Hi all,
I've got a project upcoming that will require a frequency of 32.768 Khz
in a harsh environment (Imagine a thousand G's at 100Hz with 150 Deg C
temperatures). Also, this thing needs to be small, 2mmx1.5x1.5mm or so.
It also has to be low power. Frequency stability is probably less of a
Hi Dan,
I beg your pardon for being so curious, but where do you have to put
electronics in a thousand G's at 100Hz?
Thank you
Volker
Am 01.11.2013 17:30, schrieb Dan Kemppainen:
Hi all,
I've got a project upcoming that will require a frequency of 32.768 Khz
in a harsh environment
When I was messing with my SkyScan WWVB clocks to determine if something
that WWVB's signal had done broke them, preventing them from setting
properly and so-doing, I wanted to see what the receiver module was seeing.
(Spoiler: They didn't - they just break if the date is something later
Kind of scratching my head on that also some blade?
Regards
Paul
On Fri, Nov 1, 2013 at 5:50 PM, Volker Esper ail...@t-online.de wrote:
Hi Dan,
I beg your pardon for being so curious, but where do you have to put
electronics in a thousand G's at 100Hz?
Thank you
Volker
Am 01.11.2013
Clint
Like you I considered that and easy enough to do. But by that point you
have built well over half the receiver. So I just said to heck with it and
built the whole thing. The other issue is getting those pesky chips. There
is one fellow time-nut that has a stash of CME chips he offered. Never
Hi
There are several possibilities, each of them pretty well tells you what
industry is looking for the crystal.
Bob
On Nov 1, 2013, at 7:25 PM, paul swed paulsw...@gmail.com wrote:
Kind of scratching my head on that also some blade?
Regards
Paul
On Fri, Nov 1, 2013 at 5:50 PM, Volker
A while ago I mentioned 5MHz oscillators were used in most metrology
applications compared to the more commonly available 10MHz because 5MHz was a
sweet spot for quartz. At the time I didn't know why. I finally had a chance to
ask the person I learned this from why. The main reason is simply
I do not have any say in it but I voiced the groups concerns to a few
affiliates at NIST today. One Senior Researcher told me he has been making an
effort for some time now to document all the equipment used related to a
research project, adding the standard disclaimer that it was not an
Hi
If you pick one holder, 5 MHz will be “best”. If you pick another holder, 2.5
MHz will be “best”. Pick another one and it will be 20 MHz ….
Bob
On Nov 1, 2013, at 10:12 PM, Tom Knox act...@hotmail.com wrote:
A while ago I mentioned 5MHz oscillators were used in most metrology
On 11/1/2013 7:12 PM, Tom Knox wrote:
A while ago I mentioned 5MHz oscillators were used in most metrology
applications compared to the more commonly available 10MHz because 5MHz was a
sweet spot for quartz. At the time I didn't know why. I finally had a chance to
ask the person I learned
HI
If you doubled the diameter of the blank each time you cut the frequency in
half, all sorts of nice things might happen. If you start with a 1/2” blank in
at 10 MHz that goes to 1” at 5 MHz and 2” at 2.5 MHz. Around 1 MHz you would
get to a 5” blank.
Good luck finding high grade quartz
On 11/1/2013 8:28 PM, Bob Camp wrote:
HI
If you doubled the diameter of the blank each time you cut the frequency in
half, all sorts of nice things might happen. If you start with a 1/2” blank in
at 10 MHz that goes to 1” at 5 MHz and 2” at 2.5 MHz. Around 1 MHz you would
get to a 5”
1. There is a theoretical QF product for quartz. Being at 5 MHz basically
doubles your Q, all other things being equal.
Doesn't that Q gain from the QF product go away if you have to PLL it up to
10 MHz or 100 MHz which is what you really want?
[I was about to ask why not go to 1 MHz,
If you have a 5” blank, your OCXO scales around it. Yes you can do some
neat things, but the package is getting bigger. You now need to convince people
to buy OCXO’s that are bigger than anything they have seen since the 1960’s. In
most cases that OCXO will be 2 to 10 times larger than
their
In a free running (non crystal controlled) oscillator,
the oscillator with the highest Q (regardless of frequency)
will have the best phase noise, if all oscillators are
normallized to the same frequency by ideal multiplication.
So the Q gain doesn't go away in that sense.
Having said that, in
Hi
The real answer is that nobody knows. The economics essentially make finding
out very expensive. Q most certainly goes up, I don’t think anybody disputes
that. The questions about flicker / ADEV all revolve around small blank parts
with major edge sensitivity issues. They also probably were
HI
There’s no real reason why you would have more microphonic issues with a scaled
larger blank. The bigger blank is likely to have a lower mechanical resonance
(mount springs to blank mass) so it’s not going to be a star performer in
vibration.
Bob
On Nov 1, 2013, at 11:50 PM, Bob Stewart
This all seems to be forgetting that the crystals are usually operated
at 3rd or 5th harmonic. The crystal in a 10811A is 10 MHz/3rd
overtone. A high quality 5 MHz/5th overtone crystal is really a 1 MHz
fundamental, a large piece of quartz. Running at a harmonic greatly
reduces the
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