Hi
Lower turning point has been done, both with AT’s (back in ~ the 1950’s) and
with SC’s. Neither one showed any significant benefit.
Taking a crystal down to sub 20K sort of temps does ramp up the Q. The gotcha
is that the frequency vs temp curve is so steep that very minor temperature
Am 2022-06-08 21:53, schrieb Tom Van Baak:
Would it be advantageous, then, to run a high-performance laboratory
oscillator at its lower turnover point? Or at -78 C (CO2) or 77 K
(liquid Nitrogen)?
I have no idea about the crystal itself. Maybe Bernd or the SC
(SantaClara)
veterans can help?
On Wed, June 8, 2022 12:59 pm, paul swed via time-nuts wrote:
> Well the easiest thing is to use two level comparators on the filtered DC.
> One for high and the other for the low trip point.
That only tells you if the PLL is locked to the PPS output, it does not
tell you if the PPS output is
Hi
I would be careful with that paper since part of what it says is not
(in general) correct.
Bob
> On Jun 8, 2022, at 1:22 PM, Ross P via time-nuts
> wrote:
>
> Hi,Thank you very much, this paper answered some questions.
>
>On Wednesday, June 8, 2022 at 12:38:04 PM PDT, Hans-Georg
Hi,Thank you very much, this paper answered some questions.
On Wednesday, June 8, 2022 at 12:38:04 PM PDT, Hans-Georg Lehnard via
time-nuts wrote:
Hi,
read this paper from Connor-Winfield about differences AT/SC cuts.
http://www.conwin.com/pdfs/at_or_sc_for_ocxo.pdf
Am
Hi
Well …..
You can bash both AT’s and SC’s a *lot* harder than you might think. Both
will suffer quite a bit in terms of ADEV when you do.
Since the AT likely has a lower resistance (by quite a bit) than the SC, the
loop
current ( and thus the drive into the buffer) may not be as far
Hi
The stability depends on a long list of things. Since you can get higher
Q with an AT than you can with an SC, if Q was all that mattered, the AT
would be the king of the hill.
The oscillator circuit matters, but different parts of it matter in different
ways.
The things you might do for
That particular approach about monitoring the control voltage may have to wait
until I get the thing all buttoned up and insulated because the control voltage
changes even with the temp in the room. The oven is insulated, but apparently
not perfectly.
I did put the heatsink for voltage control
Hi Gerhard,
On 2022-06-08 20:42, g...@hoffmann-hochfrequenz.de wrote:
Am 2022-06-08 13:27, schrieb Magnus Danielson via time-nuts:
As far as I remember and know, you can achieve about the same
phase-noise properties as you hit about the same bandwidth from the Q,
and noise contribution is
Hi,
read this paper from Connor-Winfield about differences AT/SC cuts.
http://www.conwin.com/pdfs/at_or_sc_for_ocxo.pdf
Am 2022-06-08 04:04, schrieb Ross P via time-nuts:
> Hello,My first post.I have created a 64-bit frequency counter, 15.9 digits
> after converting to floating point.
>
Am 2022-06-08 13:27, schrieb Magnus Danielson via time-nuts:
As far as I remember and know, you can achieve about the same
phase-noise properties as you hit about the same bandwidth from the Q,
and noise contribution is about the same. So, it boils down to do the
supporting amplifier well.
Hi,So, highest short term stability depends on the Q of the crystal and
quality of the feedback circuit. In that case, an AT-cut with a low noise
feedback amplifier will be as good as an SC-cut with the same amp. Does pulling
the oscillator affect the short term walk?rp
On Wednesday, June
Congratulations on the fun project.
Well the easiest thing is to use two level comparators on the filtered DC.
One for high and the other for the low trip point. Then feed a LED or a set
reset flip flop so you have a memory. Unlocks are a challenge in that
everything may work just fine but then a
Hello all, Thanks for letting me join. I just built a GPSDO from some junk I
had lying aroundI used a Navman GPS Jupiter 12 and an Isotemp 118-12 which can
be controlled by the NavmanThe Isotemp is controlled by the heater in it which
can be controlled by external DC signal.
The Navman puts out
Hi,
I agree in general. However, I do see that other work to get good
resulst have been done when SC-cut is considered, so rather than SC-cut
as a cut is better, it becomes somewhat of a tell-tale of that other
work being done properly. I.e. it is meaningless to take the step to
SC-cut when
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