Re: [time-nuts] New 10 MHz Distribution Amplifier

Hello Martyn, Martyn Smith [EMAIL PROTECTED] wrote: Despite the AGC we still achieve good phase noise (-135 dBc/Hz @ 1 Hz with a -168 dBc noise floor) together with 130 dB isolation and 10 ps/C phase stability. I have problems to understand, how your amplifier can achieve phase noise of -135 dBc

Re: [time-nuts] LPRO-101 internals

I suggest not touching any of the adjustment points. Check the rb light. If it gets too reddish, then probably the lamp gets too hot. There is a resistor in the heater circuitry that may be faulty. I'm away at the moment, and don't have my notes on hand, but the resistor is on the bottom side

Re: [time-nuts] LPRO-101 internals

Sometimes trying to fix a faulty unit is simply a challenge. Some more tips. The LPRO with cover removed cannot work in the presence of artificial light coming from AC powered sources!! It locks randomly to the light ripples. My definition of the normal color of the rubidium light would be

Re: [time-nuts] Naive question on WWW stations

You heard the Russian station RWM (.-. .-- --) which transmits on 4996, 9996, 14996 and maybe 19996. It is the easiest to receive station in Europe, quite strong signal. 73, Antonio I8IOV Hi, I listened today the WWW station and I've found it on 9.996 Mhz instead of 10.000Mhz and my

[time-nuts] LPRO lamp decay

Maybe this could be of interest. I have an LPRO continuously running since ending last January. Lamp volt was 7.92V. As of October 22 (today, 9 months later) the voltage is 7.7V. The voltage dropped by 0.22V. The VCXO Volt was 6.7V, and now is 6.8V. It is powered at 24V, and the temperature at

Re: [time-nuts] Question on crystal jumps

Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. Thanks, I was missing this info. I have an LPRO rubidium oscillator. I mounted it on a heat sink with fins and placed it in an insulated box. A small

Re: [time-nuts] Question on crystal jumps

Hi Rick I'm not quite sure what the question is here The question is: may anybody tell me (date and time) when a crystal jumped? (a sample response could be: my crystal jumped on January 22, 2006 12:25 UT). I would like to map in time as many jumps as possible. I hope someone in the

Re: [time-nuts] Question on crystal jumps

Are you sure it is the tuning fork and not the reference for your counter? - 73 - Mike Hi Mike, the tuning fork jumps were in the order of e-7, while the references were a HP 10811 and a Racal Opt 04E both in the range of e-10. Thanks and 73, ANtonio

Re: [time-nuts] Question on crystal jumps

Neville, Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. I have an interest in this. May you point me to any references? 73, Antonio I8IOV ___

Re: [time-nuts] Question on crystal jumps

Hi all, Thanks for your comments, info, ideas and references. I've found the plots that Tim Shoppa pointed me to, and they are a good response to my original question. It has been interesting hearing about the jumps of pendulums too, this was new to me. Also I argue from the discussion that,

Re: [time-nuts] Question on crystal jumps

Thanks, Said. What seldom happens to my tuning forks is similar to your brown line, of course. Do you have date and time of this beatiful jump? Have you observed, by chance, a negative (restoring) jump at any time after this jump? (the sense of the latter question is that, if you observed a

Re: [time-nuts] beautiful jump

On Oct 30 SAIDJACK wrote: Hi guys, there is a very nice Crystal jump visible online today: _http://resco.ucol.mx/Fury/gpsstat.htm_ (http://resco.ucol.mx/Fury/gpsstat.htm) Has anyone else seen a similar effect today? This jump will be visible online for a couple more hours

Re: [time-nuts] beautiful jump

On Fri, 31 Oct 2008 13:59:06 EDT SAIDJACK wrote: Hi Antonio, wow, that's amazing. Your prediction was pretty accurate!! So I wonder if we have one of the most sensitive gravitational sensors out there :) You know that the issue is reproducibility. How did you correlate the jump to

Re: [time-nuts] Rb lamp lifetime...

Yuri, as a rule of thumb, read my message posted here last month: http://www.febo.com/pipermail/time-nuts/2008-October/033926.html I have 10 EFRATOM LPRO, and only one came with a faulty lamp. I think it lost vacuum, and the glass looks clear but with small white pigments. I inspected some of

Re: [time-nuts] Rb lamp lifetime...

