On 03/17/2013 01:43 AM, Bob Camp wrote:
Hi
The 53132 is indeed a fine counter. It's got another flaw though - right at 10
MHz the resolution takes a dive. If you are doing time nut stuff, that may be a
significant issue.
The frequency averaging method can make use of the beating of the
Hi
Unless the PRS10 is very unusual in it's operation there are two things to
check early in the debug process:
1) Is the oven heating up to roughly the right temperature?
2) The lamp is lit by RF energy. If the oscillator / amplifier supplying the RF
isn't putting out as much as it should
Hi
If the gate time is fairly long, the notch in the resolution is quite narrow.
You don't have to be very far off of 10 MHz to go back to fairly high
resolution. Again, not a knock on this fine counter, just something to watch
out for.
Bob
On Mar 17, 2013, at 7:45 AM, Magnus Danielson
Hi Bob,
On 03/17/2013 02:08 PM, Bob Camp wrote:
Hi
If the gate time is fairly long, the notch in the resolution is quite narrow.
As expected. The gate-time controls the width of this notch.
You don't have to be very far off of 10 MHz to go back to fairly high
resolution. Again, not a
Volker,
The error I have seen was in the high xE-011's to the low xE-010's. the only
way around it was to turn on relative measurements, which then subtracted out
this error. That error makes the unit almost useless to me.
The factory told me as long as it is within specs they will ship it
Hi Said,
That equation looks similar in form to the specs for any counter. What
are the comparable equations for the 53132A or the 5370(A or B)?
Ed
On 3/17/2013 10:41 AM, Said Jackson wrote:
Volker,
The error I have seen was in the high xE-011's to the low xE-010's. the only
way around
Ed,
the calculation is the same, however the numbers are 100ps for 53132A
versus 350ps, and I have not seen an average systemic offset being displayed on
any of the 3x 53132A units I use, and I see one on the SR-620. That's why
I sent it into SRS for calibration, paid the $$$ and got it
On 3/17/2013 1:56 PM, Ed Palmer wrote:
On 3/17/2013 10:41 AM, Said Jackson wrote:
The acceptable specs are pretty crappy in tim-nuts terms: +/-350pico
* frequency with a 1s gate time. Thats straight from the user manual
and assuming no reference error. From the manual:
Frequency Accuracy:
±
My 2 cents and it is that. The FRS use a higher voltage say 24 V and on
ignition that drops back. I have also seen on time-nuts older systems that
actually use an ignition voltage to trigger the lamp.
But I agree that it sounds like the RF might be low. The bulb does need to
be heated to get to
Hi,
I just powered on my SR and looked for the offset, when the 10 MHz
reference is connected to the input (at a gate time of 1s without
further averaging). It shows an offset of 0 to 400uHz which should
represent a mean error of 2E-11, while the manual predicts an error of
about 1E-10 (as
thank you for fast responses. As I wrote in my posting, heating seems to
be ok as reported by the PRS10 diagnostic tools. I agree with Bob and
Paul: RF seems to degrade with warming up, but how can I test this.
Remember, lamp and oscillator of PRS10 are not!!! accessible during
operation and
Hi
I'd fashion a simple loop on the end of a coax and use it to sniff the RF in
the vicinity of the cell. You are after a relative measure, so simply knowing
if it drops with time or not should tell you which way to go in the
troubleshooting. Normally a spectrum analyzer is a good device to
Hi Volker,
there are some issues here, first the worst case frequency systematic
uncertainty is 100ps for the 53132A, not 350ps as on the SRS unit or 500ps as
you stated. So they are not the same, they are 3.5x different.
From the Agilent manual:
Systematic Uncertainty:
Agilent 53131A
On 03/17/2013 08:05 PM, saidj...@aol.com wrote:
Ed,
the calculation is the same, however the numbers are 100ps for 53132A
versus 350ps, and I have not seen an average systemic offset being displayed on
any of the 3x 53132A units I use, and I see one on the SR-620. That's why
I sent it into SRS
Would anyone on this list know the present status of tours at usno DC (for
may2013) with the present state of congress. I'll be in DC the first week
of May and would really like to see the lab and learn more about
astronomical and atomic timekeeping activities there.
Eric Fort
On 03/17/2013 10:47 PM, Eric Fort wrote:
Would anyone on this list know the present status of tours at usno DC (for
may2013) with the present state of congress. I'll be in DC the first week
of May and would really like to see the lab and learn more about
astronomical and atomic timekeeping
Hi
Be very careful of what the 53132(1) reports with the ref out connected to the
input. You are guaranteed to be in the dead zone on the counter when you do
that.
Bob
On Mar 17, 2013, at 5:33 PM, saidj...@aol.com wrote:
Hi Volker,
there are some issues here, first the worst case
Bob,
Thats why the 53132A counter reduces the resolution to one digit less at that
frequency, and why we use an external divide by 2 for 10MHz measurements to
regain that digit.
I wanted to be fair and compare apples to apples. If i use our 5Mhz input, the
53132A will be even better.
We are
Hi
This brings up the basic how bad is it question. Since the counter is
fundamentally a 200 ps gizmo, a simple period measurement at 1 second will give
you ~ 10 digits per second. That's with no magic multiple sample stuff at all.
At an offset / noise / what ever state where the multiple
I am afraid the PRS-10 lamp starting algorithm is a little involved. I
believe that once the lamp temperature is in the starting range, the
microprocessor ramps up the drain and possibly gate voltage of the heating
oscillator FET until the bulb strikes as evidenced by a DC signal at the
Hi
I'd bet that something is keeping the oscillator from putting out enough RF.
The circuit is simple enough that the issue is one of a very small number of
parts. I'd bet on the FET…..
Bob
On Mar 17, 2013, at 8:24 PM, brucekar...@aol.com wrote:
I am afraid the PRS-10 lamp starting
Hi Volcker, Bob,
I guess it depends on what one needs. The SR-620 is probably more of a gizmo to
play with when one likes to manually adjust things or needs the better time
interval resolution.
The HP unit is more of a fire-and-forget unit.
Me having the benefit to be able to chose, I would
On Sun, Mar 17, 2013 at 08:24:37PM -0400, brucekar...@aol.com wrote:
I am afraid the PRS-10 lamp starting algorithm is a little involved.
I believe that once the lamp temperature is in the starting
range, the microprocessor ramps up the drain and possibly gate
voltage of the heating
On 3/17/2013 4:54 PM, Volker Esper wrote:
The HP seems to be the more modern design. As I guess, the analog
circuits are to blame, maybe HP was able to make use of newer technologies.
FWIW, the 53132A design goes back 20 years
Rick
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