Hi Bruce,
would you have pointers to good temperature sensing circuits with sub
millidegree resolution?
thanks,
Said
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[EMAIL PROTECTED] wrote:
>
>
> Hi Ulrich,
>
> good details on how to set the time constant for best GPSDO performance etc!
>
> Some issues you did not mention are but that are essential to get a good
> GPSDO are:
>
>* Aging compensation
>
>* Temperature compensation
>
>
Stephan Sandenbergh wrote:
>> charts, it is my guess that the loop bandwidth will be in the order of
> 1kHz.
> Thus, if I can't modulate the 100MHz OCXO at this rate, I will have to
> think
> of another plan.
>
First of all. realize that the modulation bandwidth of the VCO has
to be at least 10 ti
Hi Ulrich,
good details on how to set the time constant for best GPSDO performance etc!
Some issues you did not mention are but that are essential to get a good
GPSDO are:
* Aging compensation
* Temperature compensation
* fault recovery, such as mechanical shock to crystal
On Thu, 14 Dec 2006 19:00:17 -0800, Rex <[EMAIL PROTECTED]> wrote:
>Does anyone have information on the PTS 250 Synthesizer?
>
>I bought one on eBay.
With several web sources and some experimentation, I was able to figure
out how to use the remote programming connector to control my PTS 250. I
th
--- Christopher Hoover <[EMAIL PROTECTED]> wrote:
That's what i did...
Years ago, i've got a japanese OCXO (i didn't know the
brand, i just got the core..). I used an aluminum
project box as external case and filled the empty
space with styrofoam that i've cutted with an X-Acto /
razor blade.
O
John Miles wrote:
> Yeah, for one OCXO disciplining another, I'd just use a 74F90 and 74HCT4046,
> like that quick-and-dirty design did. The loop gain will be low and the
> integration period will be measured in seconds or even minutes, so I don't
> believe noise is going to be worth worrying a
Yeah, for one OCXO disciplining another, I'd just use a 74F90 and 74HCT4046,
like that quick-and-dirty design did. The loop gain will be low and the
integration period will be measured in seconds or even minutes, so I don't
believe noise is going to be worth worrying about. It would be hard to
I flipped em... didn't free run for me.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Jason Rabel
Sent: Saturday, December 16, 2006 4:06 PM
To: time-nuts@febo.com
Subject: [time-nuts] Looking For Info On A Kode/Odetics 375-642 Time DisplayUnit
Now you k
Christopher Hoover wrote:
> Folks -
>
>
>
> I've got several OXO's suffering from disintegrating insulation between the
> can and core. The insulation in these OXO's is the greenish grayish foamy
> stuff. It turns to dust over time.
>
>
>
> The two units I opened most recently also had mecha
Hi Stephan,
I have a surplus 100MHz Vectron OCXO from a Wavecrest DTS-2070
jitter-measurement system that was de-comissioned due to CPU memory failure.
The oscillator works great, and it was the main timebase in the $90K+ jitter
instrument, so I suspect it's the "best" OCXO they could buy
Sorry Stephan,
forgot to mention, the loop filter thermal instability is so small and slow
compared to the feedback loop that it will be completely compensated out by
the PLL phase comparator.
Since you are disciplining an OCXO, you probably want to set the loop filter
bandwidth to less
There are several good choices. Find a local company that does
industrial insulation and visit them with a case of beer.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL PROTECTED] | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to
Hi there,
NS has some small PLL eval boards that are controlled using a paralell cable
to your PC.
Take a look at the LMX2316 for example. The eval board is $150 - maybe a bit
pricey.
Analog devices has footprint compatible (but not software compatible!) PLL
chips that have significantl
Christopher Hoover wrote:
> Folks -
>
>
>
> I've got several OXO's suffering from disintegrating insulation between the
> can and core. The insulation in these OXO's is the greenish grayish foamy
> stuff. It turns to dust over time.
>
>
>
> The two units I opened most recently also had mecha
In a message dated 12/16/2006 12:31:31 Pacific Standard Time,
[EMAIL PROTECTED] writes:
In message <[EMAIL PROTECTED]>, Hal
Murray writes:
>
>> You still want to produce some form of quality measure for the ADEV
>> shape in order to form some form of control loop.
>
>Suppose I build I goo
I'm just guessing here, but maybe the dip switches select the input code.
Default setting IRIG B, but maybe can handle IRIG A and maybe one of the
NASA codes.
Rob K
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jason Rabel
Sent: 16 December 2006 22:06
John Miles described a clean 110 MHz PLL from a 5.5 MHz source, which he
used in his tracking generator project.
http://www.thegleam.com/ke5fx/tr503.html
It could be easily adapted to a 100 MHz output from a 10 MHz input.
