on their usage, but it should be easy enough.
I will check what I have...
Il 2013-05-24 14:06 Ziggy9 ha scritto:
A few months ago Fabio Eboli posted some Python functions that might
be useful. I haven't used or tested them myself, but they might be of
interest. Still up on pastebin at
http
this helps.
I'm sorry I cannot keep working with Rb,
(busy looking for new job now, no luck
so far...) but if there are any questions
I will try to answer as far as I can :)
Ciao!
Il 2013-05-24 14:06 Ziggy9 ha scritto:
A few months ago Fabio Eboli posted some Python functions that might
be useful
Hello, interesting discussion about noise.
It's all way over my knowledge, so my contribution
to discussion maybe is only noise :)
Re batteries I agree with Mark, see below:
Il 2013-01-31 06:42 Mark Sims ha scritto:
A123 20Ah LiFePO4 cells have an internal resistance in the milliohm
range.
Sorry, Poul-Henning Kamp, I answered directly
to your mail address, I repost it here...
Il 2013-02-01 18:09 Poul-Henning Kamp ha scritto:
Content-Type: text/plain; charset=ISO-8859-1
In message 2bf4f4e8c8207ae0f94a7e1a1e63c...@quipo.it, Fabio Eboli
writes:
Il 2013-01-31 06:42 Mark
Il 2013-01-26 14:58 Bob Camp ha scritto:
Hi
Platinum RTD's are a pretty good bet for -80C, they hold up well down
there. For calibration, ammonia and acetylene both have triple points
in the vicinity. I'd probably try ammonia first, but not for any good
Doesn't acetylene have a bad habit of
Hi
As with the one kg resonator, you need to mount the bar *somehow*.
The idea is generally to suspend the resonator at a point that
least affects the resonance (a dead spot). With a large bar, making
it manually adjustable is practical. Not so much with a smaller part.
Bob
Il 2013-01-23
Il 2013-01-23 13:39 Bob Camp ha scritto:
the mode that the bar is resonating in, it's a bit hard to guess
where
the nodes will be. Just looking at the bar, you wouldn't *guess* that
the end points would be nodes...
Bob
Sorry Bob I didnt understand last part.
You say that the end faces are
Il 2013-01-22 23:19 Tom Van Baak (lab) ha scritto:
Yes, Don, those old quartz bars are rare and amazing:
http://leapsecond.com/museum/gr676b-50kc/
http://leapsecond.com/museum/gr1190a/
What is the function of the (metal?) disc
plates near the two ends of the rods?
Their position seem to be
Il 2013-01-14 22:15 Charles P. Steinmetz ha scritto:
Because the oscillators are sealed assemblies, I'm not aware of
anyone who has taken one apart for analysis -- so the reason for this
behavior must be considered unknown until we know what is going on
inside.
By the way, there is a non
Robert,
I asked the seller for the least expensive way to
send that OCXO here (nothing to lose on a marginal
packaging, let's assume the item is non working)
and he quoted 12USD. I think I must refrain
from spending 20USD (assuming I will be the only
bidder) for a device to be dissected, althoug
Il 2013-01-15 15:31 David C. Partridge ha scritto:
Yes the 1992 4E adjustment is a bear. Mine behaves pretty much the
same, ISTR it took me a few days to get it adjusted to my
satisfaction
and it was still drifting a bit.
The strange thing is that mine now is changing frequency at
more than
Hello,
recently I tried to trim the Racal Dana
1992 04E internal reference, using the
GPS pps as a reference. I'd like to ask
a pair of questions...
- First is about the method.
I'm using the counter TI to measure it's
own OCXO. The GPS is starting the count,
the internal reference 10MHz (on the
I answer here to all, thank Ed David and Charles for your thoughts.
David, LOL, you posted the pic of the exact counter in question.
Not a similar unit, I mean it's exactly *that* 1992 that is being
measured ;)
The pictures on eevblog show the early measurements I made with
the counter. One of
Il 2013-01-15 00:08 Fabio Eboli ha scritto:
Trying to be more clear:
10MHz period error (vs. GPS) changed from -0.8x10^-10 soon after
the trim, to +1x10^-10 after two days (top right).
Top right is change of phase in time, i.e. period error
measured using GPS as reference.
The OCXO period
Hello,
I've read about undocumented FE5680A commands
(On excellent Didier' FE5680 FAQ page).
This python script is a collection of the
functions I'm using to connect to FE5680:
http://pastebin.com/VpZVuw0t
And I will add to it more functions based
on these new fields.
I'd like to know if
for now.
Fabio.
Il 2012-12-31 16:45 Fabio Eboli ha scritto:
Positive update, in the broken unit
the pin 10 goes to power module input,
while the pin 8 goes to power module
ground, and there is grounded.
I powered the good unit and
it locked in few minutes, wothout driving
the EFC, the frequency seem
Hello, in the last day of this ugly year
I received a pair of FE5682A.
The two have visibly different tags,
probably are from differen age, and
one has the word FAIL written on
it. The pinut is similar to LPRO-101
see:
http://www.febo.com/pipermail/time-nuts/2012-November/071937.html
but the
By the way, about the psu the unit contains this module:
http://www.farnell.com/datasheets/14431.pdf
so probably internally it works at 12V.
