On 12/10/2012 02:53 PM, Jim Lux wrote:
On 12/9/12 10:14 PM, DaveH wrote:
http://www.scmagazine.com.au/News/325731,researchers-find-crippling-flaws-in
-global-gps.aspx
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I've got a couple questions on a early S/N 5061A I got a few days ago.
It took a couple days but the Ion Pump current is now down to "zero"
or at least less then one division on the meter.
I'm able to get the unit to go into continuous operation mode by
following the TURN-ON PROCEDURES but have
a
Hi Charles,
Well, perhaps you are not looking close enough. That is you need to be
observing
at a finer level of comparison. The changes, observed here and at another
location, are in parts in 10-10 to 10-11 range, sometimes larger. At one of the
locations there was a direct correlation to the
That temperature sensor does have an effect on the final outcome as
it is part of
the internal equation. So buffering the ambient temperature is important.
I've heard this before, but the evidence I have seen does not seem to
support the proposition.
While switching the Dallas chip in one
Hello S.W.,
On occasion I get an "ALARM 4000" with Lady Heather V3.10,
However I know not what it means. The alarm is transient.
Over the past weeks it only occurred twice.
I just checked my T'Bolts and 2 of them displayed a partial PPS Adev
(upper) table
but a full OSC Adev table (lower). I
Sarah -
As others will point out the temperature reported by the T-bolt is NOT the oven
temperature. Rather it
is the temperature of a temp sensing chip on the PWB. There were several
versions of this chip installed
and they did not all work the same - on the time nuts archive there is a weal
If it *was* missing codes in reality, it would not be the first time
TI made that kind of mistake. One of their not so early multi-slope
integrating converters was advertised to *not* return both plus zero
and minus zero which was a big feature at the time . . . but it did.
Almost nobody noticed t
Hi
It's not at all uncommon for the seismic guys to go a bit uber-nuts on clean
supplies and references.
Bob
On Dec 10, 2012, at 7:54 PM, David wrote:
> On Mon, 10 Dec 2012 23:01:49 +, "Poul-Henning Kamp"
> wrote:
>
>> In message , David writes:
>>
>>> The gain drift is specified at 2p
On Mon, 10 Dec 2012 23:01:49 +, "Poul-Henning Kamp"
wrote:
>In message , David writes:
>
>>The gain drift is specified at 2ppm per degree C. There are
>>provisions for a calibration cycle but that requires external
>>multiplexing.
>
>That's the really smart thing about this particular chip:
Sarah,
That temperature sensor does have an effect on the final outcome as it is part
of
the internal equation. So buffering the ambient temperature is important.
You do not need to go crazy, but having it contained in a box with some small
amount
of heat applied and maintained by some control
On 12/10/2012 6:10 PM, Arthur Dent wrote:
> I believe that the high temperature alarm you see is triggered at 50 degrees
> C. If that is what you're seeing without artificially raising the
> temperature
> of the Thunderbolt by insulating it so it can't radiate the heat, what I said
> about rep
I believe that the high temperature alarm you see is triggered at 50 degrees
C. If that is what you're seeing without artificially raising the temperature
of the Thunderbolt by insulating it so it can't radiate the heat, what I said
about replacing the chip is correct but if it is staying withi
In message
, Didier Juges writes:
>I do not understand how anyone can guaranty no missing codes when the lower
>11 bits are essentially noise? (31 bits resolution versus 20 effective bits)
No missing codes is guaranteed by the design, you'd have to screw up the
digital filters to come o
On 12/10/2012 5:22 PM, Bob Camp wrote:
> Hi
>
> The oven in the OCXO keeps the crystal at a constant temperature. It is
> normal for the TBolt it's self to idle 10 to 20C above ambient. The
> temperature sensor is located near the 9 pin D connector. It shows a
> temperature somewhere in between
In message , David writes:
>The gain drift is specified at 2ppm per degree C. There are
>provisions for a calibration cycle but that requires external
>multiplexing.
That's the really smart thing about this particular chip: You can
drive the geophone calibration signal in through the s
>I feel like shouldn't need to fuss with ambient conditions this heavily
>for an OCXO, and find myself researching construction / design for a DIY
>outer-oven to wrap the thunderbolt in.
