12, 2010 7:44 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT loosing things

LOL-  They don't get lost, it's mine that vanish and turn up randomly.

Dave
----- Original Message -----
From: "Mike Feher" mfeher@eozinc.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 4:35:54 PM
Subject: Re: [time-nuts] OT loosing things

Well, how often do you loose your daughters socks? -

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of d.seiter@comcast.net
Sent: Friday, November 12, 2010 7:10 PM
To: jfor@quik.com; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT loosing things

Not ususally, anyway; my daughter has some with toes that are.  Maybe high-end socks?

-Dave
----- Original Message -----
From: "J. Forster" jfor@quik.com
To: "Steve Rooke" sar10538@gmail.com
Cc: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, November 12, 2010 3:52:06 PM
Subject: Re: [time-nuts] OT loosing things

Socks, not gloves. AFAIK, socks are not handed.

-John

=============

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The discussion is just heading toward the measurement of the time it takes for disappeared things to re appear.

At 13-11-2010, you wrote:

--
Raj, VU2ZAP
Bangalore, India.

Mike Feher wrote:

You just need to look at a different kind of communication system.  If
you're working at 8 bps like I do, or you want to measure the distance
to a spacecraft around Saturn with an accuracy of millimeters, ADEV is
important.

Hi

You and a lot of other people. There have been a lot of papers using ADEV as an example of what not to do in the past two years.

Bob

On Nov 12, 2010, at 8:15 PM, Mike Feher wrote:

On 13 November 2010 16:14, Raj vu2zap@gmail.com wrote:

I think that my original post may have been sent to the wrong group, Raj :)

Cheers,
Steve

--
Steve Rooke - ZL3TUV & G8KVD
The only reason for time is so that everything doesn't happen at once.

• Einstein

At 08:15 PM 11/12/2010, Mike Feher wrote...

GFY

Mike S,

We also used to be a polite group... until you came along.

-Chuck Harris

Mike S wrote:

I sure do agree, that with very low data rate systems it is significant. In
fact, when David Allan & Fred Walls came up with the proposal of using this
measurement as an FOM for oscillators over 30 years ago, digital
communication rates were slow, and, the measurement was a good one. Due to
the filtering process within ADEV by collecting and integrating a large
number of samples, has a filtering effect of its own. Therefore, it can, and
will, miss the fact that there may be instantaneous phase transitions that
could cause havoc with high data rates and higher order PSK modulation
schemes. So, again, I apologize, as I should have mentioned higher data
rates. However, you must admit that your application, while extremely
critical, is in the minority. I like to use the example of something like
DirecTV. Here, they use a down-converter that utilizes a free running DRO,
that is ridiculously noisy, and, varies all over in frequency, especially
over the temperature ranges it subjected to. In spite of all of that, one
gets a perfect pictures. Regards - Mike

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of jimlux
Sent: Friday, November 12, 2010 11:33 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT loosing things

Mike Feher wrote:

today's

Mike

You just need to look at a different kind of communication system.  If
you're working at 8 bps like I do, or you want to measure the distance
to a spacecraft around Saturn with an accuracy of millimeters, ADEV is
important.

time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.

This is interesting. I responded to a dismissive, condescending,
personal reply which was telling me how to behave with one using the
same style so the OP would understand it, yet you ignored the original
and choose to criticize me. You have an unusual definition of "polite."

But, it's not my list, and it's obviously not moderated.

At 07:45 AM 11/13/2010, Chuck Harris wrote...

On 11/13/2010 02:20 PM, Mike Feher wrote:

ADEV can be trace back to 1966, but even prior to that similar estimates
was being used in the scientific research, but the Allan article of 1966
provides part of the critical analysis which makes the M-sample analysis
into the Allan-variance as we know it.

Their concerns where with oscillators and not data-communication which
has its own set of problems and measures.

Data-rates is actually not particularly interesting, it is the dynamic
properties regardless of rate, which is only a scale-factor. The
property of phase-jumps is well covered in the MTIE measurement which is
used along-side the TDEV measurement for telecommunication systems.
MTIE provides the Maximum Time Interval Error... so for a window of
length tau, what is the maximum difference between high and low? This is
measured by taking the difference between max and min in a window, slide
it over the data and take the maximum difference. This relates very well
to buffer-size action and if converted over to a sine-tolerance curve
(using f=1/(pi*tau) ) also can be made to match up with PLL responses.

