You may find the following Master's thesis useful:
http://www.ko4bb.com/manuals/download.php?file=08_Stuff_Not_Sorted/8_Sept_28_2014_Uploads/Adaptive_OCXO_drift_correction_thesis_Zhou_2009.pdf
Best regards,
Charles
___
time-nuts mailing list --
You might want to join the Racal-Dana Yahoo group for help on this. There is a
gotcha with these cards in that S4 selects which 488 protocol is used( Airforce
or normal). Apparently you just have to swap it over and re-power.
Sorry cannot help you with your software level matching question.
Several of the reciprocal counters (DC509, DC5010) Tektronix built for their
TM500/TM5000 test equipment mainframes use a National Semiconductor noise
generator chip to dither their reference clock. They do this mainly to handle
the case where the input freq and reference clock are very close.
cdelect@... writes:
Joe,
Nice find.
Don't worry about the lamp, they VERY seldom fail.
Of course there are electronics failures that crop up.
What color is your physics package?
Blue paint= old style
Olive green paint = mid production
Silver (no paint) = late production
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short,
causing a relatively high rate of cycling, which hearable as a beating.
However, for some uses, that is OK.
Cheers,
Magnus
On 02/06/2015 07:16 PM, Mark Sims
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating. However, for
some uses, that is OK.
The buzzword
Could it maybe be that you're actually writing the delay value into the
chip while the pulse is high? I've had that problem with a DS1023-100. The
solution was to wait until the pulse goes low, and then set the delay for
the next pulse.
Regards,
Tom
On Wed, Feb 4, 2015 at 2:47 PM, Dan
In message 20150206153214.4d5f42edbdda4639fee1a...@kinali.ch, Attila Kinali w
rites:
On Mon, 26 Jan 2015 20:15:12 +
Poul-Henning Kamp p...@phk.freebsd.dk wrote:
The basic math of PID has been around for about 100 years. The invention
of the servo (and synchro/resolver) is what
Hi Time-Nuts:
Not sure what the protocol is here but I'll just jump in.
I've just purchased an HP53310a modulation domain analyzer. Most you already
know that these amazing instruments are basically a TIC with a graphic display
of frequency vs time. I've always wanted one to record PLL settling
Joe a very nice find.
The light won't change to lock unless you toggle the little switch inside
the cover on the left to reset. Its intended to be that way so that you
know you lost lock
Regards
Paul
WB8TSL
On Fri, Feb 6, 2015 at 7:16 AM, Joe D'Elia j...@windrushadv.co.uk wrote:
cdelect@...
On 2/6/15 12:42 PM, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating. However, for
Hi Attila,
On 02/06/2015 08:30 PM, Attila Kinali wrote:
On Fri, 06 Feb 2015 19:29:46 +0100
Magnus Danielson mag...@rubidium.se wrote:
Since then interpolation of single-shot events have been investigated,
and is now down to 200 fs in the best counter I know of (and have).
Which counter is
On 2/6/2015 4:16 AM, Joe D'Elia wrote:
I shall see if I can find something of the same
vintage that uses the same top and bottom covers and side rails that I can
cannibalize to fix this unit.
Joe, You may find the side panels / handles castings since they are
common to a lot of that vintage
The state of the art 20 years ago is described here:
http://www.hpl.hp.com/hpjournal/96dec/dec96a9.pdf
They understood their OCXO very very well. And you can find EFC trends on
the web for hundreds of different Z3801A's (and similar) if you want to see
how the EFC trends (and occasionally jumps).
I have a colleague who's using the Systron-Donner MMQ IMU/GPS unit, and
he's wondering if there's a way to get integer seconds out of it. It
uses a Jupiter Pico GPS, I believe, and one of the messages provides
Seconds of Week GPS time, as well as UTC seconds and UTC day, month, year.
So
On Fri, 6 Feb 2015 10:21:08 +0100
Javier Serrano javier.serrano.par...@gmail.com wrote:
We would like to start working on holdover performance for White
Rabbit [1]. This is a new domain for us. Our main use case is a WR
switch losing its reference because someone disconnects a fiber. We
can
Javier,
If you are aim to do hold-over as you switch between two sources, you
are looking at reasonably short times, then just keep a fixed voltage to
the oscillator suffice.
Even if you need a little longer times, say 10-20 s, it suffice.
Temperature changes and oscillator drift may be the
Bill,
A technique similar to this is used in the HP5328A counter, when
equipped with the option 040, and when doing the TI averaging.
Noise is intentionally added into the 100 MHz control loop, and then
multiple measurements is averaged. This way, the sample point moves
around it's average,
Moin Magnus,
On Wed, 21 Jan 2015 07:07:54 +0100
Magnus Danielson mag...@rubidium.dyndns.org wrote:
For oscillators, they should have been turned on long enough such that
any drift is negligible. Alternatively you process out the quadratic
trend out of it. The later should be accompanied by
On 2/6/15 1:21 AM, Javier Serrano wrote:
Dear all,
We would like to start working on holdover performance for White
Rabbit [1]. This is a new domain for us. Our main use case is a WR
switch losing its reference because someone disconnects a fiber. We
can have redundancy, but it will take some
On Mon, 26 Jan 2015 20:15:12 +
Poul-Henning Kamp p...@phk.freebsd.dk wrote:
The basic math of PID has been around for about 100 years. The invention
of the servo (and synchro/resolver) is what makes its day...
If anyone wants to dive into control theory I recommend reading the
book
Thanks for your ideas.
On Fri, Feb 6, 2015 at 11:09 AM, Hal Murray hmur...@megapathdsl.net wrote:
Is your PLL analog or digital? I'll assume digital since it's hard to hold
analog voltages stable for several seconds.
Yes, it is digital. It's even software. It runs on an LM32 [1] soft
core
Pulse width modulation.
Suppose the readings go like this:
6,5,5,5,5,5,5,5,5,5,6,5,5,5,5,5,5,5,5,6,5,5,5,5,5,5,5,5,5,5
you would be able to interpolate that result to be 5.1
If it went:
6,6,5,5,5,5,5,5,5,5,6,6,5,5,5,5,5,5,5,5,6,6,5,5,5,5,5,5,5,5
You would be able to interpolate that result
On Fri, 06 Feb 2015 19:29:46 +0100
Magnus Danielson mag...@rubidium.se wrote:
Since then interpolation of single-shot events have been investigated,
and is now down to 200 fs in the best counter I know of (and have).
Which counter is that? I'm only aware of an experimental TDC that does
Dear all,
We would like to start working on holdover performance for White
Rabbit [1]. This is a new domain for us. Our main use case is a WR
switch losing its reference because someone disconnects a fiber. We
can have redundancy, but it will take some time for a switch to change
over to another
javier.serrano.par...@gmail.com said:
We have never worked on holdover, and I am wondering if we can do something
smarter than the obvious feeding of some constant voltage to the VCXO, based
on averaging during the locked state. Does anybody know of any good
references on holdover?
I doubt
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