Hi Jim
Thank you for your reply, especially for your input on how science fair is
judged. I've saved your reply and I'll be sure to read over it again
before regional competition in a few weeks!
No I have not done any research into Peter Siegel's work...Thanks for
pointing that out to me.
On 2/9/2012 3:36 AM, John Ackermann N8UR wrote:
As threatened, I've measured stability (out to a trustworthy 10K
seconds) and phase noise of the three popular telecom surplus Rb
standards. I looked at two units of the FE-5680, two units of the
Efratom FRS, and one Datum LPRO.
Which variety
Important note: there's known to be a lot of variability among these
units, so my sample size of one or two each isn't a guarantee that your
unit will perform similarly.
Neat. Your FE-5680 noise plots look just like the ones I took. Seems
clear that this particular variant was meant for
Don't be afraid and open up your MV89. I have done this with many MV201
without problems.
On Thu, Feb 9, 2012 at 8:25 AM, Sam li...@digitalelectric.com.au wrote:
I just powered up one of my MV89A's and measured ~7 dBm into my HP 8920B,
but as Tom has mentioned some MV89A's develop
a dry joint
Lady Heather supports several versions of the Mayan and Aztec calendars (plus a
bunch of others). You can also specify a correlation constant offset to match
the date to whatever value your local high priest deems correct.
---
I thought the same thing but I think Mark
Hi
Indeed the phase noise goes up by 20 log N when multiplying. To be precise,
only the phase spurs go up by 20 log N. If they are incoherent they still
multiply, but you get a bit of an offset.
Bob
On Feb 9, 2012, at 2:03 AM, Javier Herrero wrote:
El 09/02/2012 01:40, Bob Camp escribió:
Hi
Hi
Past 100 seconds I have seen some FE's that look better than your LPRO plot and
some FE's that look worse than your FE plots. Running in a +/- 2C room
apparently is not the best way to operate them for good long tau performance.
Bob
On Feb 8, 2012, at 9:36 PM, John Ackermann N8UR wrote:
Hi
It's a solder seal can and if you have the right gear it comes open easy. If
you happen to have a 1KW RF induction heater they are very easy to open. If by
the odd chance you don't have one of those, a nice big soldering iron (or two)
can come in handy. Solder wick and working your way
Hi
If you look at all of the phase noise plots, the noise (ignore the spurs) gets
very similar between the units below 20 to 30 Hz. They all seem to be locking
their VCXO up to the RB resonance at roughly the same point and it's Q / noise
is taking over below this region. If you are using a
Would it be better to apply heat the metal shell or to apply heat the
bottom part with the I/O pins ?
I would start using a propane gas torch. Heating quickly till I saw the
solder flow.
Stan, W1LECape Cod
On 2/9/2012 6:04 AM, Azelio Boriani wrote:
Don't be afraid and open up your MV89.
Indeed,
ADEV is for random freq variation not easily measured by other means.
Temperature fluctuations do not cause random freq changes and the
temperature's effect should be removed if one wants accurate long term ADEV
numbers.
Even daily diurnal cycles due to temperature can have major
I use a hot gun directing heat on the soldered edge. Use a soldering iron
and the solder wick as suggested gives the best result, in my opinion. It
helps if more than 1 working around the OCXO as at some moment you have to
use one or two pins to lift the bottom cover using pliers. I have done this
If you do open it up Scott, Don't forget to take some photos of the guts of it.
I wouldn't mind seeing inside one of these.
Sam
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On 2/9/2012 4:56 AM, Alberto di Bene wrote:
On 2/9/2012 3:36 AM, John Ackermann N8UR wrote:
As threatened, I've measured stability (out to a trustworthy 10K
seconds) and phase noise of the three popular telecom surplus Rb
standards. I looked at two units of the FE-5680, two units of the
Actually, I do have an earth available for calibration to my lab. It's
just outside the window. During the day I can take sun sightings, and
during the night star sightings (barring cloudy weather). I cannot
measure the length of a second as accurately as other lab equipment can,
but the
On 2/9/12 4:51 AM, WarrenS wrote:
Indeed,
ADEV is for random freq variation not easily measured by other means.
Temperature fluctuations do not cause random freq changes and the
temperature's effect should be removed if one wants accurate long term
ADEV numbers.
Even daily diurnal cycles due to
Hi Jim:
Check out:
http://www.ted.com/talks/lang/eng/clifford_stoll_on_everything.html
Here's part of an email from Clifford:
Oh, the speed of light?
For detectors, I use two fast-response photodiodes and feed their outputs into
opamps.
The experiment uses one cheap laserpointer (they cost
On 2/9/2012 7:51 AM, WarrenS wrote:
Indeed,
ADEV is for random freq variation not easily measured by other means.
