[time-nuts] My HP 5370B reads 6 nS out!

Pete, you do not specify, whether you use FREQ or T.I. when you use the averaging function. First of all, its OCXO can be adjusted to a few parts in 1e-9 only, as the trimmer is too unprecise. If the OCXO is running for several weeks already (idle state), its drift may be as low as a few par

[time-nuts] HP 10544A Repair

Hello Nigel , I already have done a similar repair on a 10811, described here: https://www.febo.com/pipermail/time-nuts/2012-January/062228.html A comparison of the 10811 manual, p. 8-16 and schematic, let me strongly assume, that the 10544 has exactly the same type of NTC inside. This NTC a

[time-nuts] OT, looking for a good science forum

Hello Chris, I don*t know a good scientific forum, either. But I would also be interested, at least to have some ideas, what to do try out with those high precision gadgets, I have collected already ;-) For the question about low temperature measurements, I recommend sensors following a stan

[time-nuts] Typical HP 5370B resolution ?

Mark, The jitter is always around 35ps, typ. I think, you won't change anything on the latter parameter by re alignment, because it's given mainly by the jitter of the Time Interpolators and the zero crossing detectors. The alignment procedure mainly calibrates the absolute T.I. accuracy to

[time-nuts] HP3325B frequency jitter specification

Hello, I purchased an early vintage HP3325B synthesizer generator, from about 1988. Unit is working all right, as I were checking most of the verification items. I have locked the HP3325B to my HP5370B OCXO, and measured the stability of the synthesized frequency with the same 5370B. I recog

[time-nuts] Yb clock - NPR Story on Atomic Clocks

Wow, this new type of clock is not even 100 times more longterm stable than the Cs fountain clock, it's even short-term stable as a H-maser, obviously. In the NIST article: http://www.nist.gov/pml/div688/clock-082213.cfm it's told, that the 1s instability is the same as the 400,000 sec or 5 d

[time-nuts] Yb clock Allan deviation

Hi, Andrew Ludlow himself was so kind to send me the Sciencexpress article, just a few minutes ago.. A pity that I can't post it here (2.2MB). The Allan deviation is nearly linear, following roughly a 3.2E-16/sqrt(tau) equation (calculated for a single clock). At tau = 1 sec, the instability

[time-nuts] Yb clock - stability estimation procedure?

Hello time-nuts, The NIST paper describes the estimation of the stability of one Yb clock by simply comparing two equivalent clocks, and dividing by sqrt(2). This is obviously a common Metrological Practise, every time if "something better" is not existent or not available. This practise can

[time-nuts] Getting a 5370A tomorrow - How do i test it works

Bingo, welcome on time-nuts, also! Follow the manual, the first basic test is simply connecting the reference output on the rear to the input and measuring frequency and T.I. This lets you test function and base noise level (35ps)hat. If this test passess, the machine is running well in fir

[time-nuts] Trouble with Timelab and HP-5370B

Paul, the last two weeks, I made measurements with Timelab, updated to the latest version, to acquire data with my HP5370B. I have a standard NI GPIB card in one slot of my PC, i.e. no converter card. Everything is still working fine, as before with the old Timelab version. So I suggest, that

[time-nuts] time poetry slam @ NIST

There's a really nice time-rap or time-poetry slam on NIST, which I want to bring to your attention: https://www.youtube.com/watch?v=e5VdQ1JCVHI&t=0s regards Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.fe

[time-nuts] HP 5335A Question

  >The gate time on a 5335 can be set via GPIB. It can be set to some *very* long gates (well past 100 seconds). >When you do this, the data reported on GPIB does “stretch” to cover the added >digits. The problem is that there >are internal register overflows. The designers did not antici

[time-nuts] Agilent 53230A Counter

Hello, Does anybody know details about the time interpolator in the 53230A? I did not find service manuals online containing the 'Theory of Operation'. The 5370 interpolator obviously was well-respected for its high linearity and low jitter, based upon the dual-vernier digital interpolator,

[time-nuts] Primary Time Standards

Hi, I think, the correct definition for a "Primary (Time) Standard" is not yet given here, yet. And I wonder, if there really exists an official definition, in form of a norm / a standard by BIPM. There should be one, does anybody know? I try to give some characteristics which have to be ful

[time-nuts] 5370 firmware hacking status report

Hi, the 5370 is capable of measuring up to 10s long time events or frequency/period with 10s gate time. (I.e. 2^39 * 19.53ps) Pressing 'external holdoff' activates external gating on 'EXT' input. Then you may apply a 10s long positive pulse from an external generator, with a few ms long paus

[time-nuts] 5370B airflow

Hi, The perforated sheet belongs to the left, seen from front of instrument. Frank ___ 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] HP10811-60111 oven failure + repair

Hello Achim, nice pictures, how to access the thermal fuse, thankys for sharing. Sorry to say, but a poly-/multifuse is the totally wrong component for this purpose. It will neither help on overcurrent, nor on overheating. The trip current (where MF opens) will be ca. 3A @ 23°C, and ca. 1.5A

[time-nuts] HP 3420B calibration assistance

Hi Dick, I'm sure, I met the 3420B long time ago..that's a nice unit,.. but I do not have the schematics of the 3420B at hand, also did not find them on the agilent site, only the HP catalogue from 1970. The instrument - as far as I remember - compares the input voltage directly against 0-10

[time-nuts] HP 3420B..

