On Wed, 21 Sep 2011 18:36:43 -0500
Chris Howard ch...@elfpen.com wrote:
Thanks!
Would it do any good to have the control board, GPS, or anything else
within
its own shielded box?
I'd put everything into one big metal box, but seperate the different
submodules, probably shield them from each
Hello,
I'm trying to measure the Allan Deviation of an amplifier and need help with
the maths.
My measurement process uses the SR620 in time interval mode and I make one
measurement per second for about a day.
I then use Ulrichs excellent plotter to calculate the Allan Deviation.
The Allan
Le 22/09/2011 12:35, Martyn Smith a écrit :
Hello,
I'm trying to measure the Allan Deviation of an amplifier and need
help with
the maths.
My measurement process uses the SR620 in time interval mode and I make
one
measurement per second for about a day.
I then use Ulrichs excellent
mike cook wrote:
Le 22/09/2011 12:35, Martyn Smith a écrit :
Hello,
I'm trying to measure the Allan Deviation of an amplifier and need
help with
the maths.
My measurement process uses the SR620 in time interval mode and I
make one
measurement per second for about a day.
I then use
Le 22/09/2011 13:45, Bruce Griffiths a écrit :
I have always thought of a noise floor as the lower limit to which
you can trust your measurement. Measurements below the floor can be
statistically derived IIRC, but calculating the Allan deviation of it
makes no sense to me. As your
A couple of things to consider
If you have two independent noise sources they add with their RMS sum
But for two noise readings that are close, the difference is more likely
statistical variations than RMS adding, especially at your 100 sec time
periods.
Assuming you have a system that is
Hello,
My measurement technique is from Stanford's own application note.
The two 10 MHz are fed to Ch A and B. The measurement is a time interval
gated at 1 kHz from the SR620's ref out.
So we make 1000 measurements per second.
So the one shot 25 ps SR620 spec is reduced by square root of
Sqrt(adev_meas^2-adev_ref^2) should do it, but you are close to the floor so
confidence bounds will have to be small for meaningfull values.
Cheers,
Magnus
Martyn Smith mar...@ptsyst.com skrev:
Hello,
I'm trying to measure the Allan Deviation of an amplifier and need help with
the maths.
Fellow time-nuts,
I am in need of the pinning for the HP5062C connectors, in particular the AC
and time code connectors. A manual would be great.
Cheers,
Magnus
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-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-
boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Thursday, September 22, 2011 5:37 AM
To: time-nuts@febo.com
Subject: [time-nuts] HP5062C connector pinouts
Fellow time-nuts,
I am in need of the
On 09/21/2011 04:57 AM, David C. Partridge wrote:
Howsabout HFC-236fa - very similar properties to R114 but not banned.
Tektronix used a Freon in their 40 KV High Voltage probes. The Vapor
pressure of some of those compounds is low at 70F, but they do have to
be sealed.
I use several of
John:
One big difference is that when most of the butane leaked out and
air leaked in, you'd get a very clear indication when arcs occur. I
wouldn't want to be holding it.
I think Tek degrades the P6015 to 13kV without Freon - enough for my
needs. Maybe someone will find out
For those that reflexively will add that butane is explosive in air:
There isn't any air in the probe if you let the butane boil for a few
seconds, and as long as there is liquid butane in the probe there won't
be any air leaking in.
However, if there is no liquid, you will need to purge out
On 9/22/11 10:34 AM, NeonJohn wrote:
On 09/21/2011 04:57 AM, David C. Partridge wrote:
Howsabout HFC-236fa - very similar properties to R114 but not banned.
Tektronix used a Freon in their 40 KV High Voltage probes. The Vapor
pressure of some of those compounds is low at 70F, but they do
Note that if you change the dielectric in the probe, especially to a
liquid, you may no longer be able to compensate it properly.
The higher dielectric constant will increase the stray capacitances.
Best,
-John
On 9/22/11 10:34 AM, NeonJohn wrote:
On 09/21/2011 04:57
It's going on 10 years now since I last filled a probe. That's the
major advantage of butane. It doesn't diffuse out like the freon did.
On 09/22/2011 01:53 PM, Jose Camara wrote:
John:
One big difference is that when most of the butane leaked out and
air leaked in, you'd get a very
Neither diffuses out. They leak. They could certainly leak at different
rates because of differing MWs, but how tight you made the sealing screw
is likely far more important.
-John
==
It's going on 10 years now since I last filled a probe. That's the
major advantage of butane.
Just a FYI, some claim Ronsonol butane isn't very pure as compared to
other brands. Some lighter manufacturers suggest not to use it in their
devices. I have no idea what trace substances they object to.
Reality? Who knows. Seems most butane comes out of Korea and could
simply be
Esteemed Colleagues,
I will attempt to make a coherent technical reply to the remarks made about my
10811 posting.
But first a bit of qualification. My remarks refer to the 10811 and that
vintage of OCXO’s.
Wrote: Doing what you describe will result in a very sensitive humidity sensor,
Perry Sandeen wrote:
Wrote: Doing what you describe will result in a very sensitive humidity
sensor, having eliminated the thermometer effect.
I do not understand. I believed that since the OCXO temperature will be
substationally higher than the surrounding temps, any residual moisture
You had a leak. If epoxy was really as bad as you indicate,
it would not be usable for holding pressure, or mild vacuum,
and yet it is. Somehow, someway you left a big hole in the
bucket.
-Chuck Harris
Rick Karlquist wrote:
Perry Sandeen wrote:
Wrote: Doing what you describe will result in
A problem I've seen when using the hermetic sealed soldered version of the
10811 from a dual oven unit,
is when the case is sealed the osc makes a good barometer because of changes
in its case due to barometric changes.
A 1 inch difference (such as 30 to 29) caused something on the order of
Within minutes the frequency changed more than the spec
For humidity to get thru something like that it takes weeks or more it does
it at all.
That fast of reaction, Sure sounds like some other effect like blowing a
little air on the case or loading the osc output with water in the output
Humidity is a confusing subject to many engineers and scientists.
Unlike most parameters it is a quantity with two input variables,
concentration and temperature. There are many ways to combine
these to give different units.
As a research scientist I spent most of my career working with
composite
On 9/22/2011 5:17 PM, ws at Yahoo wrote:
Within minutes the frequency changed more than the spec
For humidity to get thru something like that it takes weeks or more it
does it at all.
That fast of reaction, Sure sounds like some other effect like blowing a
little air on the case or loading the
For those of you who may be interested, here's the paper.
http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf
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