On machines W2000 and before you added a switch in BOOT.INI /NoSerialMice.
On XP and maybe earlier, you can go to the mouse and disable the serial
mouse.
Steve wrote:
I remember seeing a posting on this reflector in the last year or two
about how to disable the PC's serial mouse so a
It can be altered, but only by 50ns. You can invert the phase of the osc
sense (feature not available on Thunderbolt-E or Thunderbolts built before
March 1998). Use the '^' command in Lady Heather.
The PPS output is synchronous with the 10MHz signal
Hello all,
I'm trying to adjust the time between the leading edge of the PPS square
wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The
manual seems to indicate the cable delay compensation setting will do this.
As I understand things, this is also called the PPS Offset in the
Bob
Robert Darlington wrote:
Hello all,
I'm trying to adjust the time between the leading edge of the PPS square
wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The
manual seems to indicate the cable delay compensation setting will do this.
No, it doesnt.
This only
Ah ha! That explains the changing numbers I see on the 5370B (jitter), and
explains why I see no change on the scope other than the jitter. Reading
the manual, I don't see any clear explanation like what you just gave me. I
see my mistake in manual interpretation but not until after reading
Bob
One way of reducing the effective noise/jitter on the PPS signal when
using it with the 5370 to measure the instability of a source with
respect to the Thunderbolt is to use the PPS to ARM the 5370 whilst the
10MHz from the thunderbolt starts the 5370 and the source (or a
frequency generated
I have developed some code that processes a 24-48 hour survey
to calculate a precise position. With a good (geodetic/survey)
quality antenna I get my location to within a few inches. With a
conical timing antenna, I get around 8 inches of error. With a
cheap patch antenna, around a foot.
With a good (geodetic/survey) quality antenna I get my location to
within a few inches. With a conical timing antenna, I get around
8 inches of error. With a cheap patch antenna, around a foot.
HI Mark,
A couple more thoughts.
I still question the value of all this for a cheap receiver
...@febo.com] On
Behalf Of Tom Van Baak
Sent: Thursday, August 13, 2009 10:23 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt precise positions needed
With a good (geodetic/survey) quality antenna I get my location to
within a few inches
A couple weeks ago (check the archives around 26 July 2009) I posted some
plots of the PPS/OSC error estimates when the receiver's position was
intentionally offset from its true position. The results were rather
dramatic... And the quality of the data scaled with the position error. It
Does anybody have their Thunderbolt antennas located at precisely surveyed
positions?
I have developed some code that processes a 24-48 hour survey to calculate a
precise position. With a good (geodetic/survey) quality antenna I get my
location to within a few inches. With a conical
Hi Mark:
I know where my Thunderbolt antenna is.
Have Fun,
Brooke Clarke
http://www.prc68.com
Mark Sims wrote:
Does anybody have their Thunderbolt antennas located at precisely surveyed positions?
I have developed some code that processes a 24-48 hour survey to calculate a
precise
I also know where my antenna is.
Brian KD4FM
Mark Sims wrote:
Does anybody have their Thunderbolt antennas located at precisely surveyed positions?
I have developed some code that processes a 24-48 hour survey to calculate a
precise position. With a good (geodetic/survey) quality antenna
Hi,
I've been lurking on this list for a long time but now it's time to unlurk.
I don't remember if it's appropriate to introduce oneself on this
list, but I'll do it anyways. :)
I've been tinkering with electronics for some thirty odd years now -
mostly just as a hobby but also occasionally
@febo.com
Subject: [time-nuts] Thunderbolt temperature measuring
Hi,
I've been lurking on this list for a long time but now it's time to unlurk.
I don't remember if it's appropriate to introduce oneself on this list, but
I'll do it anyways. :)
I've been tinkering with electronics for some thirty odd
Engstrom
Sent: 26 July 2009 19:14
To: time-nuts@febo.com
Subject: [time-nuts] Thunderbolt temperature measuring
Hi,
I've been lurking on this list for a long time but now it's time to unlurk.