>
>Anyone have experience with non-stable temperature on a trimble thunderbolt?"
The temperature you see is not
I agree, but there is a difference between something that you should be
able to achieve by design and being able to prove it, or even if it's
useful in practice.
In a case like this, the wide span between resolution and effective bits
makes me wonder what's the point of advertising the former other
Sarah,
The reported temperature is not the oven temp, but rather the temp of the
circuit board just behind the DB-9 serial connector. As far as I know, the
actual oven temp is not available outside the OCXO.
Regards,
geo
On Mon, Dec 10, 2012 at 5:15 PM, Sarah White wrote:
> Ended up with a ge
Hi Sarah,
The temperature you are seeing is that of a Dallas IC mounted on the main PC
board. You are seeing the ambient temp of the board, not inside the OCXO
oven.
Regards,
Tom
- Original Message -
From: "Sarah White"
To: "Discussion of precise time and frequency measurement"
Hi
The oven in the OCXO keeps the crystal at a constant temperature. It is normal
for the TBolt it's self to idle 10 to 20C above ambient. The temperature sensor
is located near the 9 pin D connector. It shows a temperature somewhere in
between the ambient and the OCXO case temperature. Some ha
Ended up with a gently used trimble thunderbolt a few months ago, and
been trying to figure out the best settings to use (time constant,
damping, etc.) for best performance.
I got distracted though. There is something which I find rather
annoying, and I'm spending more time messing with this facto
The gain drift is specified at 2ppm per degree C. There are
provisions for a calibration cycle but that requires external
multiplexing.
On Mon, 10 Dec 2012 07:26:55 -0800 (PST), Robert LaJeunesse
wrote:
>. . .
>
>typical for better monolithic sigma-delta converters. Nonetheless 20 bits
>indica
Integrating converters including delta-sigma converters can be no
missing codes by design without being able to take advantage of the
full resolution that implies. Integral nonlinearity, drift, and noise
will limit the usable resolution.
On Mon, 10 Dec 2012 15:08:38 -0600, Didier Juges
wrote:
>
Hi
I suspect you can prove it mathematically. You could also just sit there and
watch what it puts out for a year or so. With a reasonable ramp it likely would
put out all codes. That's not to say you could prove they are in order, only
that you saw all 4 billion codes. More or less:
1,000 sam
Regarding feedback loops, I had a brain fart. I mean monotonic and no missing
codes, not no missing codes in general.
I think it was Fluke or Analog that had a small booklet on understanding data
converter specifications.
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time-nuts mailing li
How long does it take to prove it?
And what's the point?
On Mon, Dec 10, 2012 at 3:04 PM, Gerhard Hoffmann wrote:
> Am 10.12.2012 21:53, schrieb Didier Juges:
>
> I do not understand how anyone can guaranty no missing codes when the
>> lower
>> 11 bits are essentially noise? (31 bits resolutio
Am 10.12.2012 21:53, schrieb Didier Juges:
I do not understand how anyone can guaranty no missing codes when the lower
11 bits are essentially noise? (31 bits resolution versus 20 effective bits)
With that much noise it is really guaranteed that no code will be missing.
:-) Gerhard
_
I do not understand how anyone can guaranty no missing codes when the lower
11 bits are essentially noise? (31 bits resolution versus 20 effective bits)
On Mon, Dec 10, 2012 at 2:19 PM, wrote:
> It is 31 bits with no missing codes. Usually missing codes is of concern
> in feedback systems, but
It is 31 bits with no missing codes. Usually missing codes is of concern in
feedback systems, but I don't see the use in a geophone. Perhaps they will
average the digital signal further to reduce the noise, hence the noisy bits.
___
time-nuts mailing
Hi
When your "sound source" is a thumper truck, you do indeed care about some
pretty low frequencies.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Hal Murray
Sent: Monday, December 10, 2012 1:33 PM
To: Discussion of precise time
rlajeune...@sbcglobal.net said:
> Nonetheless 20 bits indicates a matching reference would have to hold 1PPM
> over temperature, no simple task.
The initial post called it "TI's ADS1282 geophone ADC".
