Quoth Kasper Pedersen at 24/02/10 17:44...
It will.
Set the fuses as you would have for a 10MHz crystal, and capacitively
couple the source to XTAL1. Leave XTAL2 open.
Do not set the fuses for 'external clock mode'.
Do put something like 100pF+1k Ohm in series with the input. While they
Something for the more adventurous, link your wrist watch to your own time
standards. TI have brought out a 'sports watch' based development system,
the 'eZ430-Chronos' based on their 430 processor. It includes an RF data
link so you should be able to write code to automatically sync the watch to
Quoth David at 24/02/10 19:35...
Something for the more adventurous, link your wrist watch to your own time
standards. TI have brought out a 'sports watch' based development system,
the 'eZ430-Chronos' based on their 430 processor. It includes an RF data
link so you should be able to write code
At 07:46 PM 2/23/2010, Rick Karlquist wrote...
The TAI is a weighted average to improve short term stability and
to average out random frequency errors.
IOW, there is a variance from clock to clock. So, if there are 80
different clocks, are there 80 different seconds, or 80 imperfect
Yes, and no..
Time as we know it (UTC) is coordinated at the BIPM in Paris between
observations from primary standards at contributing laboratories and also
earth rotation measurements. Each lab contributing will at any time (excuse
the pun) have a small time offset with regard to UTC. E.g. time
On 2/24/10 4:38 AM, Rob Kimberley r...@timing-consultants.com wrote:
Yes, and no..
Time as we know it (UTC) is coordinated at the BIPM in Paris between
observations from primary standards at contributing laboratories and also
earth rotation measurements. Each lab contributing will at any
Dave...
I went back and checked in my college Physics textbook, Halliday Resnick,
Vol. II, circa 1960, and you are correct about the Ampere being defined
based on the force between two parallel wires. However, HR does not specify
a vacuum nor negligible wire cross section. The latter seems
That is indeed neat.
Just no time for another project to tinker with.
$49 quite the deal
Whats funny is it eats a battery at least every 6 months for average use.
On Wed, Feb 24, 2010 at 4:12 AM, Matthew Smith m...@smiffytech.com wrote:
Quoth David at 24/02/10 19:35...
Something for the more
When the 5071A product line was sold to Symmetricom ~4 years ago,
the production manager and his team of 15 moved with the product.
The manager left Symmetricom a few years ago, and recently most
of the rest of the team left Symmetricom. The 5071A will now
be made on the east coast at the
Which means a battery every month for somebody actively developing projects
that talk to wireless sensor networks. Still not a bad deal.
-Bob
On Wed, Feb 24, 2010 at 8:08 AM, paul swed paulsw...@gmail.com wrote:
That is indeed neat.
Just no time for another project to tinker with.
$49 quite
2 big alligator clips to an external supply.
Limitless operation. Maybe a 6v car battery and regulator. Worn around the
waste
get the cardio up
On Wed, Feb 24, 2010 at 11:03 AM, Robert Darlington
rdarling...@gmail.comwrote:
Which means a battery every month for somebody actively developing
Hi
A square foot of solar cells fashioned into geek stylish hat would keep it
running for quite a while.
-
Has anybody actually poked at one of these yet?
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent:
Hi
One significant point there about BIPM - earth rotation measurements. UTC
is not a straight count of standard seconds. Somebody has to decide when
to slip it to match our wobbly planet. Not because of an error in the
second, it's the planet that's not stable enough...
--
Stuff that's
In my checkered past, I once legally owned, for about two minutes between
signatures, the British Standard Pound weight. It was a bar of platinum.
I confess I did wonder how easy it would be to sell a pound of platinum, as
it would have been a bit difficult to cut it up...
- Original
Rick Karlquist wrote:
If you want to get technical, the frequency of a cesium standard
also depends on the gravitational acceleration, but for relativistic
reasons, not newtonian physics. Any decent cesium is accurate
enough that it will noticably speed up at NIST in Boulder. NIST's
best
Poul-Henning Kamp wrote:
In message 20100223214204.eae71117...@hamburg.alientech.net, Mike S writes:
renamed, since the discussion has shifted.
In the time and frequency field, the term primary standard is
sometimes used to refer to any cesium oscillator, [...]