I don't remember if it's appropriate to introduce oneself on this list, but
I'll do it anyways. :)
I've
Mat,
I think the purpose of the DS1620 is to integrate the ambient temperature into
the equation used by the T-bolt. I suspect that the ovenized internal
oscillator
has its own temperature control. That being the case, then it would be
counterproductive to couple the DS1620 to the oscillators
Hi Mats,
welcome!
As you are working already with a wired interface, I think
you don't risk anything when trying it - you can not really lose anything,
I think you may have a problem to see a difference because
the missing reference.measurements. I do not expect a EMC problem,
but it's as
From my poking and prodding, I think the temperature sensor serves two
purposes. First as an environmental alarm. Second as compensation for
temperature effects on the system as a whole. As such, you want it near
where it was. Sticking it on the oscillator would mask a lot of the ambient
configuration.
Didier
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims
Sent: Sunday, July 26, 2009 5:37 PM
To: time-nuts@febo.com
Subject: [time-nuts] Thunderbolt temperature measuring
From my poking and prodding, I think
Hi Mark,
Mark Sims wrote:
I wanted to have Heather make a RINEX file that could be submiited to OPUS-GIS to get a more precise antenna location. The Tbolt does not support carrier phase measurements. It does output doppler values.
The code phase (pseudorange) values that it outputs look
While toying with an attempt to use a Thunderbolt to generate a RINEX file for
GPS precision post processing I discovered a difference between the 2.22 and
3.00 App firmware. The 2.22 firmware generates the ECEF position/velocity
messages as documented. The rev 3.00 firmware does not
While toying with an attempt to use a Thunderbolt to generate a RINEX file
for GPS precision post processing I discovered a difference between the
2.22 and 3.00 App firmware. The 2.22 firmware generates the ECEF
position/velocity messages as documented. The rev 3.00 firmware does not
I wanted to have Heather make a RINEX file that could be submiited to OPUS-GIS
to get a more precise antenna location. The Tbolt does not support carrier
phase measurements. It does output doppler values.
The code phase (pseudorange) values that it outputs look to be VERY difficult
to
Is there another planned Thunderbolt group buy ?
-pete
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
From: Pete Lancashire p...@petelancashire.com
To: time-nuts@febo.com
Is there another planned Thunderbolt group buy ?
-pete
Very close to an announcement. Just waiting to resolve one administrative
issue and we'll be ready.
--
73,
John, W9DDD
Hello David,
I'm a complete beginner in this field, but after a lot of reading and
following these threads, I finally bought a Tbolt from China via
e-bay. Arrived in just under a week by post, plugged it in to power
and antenna and got 10 MHz output.
I eventually connected a lap-top PC via
The other issue is noise from a switcher.
And be mindful that some frequency-standard devices contain integrated DC-DC
switching converters -- like my HP 58540A GPS-DO. The noise from the HP DC
converters was spraying RFI every 100 kHz or so on the HF bands. After
trying various RFI
And be mindful that some frequency-standard devices contain
integrated DC-DC switching converters - like my HP 58540A GPS-DO.
The noise from the HP DC converters was spraying RFI every 100 kHz
or so on the HF bands. After trying various RFI abatement
measures,
Hi Mike:
I think it's National semi that has an app note talking about how the topology
relates to noise output. Some are bad others are much better.
Have Fun,
Brooke Clarke
http://www.prc68.com
Mike Monett wrote:
And be mindful that some frequency-standard devices contain
Mike,
That PS is a most curious problem. For reduced leakage fields from
60Hz transformers, it was common to have a wide copper strap
wrapped around the transformer in the same orientation as the windings.
This strap was the full width of the winding bobbin, but formed a shorted
turn on the
Hi Mike:
I think it's National semi that has an app note talking about how
the topology relates to noise output. Some are bad others are much
better.
Have Fun,
Brooke Clarke
http://www.prc68.com
Hi Brooke,
Do you recall the number or title of the National app note?
One of the
Mike,
That PS is a most curious problem. For reduced leakage fields from
60Hz transformers, it was common to have a wide copper strap
wrapped around the transformer in the same orientation as the
windings.
