On Dec 2, 2011, at 4:12 PM, Azelio Boriani wrote:
> Man, what should we follow if not the manufacturer datasheet? Everyone can
> [...]
Oh, I have an active imagination and tried a 1/2 dozen different ideas.
But, lesson learned!
Kevin
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Man, what should we follow if not the manufacturer datasheet? Everyone can
predict that the best results are obtained following the component's
datasheet. Indeed maybe, after having followed the datasheet, that you can
improve something.
On Fri, Dec 2, 2011 at 11:51 PM, Kevin Rosenberg wrote:
> O
On Dec 2, 2011, at 10:59 AM, Hal Murray wrote:
> I've been playing with one of the Dallas DS32KHZ parts. I'm guessing you are
> [...]
> Another possibility is that I didn't ground the NC pins. (I didn't notice
> that in the data sheet until I read it again looking for crap like that.)
Using a
> The need for this is that the RTC chip for a product has the engaging
> property of shifting it's frequency by several ppm after being soldered to
> the board, and I need to characterise this to get accurate timing for the
> product.
Are you sure you have the exact same setup?
Have you tried
On 12/2/11 7:28 AM, Attila Kinali wrote:
dispersion in the components after the comb generator. You may generate
them all in phase at the diode, but by the time they've propagated
through the buffer amplifier, filter, coax, they're no longer aligned.
Again, if you're just looking for nanosecond
On Fri, 02 Dec 2011 07:11:38 -0800
Jim Lux wrote:
> On 12/2/11 6:28 AM, Attila Kinali wrote:
> > On Fri, 02 Dec 2011 05:57:35 -0800
> > Jim Lux wrote:
> >
> >> Combs are used all the time for this kind of thing (e.g. calibrating
> >> Deep Space Network). There's an old paper about calibrating a
On 12/2/11 6:28 AM, Attila Kinali wrote:
On Fri, 02 Dec 2011 05:57:35 -0800
Jim Lux wrote:
Combs are used all the time for this kind of thing (e.g. calibrating
Deep Space Network). There's an old paper about calibrating a
interferometer radio telescope at Stanford using this kind of thing (by
On Fri, 02 Dec 2011 05:57:35 -0800
Jim Lux wrote:
> Combs are used all the time for this kind of thing (e.g. calibrating
> Deep Space Network). There's an old paper about calibrating a
> interferometer radio telescope at Stanford using this kind of thing (by
> Bracewell, as I recall)
My goog
mike cook wrote:
Le 02/12/2011 01:53, Bob Camp a écrit :
Hi
Ok, 62.5 ppb at 1 second would be 62.5 ns. that sounds right for a 16
MHz clock.
Your accuracy will be related to the offset between the two 1 ops
events (divided TCXO and GPS PPS) and the accuracy of your crystal.
With some luck
On 12/2/11 4:59 AM, Attila Kinali wrote:
On Thu, 1 Dec 2011 19:56:12 -0800
Peter Monta wrote:
So, that'd mean there would be an automatic calibration system inside
the device, because i dont have any equipment with which i could
calibrate delays over a temperature range.
I suppose they could
On 12/2/11 12:05 AM, Hal Murray wrote:
Well, it would have to be the front end. DSP doesn't drift with
temperature.
What if the crystal driving the DSP changes frequency with temperature?
That's really no different than the local clock changing frequency,
isn't it? It's essentially one o
Tom,
supposed your micro features latch inputs by which the internal counter
values can be latched in hardware then
a) use two counters @ your system clock rate to latch their values with the
TCXO's PPS and the GPS's PPS
b) extend the 8/16 bit counters in software to at least 32 bit so that you
On Thu, 1 Dec 2011 19:56:12 -0800
Peter Monta wrote:
> > So, that'd mean there would be an automatic calibration system inside
> > the device, because i dont have any equipment with which i could
> > calibrate delays over a temperature range.
>
> I suppose they could do that---provide a weak bro
On Fri, 2 Dec 2011 01:33:45 -0800
Peter Monta wrote:
> > What if the crystal driving the DSP changes frequency with temperature?
>
> I believe it would have no effect. The local clock should drop out of
> any navigation or timing solution, so long as the changes are slow
> enough to avoid loss
> What if the crystal driving the DSP changes frequency with temperature?
I believe it would have no effect. The local clock should drop out of
any navigation or timing solution, so long as the changes are slow
enough to avoid loss of lock in carrier tracking.
Let's take a GPS module with 1 PPS
I agree: better using a cheap counter (using the GPSDO to sync it). However
to do a time interval measurement your sampling frequency must be stable
enough between the reference PPS and the PPS-under-measure. The trick is to
offset the PPS-under-mesure enough (say 100mS) to gether some stable
sampl
> Well, it would have to be the front end. DSP doesn't drift with
> temperature.
What if the crystal driving the DSP changes frequency with temperature?
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