I'm pretty sure that the geologists using geophones don't care about super
low frequencies s
Well, that obviously went to the wrong place.
That was a private message, sorry for the bandwidth.
Didier
On Mon, Dec 10, 2012 at 12:06 PM, dlewis6767 wrote:
> Thanks, Didier, if you ever find a mainframe for it, please keep me in
> mind.
>
> Thanks, -Don
>
>
>
>
> -
Thanks, Didier, if you ever find a mainframe for it, please keep me in
mind.
Thanks, -Don
--
From:
Sent: Monday, December 10, 2012 11:23 AM
To: "Discussion of precise time and frequency measurement"
Subject: [time-nuts] Counter
I
Is shipped, tracking number
1Z30VR960337713831
due Wednesday
Didier
Sent from my Droid Razr 4G LTE wireless tracker.
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and fol
Hi
The oven monitor pin on most OCXO's is not a real good thing to switch
directly off of. They generally go low well before the output is very
stable. A timer is run off of the oven monitor pin would give you a pretty
good switch point (switch X minutes after the oven monitor shows good).
Bob
-
Hi
What is atypical about these parts is:
1) The excellent noise performance inside 10 Hz
2) The built in Nyquist filters
The first is very impressive compared to just about anything else out there.
The second is available in some, but not all similar parts.
Bob
-Original Message-
From
Yes. There is a Yahoo Group spwecifically about EIP products.
-John
>
>
>> I have an EIP counter with a problem, stashed, that I need to look at
>> eventually. So have been following the thread a bit.
>
>> If you guys get somewhere conclusive (or not), might be nice to post a
I see that there is a high resolution 130dB mode too that can give 21 bits
@ 250 samples per second, good for very slow, high resolution DMTD (but
also very stable voltage reference and ADC temperature, seems very
challenging).
On Mon, Dec 10, 2012 at 4:26 PM, Robert LaJeunesse <
rlajeune...@sbcgl
Le 10/12/2012 13:44, Chris Howard a écrit :
If it were me, I'd suspect that my window of bits is off
to the left or right by one bit. The old "first bit is
called zero" problem.
And the relationship between 7-> 3 and 5-> 1 makes me
wonder.
Chris
On 12/10/2012 5:00 AM, Tom Harris wrote:
I
31 bits is just a convenient word size that comes out of the on-chip filter,
and
does not really relate to performance. Better to look at SNR which, at worst
case, is 120dB in high-res mode. That indicates performance just under 20 bits,
typical for better monolithic sigma-delta converters. Non
I'm already over there. The thread just migrated back here.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Steve
Sent: Monday, December 10, 2012 8:43 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-n
In message
, Azelio
Boriani writes:
>31-bit is 186dB... with what do you compare that device? What kind of
>reference is needed?
It's not 31 noise-free bits, but the SNR is in the 120-130dB territory.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org |
Or join and post to the EIP_Microwave Yahoo group - lots of good info showing
up there!
Steve
WB0DBS
On Dec 10, 2012, at 8:00 AM, "J. L. Trantham" wrote:
> Me too.
>
> I have two 545A's, one of which works and the other of which has issues with
> Band 3, failing to read in a very interest
31-bit is 186dB... with what do you compare that device? What kind of
reference is needed?
On Sun, Dec 9, 2012 at 11:18 PM, Bob Camp wrote:
> Hi
>
> It's the "big brother" of the ADS127x parts that I mentioned a little
> while back. I'm sure it works quite well. The 127x's are fine parts. The
>
Chris and I took this offline so as not to bother the time-nuts thread.
Hopefully we can work it through. Chris is lucky as he only has a band 2
problem.
Band 3 in nastier o deal with.
Chris since several have expressed interest perhaps we just add them to
your new thread.
We can still skype for th
Me too.
I have two 545A's, one of which works and the other of which has issues with
Band 3, failing to read in a very interesting pattern suggesting a YIG
filter issue, probably the control circuit.
Just no time to chase it right now.
Please post the resolution.
Thanks.
