Re: [time-nuts] HP 3010Axxxxx oscillator

[Charles Steinmetz]

Corby wrote:


The 3010A prefix identifies that date it was made.


Specifically, it identifies the "series" of the product -- the date the 
last revision to the product was adopted.  The "3010" part is the 
encoded date for that particular series (10th week of the 30th year past 
HP "year one"), and the "A" indicates that it was manufactured in the 
US.  [I've forgotten what "year one" was for the Instrument Division. 
It was 1960 for the calculators -- I/D may also have used 1960.]


Best regards,

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

[Paul]

On Tue, Aug 16, 2016 at 3:36 PM, Attila Kinali  wrote:

> I disagree here. With the APU and its IRQ system you get already to
> sub-us PPS time stamping (probably in the 10ns-100ns range).
>

An APU1 post said they had 50ms of jitter (as measured by Chrony) so they
assumed the PPS driver was broken on the hardware.  Pascal suggested
elsewhere that the combined LPC plus system IRQ jitter would be too much
for NTP.  While I don't believe this I'm disinclined to test it .  So I was
-- clearly too briefly -- implying that there are solutions that should be
less expensive* and known to achieve micro-second jitter.

I had no reason to suspect Pascal would overestimate the issues however
another APU1 owner** used an mPCIe serial card and an mPCIe GPS card and
got expected microsecond jitter (as measured by NTP) results.  Again this
is not quite what the OP is proposing but it's encouraging.

These are time sync. protocol results and don't speak to sub-microsecond
time-stamping in the hardware.

* which is not to say pcengine hardware is expensive.  It's not.
** https://wiki.polaire.nl/doku.php?id=versalogic_vl-mpeu-g2_ntp
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Holdover

[Magnus Danielson]

Bob,

On 08/16/2016 11:31 PM, Bob Stewart wrote:

Hi Attila,
In my unit, which is a frequency standard, I chose to tell the receiver to stop 
sending 1PPS pulses when it loses sync to the sats.  And since the 1PPS is no 
longer coming, the PLL does nothing and the DAC doesn't change.  (Let's avoid 
the question of aging correction for now.)  So, I'm wondering where to go and 
what to do if I want to get time from my unit.  Clearly I could just tell the 
receiver to continue to send 1PPS pulses and sync to those - marking the time 
as unreliable.  When the receiver synced back up, then it would warp the time 
output, the 1PPS would warp in phase, and the PLL would correct the phase error.

So, that's one way, but probably not a desirable way.  My interest was in the 
option of using the OCXO to create the time, which clearly gives a better 
option when the receiver syncs back up to the sats.  Is there a published 
standard for this, or is this something that everyone (except the newbie) knows 
so well that it's not worth discussing?


There is no standard, but a few basic ways to go about which seems 
reasonable and used by most is:


1) As you go into hold-over, keep producing PPS etc
2) As you leave hold-over, attempt to adjust the phase back.
3) If your system been in hold-over for a longer time, say that it 
reasonably deviates outside of +/- 10 us (or some other limit), alarm 
and turn output off


I have selected a somewhat more intricate setup in which you can set a 
re-assignment limit, so when the phase error is outside of that limit, 
you turn the output off, jumps the phase difference, and then starts to 
track in from there. The reason being that at some time deviation, the 
time it takes to track in the phase error is too large to be practical 
so turning of and jump has less impact.


Cheers,
Magnus


Bob
 -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

  From: Attila Kinali 
 To: Bob Stewart ; Discussion of precise time and frequency 
measurement 
 Sent: Tuesday, August 16, 2016 3:46 PM
 Subject: Re: [time-nuts] Holdover

On Tue, 16 Aug 2016 04:35:40 + (UTC)
Bob Stewart  wrote:


It's been pointed out to me that I didn't understand the function of
the 1PPS of a time standard.  I confess that somehow I had confused the
term to be timing standard; which would be an entirely different thing.
But, this is time-nuts, so I should have realized...
Anyway, is there a standard, or at least an accepted practice, for how
holdover is handled in a time standard?


There are many ways how to do that and which one you choose depends
on the application and its requirements. You can find everything between
"jump imediatly" and "just keep the frequency stable and don't care about
alignment".

Attila Kinali


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lady Heather

[John Miles]

> I am just starting out using Lady Heather.
> 
> I am trying to create a .cfg file to set the program to COM 3 at startup.
> 
> I created the file and saw the instructions to put it in my “Documents” 
> folder.
> The only documents folder in Windows is “My Documents.”
> 
> I created a text file and called it “Heather.cfg” and put it in the My 
> Documents
> folder, but it does not work.  I just put “/3” to change the COM port to COM 
> 3.
> 
> I also tried putting in the “Heather” program folder.

