Very true
Sent from my iPhone
> On Apr 3, 2018, at 7:51 PM, Bob kb8tq wrote:
>
> Hi
>
> If the objective is great phase noise far removed from carrier, there’s a
> gotcha.
>
> Let’s say you have a 10 dbm source at room and it’s broadband is at KTB of
> -174 + 1db.
> That gives you -183 db
Hi
If the objective is great phase noise far removed from carrier, there’s a
gotcha.
Let’s say you have a 10 dbm source at room and it’s broadband is at KTB of -174
+ 1db.
That gives you -183 dbc. You cool your oscillator to whatever and KTB goes down
to -194. You do a bang up job at that temp
Hi Mark:
When Aetech started to make their own Tunnel Diodes there was a problem with
the neck breaking.
Note they were made by alloying a ball of metal onto a highly doped chip, bonding from the lip of the ceramic package to
the ball then on to the opposite lip, then etching the chip away leav
Many years ago, circa 1977, I was moved to try some crude tests on a few
semiconductor devices at LN2 temperature (77K).
These tests were very crude, involving dunking the parts into the LN2 bath,
and
many failed outright. Most of the devices tested were in plastic packages.
Here are the results
Hi
> On Apr 2, 2018, at 11:18 PM, jimlux wrote:
>
> On 4/2/18 1:39 PM, Hal Murray wrote:
>>> If not Nitrogen, how about dry ice (-109F -78C)?
>> Dry ice is relatively easy to get. It wouldn't be hard to try a quick
>> experiment.
>
>
> CTE mismatch in packages will be a significant problem -
And you want your semiconductors to be in ceramic/lided packages with the bond
wires flapping in free air. Bond wires embedded in epoxy like to break...
don't ask how I found this out ;-) ... it brings back bad memories... and
makes bad memories... Quantum chips have very elaborate/specia
On 4/2/18 1:39 PM, Hal Murray wrote:
If not Nitrogen, how about dry ice (-109F -78C)?
Dry ice is relatively easy to get. It wouldn't be hard to try a quick
experiment.
CTE mismatch in packages will be a significant problem - you might find
that your ICs don't work because bond wires have
Hi
> On Apr 2, 2018, at 5:38 PM, Attila Kinali wrote:
>
> On Mon, 2 Apr 2018 12:46:26 -0700
> "Tom Van Baak" wrote:
>
>> Has anyone tried running a quartz oscillator at liquid nitrogen
>> temperatures: -196 C (-321F, 77K)? It's probably impractical commercially,
>> but maybe something of v
On Mon, 2 Apr 2018 12:46:26 -0700
"Tom Van Baak" wrote:
> Has anyone tried running a quartz oscillator at liquid nitrogen
> temperatures: -196 C (-321F, 77K)? It's probably impractical commercially,
> but maybe something of value to a time nut. Would that dramatically lower
> temperature impro
Hi
If you dig back in the FCS archives, you will find papers on “cold” OCXO’s. You
also
will find papers on cryo cooled quartz. The bottom line appears to be that if
you are
going to all the trouble of cooling things, sapphire (or other exotic
materials) are a
better bet.
Quick simple answe
Tom: I sense a nice experiment! Dry ice temps can be attained with
modest Dewars and thermoelectric fridge devices. PID controller and
bob's your uncle. Type K thermocouple modules on epay. With that
apparat, a nice set of adev vs temperature possible? Dry ice/acetone or
ethyl alcohol (eve
Hi Tom:
Put the dry ice in acetone to the lowest temp.
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
Original Message
Has anyone tried running a quartz oscillator at liquid nitrogen temperatures: -196
C (-321F, 77K)? It's
You also run in to mechanical vibration issues from the cooling system. At
the temperatures involved you are looking at something like a Stirling
cycle cooler.
Here is a good article;
https://arxiv.org/pdf/1309.5445.pdf
Maintaining a very stable temperature probably has a much greater impact.
T
> If not Nitrogen, how about dry ice (-109F -78C)?
Dry ice is relatively easy to get. It wouldn't be hard to try a quick
experiment.
--
These are my opinions. I hate spam.
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Is the thermal noise generated in the loss in a quartz resonator a
significant part
of the overall phase noise picture? I would have not thought so. I'd
think that a
greater benefit ought to be derived from chilling the other parts in the
oscillator,
such as the active devices. Unless, of course
In message <299B45118C9248498D7B4F3AFE72231E@pc52>, "Tom Van Baak" writes:
>Has anyone tried running a quartz oscillator at liquid nitrogen
>temperatures: -196 C (-321F, 77K)? It's probably impractical
>commercially, but maybe something of value to a time nut.
Whispering gallery sapphire
Has anyone tried running a quartz oscillator at liquid nitrogen temperatures:
-196 C (-321F, 77K)? It's probably impractical commercially, but maybe
something of value to a time nut. Would that dramatically lower temperature
improve phase noise & short-term performance? Is there a crystal cut th
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