This strap was the full width of the winding bobbin, but
, June 13, 2009 12:16 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient
temperature
More to the point, you will be disappointed to find the bottles
will
NOT last that long.
Cleaning out the cupboard recently, I
Joseph M Gwinn wrote:
That is only 0.54 cal/cc C compared to water with a figure of 1.0.
So water still has greater merit as a thermal buffer.
Cheers, Neville Michie
Yep. But it's runny.
I have a modest proposal to combine the benefits of water and silica: We
will use wine bottles in the
Chuck Harris skrev:
Joseph M Gwinn wrote:
That is only 0.54 cal/cc C compared to water with a figure of 1.0.
So water still has greater merit as a thermal buffer.
Cheers, Neville Michie
Yep. But it's runny.
I have a modest proposal to combine the benefits of water and silica:
We will use
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Tuesday, June 16, 2009 3:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
Lux, James P skrev:
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Tuesday, June 16, 2009 3:05 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of gandal...@aol.com
Sent: Tuesday, June 16, 2009 5:20 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
In a message dated 16/06
gandal...@aol.com skrev:
In a message dated 16/06/2009 23:15:50 GMT Daylight Time,
james.p@jpl.nasa.gov writes:
One might wish to be careful about this process. If the time-nut leading
you to the temperature controlled chamber is named Montressor, and the
first bottle you sample is
In a message dated 17/06/2009 01:31:00 GMT Daylight Time,
james.p@jpl.nasa.gov writes:
Well.. When one starts talking about bottles and temperature stability,
it's the first thing that springs to mind. And I just realized, there's
another time-nuts relevant story (even more
In a message dated 17/06/2009 01:31:00 GMT Daylight Time,
james.p@jpl.nasa.gov writes:
Well.. When one starts talking about bottles and temperature stability,
it's the first thing that springs to mind. And I just realized, there's
another time-nuts relevant story (even more time-nuts
Hi All...
Some interesting semi off topic discussions of late, very interesting.
Re the water in plastic bottle problem. (I seem not to have seen the
original message, there again we've had transient email/isp problems
here recently)
A Vacuum formed by any migration of the contents will not
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Thomas A. Frank
Sent: Saturday, June 13, 2009 12:16 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
More
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient
temperature
More to the point, you will be disappointed to find the bottles will
NOT last that long.
Cleaning out the cupboard recently, I can across some bottled water
that had
Joseph M Gwinn wrote:
I was the one who originally rained on the use-water-in-a-bottle approach.
The response was that even a child could store water. Well, that is not
the common experience with water-cooled equipment, which always manages to
require continual maintenance attention, so I
Hey Guys,
For time and less effort you could likely cobble up a Hydrogen Maser and
be done with it. :=))
-John
===
Joseph M Gwinn wrote:
I was the one who originally rained on the use-water-in-a-bottle
approach.
The response was that even a child could store water. Well, that is
Could we please get off the water kick? Every time I read one of these
posts I have to pee.
D
Joseph M Gwinn wrote:
I was the one who originally rained on the use-water-in-a-bottle
approach.
The response was that even a child could store water. Well, that is
not
the common experience
-boun...@febo.com] On Behalf Of Thomas A. Frank
Sent: Saturday, June 13, 2009 12:16 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient
temperature
More to the point, you will be disappointed to find the bottles
will
NOT last
measurement
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
More to the point, you will be disappointed to find the bottles will
NOT last that long.
Cleaning out the cupboard recently, I can across some bottled water
that had 1998 date codes. Several had leaked
Hi Rex,
I just did something similar. I was doing some heavy grinding on a
6 inch long rod that was to become a new tool, and as I started
to perceive that the rod was getting hot, I dunked the end I was
grinding into cool water. And, I almost immediately started to feel
the rod, where I was
I just don't know what to say to that! Even a child can put a
case of bottled water in a box, and not have it evaporate or leak.
I would venture that said case of bottled water will still be full
up when the child graduates from college, and has kids of his own.