Sorry, this post went to wrong mailing list. Frank ___ 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 5335A Option 040

Hi, there exist three manuals, 5335-90005 - Serial #2024A and below, 1980, preliminary pdf manual on agilent.com 5335-90021 - Serial #2224A and below, 1983, pdf from Artekmedia, very good scan for $7.50 5335-90044 - Serial #3154A and below, 1994, very good reprint from manualsplus for about 70

[time-nuts] Faulty GPS SAT # 16 on Lady Heather

Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that s

[time-nuts] LCD monitor for TBolt

Dick, I also ordered an LCD monitor from fluke.l (beneath an LPRO Rubidium). For Lady Heather, do I have to add a switch between the monitor and the PC, or does the monitor have an additional RS232 port to feed through the PC communication automatically? Frank __

[time-nuts] My old new 53132A just arrived

Bonsoir Loïc, and congratulations for your new, nice device. You should order the T.Bolt from fluke.l on e...y, standard easy kit with power supply and antenna, just working fine, The LCD monitor is also quite handy. You may also order an LPRO 101 Rb standard from him, so you have always a ver

[time-nuts] VRefs - I'm a bigger Voltnut than a timenut..

h and improve the system, and to do the repair on an old 332B standard, but would like to share my knowledge, if anyone's interested. Frank Stellmach ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-b

Re: [time-nuts] VRefs - I'm a bigger Voltnut than a timenut..

@Bill Ezell: Well, I have the same motivation to invest time and money into "precision". I started with metrology working in a German Airforce cal lab in 1980. We had all that goddie equipment, ie. a bank of Weston standard cells, the Fluke cal system, DCF receiver, a HP caesium standard, and s

Re: [time-nuts] Some pics of the Datron 491x DC reference cell

side of the ref board. Would be great to get a photo also from that side, as Datron made some efforts to get rid of strain and heat conduction effects. Best regards - Frank Stellmach ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

Re: [time-nuts] Some pics of the Datron 491x DC reference cell

Bruce, good hint, I think you are right.. Then it's a custom specific R array, metal foil technolgy (S105 or similar) from Vishay, perhaps oil filled. Makes it very difficult to read the circuitry and design a replacement with discrete resistors. Frank ___

Re: [time-nuts] Some pics of the Datron 491x DC reference cell

> NB use the latest datasheet which has a corrected schematic showing the > location and polarity of the parasitic diodes. > Bruce Thank you, I already got that... When I used the first datasheet, I reversed the heater as there was no hint, just to discover those hidden parasitic diodes. I ob

[time-nuts] OT: Basics of voltage calibration?

Resistor, Ten Fold Improvement in Tempertaure Coefficient", Reuven Goldstein et.al. Brian Kirby already summed up the other most important sources. Frank Stellmach ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.

[time-nuts] OT: Basics of voltage calibration? Fluke manuals

Chuck, try '341A', this manual covers the 343A also. (different beta string only) I've got the 5100, 5205, 5215 manuals from their site, perhaps something comes close to your 5200. Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe

[time-nuts] OT: Basics of voltage calibration? Fluke manual 5200A

Chuck, I just have found the 5200A manual & addendum here: http://us.fluke.com/usen/support/manuals/default.htm?prodcategory=OBS The others I mentioned are the power amps only. Fluke still scans on, so look for other manuals later. Frank ___ time-n

[time-nuts] New request for HP 3458A info

valid. If 7V ref constant is corrupted or out of range, a basic calibration might help. Btw.: Any clue about the history of your instrument? Best regards - Frank Stellmach ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https

[time-nuts] 3458A info

Dick, did you already try an ACAL DCV, or ACAL ALL from the front panel? Maybe the false cal constants will be set correctly. In the calibration manual, its explained, which constants are set by atocal (and cured), and which one are set by basic calibration, requiring external standards (10 v

Re: [time-nuts] Finding precision resistors, tip

ppose). On the search for new wirewound resistors, I found the 'econistors' at UK, Rhopointcomponents.com. They also deliver TK 0.3 metal foil type FLCY, all for convenient prices. Vishay - with some 'relationship' - delivered to me a small volume of Z201 - great ones, but

[time-nuts] I think I've become a Volt nut too.

Hi All, I have been a time nut for some time now. I think I've become a Volt nut too! I build the Silicon Chip magazine Voltage reference late last year but didn't have anything to compare it against so I bought a Fluke 732A DC reference standard. I there a group I can subscribe to that

[time-nuts] I think I've become a Volt nut too.

True, but there is always a probability that they all happen to be off one way. Quite a small probability, but not impossible. Sorry for the disturbing thought. In the case of the 732A, and the early 732B, this is in fact the case! Fluke mentioned, that all the 732A and the early 7

[time-nuts] GC-1000 Clock Cap Choice?

Hi Brooke, Our electronics designers (@automotive electronics supplier) have to take lot of care concerning voltage stabilizers, that the cap provides sufficiently low ESR, which electrolytics deliver only at much higher capacitance value; and a series resistor is introduced to limit loading

[time-nuts] GC-1000 Clock Cap Choice?

Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? Poul-Henning, Pls. check the spec for dielectric material. X5R is a

[time-nuts] GC-1000 Clock Cap Choice?

I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, a

[time-nuts] GC-1000 Clock Cap Choice

Sorry, epcos sold ceramics business, and was itself swallowed by TDK. If looking for X5R and X7R cer caps, visit vishay, kemet, taiyo yuden, murata and others instead. This special material specification is well hidden at the official manufacturers specs. Those are high grade ceramic dielectr

[time-nuts] manual 5370A

; unit, 3 PCB spares can be seen, plus one additional space without a socket. Frank Stellmach ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

[time-nuts] HP5370B - 10 sec Gatetime via GPIB

ands, but nothing works. Has anybody got an idea how to program the HP5370B for a gate time up to the maximum of 10sec? Dr. Frank Stellmach ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/