I'm now using the SKG25A1 as a PPS source for an NTP server. Aside from
the offset, I noticed a large offset jump in the NTP loopstats
(attached) occurring about once a day. This is not the server oscillator
drifting since the frequency graph looks good at this point and this
behavior can
On Tue, Dec 11, 2012 at 5:55 PM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
Gabs,
I've seen similar jumps, and it happens when the GPS/PPS signal drops out
for a while. In my case, the GPS receiver is sitting just in an upstairs
room, not near a window or the root (as I normally
From: Gabs Ricalde
[]
David,
I forgot to thank you for your helpful site and NTP plotter.
I have the antenna outside with a 180 degree view of the sky, outages
should be rare. Looking at the loopstats, the outage during the 4 us
jump is about 12 seconds. This is a test server, I only have the
Hi
I suspect that to use the temperature chip data, it needs to be running on GPS
for several days while ramping temperature. After that, put it in holdover,
observe the time drift over the next four hours with a similar ramp. Since they
work with the later chip, the ramp would have to be
Bill wrote:
Well, perhaps you are not looking close enough. That is you need to
be observing
at a finer level of comparison. The changes, observed here and at another
location, are in parts in 10-10 to 10-11 range, sometimes
larger. At one of the
locations there was a direct correlation
On Tue, Dec 11, 2012 at 8:00 PM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
From: Gabs Ricalde
[]
David,
I forgot to thank you for your helpful site and NTP plotter.
I have the antenna outside with a 180 degree view of the sky, outages
should be rare. Looking at the loopstats,
Pete,
There are two HV power supplies, +3500 (A18) and -2500 (A19), both of which
can 'sing'. A18 comes on when power is applied and in CS OFF mode. A19
comes on when you move to any mode other than CS OFF. There is also a
battery back up option, Option 002, that has a battery charger board
11/12/2012 13:53
Is there a version of Lady Heather for Linux, or any equivalent
application please? Thanks.
--
Best Regards,
Chris Wilson.
mailto: ch...@chriswilson.tv
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Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on pressing the SHIFT key.
By changing pcbs against a working one the display board has shown to be ok.
There must be a problem with the main board. Without knowing whats inside
the ASICs make
Gentlemen,
a new EZGPIB version is available from the usual place. The improvement
against the former version is increased speed in writing large data files.
Enjoy
Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener
___
Antonio,
when I read the question I went into my cellar to return with an AVANTEK 2-4
GHz YIG that I had once moved out of a defective spectrum analyzer. I used
an analogue regulated power supply for the oscillator power and my HP6632 in
constant current mode (this YIG NEEDS a tuning current) to
Lady Heather runs very nicely from Wine.
-Chuck Harris
Chris Wilson wrote:
11/12/2012 13:53
Is there a version of Lady Heather for Linux, or any equivalent
application please? Thanks.
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To
On Tue, 11 Dec 2012 13:54:24 +, Chris Wilson wrote:
Is there a version of Lady Heather for Linux, or any equivalent
application please? Thanks.
LH runs fine in Wine - I have 2 instances running on my Ubuntu server.
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Ulrich,
Yes indeed modern stuff is tough. I believe what you are seeing is a dead
man timer. The system is not booting correctly, times out and resets and
the process keeps going.
Typically a good place to look is at the interrupt lines to see what is
triggering the behavior.
If neither of these
I'm not sure about the jammer but I'm running a timing receiver in
position hold several floors up, I haven't seen dropouts like this.
ntpd is running with a noselect NMEA source since I'm having problems
with ntpd marking the PPS and NMEA as falsetickers. The startup sequence
for the server is
Rex, let me check status and I will get back with you by Thursday. I am
presently finalizing a detailed outline of the total package.
Bert
In a message dated 12/10/2012 7:23:43 A.M. Eastern Standard Time,
r...@sonic.net writes:
Bert,
I have been waiting for more details to become
Thanks for all your suggestions!
Ends up that I seem to have found yet a different version of the 5680a :)
My DDS board did have an RS232 level shifter but for some reason, the RS232
TX signal was not being brought out to the 5 pin connector. Once I soldered
the TX wire directly to the SP233ACT
If it is used for tempco it should affect the temp by stabilizing offset with
temp changes correct? Maybe a more correct approach would be to disconnect it
and test. Has been awhile since I read that testing stuff.
