Hi Corby,
That was really what I was hoping for from the small Rb's too, but
there appears to be other things at work with them.
I had not really considered that they might be sealed, but it's
something to look at. I had been thinking more about how it was fixed
into the package and with what ma
On 5/22/16 10:25 AM, Bob Camp wrote:
Hi
In 40 years of getting phone calls, the one that never seems to go away starts
out with:
“We … errr… measured the temperature rise in our box and need to adjust the
upper end
temperature on your part”.
Or, as a designer using an OCXO part, you have
In message <5741e08b.9080...@rubidium.dyndns.org>, Magnus Danielson writes:
>The negative voltage switcher of A15 board should be replaced with a
>suitable switcher, and some of the DC/DC switcher modules is built with
>isolation, so it should allow for mounting two in parallel such tha
In message <02878e59-0bae-4220-8a86-5e59f0ca5...@n1k.org>, Bob Camp writes:
>'We ... errr... measured the temperature rise in our box and need to adjust
>the upper end temperature on your part'.
yeah, I know that story:
http://phk.freebsd.dk/hotsun/
That's the CPU/fan cover for
Hi
In 40 years of getting phone calls, the one that never seems to go away starts
out with:
“We … errr… measured the temperature rise in our box and need to adjust the
upper end
temperature on your part”.
The really interesting part is that you can get multiple calls that go the same
way from
In message , Bob Camp writes:
>At least 5C offset relative to an external sensor. Likely more in some rack
>installations. Past that it depends on how close the item of
>interest is to the oven assembly.
That's only part of it.
The rather important zener diode regulating the C-field is
Hi Bob,
On 05/22/2016 05:21 PM, Bob Camp wrote:
Hi
On May 22, 2016, at 10:49 AM, Attila Kinali wrote:
Hoi Poul-Henning,
On Fri, 20 May 2016 09:52:39 +
"Poul-Henning Kamp" wrote:
Temperature effects are by far the largest effects we have to deal with.
Which is why you'd be much bett
Hi
> On May 22, 2016, at 10:49 AM, Attila Kinali wrote:
>
> Hoi Poul-Henning,
>
> On Fri, 20 May 2016 09:52:39 +
> "Poul-Henning Kamp" wrote:
>
>>> Temperature effects are by far the largest effects we have to deal with.
>>
>> Which is why you'd be much better of with 20 sensors at 16 bi
In message <20160522164909.9fbc6cc820403cc70904e...@kinali.ch>, Attila Kinali
writes:
>Hoi Poul-Henning,
>
>On Fri, 20 May 2016 09:52:39 +
>"Poul-Henning Kamp" wrote:
>
>> >Temperature effects are by far the largest effects we have to deal with.
>>
>> Which is why you'd be much bett
Hoi Poul-Henning,
On Fri, 20 May 2016 09:52:39 +
"Poul-Henning Kamp" wrote:
> >Temperature effects are by far the largest effects we have to deal with.
>
> Which is why you'd be much better of with 20 sensors at 16 bits,
> than a single sensor at 24 bits.
Does the HP5065 have such huge tem
I know Corby is working on it and he will share his results. I think he is
right now on vacation that is most likely why he is not commenting.
Bert Kehren
In a message dated 5/21/2016 10:02:59 P.M. Eastern Daylight Time,
mag...@rubidium.dyndns.org writes:
Hej Poul-Henning,
On 05/20/2016
In message <57410d11.8050...@rubidium.dyndns.org>, Magnus Danielson writes:
>> The C-field circuit in particular. (Yes, I'm still working on it, just not
>> very fast...)
>
>I was actually wondering how that was getting along.
Slowly, we're starting our house-building project now, so I'v
Hej Poul-Henning,
On 05/20/2016 04:27 PM, Poul-Henning Kamp wrote:
In message <573edc73.9040...@rubidium.dyndns.org>, Magnus Danielson writes:
Humidity and pressure play a role with surrounding temperature in
cooling in that it they will shift the thermal resistance through which
the
>when I made the correlation the best fit was obtained comparing a frequency
>difference data-set delayed 1 hour to the pressure measurements. But I have to
>dig into the data-set again there might be an error calculating the MJD from
>Middle European Time. As far as I understood from Corby´
In message <573edc73.9040...@rubidium.dyndns.org>, Magnus Danielson writes:
>Humidity and pressure play a role with surrounding temperature in
>cooling in that it they will shift the thermal resistance through which
>the cooling of the ovens goes, [...]