Come to think of it, I have not seen any good Wikipedia article on it.

Anyway, one really has to understand what kind of measurement is
adequate for the technical problem one is trying to address.

Cheers,
Magnus

Mike S,

How is your attempt at controlling the content of this group any
different from Mike F's asking you to be tolerant?

Any post where you wield to the F word (cloaked or otherwise) against
one of your fellow netizines, is not polite.

As to moderation: John Ackerman owns this group, guides it with a very
gentle hand, hosts, and administers the server the group lives on, pays
the power and phone bill....  In every sense of the word it is his baby.
He has made it clear that he too would prefer the group stay on topic,
but ever the gentleman that he is, he recognizes that the content of
this group is a gift from those that create it... and a polite person
accepts a gift in both the spirit, and the manner it which it is given.

I will present you with the same request Mike F did, only more bluntly:
Please be tolerant.  If you don't like a thread, please spare us the
rebuke, just ignore it.

Although it is difficult, I will attempt to live by my own advice.

-Chuck Harris

Mike S wrote:

Hi

I see ADEV not as a solution to a system design problem, but an oscillator measurement issue. If you look at the measures being used in the 60's, most of them had serious statistical flaws. You could measure them several ways and get multiple results. What ADEV gave us is a measure that could be done repeatably. You still have to do it right, but if you do it repeats.  If there is a systems rationale in the development of the measurement it's awfully well hidden in the early papers.

Bob

On Nov 13, 2010, at 8:53 AM, Magnus Danielson wrote:

I agree with all of the comments. My problem now is attempting to fight an
internal Gov't battle, where there is too much emphasis on ADEV, as an
indicator to overall system performance. Thanks for all the replies. Regards

• Mike

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-901-9193 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Saturday, November 13, 2010 9:06 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] ADEV

Hi

I see ADEV not as a solution to a system design problem, but an oscillator
measurement issue. If you look at the measures being used in the 60's, most
of them had serious statistical flaws. You could measure them several ways
and get multiple results. What ADEV gave us is a measure that could be done
repeatably. You still have to do it right, but if you do it repeats.  If
there is a systems rationale in the development of the measurement it's
awfully well hidden in the early papers.

Bob

On Nov 13, 2010, at 8:53 AM, Magnus Danielson wrote:

In

this

was being used in the scientific research, but the Allan article of 1966
provides part of the critical analysis which makes the M-sample analysis
into the Allan-variance as we know it.

its own set of problems and measures.

large

and

that

properties regardless of rate, which is only a scale-factor. The property of
phase-jumps is well covered in the MTIE measurement which is used along-side
the TDEV measurement for telecommunication systems.

tau, what is the maximum difference between high and low? This is measured
by taking the difference between max and min in a window, slide it over the
data and take the maximum difference. This relates very well to buffer-size
action and if converted over to a sine-tolerance curve (using f=1/(pi*tau) )
also can be made to match up with PLL responses.

for the technical problem one is trying to address.

https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

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Hi Bob,

On 11/13/2010 03:05 PM, Bob Camp wrote:

I completely agree, having spent quite some time in those early papers.
They had problems to handle the noise of oscillators, and having those
problems, how can you attack the system design problems? They had
obvious needs for it in developing doppler radars for instance, but also
for the space program. One of the big meetings on this topic was in the
NASA Goddard space center, and the result of that is found in the NASA
Special Publication 80 (SP-80):
http://hdl.handle.net/2060/19660001092

Un the part 1 "User's viewpoint and requirements"
First article in there is "Short-term stability for a doppler radar:
Requirements, Measurements and Techniques" by D.B. Leeson and G.F. Johnsson.
Fifth article is "Satellite Range and Tracking Accuracy as a function of
Oscillator STability" by J.J. Caldwell Jr.
Sixth article is "Short-term Stability Requirements for Deep Space
Tracking and Communications systems" by R. L. Sydnor.

I think the system applications for short-term stability measurements
was quite clear, and was brought out specifically.

ADEV addresses the oscillator noise issues, but isn't particularly well
suited for the numerous of systematic effects that comes on top of the
oscillator noise in the system.

Cheers,
Magnus

At 09:01 AM 11/13/2010, Chuck Harris wrote...

First, his was a demand, not a request. Second, his was personally
directed.

