Sent: Saturday, July 11, 2009 1:54 PM
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Subject: Re: [time-nuts] 10811 crystal orientation
That is interestng and brings a question that I should be able to answer
but
have been too busy (or lazy...) to try...
The HP
Said and Björn,
saidj...@aol.com wrote:
Hello Bjoern,
that would work well for static acceleration (tilt) but for vibration
resistance the crystal must be low-g, or complexly compensated with wide loop
bandwidths such as the FEI papers describe.
It could work for low-frequency
Didier wrote:
That is interestng and brings a question that I should be able to answer but
have been too busy (or lazy...) to try...
The HP 5370 has a noisy fan, and an HP 10811 in the same box. Has anyone
been curious enough to measure the effect of fan vibration on the oscillator
and p-p
Hi Magnus,
Agree with all your points.
On the added noise due to an accelerometer, my thoughts are that this needs
to be carefully designed so as not to add more error than we are actually
removing (due to phase shifts between crystal sensitivity and the
accelerometer response for
saidj...@aol.com wrote:
Hi Magnus,
Agree with all your points.
:)
On the added noise due to an accelerometer, my thoughts are that this needs
to be carefully designed so as not to add more error than we are actually
removing (due to phase shifts between crystal sensitivity and the
Hi Said,
Hi Magnus,
Agree with all your points.
On the added noise due to an accelerometer, my thoughts are that this
needs
to be carefully designed so as not to add more error than we are actually
removing (due to phase shifts between crystal sensitivity and the
accelerometer response
Hello Bjoern,
that would work well for static acceleration (tilt) but for vibration
resistance the crystal must be low-g, or complexly compensated with wide loop
bandwidths such as the FEI papers describe.
Initial Calibration would also be tricky, and having an algorithm to
measure one
Hi Said,
What GPSDO-products do compensate for tilt?
It seem like a major error source -- if the user for some reason want to
tilt a unit in holdover. It seems to be a low hanging fruit to attenuate
this error substantially even with a $2 MEMS accelerometer.
Once the ambitions grow -- more
A lot of the ballistic GPS systems are actually GPS transponders attached to
the back of the shell. They just retransmit the received GPS signal spectrum
to a remote receiver. Much cheaper and more robust than slinging a full GPS
receiver. Google TIDGET for more info...
Hi
Most of the GPSDO stuff is made for fixed location use. In that case,
paying for acceleration compensation doesn't make much sense.
About the only people who try to do this stuff mobile (and have the
ability to pay) are the military.
Bob
KB8TQ
On Jul 11, 2009, at 5:55 AM,
measurements?
Didier
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak
Sent: Friday, July 10, 2009 5:51 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 10811 crystal orientation
One
b...@lysator.liu.se said:
What GPSDO-products do compensate for tilt?
It seem like a major error source -- if the user for some reason want
to tilt a unit in holdover.
I would assume most GPSDOs are rack mounted and are unlikely to get tilted.
If tilt is this interesting, it should show up
One is do crystal oscillators change frequency when they
are turned. The answer to that is yes. This gravitational
acceleration effect is rather huge, parts in ten to the 9th
or so, and anyone can see this. This is why you never
touch, bump, or move, or rotate a laboratory frequency
standard
Hello Tom,
this plot looks very similar to our standard double oven units. We
have our low-g option, which reduces the deviation to about 2- 3E-10
per g, they work great but do cost more than standard units..
Coincidentally they also reduce sensitivity to vibration and tapping
by 5x to
Hi Said Tom,
The below url links some low-g-osc papers.
http://www.freqelec.com/tech_lit.html
Said, did you contemplate adding a cheap 3d-accelerometer and try to teach
your holdover algorithms use the accelerometer measurements in the same
way as your temperature measurements?
--
Hi Said Tom,
The below url links some low-g-osc papers.
http://www.freqelec.com/tech_lit.html
Said, did you contemplate adding a cheap 3d-accelerometer and try to teach
your holdover algorithms use the accelerometer measurements in the same
way as your temperature measurements?
Björn,
I have another reading key.
When the manufacturer publishes the specs of its crystals, it
alrady took into account all of the possible known variables,
some of them very tiny such as dependences on orientation
(which do exist), so freeing the assembler (and the end-user)
from caring of.
iov...@inwind.it wrote:
I have another reading key.
When the manufacturer publishes the specs of its crystals, it
alrady took into account all of the possible known variables,
some of them very tiny such as dependences on orientation
(which do exist), so freeing the assembler (and the
I have seen one instance where crystal orientation does matter. Among
other things, I'm interested in WW II military radios. Admittedly long
ago.
The Canadian Wireless Set 19, the standard radio for many tanks, etc., in
WW II had an external crystal calibrator. It put out 1 MHz, 100 KHz, and
10
Bob Camp wrote:
Hi
I think that if you dig into it, you will find that there is a polarized
light process to orient the blank before the base plate is applied.
Unfortunately for the discussion at hand, the direction of maximum G
sensitivity is still random relative to the mount.
Bob
Richard (Rick) Karlquist wrote:
Bob Camp wrote:
Hi
I think that if you dig into it, you will find that there is a
polarized light process to orient the blank before the base plate is
applied.
Unfortunately for the discussion at hand, the direction of maximum G
sensitivity is still
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM Hi Chad,
the sketch you sent seems to indirectly answer my question, as I
could rely on the axis of minimum g sensitivity to orient my three
10811 assemblies
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Jim Palfreyman
Sent: 08 July 2009 23:37
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 10811 crystal orientation
All,
Can you please follow John's
Agreed. Has anyone done the crucial experiment? establish stats, rotate
assembly, establish stats, etc? Should be able to measure at least if
there is an effect, and also if it is present, an approximate magnitude...