Joe
-Original Me
On 12/9/12 10:14 PM, DaveH wrote:
http://www.scmagazine.com.au/News/325731,researchers-find-crippling-flaws-in
-global-gps.aspx
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On 12/9/12 10:14 PM, DaveH wrote:
http://www.scmagazine.com.au/News/325731,researchers-find-crippling-flaws-in
-global-gps.aspx
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> I have an EIP counter with a problem, stashed, that I need to look at
> eventually. So have been following the thread a bit.
> If you guys get somewhere conclusive (or not), might be nice to post a
> summary of all important details, techniques, or circuit notes beyond
> the manual, found, t
On 12/10/2012 7:10 AM, David Kirkby wrote:
On 10 December 2012 09:24, David C. Partridge
wrote:
Related to time-nuttery as astonomical observation was used for time-keeping
until C20.
Sir Patrick Moore, the great amateur astonomer died yesterday at the age of 89.
Although considered an amat
Not sure why you would want to do this but, if you have a Rb, such as an
LPRO-101 or others, there is a signal that lets you know the Rb is 'locked'.
You could use that to drive a relay that would switch the output of the Rb
to the external input of your device.
This presumes you do not have to me
I have an EIP counter with a problem, stashed, that I need to look at
eventually. So have been following the thread a bit.
If you guys get somewhere conclusive (or not), might be nice to post a
summary of all important details, techniques, or circuit notes beyond
the manual, found, to this thr
If it were me, I'd suspect that my window of bits is off
to the left or right by one bit. The old "first bit is
called zero" problem.
And the relationship between 7-> 3 and 5-> 1 makes me
wonder.
Chris
On 12/10/2012 5:00 AM, Tom Harris wrote:
> I am logging the data from this strange master
Bert,
I have been waiting for more details to become available. Thanks for the
update.
Not sure exactly what this means:
but I have to depend on volunteers to do the drawings and they have to make
their time available when convenient.
Depending on if the input is in some kind of standard, or
On 10 December 2012 09:24, David C. Partridge
wrote:
> Related to time-nuttery as astonomical observation was used for time-keeping
> until C20.
>
> Sir Patrick Moore, the great amateur astonomer died yesterday at the age of
> 89.
Although considered an amateur, I assume he got paid for present
Hi
You may have a TTL output level version of the FE.
Bob
On Dec 10, 2012, at 1:24 AM, James Peroulas wrote:
> For the record, my device did have an OSMT (not Hirose) connector on the
> DDS board.
>
> I'm having trouble getting the internal RS232 port on the DDS board to work
> and I was wond
Hi
Perkin Elmer does everything that EG&G used to do - same company, new name.
Bob
On Dec 9, 2012, at 11:07 PM, Jim Lux wrote:
> On 12/9/12 5:38 PM, Bob Camp wrote:
>> HI
>>
>> Princeton was part of EG&G for quite a while. EG&G bought out Perkin Elmer
>> in the 90's. The EG&G name was not a
Hi
On Dec 9, 2012, at 9:07 PM, WB6BNQ wrote:
> Bob,
>
> I don't know where you got your multiple versions.
Quite possibly from having spent the last 40 years in the business of designing
and building OCXO's.
> RETRACE deals with the object in a fully realized steady state operating
> cond
That's the funny thing, the parity bit is correct for the value of DOW,
just that the DOW value is wrong.
On 9 December 2012 23:27, Azelio Boriani wrote:
> Is the parity bit P3 consistent? It protects the day of the month and that
> of the week.
>
> On Sun, Dec 9, 2012 at 1:24 PM, mike cook wro
I am logging the data from this strange master clock, and the none of the
bits 42 through 44 are stuck. Good idea, though. I have just checked
tonight, and the DOW is indicating as 5 (Friday), despite it only being
Monday.
Good idea though.
On 9 December 2012 23:24, mike cook wrote:
> Le 09/12/
Related to time-nuttery as astonomical observation was used for time-keeping
until C20.
Sir Patrick Moore, the great amateur astonomer died yesterday at the age of 89.
A gentleman, astronomer, and true scholar. His death was predicatable as he's
been very ill for a long time, but nonetheless
The trip point is specd to be between -3 to +3, which is why 5V works,
especially since the trip point is usually positive. I would set it
around 1.5V. The transmitters are required to swing +/- 5V.
I'm not sure the 232 "allowed" lower voltage as much as all we had to
work with were charge pum
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