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Bernd T-Online wrote:
> Hal Murray wrote:
> > Why is the top domed? I assume flat would be easier to manufacture.
>
>> Why is it not symmetrical? If the top is domed, why not the bottom too?
>>
> For a plano-parallel qaurtz resonator the diameter must be at least 60
> times larger than
From: Bernd T-Online <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
Date: Sat, 08 Dec 2007 09:27:28 +0100
Message-ID: <[EMAIL PROTECTED]>
> Hal Murray wrote:
> > Why is the top domed? I assume flat would be easier to manufacture.
> > Why is it not symme
Slightly off topic:
In case any of you have a HP662xA power supply, I have a C program
that performs the calibration using the Prologix USB-GPIB adapter.
Mail me if interested.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL PROTECTED] | TCP/IP since RFC 956
FreeBSD comm
At one time I was really hot after getting some triaxial connectors, to use
with an Austron 5 MHz distribution amplifier. Well, as with most of my
projects, I managed to buy a whole bunch of connectors (found some on ebay
and a bunch at a hamfest) and, as usual, never did anything with them. So,
if
Bernd T-Online wrote:
> Hal Murray wrote:
> > Why is the top domed? I assume flat would be easier to manufacture.
>
>> Why is it not symmetrical? If the top is domed, why not the bottom too?
>>
> For a plano-parallel qaurtz resonator the diameter must be at least 60
> times larger than
Hal Murray wrote:
> Why is the top domed? I assume flat would be easier to manufacture.
> Why is it not symmetrical? If the top is domed, why not the bottom too?
For a plano-parallel qaurtz resonator the diameter must be at least 60
times larger than the thickness, otherwise the vibration ampl
Y-cut crystals are commonly used for temperature measurement.
One typical application is to mount a Y-cut and an AT-cut device in the
same housing with two identical oscillators, and use one to predict
(with limitations) the frequency of the other over temperature.
You can also use two oscillatio
In the BVA device, it's not so much that the 'top is domed', but that
the resonator is plano-convex. I stand to be corrected, but I believe
plano-convex crystals are used in high quality oscillators because the
shape leads to a lower level of spurious responses, hence fewer 'dips'.
BVA (and QAS, w
At 3:21 PM +0100 12/9/07, Bernd T-Online wrote:
>BTW: I proudly own a HP2801A plus two crystal sensor elements. However I
>cannot connect them to the instrument, because the 2801A has a special
>connector for it. It looks like a smaller version of a BNC connector,
>but the bayonet has three "nipple
At 17.58 09/12/2007, Bernd wrote:
>Thanks, Marco. I have the unit in my QRL lab, so I can take a photo only
>by tomorrow.
Ok, good. There are triax connectors with three and two bayonets
around - ask Keithley... they have used both types.
Or it may be something else, HI.
73 - Marco IK1ODO / A
Yes, I know... I was only exposing it as an example of how the
temperature coefficient can be quite higher compared with the aging
effect even if the quartz crystal is not intended to be used as a
temperature sensor :)
Regards,
Javier
Bernd T-Online escribió:
> Javier wrote:
>
>> Anyway, a
Marco IK1ODO wrote:
> may you send me a picture of the connector?
> Direct email
Thanks, Marco. I have the unit in my QRL lab, so I can take a photo only
by tomorrow.
Regards
Bernd
DK1AG
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Yes, but that doesn't account for this part of his request
(emphasis added):
"It looks like a *smaller* version of a BNC connector,
but the bayonet has three "nipples" instead of two."
-Chuck Harris
Alan Melia wrote:
> Berndt I believe you are describing a "Triax" connector I found them thr
Berndt I believe you are describing a "Triax" connector I found them through
Trompeter but I believe they are sold by Farnell and RS Components in the
UK. The same connector was used I think on some of the HP system digital
voltmeters.
Cheers de Alan G3NYK
- Original Message -
From: "Bernd
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Bernd T-Online
> Sent: Sunday, December 09, 2007 8:44 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA??
>
> Not the
DK1AG wrote:
>... the 2801A has a special
>connector for it. It looks like a smaller version of a BNC connector,
>but the bayonet has three "nipples" instead of two. Does anyone on the
>list know what kind of connector that is and where to get the
>counterpart (plug)?
>
>Regards
>
>Bernd
>DK1AG
B
Javier wrote:
> Anyway, a 10544 oscillator has a cold
> offset that can easily be of 1000Hz, so if at 80 deg. C the offset is
> zero, and at 25 deg. C the offset is 1000Hz, you easily have a rough
> 15Hz/deg C average tempco in that range - and the aging drift for this
> oscillator is quite les
Tim Shoppa wrote:
> For a while, didn't HP sell temperature probes which were in fact
> quartz crystals? Oscillation frequency was converted by some simple
> electronics to a temperature, and at the time (60's?) they were
> exquisitely convenient for measuring way better than a tenth of a
> degree.
Javier <[EMAIL PROTECTED]> wrote:
> Tim Shoppa escribi?:
> > For a while, didn't HP sell temperature probes which were in fact
> > quartz crystals? Oscillation frequency was converted by some simple
> > electronics to a temperature, and at the time (60's?) they were
> > exquisitely convenient for m
Tim Shoppa escribió:
> For a while, didn't HP sell temperature probes which were in fact
> quartz crystals? Oscillation frequency was converted by some simple
> electronics to a temperature, and at the time (60's?) they were
> exquisitely convenient for measuring way better than a tenth of a
> degr
Bernd T-Online <[EMAIL PROTECTED]> wrote:
> I can confirm Rick's statement, that there is no noticable effect of
> aging on the turnover temperature (TOT).
> Looking at it from physics standpoint, frequncy aging is mainly caused
> by minor changes of vibrating mass and/or by changes in elastic
Poul-Henning Kamp wrote:
> You got me wondering: How is the TOT determined ? Is it per unit
> or is it per batch ? How precisely does an OCXO hold the temperature
> on the TOT ?
For crystals used in precision OCXO the TOT is measured and recorded per
unit.
There are two main methods: passive an
In message <[EMAIL PROTECTED]>, Bernd T-Online writes:
>Jeff Mock wrote:
>I can confirm Rick's statement, that there is no noticable effect of
>aging on the turnover temperature (TOT).
You got me wondering: How is the TOT determined ? Is it per unit
or is it per batch ? How precisely does an
Jeff Mock wrote:
> How does crystal aging look on a graph of temp versus frequency
> What does this graph look like as a crystal ages? Does the optimal
> operating temperature change over time, that is, does the graph tend to
> move left and right, or does aging tend to move the graph vertic
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