> OTOH, if you carefully
>adjust a couple of HP10811's to zero beat, you will have to
>go to extraordinary measures to keep them from injection locking.
>A lot more than just running them on individual voltage
>regulators.
How are they connected, or coupled? They seem to be well shielded, do
Forrest as Taka says pump it down. But I can add a bit to that. Old cesiums
seem to have trouble pumping down. Say you get it to pump down but it took
a week or two. In 30 days does it pump down quick or take a week. To me
that establishes how often the tube needs to be pumped down. I typically do
Hi
To “see” the zero beat, they have to be hooked to some sort of test gear.
It’s only going to have just so much isolation.
The fine old 3048 phase noise test set was pretty good at injection locking
the devices you were testing ….
Loaded Q on a “typical” 10 MHz OCXO is likely in the 500K
Hi
One of the biggest issues in all this is that while a group of OCXO’s
may have some similar characteristics, they most certainly will not all
have the *same* characteristics. This one is at 5x10^-13 at 1 second
and the next one out of the box is at 5x10^-12 at 1 second.
On top of that, your
On Tue, 10 Mar 2020 03:38:11 +0100
Magnus Danielson wrote:
> Now, to raise the complexity, the state-model of noise does not allow
> for flicker noise variants. There just isn't a a good way to express
> that. There is a few articles that give rough estimates, but no
> half-integrators to be
Is this effectively dither on the control voltage?
On 2020-03-10 10:30, Skip Withrow wrote:
Hello Time-Nuts,
A couple of weeks ago I posted regarding some weird behavior of the
Trueposition GPSDO that I was seeing. I have now been able to get
back to the problem and have further results to
I think it would be a dead-band.
David N1HAC
On 3/10/20 2:41 PM, djl wrote:
Is this effectively dither on the control voltage?
On 2020-03-10 10:30, Skip Withrow wrote:
Hello Time-Nuts,
A couple of weeks ago I posted regarding some weird behavior of the
Trueposition GPSDO that I was seeing.
Hi,
On 2020-03-10 12:53, Attila Kinali wrote:
> On Tue, 10 Mar 2020 03:38:11 +0100
> Magnus Danielson wrote:
>
>> Now, to raise the complexity, the state-model of noise does not allow
>> for flicker noise variants. There just isn't a a good way to express
>> that. There is a few articles that
Hello Time-Nuts,
A couple of weeks ago I posted regarding some weird behavior of the
Trueposition GPSDO that I was seeing. I have now been able to get
back to the problem and have further results to report.
I have several of these GPSDOs that are version 12.0.1 (I believe the
latest is 12.1.1)
In message , Magnus Danielson
writes:
>It should be said that Kalman is kind of optimum for "white" noise
>(what-ever that is), but we are far from white noise. Variants of Kalman
>filters use noise-colour compensation of some sort, and that kind of
>solves some of the issues. It does
I noted Skip Winthrow's message about the listing of a Cesium standard on
eBay.
I've had some questions generally about these used standards for some time
now, figured this was a good time to ask them.
So let's assume I buy a used unit in working condition. I get it here, it
works fine, and
I appreciate this discussion. I'm a statistician, not an engineer. I teach
linear quadratic estimation, of which Kalman is the archetypal example, as
a mathematical exercise without dealing more than very superficially with
practical applications. I've been following these posts with interest.
I am a Time-Nut in training. I am still learning. So I can only contribute a
small amount.
I have an old Cesium standard by FTS, model FTS4040A. Amazingly, it still
locks. Amazingly, it's still holding stable. So far, works every time and
frequency is the same. But a big question
Hello Time-Nuts,
I just listed a good working HP 5061A cesium beam frequency standard
on ebay (auction #
233521981160). I have not used it much since I acquired it and
figured someone else could better utilize it (and I can use the room).
Starting price is very reasonable for a working unit. If
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