Hi
The “normal” approach is to stabilize the inner wall and cross section (= open
tube)
of the dewar. Often this is done with a metal “plug”. It may or may not extend
to the
bottom of the dewar. A lot depends on fiddly little details about how much heat
you are generating in the circuitry
Question:
Do you stabilize the oscillator inside the dewar, or do you stabilize the
temperature of
the dewar's outside environment?
This may boil down to a slightly different expression: Where do you *sense*
the temperature for
the stabilization loop? On the crystal itself, or on the outside
Hi
There are a lot of dewar / vacuum flasks on eBay in a wide variety of
shapes and sizes. Some get into the proper combination of affordability,
size and shape. There does not appear to be a constant supply of any
one version so it is very much shop and see.
Dewar based OCXO’s go way back ( in
Hello!
I have done this and can attest that it works well. I did not use a TCXO,
though. I used a 48 MHz, third-overtone AT-cut crystal in a Colpitts
oscillator configuration. The vacuum flask was ovenized to maintain
temperature near the stationary point of the temp characteristic (near 50
Tom Van Baak writes:
> An email came in asking if it was possible to improve the performance
> of a TCXO if one monitors the temperature of the PCB or enclosure and
> then applies timekeeping corrections in s/w based on that data. I
> don't have specific P/N or other details so treat this as a
Yo Bubba Dudes!,
If one has the space, a simple cure might be to get one of the wide mouth
thermos containers that they sell in large variety stores such as Wal-Mart for
being able to eat something like stew or some semi-solid hot food out of the
container itself.
Regards,
Perrier
I am purchasing TCXOs from a reputable supplier and building boards to
install in Ham radios. Every one is indeed different. They also exhibit
hysteresis, sometimes very strong, more than the variation with
temperature. They test in one direction and meet the .25 ppm variation spec
over temp, but
Hi
If you look at any sort of “TimeNut” sort of level of detail, every unit
in the batch will be different.
Bob
> On Aug 1, 2019, at 3:05 AM, Clint Jay wrote:
>
> I'd imagine the effort required to characterise a TCXO to that level and
> add the monitoring hardware/software would put the
Hi,
On 2019-08-01 08:50, Tom Van Baak wrote:
> An email came in asking if it was possible to improve the performance
> of a TCXO if one monitors the temperature of the PCB or enclosure and
> then applies timekeeping corrections in s/w based on that data. I
> don't have specific P/N or other
I'd imagine the effort required to characterise a TCXO to that level and
add the monitoring hardware/software would put the cost in the region of an
OCXO but it's an interesting idea, I wonder what the variance across a
batch would be
On Thu, 1 Aug 2019, 08:01 Tom Van Baak, wrote:
> An email
An email came in asking if it was possible to improve the performance of
a TCXO if one monitors the temperature of the PCB or enclosure and then
applies timekeeping corrections in s/w based on that data. I don't have
specific P/N or other details so treat this as a generic question. Has
anyone
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