Hi, nuts -- I have an old (70's?) Vectron Model CO-203-3 1MHz OCXO which is the
time-base out of a Monsanto 1500A counter. The coarse and fine adjustments in
the top of the osc. case don't seem to make much difference in frequency, which
is about 10Hz off when the OCXO is warm. That seems like
Hi,
I've recently completed a GPSDO using the pps output of a uBlox Antaris
TIM4 GPS module to discipline a 10MHz OCXO. I'm now investigating the
motion effects (acceleration/uniform velocity) on the accuracy of the
time-pulse and hence on my frequency output.
I've been unable to find any
Hi Daniel,
Hi,
I've recently completed a GPSDO using the pps output of a uBlox Antaris
TIM4 GPS module to discipline a 10MHz OCXO. I'm now investigating the
motion effects (acceleration/uniform velocity) on the accuracy of the
time-pulse and hence on my frequency output.
Are you moving
Moin,
On Sun, 27 Jun 2010 02:24:31 -0700
Said Jackson saidj...@aol.com wrote:
The 4002 expects a tight phase lock on the two inputs to properly stay
locked,
Why does the ADF4002 need that? Or do you mean by locked that the
locked output of the ADF4002 does reflect the actual locked state?
If
Hi,
What would be easier to try is to replace the gps internal Tcxo with
an external ocxo, but you have to generate the frequency the gps is
using, such as 26 MHZ and do some soldering on the gps itself.
Yes, that would be an idea. But it's not that easy. I dont know
how the control loop in
Moin,
On Sat, 26 Jun 2010 21:14:02 EDT
ewkeh...@aol.com wrote:
What you want is basically a Shera Board. That design has been around for
quite some time and has served me very well.
Yes. The Shera Board and similar designs serve as an example for me.
I have a total of six running
On Sun, 27 Jun 2010 20:59:51 -0400
Robert Benward rbenw...@verizon.net wrote:
All this talk about interpolation reminds me of a little neat chip by Analog
Devices, AD9500. It's programmable digital delay, bit, with lops resolution
with a loons full-scale range. I believe (from app notes)
Attila Kinali wrote:
Moin,
On Sat, 26 Jun 2010 21:14:02 EDT
ewkeh...@aol.com wrote:
What you want is basically a Shera Board. That design has been around for
quite some time and has served me very well.
Yes. The Shera Board and similar designs serve as an example for me.
I
Unfortunately, the AD9500 line is obsolete with no replacement. Which means
it will be quite soon not available anymore.
On-Semi makes a programmable delay: MC100EP195, 2.2 to 12.2 ns in 10 ps steps
There are a couple of other similar chips.
Moin,
There are currently a few HP10811-60111 for 125USD on ebay
(with only 5h left). Could anyone tell me whether this is
a good buy or whether i should wait for another OCXO to apear?
Thanks in advance
Attila Kinali
--
If you want to walk fast, walk alone.
If you want to
Hi,
just a clarification, I did write 4066 it is a 4046 that I replaced. Take
a look at the MCP 4822 dual 12 bit D/A In the data sheet they have an
example using one for coarse, the other for fine steps, I realize that the
transition is not perfect but maybe code can compensate for the
The problem is that the gain and offset of the 2 DACs changes with time
and temperature so that the required corrections also change.
Ideally an autocalibration technique would be used to dynamically track
such changes.
Since changes in the coarse DAC are only required infrequently and the
On 28/06/10 21:36, Julien Goodwin wrote:
Up next is to convert the darn thing to Rubidium, like it was meant to
be when I purchased it (insert rant here).
OK so the pinout vaguely matches, the TS-2100 is *very* twitchy on the
alarm circuits, even a 1Mohm scope (well, it's 1M in theory, cheap
Not being able to write code and not understanding what is required it is
easy for me to suggest a fix. In the case of a good Rub. the annual aging
rate is 1 E-10 which would mean the lower 12 bits would cover one month.
During transition the PIC could modify the time constant and at the
Hi
The problem with the 10811 is the wide distribution. You do not know what
you get. I am in the fortunate position that eight out of ten 10811 are way
below 1 E-12 between 1 and 100 seconds one even out to 1000 seconds. As a
matter of fact some of the plain 10811's are better than the
Hi,
So it goes without saying that you really don't know what you have
unless you can test it in some way. It's OK looking at a table of what
someone else has tested for their 10811 but that doesn't mean yours is
exactly the same.
Steve
On 29 June 2010 23:57, ewkeh...@aol.com wrote:
Hi
The
Exactly, and I think that goes for most Osc. That you and I can afford.