Don
Hi Don,
There are two rather different topics here.
One is do crystal
You are right, Tom, there are two mixed topics.
On the on-topic subject, instead of making tests to measure the frequency
dependence on orientation, It would be much more interesting looking at
possible ADEV dependences on orientation, particularily for small tau (the
bottom of the curve). I
iova...@inwind\.it wrote:
You are right, Tom, there are two mixed topics.
On the on-topic subject, instead of making tests to measure the frequency
dependence on orientation, It would be much more interesting looking at
possible ADEV dependences on orientation, particularily for small tau
: [time-nuts] 10811 crystal orientation
You are right, Tom, there are two mixed topics.
On the on-topic subject, instead of making tests to measure the frequency
dependence on orientation, It would be much more interesting looking at
possible ADEV dependences on orientation, particularily for small
Ah, never touch, bump, etc. implies that the effect of
changing the orientation of gravity is not reversible.
Or is it that returning to the original orientation undoes
the 10E9 effect but leaves a 10E12 permanent change?
I'd like to do the experiment myself, but I'm still getting
rid of stuff
Don Latham wrote:
Thanks. Tom. Glad to see the references.
I've some experience with clock time difference, as I showed an
astonishing number of years ago that the phase changes between two
clocks as measured by their respective LORAN-C signals was due to
changes in the atmospheric index of
iov...@inwind.it wrote:
You are right, Tom, there are two mixed topics.
On the on-topic subject, instead of making tests to measure the frequency
dependence on orientation, It would be much more interesting looking at
possible ADEV dependences on orientation, particularily for small tau (the
The Zhou paper should be taken with a grain of salt. It does report on a
number of deviations measured during eclipses. More investigations is
needed to characterize the cause of these deviations.
Agreed. It is not uncommon for well-done experiments to
spend more time on analysis of error
Dear all,
does anybody out there know the orientation of the crystal faces relative to
the outer case in a 10811-60111?
(The sense of the question is that we are considering building a 3-axis
apparatus for gravity-related tests. Note, based on our tentative modelization,
crystals are not
Hi Chad,
the sketch you sent seems to indirectly answer my question, as I could rely on
the axis of minimum g sensitivity to orient my three 10811 assemblies, but
for my purpose it seems that there is still a margin of ambiguity. I don't take
from the sketch how the crystal is actually fitted
:
From: iov...@inwind.it iov...@inwind.it
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question,
as I could rely on the axis of minimum g sensitivity
: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question,
as I could rely on the axis of minimum g sensitivity to
orient my three 10811 assemblies, but for my
Remember that the SC cut is doubly rotated, so the crystallographic
axes are tilted relative to plane of the blank. These angles are
published in papers on the SC cut and controlled to extremely tight
tolerances (a few seconds of arc). However, the 10811 crystal
package is free to rotate to any
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question,
as I could rely on the axis of minimum g sensitivity to
orient my three 10811
/09, iov...@inwind.it iov...@inwind.it wrote:
From: iov...@inwind.it iov...@inwind.it
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question,
as I
On Wed, Jul 8, 2009 at 10:27 AM, iov...@inwind.it iov...@inwind.it
wrote:
Dear all,
does anybody out there know the orientation of the crystal faces
relative
to the outer case in a 10811-60111?
(The sense of the question is that we are considering building a 3-axis
apparatus for
I think several of us have an HP document on-line that explains at least
a bunch of the various models. My copy is at
http://www.febo.com/pages/hp10811/HP10811-Specs.pdf
John
Dave M said the following on 07/08/2009 08:02 PM:
On Wed, Jul 8, 2009 at 10:27 AM, iov...@inwind.it
pictures.
The crystal element is a disc mounted parallel to the flat end of the
can,
see http://www.bliley.com/index_088.htm
Robert G8RPI.
--- On Wed, 8/7/09, iov...@inwind.it iov...@inwind.it wrote:
From: iov...@inwind.it iov...@inwind.it
Subject: Re: [time-nuts] 10811
/09, iov...@inwind.it iov...@inwind.it wrote:
From: iov...@inwind.it iov...@inwind.it
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question
I certainly posted to thaqt thread several times.
However, I just remembered that about 10 or 15 years ago, I was really
stupid and split the female threaded boss on the bottom of a GPS antenna
by putting a layer ot two of Tellon tape onto a Male PVC fitting. That
'lubricated' the joint enough
: iov...@inwind.it iov...@inwind.it
Subject: Re: [time-nuts] 10811 crystal orientation
To: time-nuts time-nuts@febo.com
Date: Wednesday, 8 July, 2009, 7:01 PM
Hi Chad,
the sketch you sent seems to indirectly answer my question,
as I could rely on the axis of minimum g sensitivity
. Date: Wed, 08 Jul 2009 20:05:54 -0400
From: John Ackermann N8UR j...@febo.com
Subject: Re: [time-nuts] 10811 crystal orientation
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Message-ID: 4a553462.8010...@febo.com
Content-Type: text/plain; charset=us-ascii; format
: Wednesday, July 08, 2009 5:49 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 10811 crystal orientation
Hi Bruce,
Well, I am glad you are not mad at me.
As you know most humor is fact based and such is the case I made
about the humor. I really
do
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