An alternative to a PLL would be a frequency multiplier, if the original
Folks -
I've got several OXO's suffering from disintegrating insulation between the
can and core. The insulation in these OXO's is the greenish grayish foamy
stuff. It turns to dust over time.
The two units I opened most recently also had mechanical damage (broken
crystal, broken solder
Hal Murray wrote:
>> You still want to produce some form of quality measure for the ADEV
>> shape in order to form some form of control loop.
>>
>
> Suppose I build I good GPSDO. How do I determine how good it is? (or even
> if it is any good)
>
> How much do I learn by just plotting the co
Stephan Sandenbergh wrote:
> Hi,
>
>
>
> Another question for today - I have checked out some digital PLL ICs (more
> specifically the one's from AnalogDevices. It seems as if they've got some
> pretty neat stuff.) As I mentioned in my previous mail: I want to lock a
> GPSDOs 10MHz to a 100MHz OC
Now you know why I was wanting a poor man's IRIG-B generator, which I'm
having issues getting the audio drivers to compile on my Geode box, so until
I fix that I can't use the other file from the NTP distro.
Anyhow, I got a Kode/Odetics 375-642 Time Display Unit. Basically it just
displays the tim
Hal,
> Do I have to get a cesium clock so I have a better reference?
In the last consequence: I fear, yes! A disciplined H2 Maser might even
be the better choice.
> But then how do I tell how good my cesium clock really is?
The manual tells you. If you don't believe the manual ask TVB as a
sec
In message <[EMAIL PROTECTED]>, Hal Murray writes:
>
>> You still want to produce some form of quality measure for the ADEV
>> shape in order to form some form of control loop.
>
>Suppose I build I good GPSDO. How do I determine how good it is? (or even
>if it is any good)
Since you pretty much
> Yes. I'll leave this as an exercise to the reader
Oh dear, this one follows me since my university days centuries ago!
Ulrich Bangert, DF6JB
> -Ursprüngliche Nachricht-
> Von: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Im Auftrag von Poul-Henning Kamp
> Gesendet: Samstag, 16.
> You still want to produce some form of quality measure for the ADEV
> shape in order to form some form of control loop.
Suppose I build I good GPSDO. How do I determine how good it is? (or even
if it is any good)
How much do I learn by just plotting the control voltage?
How much do I learn
"Stephan Sandenbergh" <[EMAIL PROTECTED]> wrote:
> Another question for today - I have checked out some digital PLL ICs (more
> specifically the one's from AnalogDevices. It seems as if they've got some
> pretty neat stuff.) As I mentioned in my previous mail: I want to lock a
> GPSDOs 10MHz to a 1
From: "Stephan Sandenbergh" <[EMAIL PROTECTED]>
Subject: [time-nuts] Digital PLL ICs, alternatives and digital loop filters
Date: Sat, 16 Dec 2006 20:52:25 +0200
Message-ID: <[EMAIL PROTECTED]>
> Hi,
Hi Stephan,
> Another question for today - I have checked out some digital PLL ICs (more
> speci
In message <[EMAIL PROTECTED]>, Magnus Danielson writes:
>You still want to produce some form of quality measure for the ADEV shape in
>order to form some form of control loop. It needs to be articulated.
Yes. I'll leave this as an exercise to the reader, only with the footnote
that what Dave Mi
From: "Poul-Henning Kamp" <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] LPRO-101 with Brooks Shera's GPS locking circuit
Date: Sat, 16 Dec 2006 17:06:00 +
Message-ID: <[EMAIL PROTECTED]>
> In message <[EMAIL PROTECTED]>, Magnus Danielson writes:
>
> >> The way you do this is by measuring the
Poul-Henning,
Since the cost of the SC-10 gets pretty high if you go for all the best
options, I only specified one "A" grade parameter: 2 x 10E-12 Allan
variation combined with lowest phase noise. Otherwise the operating
temp is 0-50 C, total temperature stability is 2 x 10E-9 over 0-50 C,
Hi,
Thanks for the quick replies and good hints. I haven't actually purchased a
100MHz OCXO so I'll prefer to know what the spec is before hand. I just
thought that there might be something strange about it since I couldn't find
it in the datasheets. Nonetheless, I have contacted some manufacturer
Hi,
Another question for today - I have checked out some digital PLL ICs (more
specifically the one's from AnalogDevices. It seems as if they've got some
pretty neat stuff.) As I mentioned in my previous mail: I want to lock a
GPSDOs 10MHz to a 100MHz OCXO using some sort of PLL. I find the PLL
In message <[EMAIL PROTECTED]>, Robert Crawford writes:
>I bought a Stanford Research SC-10 directly from the factory about 6
>months ago, but now I know I don't have the equipment to really test the
>stability of this oscillator.