Bert
In a message dated 6/29/2010 8:18:12 A.M. Eastern Daylight Time,
sar10...@gmail.com writes:
Hi,
So it goes without saying that you really don't know what you have
unless you can test it in some way. It's OK
Daniel,
This has been covered previously on time-nuts, a look through the archives
would probably answer your question to a large extent. I do not remember the
time frame though, probably a year or more ago.
Sometimes, googling around that kind of search term does return time-nuts
postings :)
Affordable because we haven't paid someone else to do the testing ;-)
Operating age seems to correlate well with most of the 10811 family,
well-used older is almost always better. Seems to apply the HP 105s and
Sulzer 5As as well. They are almost always a few orders of magnitude
better
Hi Bert,
What test set and reference you have used to measure your OCXO stability?
Luciano
Luciano P. S. Paramithiotti
IZ5JHJ
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of ewkeh...@aol.com
Sent: martedì 29 giugno 2010 14.21
To:
Corby did it using his NBS Dual Mixer set up, the one I am now in the
process to duplicate with the D/M using a five channel counter. As soon as the
test results from the three testers are in a final mod will be done and
than a $ 200 D/M with its own counter will be available.
Bert
In a
Bruce Griffiths wrote:
Attila Kinali wrote:
Moin,
On Sat, 26 Jun 2010 21:14:02 EDT
ewkeh...@aol.com wrote:
What you want is basically a Shera Board. That design has been around
for
quite some time and has served me very well.
Yes. The Shera Board and similar designs serve as an
Thanks for the response Björn. Also thanks to Didier Juges for pointing
out that this has been covered on a previous thread. I'll go and find it
in the history.
Unfortunately the device will be used in urban areas so some multipath
obstruction of skyview is expected. I've just done some
On Wed, 30 Jun 2010 00:17:53 +1200
Steve Rooke sar10...@gmail.com wrote:
So it goes without saying that you really don't know what you have
unless you can test it in some way. It's OK looking at a table of what
someone else has tested for their 10811 but that doesn't mean yours is
exactly the
On Tue, 29 Jun 2010 07:57:19 EDT
ewkeh...@aol.com wrote:
Personally I am happy with my Datum and HP 10811's but I think there are
many later model Osc. out there that may give them a run for the money.
What other, later model oscillators are out there that i could afford?
And trough which
On Tue, 29 Jun 2010 21:32:10 +1200
Bruce Griffiths bruce.griffi...@xtra.co.nz wrote:
Its possible to build a 24 bit resolution D/A using a synchronously
filtered PWM circuit.
A pair of PWM outputs and a few relatively low precision resistors and
capacitors together with a low noise low
If you want to walk far, walk together so, the best solution is to buy a
surplus ocxo calibrated. May be some frquency standard hobbist have one for
you. The 10811 sometime is sold with a small board with a frequency divider to
1MHz and a trimmer to fine tuning it.
I remember you the 10811
I don't necessarily agree with that last statement. It would depend on the
receiver type and the number of SVs being tracked.
Rob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of b...@lysator.liu.se
Sent: 29 June 2010 9:33 AM
To:
I seem to remember that we did a field upgrade on a TS2100 to add an LPRO
when I was selling Datum stuff in the UK in the mid/late 90's. It did bolt
on the chassis, with a small PSU mod board, and I believe a firmware
upgrade included.
Unfortunately I don't have any info on file any more.
If
It was really meant to test it's ADEV not it's current frequency.
Steve
On 30 June 2010 01:32, Paramithiotti, Luciano Paolo S
luciano.paramithio...@hp.com wrote:
If you want to walk far, walk together so, the best solution is to buy a
surplus ocxo calibrated. May be some frquency standard
On 30 June 2010 01:17, Attila Kinali att...@kinali.ch wrote:
On Wed, 30 Jun 2010 00:17:53 +1200
Steve Rooke sar10...@gmail.com wrote:
So it goes without saying that you really don't know what you have
unless you can test it in some way. It's OK looking at a table of what
someone else has
On Tue, 29 Jun 2010 13:32:33 +
Paramithiotti, Luciano Paolo S luciano.paramithio...@hp.com wrote:
If you want to walk far, walk together so, the best solution
is to buy a surplus ocxo calibrated. May be some frquency standard
hobbist have one for you. The 10811 sometime is sold with a
Ha! Ok,sorry for misunderstanding.
I am working jus now in understanding what can be my best reference to use as
reference in ADEV measuring.
My test set is an HP53132a counter national interface and I am currently using
the KE5Fx time interval anlysis software.