Temperature fluctuations do not cause random freq changes and the
temperature's effect should be removed if one wants accurate long term
ADEV numbers.
Even daily diurnal cycles due
I was just about to write the same thing as below. Yes you can
measure ADEV with the unit in a temperature controlled box but unless
you intend to use the unit in that same box what does the test tell
you? These are spec'd for use in unheated cell towers and the
engineer looked at the worse
I think it's odd that all these science projects are NOT doing any
science. They sound like engineering to me.
So you build a neat mouse trap? That is not science unless you have a
theory about mouse behavior and your trap is intended to test the
theory.Around here we do have these
John,
Thank you for your offer but my PTS-040 has its own front panel controls
so I'm served on this side.
I was asking about the remote interface figuring out it was something
that Bill Fuqua had published for controlling the synthesizer, maybe
from a PC.
About the remote control info, I
On 02/09/2012 04:10 PM, Jim Lux wrote:
On 2/9/12 4:51 AM, WarrenS wrote:
Indeed,
ADEV is for random freq variation not easily measured by other means.
Temperature fluctuations do not cause random freq changes and the
temperature's effect should be removed if one wants accurate long term
ADEV
On Wed, Feb 8, 2012 at 11:25 PM, Sam li...@digitalelectric.com.au wrote:
...but as Tom has mentioned some MV89A's develop
a dry joint around the output bypass capacitor
Now that I think of it, it is surprising to me that OCXOs even work.
About the worst thing you can do to kill the
Hi
I would avoid super heat type approaches. The risk is getting the glass to
metal seals on the base to hot to fast. Normally the can needs more heat
than the base, but not always. A lot depends on just how thick each one is
and what they are made of.
Bob
-Original Message-
From:
Hi
Are you worried about phase noise at 100 Hz and above (Trimble OCXO) or
about sort term stability at 1 to 100 seconds (MV89)? Two different things,
and you don't get both at the same time on the crop of what's up for auction
at the moment.
Of course you can get a broken one in either batch
My experiments with CW laser diodes is that they don't take well to
being switched on and off with out a soft start.
They will only last a certain number of on off cycles before output begins
to drop and they quit working. Perhaps something
has changed in the last few years.
I need to
Hi
There are at least two possible sources of the spurs in the FE. One is the
DDS, the other is cross talk in the CPLD divider. In one sense it really
does not matter which it is from, they are indeed there on the output. In
another sense it does. If they are from the CPLD, you *could* hack into
On Thu, Feb 9, 2012 at 9:25 AM, Bob Camp li...@rtty.us wrote:
Hi
Are you worried about phase noise at 100 Hz and above (Trimble OCXO) or
about sort term stability at 1 to 100 seconds (MV89)? Two different things,
and you don't get both at the same time on the crop of what's up for auction
at
On Wed, Feb 8, 2012 at 11:02 PM, Hal Murray hmur...@megapathdsl.net wrote:
Other than LightSquared, an event that made GPS go away would most likely
eliminate most interest in ultra accuracy time keeping.
By went away, I meant locally, as be being jammed or spoofed.
Possibly a car drives
In a message dated 09/02/2012 02:08:49 GMT Standard Time, e...@telight.com
writes:
I don't remember which owns which, but some PTS models are under the
Wavetek brand. I have a Wavetek 5135A, which looks and acts just like
the PTS 160
-
As far as I can tell, it seems to
Thanks, Nigel, I think your history description is about right - I
vaguely recall seeing the Rockland brand too. I guess PTS is the
current survivor - the PTS D310 seems quite new, and the company
seems to be still in business in their niche.
Ignacio sent me a pinout page for the PTS
Hi Bob,
On 02/09/2012 07:03 PM, Bob Camp wrote:
Hi
There are at least two possible sources of the spurs in the FE. One is the
DDS, the other is cross talk in the CPLD divider. In one sense it really
does not matter which it is from, they are indeed there on the output. In
another sense it
A couple points that some may of missed.
I've seen even slow 24 hr temperature cycles be the cause of poor ADEV numbers
at MUCH less than 24 hr ADEV taus in otherwise low drift Rb's Osc like a LPRO
that had showed little ageing drift.
From what I've seen, more often than not, the bathtub turn
Hello,
El 09/02/2012 21:06, Magnus Danielson escribió:
I was just thinking about that. For these more modern 5680A, just the
Q of the resonance and the loop filter / loop bandwidth would not
allow for so much high frequency side-bands of the DDS to pass through.
The loop filter at least
On 02/09/2012 07:21 PM, Chris Albertson wrote:
On Wed, Feb 8, 2012 at 11:02 PM, Hal Murrayhmur...@megapathdsl.net wrote:
Other than LightSquared, an event that made GPS go away would most likely
eliminate most interest in ultra accuracy time keeping.