That rhymes with and Karls
Hi,
I remember a reference, probably by Bruce, that LEDS provide a low
noise voltage reference.
I am proposing to build a voltage regulator for a thermally
controlled LPRO rubidium oscillator,
with the voltage regulator being mounted on the 0.5 inch thick
aluminium heat sink plate.
The LEDS
Quoth Neville Michie at 2010-02-25 08:27...
...the LM317 output
would provide a low noise power source? What would be better?
Can't give you a proper answer, but the last time I saw this type of
question raised, someone pointed me to a linear regulator made from
discrete components, designed
Hi neville:
My old Gibbs rack mount 5 MHz standard used the LM723 linear regulator.
I believe it's one of the lowest noise regulators you can use.
http://www.national.com/mpf/LM/LM723.html#Overview
Have Fun,
Brooke Clarke
http://www.PRC68.com
Neville Michie wrote:
Hi,
I remember a
In message 4b85a2eb.4000...@pacific.net, Brooke Clarke writes:
My old Gibbs rack mount 5 MHz standard used the LM723 linear regulator.
I believe it's one of the lowest noise regulators you can use.
http://www.national.com/mpf/LM/LM723.html#Overview
If you really want to get low noise, you do
Hi
Since the LPRO has a noisy 3 terminal regulator inside it, making the
outside voltage quiet (as in noise density) probably will not help much.
Keeping the voltage *stable* will indeed help things. I think you need a
high stability linear regulator rather than a low noise one.
One other thing
Hi,
NS gives some informations about improvements in their AN-173.pdf
http://www.national.com/ds.cgi/LM/LM117.pdf
Audio freaks are discussing it in
http://www.diyaudio.com/forums/solid-state/28978-improving-lm3x7-regulator-circuit.html
Is that what you are looking for?
73
Arnold
On Thu, 25 Feb
Bob Camp wrote:
Hi
Since the LPRO has a noisy 3 terminal regulator inside it, making the
outside voltage quiet (as in noise density) probably will not help much.
I've seen people insist on a low noise regulator ahead of a fluxgate
magnetometer that used an LM7805 regulator.
The plastic
The original 723 (I remember the uA723 made by Fairchild, I still have a couple
of 30 year old parts here) had a buried Zener and was considered pretty quiet
at the time.
I am not sure how it would compare with today's low noise references, but the
last time I checked, it was pretty good,
The LM723 from STMicroelectronics still uses a buried zener and its
typical noise specs about 4x less noisy than the National part.
With an LM329 4reference it should be about 2x quieter than the ST version.
Bruce
Didier Juges wrote:
The original 723 (I remember the uA723 made by Fairchild, I
I'm trying to identify the OCXO in my Tbolt; hoping that it's one
of the newer parts, as in the TAPR units.
Is there a P/N, or other obvious means of identifying the newer,
low noise OCXOs?
Pete Rawson
___
time-nuts mailing list -- time-nuts@febo.com
CR2032, expensive at the store but cheap online:
http://www.dealextreme.com/details.dx/sku.751
Good value even if 75% of them are poor (which is unlikely).
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Darlington
Sent:
I meant something like the attached circuit schematic for an LM723 based
15V regulator.
The circuit can be easily extended to use an external pass transistor
where more current is needed.
The LM329 is biased from the regulator output which improves the
reference line rejection.
The 723's
On Wed, 24 Feb 2010 12:03:32 -0500, Bob Camp li...@rtty.us wrote:
Hi
A square foot of solar cells fashioned into geek stylish hat would keep it
running for quite a while.
-
Has anybody actually poked at one of these yet?
Bob
The MSP430F5438 combined with a Zarlink ZL70250 RF transceiver
Bruce,
Why not just use a diode in place of the 2M3904 circuit ? Seems like it would
do the same
thing with less parts.
Also, would not the Texas Instruments TL-431 be a better choice as it has a
lower noise spec
them the LM329 part. In addition, with its adjustable nature, the TL-431 would
Nigel, I bet there is more than a few companies re-badging these things.
That photo of the HP base and two screw clamp is exactly the same as the
VIC100, The PCB in the VIC100 is flat and you could have a puck cover like the
HP, the VIC100 pointy shape cover is designed as a snow retardant
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