I have in my shack 3 GPSDO
From memory, I believe tvb did some experiments with an OCXO or Rb measuring
AVAR while flipping the oscillator upside down (+/- 1g). You may find links on
tvb's web site www.leapsecond.com
At the moment, I cannot find the link...
Didier
PS: Note to tvb: Tom, when you have time, a search or
On Wed, 30 Jun 2010 02:10:03 +1200
Steve Rooke sar10...@gmail.com wrote:
I seem to remember some discussions on a lost cost test instrument,
which would give good enough: results, on this list very recently.
I think i remember this one as well :-)
That would be the sort of gadget which would
I know for a fact I did not have anything to contribute, but it was a good
read.
I found a thread called Pendulums Atomic Clocks Gravity going on in May
2007, you may find something there. I think that's what I had in mind.
I found a convenient archive thread reader at
From one of our papers
http://timesofindia.indiatimes.com/articleshow/6090902.cms
Cheers
--
Raj, VU2ZAP
Bangalore, India.
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Attila
The fact that is possible to build a 24 bit D/A dos not make it a practical
solution for any that CAN not build it or that do not want to put in ALL the
engineering time that would be needed to perfect such a design or the cost
to buy one.
There is a simple and low cost compromise
If we lower the size of each step to over lap more would this lower the error
? Software would adjust both converters at the cross over point so neither
would change it's full range at this point. Two 12 bit converters would form
one 18 or 20 bit converter.
I guess taken to the extreme we
Greetings, Raj,
Many thanks for the reference that you provided.
I wonder on what method was utilized in them achieving this 20 attosecond
measurement? Nothing was mentioned as to the instrumentation utilized in
this time metrology.
Doc
NE8S
- Original Message -
From: Raj
Hi
Summing a pair of DAC's and checking them with an ADC is one way to get the
job done. It's been used quite a bit.
16 bit DAC's are sub $3 items these days with pretty good specs on the
parts. A multi channel 1 ppm accurate 24 bit DC ADC is a fairly common
part as well. Raw parts cost from
On Tue, 29 Jun 2010 09:17:39 -0700 (PDT)
Stanley Reynolds stanley_reyno...@yahoo.com wrote:
If we lower the size of each step to over lap more would this
lower the error ? Software would adjust both converters at the
cross over point so neither would change it's full range at this point.
Two
On 6/29/2010 11:10 AM, Attila Kinali wrote:
Yes, 16bit D/A seems to
be the maximum that is currently available. It crossed my mind
to build a 24bit R-2R D/A using discrete components, but this might
have actually a worse performance than a off the shelf 16bit D/A.
(temperature drifft, resistor
Hi
Some of the TI (Burr Brown) 16 bit parts are 1/4 lsb DNL on 98% of the
transitions. Most of the time you have a coarse DAC that's at 18 bits.
Some of the errors are predictable and you can take them out with a simple
training process. You won't easily get 24 bits, but 20 is very achievable.
Hi
for many 16 bits will do and one other alternative is do a design that will
also work with the AD 1861. I know it is hard to get but in the last year
I found a sizable volume on ebay, convinced them to lower their price,
bought some my self and posted it on time-nuts. With a group effort
Hi
just bought four AD 1861 on ebay with shipping was $11 each. Will see
what I get, but they are out there and 18 bit will cover in my opinion most
applications
Bert
In a message dated 6/29/2010 12:21:31 P.M. Eastern Daylight Time,
li...@rtty.us writes:
Hi
Summing a pair of DAC's and
On Tue, 29 Jun 2010 12:54:52 -0400
Bob Camp li...@rtty.us wrote:
Some of the TI (Burr Brown) 16 bit parts are 1/4 lsb DNL on 98% of the
transitions. Most of the time you have a coarse DAC that's at 18 bits.
Some of the errors are predictable and you can take them out with a simple
training
Hi again.
Any one interested should hold off for a day buying. I have contacted the
seller asked how many he has and what a quantity price would be. To much
interest and the price will go up. I think the market for audio equipment
replacement is shrinking and there will be more reasonable
Hi again
This seller has 95 AD1861 in stock. Is there a reason why they would not
work for all applications. No I do not get a cut. 95 would justify to do a
new design but I am convinced there will be plenty more.
Bert
In a message dated 6/29/2010 1:57:54 P.M. Eastern Daylight Time,
On Tue, 29 Jun 2010 14:07:17 EDT
ewkeh...@aol.com wrote:
just bought four AD 1861 on ebay with shipping was $11 each. Will see
hat I get, but they are out there and 18 bit will cover in my opinion
most
Any one interested should hold off for a day buying. I have contacted the
details at
http://www.attoworld.de/
On Tue, Jun 29, 2010 at 12:14 PM, NE8S n...@earthlink.net wrote:
Greetings, Raj,
Many thanks for the reference that you provided.
