On 12/31/12 8:13 AM, Magnus Danielson wrote:
On 31/12/12 16:56, Bob Camp wrote:
Hi
I suspect that your ion standard will have some issues from magnetic
field. Quartz it's self has no magnetic sensitivity. Most atomic
gizmos have sensitivity as part of their basic physics.
All atomic clocks th
On 31/12/12 16:56, Bob Camp wrote:
Hi
I suspect that your ion standard will have some issues from magnetic field.
Quartz it's self has no magnetic sensitivity. Most atomic gizmos have
sensitivity as part of their basic physics.
All atomic clocks that I know of have this sensitivity.
One stra
On 12/31/12 7:56 AM, Bob Camp wrote:
Hi
I suspect that your ion standard will have some issues from magnetic field.
Quartz it's self has no magnetic sensitivity. Most atomic gizmos have
sensitivity as part of their basic physics.
yes.. shielding of the physics package is part of the game..
On 12/31/12 12:55 AM, Hal Murray wrote:
jim...@earthlink.net said:
When designing the system to do coherent two way ranging to the Juno
spacecraft orbiting Jupiter, we found that the rotating magnetic field
(because the spacecraft spins at 2RPM in Jupiter's magnetic field) was
enough to modulat
Hi
I suspect that your ion standard will have some issues from magnetic field.
Quartz it's self has no magnetic sensitivity. Most atomic gizmos have
sensitivity as part of their basic physics.
Bob
On Dec 31, 2012, at 10:41 AM, Jim Lux wrote:
> On 12/30/12 8:28 PM, Bob Camp wrote:
>> Hi
>>
>
On 12/30/12 8:28 PM, Bob Camp wrote:
Hi
Indeed, there will always be some EMF into the EFC from some field. You can
never really get rid of a loop with some cross section in the EFC circuit. Most
of us don't get to worry about 1x10^-16 at 1,000 seconds on our OCXO's….
Yes. I think it's not
jim...@earthlink.net said:
> When designing the system to do coherent two way ranging to the Juno
> spacecraft orbiting Jupiter, we found that the rotating magnetic field
> (because the spacecraft spins at 2RPM in Jupiter's magnetic field) was
> enough to modulate the circuits that track the recei
Hi
Indeed, there will always be some EMF into the EFC from some field. You can
never really get rid of a loop with some cross section in the EFC circuit. Most
of us don't get to worry about 1x10^-16 at 1,000 seconds on our OCXO's….
Bob
On Dec 30, 2012, at 11:16 PM, Jim Lux wrote:
> On 12/30/
On 12/30/12 8:03 PM, Bob Camp wrote:
Hi
They are using some pretty major fields in that paper. As they point out, high
level tests likely do not extrapolate well to low level performance. Their data
shows the impact diminishing quickly as the field drops.
If you accept their 1x10^-11 per gaus
On 12/30/12 11:35 AM, Attila Kinali wrote:
On Fri, 21 Dec 2012 09:53:51 -0800
Said Jackson wrote:
Volker, I wonder if you also see fan-induced spurs in the phase
noise from 1Hz to 100Hz. I would not be surprised if the fan
vibration adds significant spurs to the 10811A crystal.
How susceptib
Hi
They are using some pretty major fields in that paper. As they point out, high
level tests likely do not extrapolate well to low level performance. Their data
shows the impact diminishing quickly as the field drops.
If you accept their 1x10^-11 per gauss number as correct, your OCXO might s
Bob Camp-
"A quartz crystal in insensitive to magnetic field. This being Time Nut's
that's
not the whole story. Ferrite core inductors can indeed exhibit a bit of static
mag field sensitivity. Your OCXO may or may not have some in it."
"Precision crystals have clips made from nickel. The posts
Hi
…. sorry for the previous blank message….
A lot depends on what kind of inductors they are. If it's a static field, then
you have to saturate the core. That's pretty hard unless the core is ferrite.
Most powdered iron and (of course) air are fairly immune to static field.