Doc
Sent from mobile
On Dec 11, 2012, at 6:39 AM, Charles P. Steinmetz
Pete Joe sure gave you the answer. So you have fallen prey to the
time-nuttery CS drug.
I would never have thought you would have. So Not that I can out do what
Joe told you.
But on my sad frankenstein of a 5061running on fumes of CS the beam current
is so low that I have to use a magnifying glass
Hi
The only place the sensor *might* be used is during holdover. There is no
practical reason to use it while the TBolt is locked to GPS.
*If* it's used in holdover, it gets trained by watching the control
voltage and the temperature while the beast is locked to GPS. That
information is then
Neat data set! This says a lot about the stability of your HP supply. The
choice of current-sense element makes a big difference in a YIG driver
circuit, and most wirewound resistors fall into the Don't ask category.
Would be interesting to try the same test with one of the cheap Chinese
I picked up one of the Nortel NTPB15AA (Trimble) GPSDO from
the common auction site and decided adding a monitor display to
the front panel would be a good idea. The entire unit draws about
300ma at 48vdc at power up and there is room inside the case for
a small AC power supply. There is
Pete,
The more likely singing offender is the old style A11 oven controller
module.
It also is off in the Cs off mode so the singing should stop when in that
mode.
The newer style A11 modules do not sing!
Corby
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Thanks
This weekend I'll stick a microphone inside a piece of tubing and go looking.
The singing only occurs when the unit is in LOOP OPEN or OPER mode.
-pete
On Tue, Dec 11, 2012 at 11:26 AM, cdel...@juno.com wrote:
Pete,
The more likely singing offender is the old style A11 oven
There are also YIG synthesizers available on epay, see eg 140894282834
Don
John Miles
Neat data set! This says a lot about the stability of your HP supply.
The
choice of current-sense element makes a big difference in a YIG driver
circuit, and most wirewound resistors fall into the Don't ask
Ulrich Bangert wrote:
Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on pressing the SHIFT key.
By changing pcbs against a working one the display board has shown to be ok.
There must be a problem with the main board. Without knowing whats
Guys,
So much speculation on how the Tbolt uses it's temperature sensor data.
Having spending hundreds of man hrs and thousands of Tbolt running hrs,
testing all kinds of things to find ways to improve my Tbolt's performance.
This is what I've found happens on My Non E TBolt with version#3
As Corby said oven control
Bert Kehren
In a message dated 12/11/2012 2:47:03 P.M. Eastern Standard Time,
p...@petelancashire.com writes:
Thanks
This weekend I'll stick a microphone inside a piece of tubing and go
looking.
The singing only occurs when the unit is in LOOP OPEN or OPER
Two comments the manuals available on agilent
What on earth is a crossguard?
On Tue, Dec 11, 2012 at 3:16 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz
wrote:
Ulrich Bangert wrote:
Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on
paul swed wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Crossguard comms (Agilents term) refers to the optoisolators used for
serial communication between the floating and earth referenced logic
sections.
Bruce
At 21:40 11/12/2012, you wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Data exchange between a floating, guarded circuit and a ground referenced one?
Marco IK1ODO
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time-nuts mailing list --
OK but why would it tie to the reset line?
On Tue, Dec 11, 2012 at 3:48 PM, Marco IK1ODO -2 ik1...@spin-it.com wrote:
At 21:40 11/12/2012, you wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Data exchange between a floating, guarded circuit and a
Long shot remedy : There is a front pannel push button sequence to turn off/on
the display.
--- On Tue, 12/11/12, Ulrich Bangert df...@ulrich-bangert.de wrote:
From: Ulrich Bangert df...@ulrich-bangert.de
Subject: [time-nuts] OT: Question on dead HP34401
To: Time nuts time-nuts@febo.com
It only resets the earth referenced micro (8051) on power up and when
pulses on the optocoupler output arent present.
There is no other connection to the reset pin of this micro.
The floating logic is reset by the LM2925 5V regulator reset output.
There is no connection to this reset line aprt
Hi,
Does anyone have a set of schematics for this guy?
My bolt has suffered a significant loss of sensitivity,
the AMU values have dropped 30 dB. It is not
the motorola antenna or feedline, works fine on an Oncore.
This appeared to have happened when I tried to operate 160 meters!
Thanks
You might try doing a cold reset. I had the same issue and that got it back.
