> Hello Said,
>
> Attached is a screen dump of a run that John Miles did. You can
> see that the envelope of the DAC voltage follows the temperature
> curve (inversely). On a finer scale the DAC voltage follows the
> PPS error. This plot was done with the unit locked to GPS. I
> believe the t
Hi Holrum,
thanks for sending the plot. It's tough to see on this plot with all that
noise.
To see how the relationship really works, the unit should be in holdover..
Would you have a plot of EFC versus temp in holdover?
thanks,
Said
In a message dated 3/8/2009 13:42:41 Pacific Daylig
Steve Rooke skrev:
> 2009/3/9 Magnus Danielson :
>
>> So, you can expect that the metal can of the OCXO reacts fairly quickly
>> and the temperature sensor is a thad slow. This also matches exercises
>> we have done by using a fan to do forced air convection tests on OCXO
>> and tempsensor. Puttin
2009/3/9 Magnus Danielson :
> So, you can expect that the metal can of the OCXO reacts fairly quickly
> and the temperature sensor is a thad slow. This also matches exercises
> we have done by using a fan to do forced air convection tests on OCXO
> and tempsensor. Putting a *plastic* hood over it
Hi Tom, Holrum,
nice plots, do you have access to the Thunderbolt EFC over that day?
Holrum mentioned:
"Also, by looking at the DAC and TEMP plots the temp sensor chip readings
ARE used in generating the DAC voltage in GPS locked mode... "
Is there any chance to post these plots?
tha
The test that I did was meant to reflect how a typical user would be using a
Thunderbolt... sitting out in free air on a piece of poly foam, covered by a
cardboard box to provide a little isolation from environmental transients.
Tbolt internal temperature changes were around 3 deg C per day
Tom Van Baak skrev:
> See: http://www.leapsecond.com/pages/tbolt-temp/
>
> Hi Mark,
>
> This is very interesting work that you're doing with Thunderbolt
> DS1620 temperature sensors. I hope you stick with it. I agree
> with Said about the double bind idea.
>
> I worry too that your TBolts are re
See: http://www.leapsecond.com/pages/tbolt-temp/
Hi Mark,
This is very interesting work that you're doing with Thunderbolt
DS1620 temperature sensors. I hope you stick with it. I agree
with Said about the double bind idea.
I worry too that your TBolts are remembering something of the
past in spi
Hi,
further to Thunderbolt holdover performance,
if you had your thunderbolt in a room that only had ± 1 degree
temperature variation
when you switched it on, then it would only learn a rather weak
temperature sensitivity.
If it was in a room with a daily swing of 20 degrees it should learn
a
Hi there,
Would you have the EFC plots while in holdover for us?
You can try to place the unit into your refrigerator. That will drop it down
to 3C or so from ambient. That will give you enough of a change so that you
can see how the EFC changes with the two sensors.. It will also give you
I come to the Tbolt conversation a little late. Is the source code for the
servo system available?
Don
Mark Sims
>
> Hello Said,
>
> The Tbolt that I used for the test was well aged (several months of
> operation) and stable prior to the tests. It was only powered down for
> the 10 minutes or so
Hello Said,
The Tbolt that I used for the test was well aged (several months of operation)
and stable prior to the tests. It was only powered down for the 10 minutes or
so that it took to swap out the old sensor.
I tried to choose data sets that were fairly comparable temperature wise. I
al
Hi,
while this is good news for Trimble's competition and may open up the avenue
for an amateur mod, I think we would have to be fair to Trimble and do the
double-blind test:
1) Put the original temp sensor back into the unit, let it run one week, and
do the drift tests exactly the same a
I did some testing on a Thunderbolt with the new revision E2 (low resolution,
flat line) and old revision D1 (high resolution, curvy line) DS1620
temperature sensor chips. The only thing that changed was the temperature
sensor chip.
Basically, I put a unit that had the new revision E2 temp
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