Fabio.
Il 2012-12-31 14:44 Fabio Eboli ha scritto:
Hello, in the last day of this ugly year
I received a pair of FE5682A
up...
Fabio.
Il 2012-12-31 14:46 Fabio Eboli ha scritto:
By the way, about the psu the unit contains this module:
http://www.farnell.com/datasheets/14431.pdf
so probably internally it works at 12V.
Fabio.
Il 2012-12-31 14:44 Fabio Eboli ha scritto:
Hello, in the last day of this ugly year
I
:) is not to be blamed
too much, I mounted it raised from the PCB,
and the only thermal contact were the few
pins used to connect to it, and it was
exposed to moving air.
But usually it will be sodered directly
on the PCB like an SMT component, and
enclosed into a box.
Il 2012-12-28 23:27 Fabio Eboli ha
http://ieeexplore.ieee.org/xpl/login.jsp?tp=arnumber=4030739url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739
http://ieeexplore.ieee.org/xpl/login.jsp?tp=arnumber=4030739url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4030739
is one of the
Il 2012-12-28 21:43 Magnus Danielson ha scritto:
The bucket statistic method is very simple.
You divide a scale into a suitable set of ranges, equally wide. The
you count how many hits you get within each of those ranges or
buckets.
By the way, since I've seen some contributors
that are from
Hello
How could I test the time to analog converter
we talked few posts ago?
Something that can be done with things I have
or can easily find.
I was thinking that would be nice to try to
feed it with signals similar to the real ones,
but that can be controlled: PPS + 10MHz reference,
without
lines.
Bruce
Bob Camp wrote:
Hi
The statistical fill approach is a cute way to go. The gotcha comes
in when you have a structure that *may* not be monotonic.
Bob
On Dec 28, 2012, at 1:04 PM, Bruce
Griffithsbruce.griffi...@xtra.co.nz wrote:
Fabio Eboli wrote:
Hello
How could I test
Little update about the PA6H GPS.
I was having problems with periodic abrutp change in drift.
I didnt like the psu of the Rb, so modifed them and started
logging temperature and voltages.
Now I have some early evidence of the suspect: the GPS receiver
seem upset by rapid changes in temperature.
Like I mentioned in a precedent message
(answering Magnus) I'm seeing some temp
effects on my GPS module, see this message:
http://www.febo.com/pipermail/time-nuts/2012-December/073310.html
In this graph there are the FE5680 voltages
and temperatures, and the temperature sensed
on the PCB near
Hello, hope you all had a happy Christmas.
Back to the topic.
Bob Camp asked:
Hi
One very simple question - how good would it do if you just did it all
with logic gates? Tri-state buffers and things like that….
Now that you are up to a 100 to 200 ns long pulse, a lot of the fiddly
stuff about
Il 2012-12-23 11:36 Bruce Griffiths ha scritto:
The simulation indicates that the TAC capacitor charging current is
far from constant whilst charging.
This is due to the use of saturated switches rather than current
steering switches.
The capacitor charging current is poorly controlled.
So in
Il 2012-12-23 07:42 Bruce Griffiths ha scritto:
The classic TAC using current mode switching is similar to the
attached circuit schematic.
Bruce I tried to replicate the circuit
you attached, the pic was low resolution
so I tried to figure the values.
This is the circuit asc text
When it comes to phase, your interpolator may also be sensitive.
Dont know if I was clear enough, just in case I wasnt able
to explain well before: the data I collected didnt came from
the analog interpolator, but from the OutD that is a digital
out. The interpolator is still in it's infancy.
Hello, Bruce
Using saturated transistors as switches in the current source and
elsewhere isn't conducive to fast switching.
The traditional arrangement using current mode switches is much
faster and more predictable.
This is something I'd like to understand better.
I'm referring to this
, Bob Camp li...@rtty.us wrote:
Hi
Ok, those plots look much more real. Thanks for sharing.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Fabio Eboli
Sent: Thursday, December 13, 2012 7:58 AM
To: time-nuts@febo.com
Subject: Re
Bob, timenutters
here are the first results, hope
I'm not boring the members with these
posts, for most participants these
are basic things.
Now I'm trying to understand if the
setup is working or I have to modify
some things.
The logging is at 47000 samples and going,
the script is working well
Racal 1992 GPIB, to Chuck Forsberg:
thank you, I will go to see your work.
A little update, after about 20 hours this
is the logging situation:
http://www.flickr.com/photos/14336723@N08/8267828444/
Not bad, seem the GPS chipset jitter claim
of 10nS is real, what do you think.
Could this unit be
Bob Camp li...@rtty.us ha scritto:
Hi
20 hours should be 20*60*60 = 72000 samples. The graphs appear to show about
17,000 samples.
Hello Bob,
unfortunately I'm not logging all the pps
samples, I'm picking one sample every about
4 pulses, because I'm triggering the counter
and waiting 4s
Bob Camp li...@rtty.us ha scritto:
Hi
Ok, so the data is already decimated and it does show a 20 hour period.