If it's an AC fiel
On Dec 30, 2012, at 9:25 PM, Said Jackson wrote:
> Bob,
>
> But all those inductors surrounding the crystal will be sensitive to magnetic
> flux variations and could cause spurs and jitter..
>
> Bye
> Said
>
> Sent From iPhone
>
> On Dec 30, 2012, at 18:04, Bob Camp wrote:
>
>> Hi
>>
>>
Bob,
But all those inductors surrounding the crystal will be sensitive to magnetic
flux variations and could cause spurs and jitter..
Bye
Said
Sent From iPhone
On Dec 30, 2012, at 18:04, Bob Camp wrote:
> Hi
>
> Precision crystals have clips made from nickel. The posts are likely Kovar.
>
Hi
Precision crystals have clips made from nickel. The posts are likely Kovar.
That's been true for a *long* time. Neither one is very magnetic. Both likely
are hard enough to be even less magnetic than they might be.
Bob
On Dec 30, 2012, at 6:27 PM, Magnus Danielson
wrote:
> Bob,
>
> On 3
Hi Attila,
Makes a big difference if there are AC magnetic fields in the system, they can
create spurs through mutual inductance.
Our Fury GPSDO is designed completely without any switching regulators for that
reason. One customer used it on helicopters for measuring magnetic field
variations
Bob,
On 30/12/12 23:27, Bob Camp wrote:
Hi
A quartz crystal in insensitive to magnetic field. This being
Time Nut's that's not the whole story.
As I recall it, the steel clips sometimes used to hold the resonators is
claimed to be one of the sources for static magnetic field sensitivity.
Th
Hi
A quartz crystal in insensitive to magnetic field. This being Time Nut's that's
not the whole story. Ferrite core inductors can indeed exhibit a bit of static
mag field sensitivity. Your OCXO may or may not have some in it.
In the case of AC fields you can always have induction. There will b
On Fri, 21 Dec 2012 09:53:51 -0800
Said Jackson wrote:
> Volker, I wonder if you also see fan-induced spurs in the phase
> noise from 1Hz to 100Hz. I would not be surprised if the fan
> vibration adds significant spurs to the 10811A crystal.
How susceptible are OCXOs on magnetic fields?
Most fan
ker Esper"
To: "Discussion of precise time and frequency measurement"
Sent: Saturday, December 22, 2012 8:44 PM
Subject: Re: [time-nuts] time-nuts Digest, Vol 101, Issue 152
Plot 1: MDEV of the time interval reported by GPSDO
Yes, Said, that are important issues.
By the way: I&#x
12 8:44 PM
Subject: Re: [time-nuts] time-nuts Digest, Vol 101, Issue 152
Plot 1: MDEV of the time interval reported by GPSDO
Yes, Said, that are important issues.
By the way: I'm now writing in two threads, I don't know, why the original
thread ("Z3805A cooling requirements
Plot 1: MDEV of the time interval reported by GPSDO
Yes, Said, that are important issues.
By the way: I'm now writing in two threads, I don't know, why the
original thread ("Z3805A cooling requirements?") was splitted... Can we
please move to the original thread?
I am sure, that the noise of
Hi Volker,
What is being plotted here? Efc? Time interval as reported by the GPSDO?
External counter versus a stable reference?
It looks like the resolution is approaching 10ns/s (1E-08 at 1s), and that the
short term effects may be hidden in this noise?
The effects are clearly visible in your
Vibration: interesting consideration. In my experiment the fan is very
softly coupled to the case (since it is lying on some soft cables),
furthermore the power supply is a different one - not the one that
powers the Z3805. I've tried to avoid those effects. I send some ADEV
plots in an hour.
Mark,
Your plot still shows excursions of +/-1E-010, about 100x higher base noise
than the Z3801A/Z3805A are capable of achieving. Wonder where that noise is
coming from? This noise is probably much higher than the thermal effects.
The original post was the question "does my Z380xA have reduced
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