But goodness knows what sort of
Sigh! I guess the point is still being missed. It isn't hard at
all to keep water in a container. The plastic water bottle scenario
was created to put the issue into perspective. Perhaps some plastic
bottles don't have the staying power to last into the next century,
but that doesn't in any
Chuck, I don't dispute that you can contain water in plastic a long time,
but, if some does escape it may not matter to the bottle contents, but it
could well raise the humidity of the surround w/in a tightly sealed
oven/box/enclosure. Electronics does not much like high humidity.
-John
Yes, but if it takes 20 years for 1 tsp of water to be lost, I just
don't see how that rules out the use of water as a thermal ballast.
Water's cheapness and availability in bulk makes it quite attractive
for this purpose.
If you don't trust plastic, use copper, or stainless steel, or...
If man
On 6/13/09 10:16 AM, Thomas A. Frank ka2...@cox.net wrote:
I just don't know what to say to that! Even a child can put a
case of bottled water in a box, and not have it evaporate or leak.
I would venture that said case of bottled water will still be full
up when the child graduates from
Hi,
Water must have a fairly high figure of merit for thermal buffering.
Unfortunately the lists of material properties are inaccurate, have
gross errors
and are inevitably listed in units such as tons per Degree F per inch
per square foot.
The tons refer to tons of ice per 24 hours, a good
Hi Everyone;
I have finally gotten around to getting my Thunderbolt operational.
Everything is working just fine but I do have a question. In the Thunderbolt
monitor screen and the [Time] window I see that the time is 15 seconds off
from my TAC and a little box tells me that the UTC Offset is set
A quick search on Google finds (among many) this short article.
http://www.seis.com.au/TechNotes/TN199901A_GPS_UTC.html
- Original Message -
From: rtime @dslextreme.com rt...@dslextreme.com
Date: Saturday, June 13, 2009 6:13 pm
Subject: [time-nuts] Thunderbolt UTC time offset
To: time
Chuck Harris wrote:
Bruce Griffiths wrote:
John
That doesn't appear to reproduce what was claimed to have been observed
at all.
The input is more like a step function that switches from hot to cold.
This allows the simulated bar to reach a steady state temperature
distribution before
Rex skrev:
J. Forster wrote:
It has nothing to do with this.
A long (length width) bar can simply be modeled as a long ladder of
series resistors's and capacitors to ground:
---zzz---zzz---zzz ... ---zzz---
_|_ _|_ _|_ _|_
___ ___ ___ ___
|
Rex wrote:
Humans are terrible witnesses when it comes to judging lengths of
time, and degrees of temperature. That's probably why clocks and
thermometers were invented.
-Chuck Harris
When I started this part of the thread I said that one of these days I
want to try to make some
Chuck Harris wrote:
I truly hope you aren't bothered by our rumination. We clearly are
enjoying the subject. Thanks for bringing it up.
-Chuck Harris
No, not at all. I brought it up because what I think I saw doesn't make
sense from anything I know.
I already have a large list of
Bruce Griffiths wrote:
Rex wrote:
Now, back to the subject of heat, I have a strange observation that I
posted on the web a few years ago. A few people thought they had seen
the same thing, but most thought what I noticed was not real. I posted
because, if it was true, it seemed unexpected
Rex
your experience with the hot bar is quite common.
Sounds like a pretty reasonable manifestation of the Leidenfrost effect.
The water in contact with the hot end of the bar vaporizes, and the
resulting steam layer (which might be microscopic) does a good job
insulating the bar. There's
2009/6/11 Chuck Harris cfhar...@erols.com:
Joseph M Gwinn wrote:
...
Yes, but water is so much easier to find, and easier to
package, plus it has a great storage capability.
And evaporates and leaks. But yes, I've used water for quick jobs.
I just don't know what to say to that! Even a
Rex skrev:
Now, back to the subject of heat, I have a strange observation that I
posted on the web a few years ago. A few people thought they had seen
the same thing, but most thought what I noticed was not real. I posted
because, if it was true, it seemed unexpected and I had never heard
In message 4a30457e.9060...@erols.com, Chuck Harris writes:
And evaporates and leaks. But yes, I've used water for quick jobs.
I just don't know what to say to that! Even a child can put a
case of bottled water in a box, and not have it evaporate or leak.