Third, I made a comment, addressed to no one in particular, about the
descent of this forum into an extended discussion about faeries
(amongst other crap), instead of time, which is its purpose. I didn't
call out anyone specifically, just provided a general observation. It
wasn't an attempt at control, I called for moderation, which is a
request for whoever is in control to make a judgement. You must be an
Internet newbie, as a call for moderation is entirely appropriate and
has a long history going back to USENET.

What I got was a response (obviously NOT from the moderator) which said
in meaning "Your observation doesn't matter, you're wrong to have such
feelings, so change the way you feel and STFU. People will talk about
what they want. Some of us don't have real lives, we desire humor and
social banter, and the only place we can get that is on technical
discussion lists."

If John Ackerman says it's fine to turn this list into
Facebook/Twitter, that's his call. But if so, I would suggest he change
the description from the current "time-nuts is a low volume, high SNR
list for the discussion of precise time and frequency measurement and
related topics," because that's not what it's going to be.

Mike, one way or another, the members of the list have formed their
judgments regarding your posts.  John has asked that we let it go.  Please
honor his request.

On Sat, Nov 13, 2010 at 9:47 AM, Mike S mikes@flatsurface.com wrote:

Mike Feher wrote:

no apologies necessary..  After all, I spend a small, but significant,
amount of time explaining why we'd care about such things, since we are
in the distinct minority of the radio comm world  (trying to write nice
comments on failed SBIR proposal evaluations to explain why they missed
the big picture)

And, on the one hand, it's frustrating being the orphan child of the RF
user community: you can't get off the shelf test equipment.  On the
other hand, it's cool, because then you have to build your test
equipment.

To the Ku-band downconverters..  They're pretty crummy (but have a
decent SNR to work with).. however, I've seen that there are two kinds..
a vanilla LNB and ones described as "crystal locked"... both are cheap
($20-30 for the former, maybe twice that for the latter)... what's the
difference?  And, getting into time-nuts territory here, where's the
reference for the "locked" variety coming from? Up the coax? inside the
LNB?  And, can it be retrofitted from a much quieter oscillator?  I was
thinking that one could build a radio camera with a small array of
Ku-band dishes, if you could lock all the receivers together.  They
are pretty low noise (20-30K)

Magnus Danielson wrote:

Basically, these are all systems where there is some "storage" or
"delay" and you are comparing a signal generated/recorded at some time t
with that signal at some time t+delta, where delta is in the seconds to
minutes range.  (well, milliseconds in the radar case)...

(the really slow speed comm application is slightly different.. there,
it's more of a reciprocal mixing of close in noise and a frequency
stability in the hours/days sense issue.. although for one-way doppler
measurements ADEV is important)

yes. but some familiarity with how ADEV is measured/computed, and the
fact that there are "test sets" out there that make a plot of ADEV means
that you can look at a ADEV plot for the system, and if it deviates from
that for the underlying oscillators, you can make some educated guesses
about the system issues.  Not that it's best, by any means, but at least
it exists.

When buying or building a complex system, one is often faced with the
problem of "how do we write a testable specification or requirement" to
show that the completed widget works.  And, further, you generally don't
want to spend more developing the test than the thing you are buying.
It does happen, though..probably part of the game for developing at the
ragged edge of performance.  However, if you can sort of back your way
into an analysis that shows that a performance of X on test Y (no matter
how unsuited philosophicaly) means that you will get performance Z on
important requirement Q, then all is good.

At work, we refer to the developing of a whole subproject to understand
and test how the primary object is working as "doing a science
project".. but that's because I work in an "engineering" area as opposed
to one of the "science" areas, where science projects are their lives.
By the time we get it, we're on a schedule and budget that doesn't allow
for much contemplation, reflection, and thinking about how to best do
things: planetary motion waits for no man, and the launch period is a
few weeks long, at best.

Hi

I don't see anybody arguing that systems work better when there's a high ADEV than a low ADEV. Most of the papers are heading in the direction of "it doesn't catch all of the problems I worry about". Based on what systems need and what ADEV measures, I don't find that a particularly surprising conclusion. The next step would be for people to come up with system related measures that do catch what they are after. Some have tried that, many have not. The next link in the chain would be getting (paying) vendors to run the tests on product. As far as I can tell - that's not happening at all. ADEV had the same issues early on. Until it became a mandatory specification, not a lot of people paid much attention to it.