Yes
The way I'm reading things - the pps's start out at zero offset on the left
side (yellow line at about sample 350). They still are at roughly zero
offset on the right side (at
Bob Camp li...@rtty.us ha scritto:
Hi
If you are driving the counter's frequency standard input with the FE5680
and simply measuring the period of the GPS output, then the data would make
sense.
Bob, the data make sense :)
I'm using the FE5680 as ext standard for
the counter, the pps is
Thanks Bob, the next logging session will
be setup as per your suggestion.
Now I'm logging with the counter
in time interval, Rb 1 is the start,
GPS is the stop and Rb2 is the ext
reference. The pulses are 670mS apart now.
Fabio.
Bob Camp li...@rtty.us ha scritto:
Hi
Yes, I would run the
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
Michael Tharp g...@partiallystapled.com ha scritto:
On 12/6/2012 4:26 AM, Fabio Eboli wrote:
Are you using the pll to obtain 72MHz (x9) for the clock?
Yes, the crystal oscillator is multiplied up to 72MHz which then
drives the timer. Even though the particular timer peripheral I
chose
Bob Camp li...@rtty.us ha scritto:
Hi
I believe your second counter (the one that starts on one edge and
stops on the other) will have trouble. It is unlikely you will get
your 14 ns resolution out of it.
Are you thinking to sync logic inside the device or
other problems? (not
Fabio Eboli fabi...@quipo.it ha scritto:
Bob Camp li...@rtty.us ha scritto:
The analog TDC is a fine idea. Cheap, easy,
Easy for many, not for me. This is why
I like the idea to play with the TAC, I have very
Here I'm using TAC and TDC for the same meaning...
little experience
Hello Michael!
Michael Tharp g...@partiallystapled.com ha scritto:
On 12/05/2012 08:03 AM, Fabio Eboli wrote:
I'm seriously thinking to attempt a gpsdo.
...
The platform I will try to use is the STM32F103
microcontroller
Coincidentally, my previous time-nut project was built around
Hello, I've written few messages on this mailing
list, I'm an absolute beginner on timing science.
I've never introduced myself, so this is a sort
of introduction...
Although this has nothing to do with
arduino, reading the post by Chris Albertson
about an arduino-based GPSDO, I will share
what
-nuts@febo.com time-nuts@febo.com
Subject: Re: [time-nuts] time-nuts Digest, Vol 100, Issue 95
Message-ID: 7c466c42-c05a-46e2-b3c4-793672874...@tiete.org
Content-Type: text/plain; charset=us-ascii
About:
{
Date: Thu, 22 Nov 2012 22:26:24 +0100
From: Fabio Eboli fabi...@quipo.it
To: time-nuts
From: Fabio Eboli fabi...@quipo.it
To: time-nuts@febo.com
Subject: [time-nuts] MT3339 chipset in Globaltop's FGPMMOPA6H
Message-ID: 2012112624.71854hb9oslin...@webmail.micso.net
Content-Type: text/plain; charset=ISO-8859-1; DelSp=Yes;
format=flowed
Hello, while asking info about the FE5682
Ziggy Bob and paul, I'll open it up and
check. I have a pair of lab psu to test
the unit and a pair of FE5680 to compare
the timing. Thank you all for the useful
info.
Fabio.
This message was sent using IMP, the Internet Messaging
Hello, while asking info about the FE5682,
I realized that for another project
(model plane data logging) I will buy
some cheap gps modules built around an
MT3339 chipset.
In my mind somewhere I stored the fact
that in the datasheet of these module
is mentioned the pps output, so I checked
and
I hope so, the 5680 takes approx 22W on startup,
if it is the same on the 5682 that shuld be less than 1/2A
Fabio.
Hi
At 48 volts I would expect the startup to be well below an amp...
Bob
On Nov 22, 2012, at 12:51 PM, paul swed paulswedb at gmail.com wrote:
Good luck and
.
Fabio.
P.S. Sorry for non-threading mails, probably I'll have the issue
sorted with the next messages.
In my opinion, you should read about GPSDOs anyway. The availability of a
precise PPS or not, should not prevent you from increasing your knowledge.
On Thu, Nov 22, 2012 at 10:26 PM, Fabio Eboli
Hello,
I have a pair of FE-5682A coming,
not that I need them, but I had flat
shipping from the seller freakyflickers
on ebay fro another item, I was asked 14USD each.
I'm a bit confused by the pinout on
the datasheet:
http://www.ko4bb.com/Manuals/05)_GPS_Timing/FEI/FE-5682A_Datasheet_REVB.pdf
Thank you, Peter and Paul.
Now I see that the pinout is almost identical
to LPRO-101, the only difference are pins
8 and 10 for power supply.
That's nice, I like the external C-Field control,
and monitor voltage for lamp, they can be useful.
I'm not familiar with telco power supplies,
I know
Hello, this is my first message on this list,
I've read the recent thread about racal dana's switches,
this is the way i've done it:
http://imageshack.us/photo/my-images/194/pulsantenuovo1r.jpg/
in this thread more details:
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