You need to use the trimble software.
Tom
- Original Message -
From: David Garnier dgarn...@wi.rr.com
To: time-nuts@febo.com
Sent: Tuesday, December 11, 2012 5:27 PM
Subject: [time-nuts] Thunderbolt
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
On Tue, Dec 11, 2012 at 11:43 PM, Tom Miller tmil...@skylinenet.net wrote:
You might try doing a cold reset. I had the same issue and that got it
back.
You need to use the trimble software.
Tom
- Original
On 12/11/2012 11:50 PM, Azelio Boriani wrote:
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
They are pretty simple, so I am amazed that there has been no major
attempt to reverse engineer them. The GPS front-end chip I haven't been
able to find a datasheet for,
Magnus Danielson wrote:
On 12/11/2012 11:50 PM, Azelio Boriani wrote:
I think that the TBolt's schematic(s) are sort of HolyGrail for
TimeNuts.
They are pretty simple, so I am amazed that there has been no major
attempt to reverse engineer them. The GPS front-end chip I haven't
been able to
Magnus, you said it:
The GPS front-end chip I haven't been able to find a datasheet for
the CPU/GPS-baseband chip seems to be an ASIC
Quest for the HolyGrail...
On Wed, Dec 12, 2012 at 12:23 AM, Bruce Griffiths
bruce.griffi...@xtra.co.nz wrote:
Magnus Danielson wrote:
On 12/11/2012 11:50 PM,
Hello,
this afternoon the post(wo)man handed
to me the little box with the PA6H
GPS modules. I bought also an antenna
with 5mt cable, so I can use it in the lab.
The module is up and running, requiring
only 3V3 supply, locking very fast,
about 30s from cold start, here is it, working
with ext
On 12/12/2012 12:28 AM, Azelio Boriani wrote:
Magnus, you said it:
The GPS front-end chip I haven't been able to find a datasheet for
the CPU/GPS-baseband chip seems to be an ASIC
Quest for the HolyGrail...
On the other hand, it's not all that many pins, so a bit of advanced
guessing should
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
Some French time nuts told us they already have one. It's very nice.
/tvb
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Tom,
On 12/12/2012 12:44 AM, Tom Van Baak wrote:
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
Some French time nuts told us they already have one. It's very nice.
Would you be able to share? Do you have a pointer? If it was here, then
more people than me missed
Warren wrote:
During normal operation my Tbolt uses the temperature and ADC data
to in its Kalman filter that then can predict a simple linear
temperature constant, and simple linear ageing rate.
* * *
But the **Only** time the Kalman filter is used is during
Holdover. It does this
This may be a newbie question, but I'm a newbie, so:
Do the HP telecom GPSDOs (Z38xx) require external airflow for cooling?
They don't have built-in fans, but they sorta look like they depend on a
rack-level cooling fan, which a telecom rack would almost certainly have.
I ask because I bought a
Another thing that could of effected the results when measuring the effect
of a low resolution sensor chip during holdover,
is that it is real hard for the Klaman filter to learn anything useful from
it, without some careful manipulation of the variables.
Mostly all it would normally record
On Dec 11, 2012, at 6:57 PM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
Tom,
On 12/12/2012 12:44 AM, Tom Van Baak wrote:
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
Some French time nuts told us they already have one. It's very nice.
Would you be
On 12/12/2012 01:52 AM, John Ackermann N8UR wrote:
On Dec 11, 2012, at 6:57 PM, Magnus Danielsonmag...@rubidium.dyndns.org
wrote:
Tom,
On 12/12/2012 12:44 AM, Tom Van Baak wrote:
I think that the TBolt's schematic(s) are sort of HolyGrail for TimeNuts.
Some French time nuts told us they
Stu,
a fan is about the worst thing you can do for your Z3805 it will
significantly worsen the stability of the output frequency. The oven inside
does get
warm, that's why it is an oven :)
The power consumption will go down once it heats itself up, the unit is
designed to work without a
The telecom closets and data centers I've visited have a significant amount of
airflow. Could it be that there is an assumption that these telecom-rack GPSDO
expect some level of air?
/tvb
- Original Message -
From: saidj...@aol.com
To: time-nuts@febo.com
Sent: Tuesday, December 11,
Hi Warren,
Starting from a factory reset, it has something it will use in under 1/2 day.