It works OK at this end.  But having just checked, I've noticed that things can 
get complicated if you want to use a config filename other than HEATHER.CFG, or 
if you want to put it in a directory other than the one Heather suggests in the 
'?' help dialog.  Heather allows you to specify a .cfg filename other than the 
default HEATHER.CFG with the /h= option, but if I run a command like:

"c:\program files (x86)\heather\heather" /h="my config file.cfg"

... it doesn't treat the quoted string as a valid pathname, even though it 
ought to.  So, there are at least two things to check if you're still having 
problems:

1) If you use a filename other than HEATHER.CFG, make sure your /h= argument 
doesn't contain any spaces.  Just use the filename itself, with no directory 
prefix.

2) Make sure the .cfg file goes in the directory that Heather suggests in the 
'?' help screen.  Again, it doesn't have to be called HEATHER.CFG (if you use 
the /h= option) but it does need to go into the directory where the program 
expects to find it, because there's currently no robust way to force it to read 
the file from another directory.

> Also, I have read and re-read the list of commands and don’t see any to change
> the display to show the “sky” view of the satellites, as is shown on the Lady
> Heather web page.

I see the line that turns it on "plot_signals = 4", but I'll be darned if I can 
see how the code gets there.  Mark?

-- john, KE5FX
Miles Design LLC


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Holdover

[Bob Stewart]

Hi Attila,
said "Ie you need to figure out what you want to do with those PPS, then figure 
out what the desired behaviour during hold-over and recovery is and from that 
you can design the frequency standard."
What is the most usual method for *time standards*?  I'm satisfied with how my 
unit works as a frequency standard.
Bob
 -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

  From: Attila Kinali 
 To: Bob Stewart  
Cc: Discussion of Precise Time and Frequency Measurement 
 Sent: Tuesday, August 16, 2016 4:37 PM
 Subject: Re: [time-nuts] Holdover
   
On Tue, 16 Aug 2016 21:31:17 + (UTC)
Bob Stewart  wrote:

> So, that's one way, but probably not a desirable way.  My interest was in 
> the option of using the OCXO to create the time, which clearly gives a 
> better option when the receiver syncs back up to the sats.  Is there a 
> published standard for this, or is this something that everyone (except the 
> newbie) knows so well that it's not worth discussing?

No, there is no standard[1]. A system like this is always tailored to
the consumer of the PPS pulses and its requirements. Ie you need to
figure out what you want to do with those PPS, then figure out what
the desired behaviour during hold-over and recovery is and from that
you can design the frequency standard.

            Attila Kinali 


[1] https://m.xkcd.com/927/

-- 
Malek's Law:
        Any simple idea will be worded in the most complicated way.

  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Holdover

[Bob Stewart]

Hi Attila,
In my unit, which is a frequency standard, I chose to tell the receiver to stop 
sending 1PPS pulses when it loses sync to the sats.  And since the 1PPS is no 
longer coming, the PLL does nothing and the DAC doesn't change.  (Let's avoid 
the question of aging correction for now.)  So, I'm wondering where to go and 
what to do if I want to get time from my unit.  Clearly I could just tell the 
receiver to continue to send 1PPS pulses and sync to those - marking the time 
as unreliable.  When the receiver synced back up, then it would warp the time 
output, the 1PPS would warp in phase, and the PLL would correct the phase 
error.  

So, that's one way, but probably not a desirable way.  My interest was in the 
option of using the OCXO to create the time, which clearly gives a better 
option when the receiver syncs back up to the sats.  Is there a published 
standard for this, or is this something that everyone (except the newbie) knows 
so well that it's not worth discussing?

Bob
 -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

  From: Attila Kinali 
 To: Bob Stewart ; Discussion of precise time and frequency 
measurement  
 Sent: Tuesday, August 16, 2016 3:46 PM
 Subject: Re: [time-nuts] Holdover
   
On Tue, 16 Aug 2016 04:35:40 + (UTC)
Bob Stewart  wrote:

> It's been pointed out to me that I didn't understand the function of
> the 1PPS of a time standard.  I confess that somehow I had confused the
> term to be timing standard; which would be an entirely different thing. 
> But, this is time-nuts, so I should have realized...
> Anyway, is there a standard, or at least an accepted practice, for how 
> holdover is handled in a time standard?  

