I had an early Phenom II that lost time while turned on but the
internal CMOS clock did not so rebooting or reading the CMOS clock
restored the correct time. There was a problem with the System
Management Mode code and The C1E CPU state which was new at that time
where an interrupt was being lost.
David,
The problem is that they start in sync and over the course of a day drift that
far apart despite having NTP running. We're not sure why NTP isn't correcting
it along the way. Though at this point, we are looking at a firmware bug.
Thanks!
Bob
On Oct 5, 2012, at 12:30 AM, "David J Taylor
The problem stems from one of the two (identical) machines drifting off by
60-70 seconds per day. So a few ms here and there are ok.
[]
Bob
==
Bob,
NTP is normally limited to a +/- 500 parts per million correction - 43
seconds per day. You may be operating outsi
David Taylor has all sorts of NTP monitoring scripts, software, and tips
at his web site. Start at
http://www.satsignal.eu/software/net.htm#NTPmonitor and look around.
Brent
Thanks for the mention, Brent. Two Windows-based programs:
Remote comparison
I bought a couple of 5071As on eBay recently, on the basis that the various
status messages shown in the auctions didn't look like tube failures. They
both reported Cs oven voltages at 0.0.
The first unit turned out to have a severe intermittent noise problem,
originating somewhere other than th
Hi
Doing the repetition may give you a more fine grained idea of what the clocks
are doing. It does not impact the resolution of the single measurement.
A single ns in 100,000 seconds is indeed 1.0x10^-14…
Bob
On Oct 4, 2012, at 6:11 PM, Azelio Boriani wrote:
> OK, because you think: (Y-X)/
Paul-
Same here! :- )
The best way is to find a REALLY dead
tube and cut it open and "see" if the EM
first and second dynodes are clean, or
covered in a film of Cs. Short of heating
the dynode to vaporize off the Cs and
let the ion pump collect it, I think it
becomes a giant physics project.
One r
OK, because you think: (Y-X)/100K is the drift of the two clocks for each
second over 100K seconds and for each second I have a 1nS/100K resolution.
Now think about this: repeat the measure over and over and after each 100K
seconds you have your table. This table (your counter is 1nS) can have
figu
I could not find any info on the Vectron Crystal Oscillator Model 224-5136,
48MHz so I decided to open one up and share what I have been able to figure out.
Currently I have two questions: supply voltage, and Adj voltage range?
There are seven solder lugs in a semi-circle, it looks like a mirror
Brian
Funny you mention the dirty emult. At the time I was wondering and if there
was any insane way to get the Cs off the e multiplier. HV to ground or
something to migrate them.
Hold upside down and shake hard. ;-)
Regards
Paul
On Thu, Oct 4, 2012 at 4:22 PM, Brian, WA1ZMS wrote:
> Rick can co
Thank you very much, Giovanni. I'm forwarding this informal quote to a
group, trust this is OK to do. Very reasonable!
Thanks again
Don
GIOVANNI D'ANDREA
>
>
> Hi Don,
>
>
>
> Sorry about the delay,
>
>
>
> 1. PN: 1009302 LC_XO GPSDO W/TCXO $355.00
>
>
>
> If you need a formal quote please s
Hi,
Cs depletion in modern tubes is a real failure mode!
However some competing modes are:
Ion pump failure (whiskers or high impedance shorts)
High Cs backround level (Gettering saturation)
Oven or ionizer filament failure (More common on older HP units with the
AC excitation, (think of those n
Rick can correct me on this...
but my understanding is that it is
almost never a case of running out
of Cs from the oven, but that the
dynodes of the electron multiplier
become covered in used Cs and so
the ultimate SNR and effective beam
current falls to a point where there is
no dependable beam c
See also this posting by Dave Carlson (ex hp):
http://www.febo.com/pipermail/time-nuts/2005-May/018354.html
/tvb
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Hi
If I have two clocks:
1) I know they are X ns apart at time = 0
2) I know they are Y ns apart at time = 100,000 seconds
3) The resolution of the X and Y measurements is 1 ns
I know the relative time between the two clocks to a lot better than
5.0x10^10...
Bob
-Original Message-
From
Hi Rick,
What I've read or heard is that high-perf 5071 tubes last about 7 years (and
then run out of cesium). However, the standard-perf tubes last much longer,
maybe 20 years or more (and eventually fail for reasons other than ovens). But
there have been different generations of tubes so I'm
I've read that the 5071A has an almost indefinite tube life. However, the
'high stability' option only has a 9 year life. What happens after 9 years?