And that would explain my and Charles' null results. Nice.
If the temperature has not been thru a few cycles and /or the Ageing is still
at a high initial cold start rate and still changing,
the
Yes they do assume this. Or at least a standard relay rack. Most of these
units should have come out of mobile telcom sites. The air in these
facilities is reasonable but often not all that great. They do get hot. But
the relay racks are 2 posters nothing else surrounding the racked equipment
so
Although the Trimble oscillator has superb phase noise performance, it has
TERRIBLE temperature sensitivity. It appears to be a single oven oscillator,
not a double oven. The PWM'ed fan temperature control implemented in Lady
Heather effectively makes the unit a double oven. Also, by
Oops. Forgot about A11.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of ewkeh...@aol.com
Sent: Tuesday, December 11, 2012 2:33 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] 5061A Beam Current question
As Corby said oven
I've written GPIB stuff for the Racal-Dana counter et al. running under
32 bit Fedora Linux and the Linux GPIB package. It is available at
ftp.omen.com in the pub/tek directory.
On 12/11/2012 03:36 PM, Fabio Eboli wrote:
Hello,
this afternoon the post(wo)man handed
to me the little box with
On 12/12/2012 02:55 AM, Tom Van Baak wrote:
The telecom closets and data centers I've visited have a significant amount of
airflow. Could it be that there is an assumption that these telecom-rack GPSDO
expect some level of air?
Well yes and no.
Traditional telecom is supposed to work with
Typical 32KHz clock crystals are very stable in frequency if you can keep them
close to the turnover temp. If you can hold 1 degC it is .04 ppm.
That is 40ppb - very good. If you can hold .1 deg C it is .0004 ppm.
That is .4 ppb. Very expensive. (it goes as the square of the
difference in
Mark wrote:
Although the Trimble oscillator has superb phase noise
performance, it has TERRIBLE temperature sensitivity.
It appears that most do but some don't. Between the results I have
seen posted on the list (Lady Heather screen shots) and my own data,
they seem to fall into two
tvb posted
Were you able to test how quickly, or how well, the filter learned the tempco
of the OCXO?
Only at a couple of very general data points.
Using a very Bad unit, the Kalman filter had an effect, although not very good
in under 1/2 day.
After a week or so on a good unit, it helped
Typical 32KHz clock crystals are very stable in frequency if you can keep
them
close to the turnover temp. If you can hold 1 degC it is .04 ppm.
That's far better than I thought. Do you have a reference for this spec?
I agree you might be able to make one accurate to 0.04 ppm, however
http://www.abracon.com/Resonators/AB26T.pdf
This quotes .038 ppm/C^2 delta T from the turn over point:
http://www.iqdfrequencyproducts.com/app-notes/timekeeping/
The fly in the ointment is the aging rate of 5 ppm the first year (13ppb/day)
and 3 ppm (8ppb/day) after.
I'm sure holding 1
Although the Trimble oscillator has superb phase noise
performance, it has TERRIBLE temperature sensitivity.
It appears that most do but some don't. Between the results I have
seen posted on the list (Lady Heather screen shots) and my own data,
they seem to fall into two groups. I have
Hi Simon,
Thanks for the URL. That's one of those tiny 6x2 mm crystals, 20 ppm crystals
(ouch). The tempco (-0.034 ± 0.006 ppm/ T²) is excellent, though. Now, you can
adjust rate; and temperature you can control. Notice they don't specify the
stability, which is the key to timekeeping.
So I
Hello Tom,
the GPS noise dominates for typical double oven OCXO's where the tempcos
are very small (say below 5E-012 per degree C).
On single oven units, the tempcos are typically 50 to 200 times larger, and
thus the required EFC change over temperature is also that much larger.
If I am
Coming very soon to a clock near you:
2012-12-12 12:12:12 UTC = MJD 56273 + STOD 43932 = MJD 56273.508472
A special prize for anyone who can capture their local microsecond time
standard:
12/12/12 12:12:12.121212
Those of you left of Greenwich and using 12/24 local time get an extra
Yes. I have already decided to do it. I want some feedback from the list before
I get past the thinking stage though.
Initial rough calibration will be easy once the temp control is functional. Let
every thing get nice and stable. Read Freq. Step 1 deg C. Wait 10 minutes. Read
frequency. Step
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