There are many ways how to do that and which one you choose depends
on the application and its requirements. You can find everything between
"jump imediatly" and "just keep the frequency stable and don't care about
alignment".

                Attila Kinali

-- 
Malek's Law:
        Any simple idea will be worded in the most complicated way.

  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Holdover

[Attila Kinali]

On Tue, 16 Aug 2016 21:31:17 + (UTC)
Bob Stewart  wrote:

> So, that's one way, but probably not a desirable way.  My interest was in 
> the option of using the OCXO to create the time, which clearly gives a 
> better option when the receiver syncs back up to the sats.  Is there a 
> published standard for this, or is this something that everyone (except the 
> newbie) knows so well that it's not worth discussing?

No, there is no standard[1]. A system like this is always tailored to
the consumer of the PPS pulses and its requirements. Ie you need to
figure out what you want to do with those PPS, then figure out what
the desired behaviour during hold-over and recovery is and from that
you can design the frequency standard.

Attila Kinali 


[1] https://m.xkcd.com/927/

-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Holdover

[Attila Kinali]

On Tue, 16 Aug 2016 04:35:40 + (UTC)
Bob Stewart  wrote:

> It's been pointed out to me that I didn't understand the function of
> the 1PPS of a time standard.  I confess that somehow I had confused the
> term to be timing standard; which would be an entirely different thing. 
> But, this is time-nuts, so I should have realized...
> Anyway, is there a standard, or at least an accepted practice, for how 
> holdover is handled in a time standard?  

There are many ways how to do that and which one you choose depends
on the application and its requirements. You can find everything between
"jump imediatly" and "just keep the frequency stable and don't care about
alignment".

Attila Kinali

-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP 3010Axxxxx oscillator

[cdelect]

Perry, 
 
The 3010A prefix identifies that date it was made.
 
It should also have a 10811A marking.
 
The resistor value is for applications needing precise EFC.
 
Usually found in HP 5065A, 5061A, and 5061B.
 
If it also has a 60109 marking it has slightly better short term
stability at one Tau.
 
Specs are otherwise the same as any 10811A.
 
There is no outer oven!
 
Since the design is a complete departure from the original 105 oscillator
it makes sense they issued a  new part ID.
 
The 10811A started to go into the 105A and the 5061A and 5065A after the
105 style oscillator was discontinued.
 
Cheers,
 
Corby

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd

[Attila Kinali]

On Mon, 15 Aug 2016 16:57:27 -0400
Paul  wrote:

> Finally, these boxes are intended to be routers (hence the three network
> interfaces) not time-servers and unless you're irrevocably wedded to the
> miniPCIe in APU2 route there are probably better choices for time servers.

I disagree here. With the APU and its IRQ system you get already to
sub-us PPS time stamping (probably in the 10ns-100ns range).
This is way than good enough for a NTP server. It should be even good
enough for an PTP system, if normal network switches are used.

The advantage of the APU is that you have a standard PC, which simplifies
the use of software considerably. Of course, with an embedded system
you can get the PPS timestamping down to <10ns precision. But at an
several times larger software complexity, which you also have to build
yourself to a large extend.

Unless time-nuts levels of precision/accuracy are required, an APU
is good enough and an easy solution. If you go for time-nuts levels,
then I would question the use of ethernet long before I question
the hardware platform.

Attila Kinali
-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Mini ovens packaging

[Attila Kinali]

Hoi Guillermo,

On Mon, 15 Aug 2016 11:07:41 +
Guillermo Sobreviela Falces  wrote:

> -Temperature stability of 0.1ºC, what means temperature control 
> included.

As Bob already wrote, this value has little meaning without the temperature
range at which you want to operate the oven. From what you wrote, i guess
it will be some office environment or a place with relatively low temperature
swing? Then it should be easy to get to that level.


> -Inner cavity of 2cm x 2 cm x 1 cm.

That is nice and small. How much space do you have on the outside?
Does it need to fit into something else?

> -In addition to the connectors needed for the oven I need 3 pins 
> reserved for the system.

That's easy to acheive. Mechanically, the easiest construction would be
to use a PCB with cut-outs and put some CNC'ed aluminium case through
these cut-outs. The PCB then acts as mounting system and electrical connection.
The thermal conductance of a PCB (without copper) is moderately low.
Maximum temperature for standard PCB's is 80°C, for higher
temperatures you need special base material with higher Tg (at least 20°C
higher than the maximum expected temperature).


