Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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.

Re: [time-nuts] HP5065A environmental sensitivities

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,

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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 >

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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)

Re: [time-nuts] HP5065A environmental sensitivities

>>> 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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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 >

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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

Re: [time-nuts] HP5065A environmental sensitivities

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