I would venture that said case of
In message 4a309b30.7000...@sonic.net, Rex writes:
My observation, from doing this
several times, is that the cold water quickly absorbes heat from the red
end, but also seems to chase a lot of the heat quickly up toward the
cold end, making the bar rapidly uncomfortable to hold.
I've seen
John Miles wrote:
Rex
your experience with the hot bar is quite common.
Sounds like a pretty reasonable manifestation of the Leidenfrost effect.
The water in contact with the hot end of the bar vaporizes, and the
resulting steam layer (which might be microscopic) does a good job
Poul-Henning Kamp wrote:
In message 4a309b30.7000...@sonic.net, Rex writes:
My observation, from doing this
several times, is that the cold water quickly absorbes heat from the red
end, but also seems to chase a lot of the heat quickly up toward the
cold end, making the bar rapidly
-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Poul-Henning Kamp
Gesendet: Donnerstag, 11. Juni 2009 00:43
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability and ambient temperature
In message 4a3033fc.6070
In message e182724b9fce4b9f9e914bcc4f374...@athlon, Ulrich Bangert writes:
For PLL steered devices, you want your device enclosed by a
thermal mass which is again enclosed by a layer of thermal
isolation. The goal is to filter/average all rapid (daily ?)
external temperature influences,
Bangert
-Ursprungliche Nachricht-
Von: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Poul-Henning Kamp
Gesendet: Donnerstag, 11. Juni 2009 12:50
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability
-Ursprungliche Nachricht-
Von: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Poul-Henning Kamp
Gesendet: Donnerstag, 11. Juni 2009 00:43
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability and ambient
Poul-Henning Kamp wrote:
In message 4a30457e.9060...@erols.com, Chuck Harris writes:
And evaporates and leaks. But yes, I've used water for quick jobs.
I just don't know what to say to that! Even a child can put a
case of bottled water in a box, and not have it evaporate or leak.
I would
Hey Bruce,
Your answers seem somewhat 'mechanical'.
Are you a 'bot? Not a joke... REAL question.
-John
==
Rex wrote:
Hal Murray wrote:
p...@phk.freebsd.dk said:
Can I get reflections without some inductance?
Is there any inductance in a system of alternating
layers of
This is an absolutely standard problem in an undergraduate Heat Transfer
course. Look for heating or cooling a block of material and thermal
diffusivity. Take a look at most any decent text (Rosenow(?) Choi,
'Heat, Mass, Momentom Transfer') for example)
That said, the geometry of a ham makes a
It has nothing to do with this.
A long (length width) bar can simply be modeled as a long ladder of
series resistors's and capacitors to ground:
---zzz---zzz---zzz ... ---zzz---
_|_ _|_ _|_ _|_
___ ___ ___ ___
| |-|- ... |-
-nuts-boun...@febo.com] Im Auftrag von Poul-Henning Kamp
Gesendet: Donnerstag, 11. Juni 2009 12:50
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability and ambient temperature
In message e182724b9fce4b9f9e914bcc4f374...@athlon, Ulrich
Bangert
of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability and ambient temperature
In message e182724b9fce4b9f9e914bcc4f374...@athlon, Ulrich
Bangert writes:
For PLL steered devices, you want your device enclosed by a
thermal mass which is again enclosed by a layer
According to your theory, there should be differences in the schematics
of the oven controllers between the single and double oven variants of
the 10811. Last year I picked up a couple of those double oven 10811s
from China that had the outer insulation removed. I wonder if I could
see any
of precise time and frequency measurement
Betreff: Re: [time-nuts] Thunderbolt stability and ambient
temperature
In message e182724b9fce4b9f9e914bcc4f374...@athlon, Ulrich
Bangert writes:
For PLL steered devices, you want your device enclosed by a
thermal mass which is again enclosed by a layer
In message ac8514a8eeb148259e3cd49b8e468...@athlon, Ulrich Bangert writes:
I'm not talking about crystal ovens, I'm talking about
timekeeping kit in general: how to filter high frequency
temperature fluctuations out, so the PLL does not have to
deal with them.