Once we get below 5e-13, the tem
Wulf,
On 05/19/2016 11:04 AM, dg...@gmx.de wrote:
Some answers to comments:
Magnus,
I don’t think I have made a closed loop. It works like UTC for poor man. I
gathered data from different master clocks and from a weather station and
produced a new software corrected time scale for my own. Bu
In message <20160519184616.39fd0ca08628b0843ce72...@kinali.ch>, Attila Kinali
writes:
>For real temperature measurements, I would use a wirewond Pt sensor
>on a 24bit ADC with a stable reference.
And where would you put the sensor ?
Where do you find a temperature so representative, th
Hi
> On May 19, 2016, at 12:46 PM, Attila Kinali wrote:
>
> On Thu, 19 May 2016 07:40:15 -0400
> Bob Camp wrote:
>
>> One advantage of doing all the compensation off of a single sensor is that
>> *if* there are cross effects and *if* you can characterize them, you can
>> correct them out. Pu
On Thu, 19 May 2016 07:40:15 -0400
Bob Camp wrote:
> One advantage of doing all the compensation off of a single sensor is that
> *if* there are cross effects and *if* you can characterize them, you can
> correct them out. Put another way, if the pressure reading changes by
> 0.01% per C, havi
Hi
One advantage of doing all the compensation off of a single sensor is that
*if* there are cross effects and *if* you can characterize them, you can
correct them out. Put another way, if the pressure reading changes by
0.01% per C, having a reasonable idea of the temperature of the sensor let
Some answers to comments:
Magnus,
I don’t think I have made a closed loop. It works like UTC for poor man. I
gathered data from different master clocks and from a weather station and
produced a new software corrected time scale for my own. But you are right.
The correction is the best fit for
On Thu, 19 May 2016 06:33:38 +0200
"Björn Gabrielsson" wrote:
> What are time-nuts using for monitoring the environment?
The Sensirion SHT21 has become the gold standard silicon based
humidity sensor over the past years. Even though it's quite old
(IIRC close to 10 years) it has performance met
>>> I got a slope of 3.86E-14/hPa frequency difference versus pressure.
>
> Did you also control for temperature ?
>
> Air pressure, in particular at high relative humidities changes the
> thermal properties of air so there is bound to be some cross coupling
> were temperature sensitivities appear
In message , James Flynn writes:
>> I got a slope of 3.86E-14/hPa frequency difference versus pressure.
Did you also control for temperature ?
Air pressure, in particular at high relative humidities changes the
thermal properties of air so there is bound to be some cross coupling
were t
writes:
> I also have a weather station at 6 km distance away, which records
barometric pressure at time intervals of
> 10 minutes. Out from these measurements, I divided
> my phase measurements into 10 minute intervals, calculated the 10 min
average frequencies and made a
> linear regression
Hi Wulf,
On 05/18/2016 08:57 AM, dg...@gmx.de wrote:
This is my first contribution to the Time-Nut list, but I am a follower for
several years.
I have made 30 days phase difference measurements of an HP5065a versus a
modified Thunderbolt GPSDO (got a MV180 oscillator) with a Fluke PM6681,
and
HI
Very neat !!!
Bob
> On May 18, 2016, at 2:57 AM, dg...@gmx.de wrote:
>
> This is my first contribution to the Time-Nut list, but I am a follower for
> several years.
> I have made 30 days phase difference measurements of an HP5065a versus a
> modified Thunderbolt GPSDO (got a MV180 oscilla
Hi Corby,
very interesting. I have some questions?
1) it is difficult to read the frequency value on the plot. Can you specify?
2) how do you set the offset of the op-amp trimmer ?
3) do you think is possible to use the -20V on the HP5065A instead the -12V
from the DC-DC converter?
4) what frequ
28 matches
Mail list logo