By went away, I meant locally, as be
Hi Javier,
On 02/09/2012 10:04 PM, Javier Herrero wrote:
Hello,
El 09/02/2012 21:06, Magnus Danielson escribió:
I was just thinking about that. For these more modern 5680A, just the
Q of the resonance and the loop filter / loop bandwidth would not
allow for so much high frequency side-bands
Hi
You might check how well buffered the 60 MHz is before you tap into it. It
may need a bit buffering.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Magnus Danielson
Sent: Thursday, February 09, 2012 4:29 PM
To:
Do not be misled by the conventional theory that scientists develop a
theory
and then do an experiment to prove it.
This theory was dreamed up by some vertical thinker who was incapable
of any scientific progress. It has been reinforced by commentators who
reconstruct the path of discovery
Yes, the pinout is the same for all models. If anyone is interested, I have
the manual for the PTS-3200 and can send the interface pinout.
Message: 9
Date: Thu, 09 Feb 2012 11:41:52 -0800
From: ed breya e...@telight.com
To: time-nuts@febo.com
Subject: Re: [time-nuts] PTS synthesizers
Hi Bob,
On 02/09/2012 11:04 PM, Bob Camp wrote:
Hi
You might check how well buffered the 60 MHz is before you tap into it. It
may need a bit buffering.
The U.FL. connector is very uncommon on JFET probes, so I assume it can
drive a 50 Ohm load. Otherwise I would agree with you. An open
El 09/02/2012 22:28, Magnus Danielson escribió:
Consider that it is de-modulated and then low-pass filtered.
Also, it is the alternating rate and not 1400 Hz difference in DDS
setting which is the key parameter here. The 1400 Hz gives a hint of
the Q-value however, which seems to be lower on
On Thu, Feb 9, 2012 at 2:04 PM, Neville Michie namic...@gmail.com wrote:
Do not be misled by the conventional theory that scientists develop a theory
and then do an experiment to prove it.
This theory was dreamed up by some vertical thinker who was incapable
of any scientific progress.
Yes
El 10/02/2012 00:13, Javier Herrero escribió:
El 09/02/2012 22:28, Magnus Danielson escribió:
Consider that it is de-modulated and then low-pass filtered.
Also, it is the alternating rate and not 1400 Hz difference in DDS
setting which is the key parameter here. The 1400 Hz gives a hint of
On 02/10/2012 12:22 AM, Javier Herrero wrote:
El 10/02/2012 00:13, Javier Herrero escribió:
El 09/02/2012 22:28, Magnus Danielson escribió:
Consider that it is de-modulated and then low-pass filtered.
Also, it is the alternating rate and not 1400 Hz difference in DDS
setting which is the key
On 2/9/2012 8:39 AM, EB4APL wrote:
About the remote control info, I have a sheet entitled
PTS-040-1600_Prog.doc that I downloaded some time ago, but I'm not
able to find from where, maybe it was from your page. I has everything
that is needed for external control.
Best regards,
Ignacio,
Indeed, ADEV is for random freq variation not easily measured by other
means.
Well, no, ADEV is the two-sample deviation of fractional frequency
differences over time. That's really all you can say about it. There's not
really any such thing as true ADEV -- a measurement either meets the
On 2/9/12 8:42 AM, Magnus Danielson wrote:
On 02/09/2012 04:10 PM, Jim Lux wrote:
Interesting point you make here. The rising ADEV at 100-1000 second-ish
tau in a system that should be better is a classic sign (at least around
here) that temperature effects are showing up.
I regularly see
Fellow time scientists,
Here's my view of the difference between science and engineering:
Someone with better measuring equipment finds a discrepant result
while verifying some physical law or accepted truth. That person
needs to know the existing truths and create ideas about testing
the new
On 2/9/12 8:23 AM, Chris Albertson wrote:
I think it's odd that all these science projects are NOT doing any
science. They sound like engineering to me.
So you build a neat mouse trap? That is not science unless you have a
theory about mouse behavior and your trap is intended to test the
Rex,
Nice to know who is the author, and I'm glad to thank you for it. And
your info about the PTS nonsense policy explain why it is so difficult
to find their manuals on line, I tried yesterday to find where were some
manuals that I fortunately had downloaded in the past but without
The pin-outs are the same on the BCD input connector, but how the
high-order controls map differs between models.
For example, the PTS-160 doesn't use the 4-bits for 100 MHz, but rather
takes input on the 10 MHz bits up to a value of 16. The PTS-250 does use
the 100 MHz bits, with values of
Hi
The CPLD may have enough stuff going on to nuke the output without any help
from the rest ou the board.