The tube stops working, or it degrades to the normal tube performance?
Tom WB6UZZ
Sent from my HTC Inspire™ 4G on AT&T
- Reply message --
If you take 2 samples out of a 1nS counter than you can estimate your
measure with a 500pS resolution (5E-10) with an uncertainty (noise) of
7E-10.
On Thu, Oct 4, 2012 at 8:58 PM, Bob Camp wrote:
> Hi
>
> What if I only take two single measurements:
>
> One at time = 0, the other at time = 100,0
Rick
Well I have the old 5060 and 61 tubes and indeed they run out O gas.
I am using a 5060 tube in a 5061 and the Frankenstein works though it has
only a few Cs. But heck it all locks after 48 hours.
So someone said with humor lets buy some 5071 tubes for a couple hundred
each.
Guess I could have
These ideas are "interesting". AFAIK, there is very little
chance of running out of Cs in many years, long past the
time when something else in the tube will have reached its
end of life. Where did this idea come from? Certainly, not
anyone working at HP, Agilent or Symmetricom. A LONG time
ag
We really need a group buy of 5071A tubes for a couple hundred each.
Thomas Knox
> Date: Thu, 4 Oct 2012 15:10:11 -0400
> From: paulsw...@gmail.com
> To: time-nuts@febo.com
> Subject: Re: [time-nuts] 5071A Cs Oven
>
> Learn something every day here. How to really extend the old dead C life a
Learn something every day here. How to really extend the old dead C life a
bit longer.
On Thu, Oct 4, 2012 at 3:04 PM, Richard (Rick) Karlquist <
rich...@karlquist.com> wrote:
>
>
> On 10/4/2012 9:45 AM, Tom Van Baak wrote:
>
>> Bob,
>>
>> Right, not good. There should be a fault message associat
On 10/4/2012 9:45 AM, Tom Van Baak wrote:
Bob,
Right, not good. There should be a fault message associated with it. Check the
internal log.
OTOH, to conserve cesium, I've heard that some people run 5071A in standby mode
most of the time and only turn on the cesium for a fraction of an hour
Hi
What if I only take two single measurements:
One at time = 0, the other at time = 100,000 seconds.
No averaging, no signal processing just two measurements. I look at the time
difference between the two signals at time = 0, and then again a bit more
than a day later.
Bob
-Original Mes
You're right: it is better to put it down correctly:
for a theoretical resolution of 10E-14@100K seconds, start with a 1nS
counter that takes 1 second samples for 100K seconds and average those 100K
samples. You have your resolution and a noise (an error bar) of 3E-12. If
you use a 100pS counter an
Hi
This is one that's been close at hand for the last 15 years or so
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Stan
Sent: Thursday, October 04, 2012 1:58 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] 5071A Cs Oven
I
If this is the 5071A on that online auction site, I found out from the
seller that the error log shows "Cs oven timeout."
This might be because of a bad oven supply (expensive) or a bad tube (really
expensive)!
Stan
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-bo
On Thu, Oct 4, 2012 at 1:31 PM, Attila Kinali wrote:
> On Thu, 4 Oct 2012 13:04:27 -0400
> Bob Bownes wrote:
>
> > The problem stems from one of the two (identical) machines drifting off
> by
> > 60-70 seconds per day. So a few ms here and there are ok.
>
> Is it drifting without ntp or with ntp
David Taylor has all sorts of NTP monitoring scripts, software, and tips
at his web site. Start at
http://www.satsignal.eu/software/net.htm#NTPmonitor and look around.
Brent
On 10/4/2012 8:44 AM, bownes wrote:
It had to happen eventually. Time Nut interest overlapped with $DAY_JOB.
Due to r
On Thu, 4 Oct 2012 13:04:27 -0400
Bob Bownes wrote:
> The problem stems from one of the two (identical) machines drifting off by
> 60-70 seconds per day. So a few ms here and there are ok.
Is it drifting without ntp or with ntp?
1minute drift per day is not unheard of for standard PC RTCs.. i've
On Thu, Oct 4, 2012 at 12:46 PM, Hal Murray wrote:
>
> bow...@gmail.com said:
> > Due to reasons I really can't go into, a systems user is concerned with
> the
> > displacement of two servers from the same pair of stratum 2 NTP servers.