Bob

On Nov 13, 2010, at 10:18 AM, jimlux wrote:

On 11/13/2010 04:01 PM, jimlux wrote:

Hmm. Should do more of that.

The key seek-term to add is "external reference" and it seems that 10
MHz sine seems to be the standard external reference frequency for LNBs
with external reference. I know it will be a tricky frequency for you to
score, but the things you do for science.

Best of luck.

Interesting approach.

Cheers,
Magnus

Magnus Danielson wrote:
One of the big meetings on this topic was in the

Thanks for this reference.. I had seen some of the papers before, but
this collects them all handy in one place.

The paper by Sydnor is quite handy, because it's basically the same way
we do things still  (well, we don't punch the Doppler estimate on paper
tape, we've moved a tiny bit forward. And, most, but not all, of our
equipment is calibrated in Hz as opposed to cps)..

Bob Camp wrote:

Yes.. and if you read the discussion following that first batch of
papers in the report Magnus linked, you can see the same sort of thing..
everyone had some measure they had developed that was important to their
particular system, but none of them were the same, or even directly
interconvertible.

The problem faced by them (and us at JPL now)is that we're a very, very
low volume customer (a few units every few years)..  We do actually
pay people to make the measurements, but sometimes, I think the
measurements we ask for aren't necessarily appropriate.  It's expensive
and time consuming to do the analysis for a new measurement, and
particularly to validate that it's actually measuring something useful
and relevant, so there's a very strong tendency to "do what we did before"..

Sometimes the previous measurement used something that happened to
depend on an artifact of the system design so that you could test
something you can measure to represent something that's difficult to
measure (e.g. IP3 vs P1dB relationships presume a certain shape to the
nonlinearity).  But if you've changed the underlying design, that
artifact may not exist.

This shows up a lot with test procedures/specifications for systems
based on all analog designs that are adopted unchanged for systems with
digital conversions.  (look at all the various ways to specify
performance of high speed ADCs).  For example, in my world, a common
specification is for performance at "best lock frequency" (BLF, that is,
the frequency at which you can acquire a carrier with the lowest SNR).
In an analog system, this is often where the input corresponds to the
rest frequency of the VCO with everything sort of in the middle of the
range.  But a lot of modern systems have no BLF... their performance is
essentially flat over some band, and any small variations are not
indicative of, e.g. minimum loop stress, etc.  The time spent to
determine BLF, and any assumptions about performance aren't necessarily
valid.

On the other hand, we don't necessarily engage in a "science project"
for each project to determine performance requirements (and
corresponding test methods) unique to the performance in that system.
There is a need for more generic performance numbers that have
moderately universal understanding.. If I tell you the P1dB for an
amplifier, and I tell you that my signals are 10dB below that, then, in
a short statement, I've actually told you a fair amount about how my
design works and the range over which it's likely to keep working.
That's because you and I have a common understanding of what a P1dB spec
"means"...

Over the past decades, I think a similar understanding has arisen with
phase noise specs and to a lesser extent Allan deviation. That is, given
a phase noise plot, a skilled practitioner can tell whether it's good or
bad in the context of a particular system.

On 11/13/2010 04:53 PM, jimlux wrote:

When researching my contributions to the Allan variance Wikipedia
article I found that many of the articles referred back to papers from
that conference, so I dug around a little and came up with that
reference. It is online from NASA if you just care to use their
web-pages a little.

http://en.wikipedia.org/wiki/Allan_variance

I took some pride of providing significant contributions to the field as
referenced articles, and also as far as possible provide linkage to them
in online form, if possible to get for free. This was indeed one of the
references I was quite happy to find. I have not read all the 300 pages,
but there is a lot of good material in there. For instance, the DMTD
technique has a precursor in the cross-correlation technique being
presented on page 111 by R. F. C. Vessot, L. F. Mueller and J. Varnier
in "A cross-correlation technique for mesuring the short-term properties
of stable oscillators". They measure the beat frequencies of two
H-masers 1,420 GHz as being mixed down to first 30 MHz and then 600 Hz.

Oh, and I still have a number of things to properly cover on the Allan
variance article for sake of completeness. Progress have just been slow.
Doing exercises like these is however very rewarding as one needs to
learn the things on a deeper level.

Cheers,
Magnus