>
>Has anyone had a good look at the SC-10 (tvb?).
It depends a
In message <[EMAIL PROTECTED]>, Magnus Danielson writes:
>Stephan,
>
>If you can't find it explicitly I strongly recommend you to measure it. What
>Poul-Henning suggested is about right, however you would like to have a FM
>detector (not AM or PM) of sufficient bandwidth.
I used my Sony AIR 7 rece
In message <[EMAIL PROTECTED]>, Magnus Danielson writes:
>> The way you do this is by measuring the ADEV between your two sources
>> and how it changes with changes in your timeconstant.
>
>I.e. out of your TIC. The trouble is that you do not get one result but
>several. Either you just drive the
Stephan,
If you can't find it explicitly I strongly recommend you to measure it. What
Poul-Henning suggested is about right, however you would like to have a FM
detector (not AM or PM) of sufficient bandwidth. A frequency sweep through
that should work well and display the amplitude responce vs fr
Stephan,
I'm still new at this subject and I'm not an expert, but here's what
I've found. The SC-10 oscillator from Stanford Research has this
paragraph in the manual:
"The EFC input exhibits a single-pole RC type response with a -3dB point
of about 3kHz when driven by a voltage source with a
From: "Poul-Henning Kamp" <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] LPRO-101 with Brooks Shera's GPS locking circuit
Date: Sat, 16 Dec 2006 15:56:32 +
Message-ID: <[EMAIL PROTECTED]>
> In message <[EMAIL PROTECTED]>, "Ulrich Bangert" writes:
> >Poul,
> >
> >i appreciate your comments always
In message <[EMAIL PROTECTED]>, "Stephan Sandenbergh" writes:
>The modulation bandwidth isn't given in the typical OCXO datasheet. Is there
>a reason for this? Has anyone got experience with this? Or does number vary
>wildly from OCXO to OCXO.
I played with it a bit once, hooking a function gener
If not in the public data sheets (the few OCXO's that I have state that info
in their sheets), you should be able to contact the manufacturer and they
can tell you. If they are no longer in business or it is a no longer
supported model, then you would have to manually test the OCXO to find the
band
In message <[EMAIL PROTECTED]>, "Ulrich Bangert" writes:
>Poul,
>
>i appreciate your comments always a lot! But dynamical methods are
>especially usefull when the input parameters are subject of change,
>aren't they?
They are also very useful for amateur projects where the users do
not have the ne
Hi,
Many thanks to all the time-nuts that has answered my questions, which I
posted during the past year so, with such eloquence.
My question I have today is regarding the modulation bandwidth of the
typical OCXO. Previously, I was concerned with locking a 1PPS GPS output to
a 10MHz OCXO. T
Poul,
i appreciate your comments always a lot! But dynamical methods are
especially usefull when the input parameters are subject of change,
aren't they? I have seen algorithms that use a a-priori knowledge of the
LO's ADEV properties to estimate the GPS's jitter and to adjust the loop
time consta
In message <[EMAIL PROTECTED]>, "Ulrich Bangert" writes:
>ONE SIMPLE RULE applies to this question despite the fact that some math
>for drawing tau-sigma-diagrams is indispensable.
Ulrich,
The real challenge is to build an algorithm which finds this point dynamically.
--
Poul-Henning Kamp
Brooks, Brooke and Bruce,
1) I do not want to talk bad Brooks Shera's design. In fact i admire it
a lot for its simpicity. It was the first to be published in amateur
literature and that makes it easily the best available in amateur use
for a long time. And I learned lots from it. Indeed i needed
On Sat, December 16, 2006 9:26, Rob Kimberley said:
> Meinberg in Germany www.meinberg.de/english produce a DCF-77
> simulator which is available as a plug in to their GPS products. See
Here is a simulator doing many of the LF time signals:
http://www.hkw-elektronik.de/deutsch/produkte/mess_testt
Hi Paul,
1) Why not consider using GPS? Much more accurate, available globally, and
you can get hardware fairly cheaply on EBay from the likes of Datum,
TrueTime and others. You can of course consider building your own, using the
excellent resources of this group.
2) If the clock was bought in Eu
Can anyone help?
1. What standard time transmissions might I be able to pick up reliably here
in South Africa? We used to have one on 2500 kHz, but it seems to have gone,
SA Bureau of Standards doesn't seem to know what I m talking about when I
asked them. WWV comes in some times, and optimum fre
Can anyone help?
1. What standard time transmissions might I be able to pick up reliably here
in South Africa? We used to have one on 2500 kHz, but it seems to have gone,
SA Bureau of Standards doesn't seem to know what I m talking about when I
asked them. WWV comes in some times, and optimum fre
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