> -The system must be included into the oven via a chip socket, or 
> pasted inside with silver paint and wire bonded to the oven connections.

I do not get what you mean with this.

> -PCB compatible oven
> 
> I have been looking for a Peltier junction in order to reduce the oven
> temperature to 50ºC (Reducing the temperature is good for my system).
> But the temperature stability is a must and I am not sure of the precision
> level I can reach with a Peltier junction.

For a classical oven, the inner temperature is defined by the maximum ambient
temperature and the minimum required temperature delta. A minimal temperature
difference is needed to keep the loop stable.

Peltier elements have the nice advantage that you can cool directly and
thus are not bound by the temperature difference to ambient. But you need
to be aware that Peltier elements are not symmetric: They are much better
heating elements than cooling elements. This means that you need to design
your loop carefully to prevent oscillation.


> 
> Also, I have been designing a temperature detector based in a power divider
> using a resistor and a RTD that will trigger an OPAMP (comparator). This
> OPAMP will activate/deactivate a high power BJT or FET transistor that will
> warm the oven. In order to reduce the thermal inertia I thought to make an
> escalated temperature detector as the shown in the attached picture. The
> main idea is have a fast heating and reduce the warming current when the
> temperature is approaching the final equilibrium temperature (120ºC).

Instead of using a bang-bang controller as you have shown, it is better to
use a linear controller, that controls how much current is flowing
through the FET. This eliminates temperature cycling and current spikes
that may disturb your oscillator.

> 
> Another problem is related to the shell of the oven. It should be metallic
> in order to equilibrate the temperature, but, would it be interesting to use
> an external shell made of an isolator material in order to reduce thermal
> loses or will it difficult the thermal stability?

Depends. In theory, it's good to have the oven well isolated. But you need
some way to get the heat out of the oven. And this thermal resistance
must be low enough to keep the loop stable. You need to calculate the
thermal parameters for this. If you are not 100% confident with this,
start with an unisolated oven, see how it performs on a step response,
add isolation (can be something as simple as some pieces of cardboard),
tweak the loop parameters a bit and check the step response again.

> 
> After this discussion, would it be possible to buy a system that meet
> the characteristics described above? I am not sure about I would be able
> to design and test this system on time, but I need this kind of oven with
> this temperature stability as soon as possible (This is why I am looking for
> a commercial solution).

It is very unlikely that you will find an off the shelf system that does
what you need. But you can find a company to design you one. Most people
with a decent electrical engineering knowledge should be able to do so.
It is also relatively easy to do it yourself, if you are not out for optimal
performance over an wide range of temperature and are ready to measure
and tweak the system parameters a bit after production.

The simplest is probably to start with a PI controller, which are fairly
easy to keep stable and only have two knobs to turn. Use that as a basis
with some simple mechanical setup. That should get you already to the 0.1°C
in an office environment. 


Attila Kinali

-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.

Re: [time-nuts] Lady Heather

[Mark Sims]

If you start Lady Heather from a command line prompt, the cfg file should be in 
the directory you are in.  If you start it clicking on an icon or the start 
menu, it should be in your My Documents folder (which depends upon the OS 
version you are running).  You can find out for sure by typing ? on the 
keyboard.   Scroll down the bottom of the help screen and Lady Heather will 
tell you where to stick it []


For screen data, generally,   RED means something is wrong/not normal/not 
usable/not available/unexpected/could affect normal receiver operation etc,  
YELLOW means something is not quite right or optimum,  GREEN means it is 
normal.  White is used for data from the receiver or program configuration 
values.


Not all program configuration options are available from the command line.   
You can create a keyboard .SCRipt file which, when read,  will simulate 
keyboard typing.  You can specify a script file on the command line with the 
/r=xxx.scr command. Script files must have a ".scr" file name extension.


Also, not all configuration options are available directly from the keyboard 
menus.  You can set most command line only options with the "/" keyboard 
command.



From: Richard Mogford 
Sent: Tuesday, August 16, 2016 3:00 PM
To: hol...@hotmail.com
Subject: Lady Heather

Mark

I am a new user on Lady Heather (LH).  Thanks for creating it!

Is there a user manual that shows what the various types of data and color 
coding on the screen mean?

I am trying to switch LH to COM3.  I figured out how to do this using the 
shortcut, but wanted to try a .cfg file.

I put “/3” in a heather.cfg text file and tried it in the Heather directory and 
in My Documents.  So far, it does not seem to get read.

What am I doing wrong?

Richard
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.