Bob
On Feb 9, 2012, at 6:34 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
On 02/10/2012 12:22 AM, Javier Herrero wrote:
El 10/02/2012 00:13, Javier Herrero escribió:
El
John,
On 02/10/2012 12:37 AM, John Miles wrote:
Indeed, ADEV is for random freq variation not easily measured by other
means.
Well, no, ADEV is the two-sample deviation of fractional frequency
differences over time. That's really all you can say about it. There's not
really any such thing
Yes, a fun project, and a fine physics lab exercise. But not a good
science fair project because it doesn't meet the originality bar.
This is something that I confess I had a hard time figuring out what
that meant when I was entering science fairs... as it happened, my
projects *were*
On 2/9/12 4:00 PM, Bill Hawkins wrote:
Fellow time scientists,
Here's my view of the difference between science and engineering:
snip
If marketing studies show a positive return on investment, engineers
are turned loose to solve the problems revealed as the details of
building or
At 11:20 AM 2/9/2012, Bob Camp wrote:
Hi
I would avoid super heat type approaches. The risk is getting the glass to
metal seals on the base to hot to fast. Normally the can needs more heat
than the base, but not always. A lot depends on just how thick each one is
and what they are made of.
Hi
To add another wrinkle to this.
Correcting ADEV for systematic errors and then not mentioning you did so
strikes is something I find a bit problematic. If say you decide to take out
13th order drift, you should say you did so. The discussion of what to correct
and how is older than ADEV.
On 02/10/2012 12:51 AM, Jim Lux wrote:
On 2/9/12 8:42 AM, Magnus Danielson wrote:
On 02/09/2012 04:10 PM, Jim Lux wrote:
Interesting point you make here. The rising ADEV at 100-1000 second-ish
tau in a system that should be better is a classic sign (at least around
here) that temperature
I don't have any PTS gear, but the Internet Archive has this old page:
http://web.archive.org/web/20080821140147/http://www.xertech.net/Tech/PTS.html
And a quick Google turned up these links:
http://w8bl.com/page/5
http://www.artisan-scientific.com/info/pts_3200_manual.pdf
I don't expect
On Thu, Feb 9, 2012 at 4:09 PM, Jim Lux jim...@earthlink.net wrote:
On 2/9/12 8:23 AM, Chris Albertson wrote:
I think it's odd that all these science projects are NOT doing any
science. They sound like engineering to me.
So you build a neat mouse trap? That is not science unless you have
On 2/9/12 4:51 AM, WarrenS wrote:
Indeed,
ADEV is for random freq variation not easily measured by other means.
Temperature fluctuations do not cause random freq changes and the
temperature's effect should be removed if one wants accurate long term
ADEV numbers.
Why? Unless the unit is
On 02/10/2012 02:31 AM, Bob Camp wrote:
Hi
To add another wrinkle to this.
Correcting ADEV for systematic errors and then not mentioning you did so strikes is
something I find a bit problematic. If say you decide to take out 13th order drift, you
should say you did so. The discussion of what
Let me strengthen the argument below. Let's say you are building and
selling Rb units to the telcom industry and you've spec'd your product
for use in the range of -25C to +85C. Now you want to include an
ADEV plot in your sales literature. Should you place the unit in an
environmental
Magnus wrote:
It's a huge difference what comes in the device and what environment
we put it in. A temperature dependence, is a systematic effect on the device.
To some degree we can control temperature, we can predict
temperature and deal with it. We can handle it as an engineering
concept
John,
Did you ever run any tests on those UCT double oven OCXOs? I've found them to
be freaky-stable long term. I have retrofitted a lot of Tek DC510/5010
counters with them and after over two years, the last digit is still right on.
They are capable of great
Ah so, master Joe, your net-fu is very good. I forgot that my stuff
might be archived. Fabulous resource.
So, while we are at it, here is some more PTS info. There are two
general families of these synthesizers. I may not get this exactly
right, from memory, but it should be close enough for
ADEV and friends was invented and most useful to better characterized and
compared oscillators.
To make any meaningful comparison test, the results MUST be reproducible to
some level.
Errors bands are there to show what the reproducible level is, but
unfortunately the error bands do not
On 2/9/2012 11:34 PM, ws at Yahoo wrote:
You can of course use the ADEV math function for anything, but MY
definition of true and accurate ADEV numbers must include a set up
that gives repeatable results.
If you test is done over different or unknown temperature changes that
have major effects,
Right all those things need to be controlled if doing high end nut-testing.
Most time nuts already know enough not to shake their Osc or tweak its Power
supply etc when taking ADEV data.
What is often left as the major error source (that can most easily be
controlled) with a careful setup is
If marketing studies show a positive return on investment, engineers
are turned loose to solve the problems revealed as the details of
building or manufacturing the new thing are studied.
The best inventions are the ones that nobody ever thought to ask for. If
Edison had done marketing studies,
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