>
>
> Assuming you are running the standard ntpd... It i
Hi
The associated log entries are:
"Ion pump over current"
"Cs oven failed"
Not encouraging...
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: Thursday, October 04, 2012 12:45 PM
To: Discussion of precise time
On Thu, 04 Oct 2012 09:46:38 -0700
Hal Murray wrote:
> If you assume the network transit times are equal, you can compute the clock
> offset. If you are on a LAN, the transit times will probably be tiny on the
> scale of 10s of ms.
Within a LAN, RTT is usually in the range of 200us with a jit
bow...@gmail.com said:
> Due to reasons I really can't go into, a systems user is concerned with the
> displacement of two servers from the same pair of stratum 2 NTP servers.
> I'm convinced that it really isn an issue as long as the two systems in
> question remain within a few 10's of ms. How
Bob,
Right, not good. There should be a fault message associated with it. Check the
internal log.
OTOH, to conserve cesium, I've heard that some people run 5071A in standby mode
most of the time and only turn on the cesium for a fraction of an hour a day or
a week (to recal the quartz). Runnin
Hi
Maybe we're talking about two different things here.
Simplistically, resolution is simply what the counter puts out as a usable
LSB. There are a lot of examples out there that will do a one nanosecond
single shot measurement. That measurement includes the normal trigger noise
and "stuff" in t
Yes, for a theoretical resolution of 10E-14@100K sec start with a 1nS and
average for 100K seconds but ending up with a noise (an error bar) of 3E-12.
On Thu, Oct 4, 2012 at 4:25 PM, Bob Camp wrote:
> Hi
>
> For a *resolution* of 1.0 x 10^-14 at 1.0 x 10^5 seconds I only need a 1.0
> x
> 10^-9 s
On Thu, 4 Oct 2012 10:44:41 -0400
bownes wrote:
> I'm convinced that it really isn an issue as long as the two systems in
> question remain within a few 10's of ms. However, I have no off the shelf
> method of collecting and correlating the data. Before I go out and invent
> the wheel, I thought
Just sold. It was not me: they was shipping USA-only. Very interesting
price, anyway they are just gone.
On Thu, Oct 4, 2012 at 4:05 PM, Pete Lancashire wrote:
> on that big internet auction site
>
> i don't know by who etc, etc.
>
> -pete
>
> ___
> tim
Hi
Is "Cs oven: 0.0V" a good thing on a 5071A?
I suspect not, since either it or GPS is off frequency.
Bob
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Bob, check http://www.febo.com/pages/plots/ntp and see if the graphs
there would provide the info you need. They're based on using one NTP
server to monitor the offset of a number of other services and plotting
the results over time. If so, I'm happy to make the (*nix-based)
scripts available
It had to happen eventually. Time Nut interest overlapped with $DAY_JOB.
Due to reasons I really can't go into, a systems user is concerned with the
displacement of two servers from the same pair of stratum 2 NTP servers.
I'm convinced that it really isn an issue as long as the two systems i
Hi
For a *resolution* of 1.0 x 10^-14 at 1.0 x 10^5 seconds I only need a 1.0 x
10^-9 second reading out of the counter. Indeed, 5 or 10X more than that
would be better if I was after a 1 x 10^-14 accuracy.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun..
Hi
But I don't *have* to take data only at one second points for a one second
ADEV. I can take data faster and then process it. That's what the counter
does in frequency mode. I can do the same thing with time readings.
The big advantage there is that with higher speed time readings, I can
contro
on that big internet auction site
i don't know by who etc, etc.
-pete
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OK, and then what about measurements beyond 1000 sec (for the same DUT's
ADEV in the 1E-13's) taken with a 500pS counter and a 50pS counter? Nice to
hear that there is exactly no difference, just use average...
On Thu, Oct 4, 2012 at 2:34 PM, Adrian wrote:
> Azelio,
>
> as an example, with a 531
Azelio,
as an example, with a 53131A you have an output 'granularity' of +/- 500
ps.
No matter how much averaging happens inside the counter, if the least
significant digit is 500 ps, then the (ADEV) measurement limit is always
5E-10 at 1 sec as I posted in the initial post to this thread. Thi
Taking 10 samples from a 1nS counter leads you to a 100pS resolution but
the noise at best (if it is really random) is reduced by SQRT(10). So, as
already pointed out here, there is no real substitute for lower noise,
higher resolution measurements.
On Thu, Oct 4, 2012 at 3:01 AM, Bob Camp wrote:
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