If you apply an overall
Poul-Henning Kamp wrote:
In message ac8514a8eeb148259e3cd49b8e468...@athlon, Ulrich Bangert writes:
I'm not talking about crystal ovens, I'm talking about
timekeeping kit in general: how to filter high frequency
temperature fluctuations out, so the PLL does not have to
deal with them.
If
Most people thought it was coincidence of heat propagating up the bar
just at that time, or steam. Could be, but I still think it is real. The
cold end of the bar was slowly getting warmer as I carried it, but after
the sudden cooling of the hot end, the cold end seemed to get hot fast.
Rex,
Tom Van Baak wrote:
Most people thought it was coincidence of heat propagating up the bar
just at that time, or steam. Could be, but I still think it is real.
The cold end of the bar was slowly getting warmer as I carried it,
but after the sudden cooling of the hot end, the cold end seemed to
Thermal conductivity even varies with the same crystalline forms of the same
element. Diamond has the highest known conductivity of any natural substance.
Isotopically pure carbon-12 diamond has twice the conductivity of natural
diamond.
The thermal
Tom
The thermal conductivity isnt constant with temperature.
It also varies between different crystalline forms of the same material.
This can be seen in more comprehensive tables of thermal conductivity.
In particular at cryogenic temperatures the thermal conductivity can
change dramatically
How about magnetic effects such as those seen with Galfenol etc. ?
Steve
--- On Thu, 6/11/09, Tom Van Baak t...@leapsecond.com wrote:
From: Tom Van Baak t...@leapsecond.com
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
To: Discussion of precise time
Thermal conductivity of iron is 0..161 at 18C, and .191 from 100C to 1245C
according to my Handbook (conditions are calories per second through a
plate 1 cm thick across an area of one sq. cm when the temperature
difference is one deg C). Point is, that's only 3 parts per 100, not
enough for the
The effect that was described was absolutely NOT a result of thermal
conductivity being a function of temperature.
It was a dynamic effect... a transient condition. The result of applying a
short heat pulse to a long Time Constant, distributed system.
Do the simulation I suggested hours ago.
The effect that was described was absolutely NOT a result of thermal
conductivity being a function of temperature.
It was a dynamic effect... a transient condition. The result of applying a
short heat pulse to a long Time Constant, distributed system.
Do the simulation I suggested hours ago.
J. Forster wrote:
It has nothing to do with this.
A long (length width) bar can simply be modeled as a long ladder of
series resistors's and capacitors to ground:
---zzz---zzz---zzz ... ---zzz---
_|_ _|_ _|_ _|_
___ ___ ___ ___
|
John
That doesn't appear to reproduce what was claimed to have been observed
at all.
The input is more like a step function that switches from hot to cold.
This allows the simulated bar to reach a steady state temperature
distribution before decaying smoothly to a lower temperature.
Bruce
J.
Perhaps the answer is somewhat more prosaic.
Radiation and convective losses from the hot end of the bar are significant.
In particular the radiative loss is (as a first approximation)
proportional to the difference of the 4th powers of the bar temperature
and ambient temperature.
When one
The problem may be due to the subjectivity of the observer, not a
real effect.
One dimensional heat flow along a bar will be close to the simple
step function
in an infinite one dimensional medium.
The solution is in the form of Gauss's Error Function, and any
cooling can only
reduce the
- Original Message -
From: Bruce Griffiths bruce.griffi...@xtra.co.nz
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Thursday, June 11, 2009 10:36 PM
Subject: Re: [time-nuts] Thunderbolt stability and ambient temperature
Perhaps the answer
Tom Van Baak wrote:
Most people thought it was coincidence of heat propagating up the bar
just at that time, or steam. Could be, but I still think it is real.
The cold end of the bar was slowly getting warmer as I carried it, but
after the sudden cooling of the hot end, the cold end seemed to
Bruce Griffiths wrote:
John
That doesn't appear to reproduce what was claimed to have been observed
at all.
The input is more like a step function that switches from hot to cold.
This allows the simulated bar to reach a steady state temperature
distribution before decaying smoothly to a lower
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