I wonder on what method was utilized in them achieving this 20 attosecond
measurement? Nothing was mentioned as to the
bruce.griffi...@xtra.co.nz said:
Its possible to build a 24 bit resolution D/A using a synchronously
filtered PWM circuit. A pair of PWM outputs and a few relatively low
precision resistors and capacitors together with a low noise low drift
reference are required. The technique takes
Thanks for the response Björn. Also thanks to Didier Juges for pointing out
that this has been covered on a previous thread. I'll go and find it in the
history.
Somebody setup a good oscillator on a pendulum. They could measure the
frequency shift as G changed slightly.
There have been
Another approach is to distribute the individual bits rather than clump them
together. If you want 1/2, send 10101010 rather than . You would
have to do something like build a bit pattern in memory and use a serial
port to send it out.
I can't determine if that's good enough.
Here's the link to the pix I have so far on the Vectron 1MHz OCXO:
http://www.moorepage.net/VectronOCXO.html
Best,
Dick Moore
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or with a pair of current output DACs and a resistive divider/summer so you
have a high order and low order voltage.
If it were that simple, the manufacturers would package it up into a single
chip. :)
I think there are two areas of interest. One is the obvious one that steps
on the
Attila Kinali wrote:
On Tue, 29 Jun 2010 21:32:10 +1200
Bruce Griffithsbruce.griffi...@xtra.co.nz wrote:
Its possible to build a 24 bit resolution D/A using a synchronously
filtered PWM circuit.
A pair of PWM outputs and a few relatively low precision resistors and
capacitors together
Hi
Are you referring to something like this:
http://www.electronicsweekly.com/Articles/2008/05/01/43680/fast-settling-syn
chronous-pwm-dac-filter-has-almost-no.htm
as a synchronous filter for the PWM?
Bob
-Original Message-
From: time-nuts-boun...@febo.com
Bob Camp wrote:
Hi
Are you referring to something like this:
http://www.electronicsweekly.com/Articles/2008/05/01/43680/fast-settling-syn
chronous-pwm-dac-filter-has-almost-no.htm
as a synchronous filter for the PWM?
Bob
Yes, that is the original article.
There's a later one (the link
Hal Murray wrote:
bruce.griffi...@xtra.co.nz said:
Its possible to build a 24 bit resolution D/A using a synchronously
filtered PWM circuit. A pair of PWM outputs and a few relatively low
precision resistors and capacitors together with a low noise low drift
reference are required. The
Hi Bruce,
This sounds like a promising idea, please could you expand on the
synchronous filter technique? I have seen some articles about how such
filters can be used to clean up the data from rotating machinery for
vibration analysis etc. but I don't follow how they can be used in a PWM
Hi
The problem taking that circuit directly to 24 bits is the drift on the
output sampling capacitor.
Even with *good* caps and op-amps, holding 16 bits is challenging for times
that are dimensioned in milliseconds. Easier if they don't get very warm ..
Bob
-Original Message-
From:
On 06/29/2010 10:32 AM, b...@lysator.liu.se wrote:
Hi Daniel,
Hi,
I've recently completed a GPSDO using the pps output of a uBlox Antaris
TIM4 GPS module to discipline a 10MHz OCXO. I'm now investigating the
motion effects (acceleration/uniform velocity) on the accuracy of the
time-pulse and
As you line up you pseudo-ranges you now have to solve only the T
variable rather than the XYZT position. This means that all
pseudo-ranges is available for solving the T solution and reducing the
TDOP error. The T-RAIM is also able to drop more false-tickers.
For receivers not having a T
Hal Murray wrote:
or with a pair of current output DACs and a resistive divider/summer so you
have a high order and low order voltage.
If it were that simple, the manufacturers would package it up into a single
chip. :)
And they do... hence delta sigma designs..
Back in the good old days
Hi
Ok, here's a BOM:
TI DAC8581 $1.85 each, two for 3.70
Linear LTC 2493 $2.95
TI LM4040C50$0.36
Freescale MCF52254AF80 $4.38
Quad Op-amp $1.00
Misc resistors and caps $3.00
Other semi's$2.00
Total $17.39 at moderate volume prices. Depending on your shopping approach
likely
I'm doing a one day trip to Indianapolis. If I have spare time is there
any place I should visit?
--
mailto:o...@ozindfw.net
Oz
POB 93167
Southlake, TX 76092 (Near DFW Airport)
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