Hi Neville, inspecting the lamp is a quite easy job. Yes, it is in the smaller housing. Unlock the check nut just enough, and unscrew the lamp (along with the check nut) using a point shaped tool (a toothpick). It is easy. Don't touch it with fingers. Before doing this, take note of how much

[time-nuts] HP 53131A question

Hi all, I'm planning to use a HP 53131A for phase measurements. In a limit case, just to understand, suppose that I'm reading, say, 100 degrees, and the next reading gives again 100 degrees, but meanwhile the signal under test jumped 360 degrees. Is there any way to detect such a case?

Re: [time-nuts] HP 53131A question

Thanks Magnus and Tom, you clarified more than enough. 73, Antonio I8IOV ___ 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] Eclipses and atomic clocks

Time-nuts, I have to admit that I have an interest in gravitational anomalies. If anybody out there has nothing better to do, here is the stuff to spend some minutes. In early 90's a Chinese researcher (Zhou) opened a debate claiming to have observed anomalous behaviour on atomic clocks

Re: [time-nuts] Eclipses and atomic clocks

I got some private answers. Sorry, I've been concise not to bias your thoughts. Only, I would precise that for unlocked I mean a clock in which the crystal is free running not locked to Rb or Cs, and not to lock between clocks, Antonio I8IOV Time-nuts, I have to admit that I have an interest

Re: [time-nuts] Eclipses and atomic clocks

Time-nuts, I was wrong with my interpretation. The clocks were all working ok. Thanks. Antonio I8IOV I got some private answers. Sorry, I've been concise not to bias your thoughts. Only, I would precise that for unlocked I mean a clock in which the crystal is free running not locked to Rb or

[time-nuts] Cesium vs H Maser clocks

What is the reference used to measure stability and accuracy of H Masers? Do Caesium clocks have something like a C field adjustment (as Rb clocks have), and in the case, what it acts upon? Thanks in advance, Antonio I8IOV ___ time-nuts mailing

Re: [time-nuts] Cesium vs H Maser clocks

In order for cesium beam standards to even work, one must apply a slight magnetic field, the so-called C-field, which rather strongly distorts the shape of the resonance peak. Tom (and all), do you think that a Cs clock, having a not-well-adjusted C field, might have a shape of the resonant

Re: [time-nuts] position determination over short distance

Rick Harold wrote: All, I'm planning doing some experiments in distance measurement. They don't deal with atomic time directly but with extreme short periods of time. I need to determine the position of a instrument with a 1mm accuracy or less. The instrument is not connected to a

Re: [time-nuts] Some More Questions

John You might also look at http://www.qsl.net/zl1bpu/PRECISION/Reference1.htm Peter ZL2AYX On Wed, 18 Jan 2006 11:27:31 -0500, Neon John [EMAIL PROTECTED] wrote: On Wed, 18 Jan 2006 00:03:37 -0800, Christopher Hoover [EMAIL PROTECTED] wrote: John- If I divided this down to 1 PPS, would

[time-nuts] Oscilloquartz S.A. BVA 8600 OCXO revisited..

Dear colleagues When I lately visited the research facility where I had worked in the 80ies*) I was told that the local timescale is still generated by the two BVA oscillators I had installed back then. One is free running and the other one is daily corrected against GPS time-scale. (The place is

[time-nuts] Z3801A - notes on the hp58533a GPSDO

to: John,KE5FX Hi John I read your question on the THUNDERBOLT look-alike sold by 'accelium'. Since I have bought this unit (for 500$!!!), I can answer some of it: The hp58533a has a similar form factor as the Thunderbolt but it's an entirely different design. I made the following notes when

Re: [time-nuts] HP 10811-60155 pinout

Agilent have a Product Overview PDF for the 10811E/D on their website: http://cp.literature.agilent.com/litweb/pdf/5091-1639E.pdf which has a pinout. Hopefully they will have stuck to the same pinout. Peter Hello, I purchased one of the HP 10811-60155 standards on ebay one month

Re: [time-nuts] HP 10811-60155 pinout

Further to my previous reply, the HP Archive website has an Operating Service Manual for the 10811A/B at: http://www.hparchive.com/Manuals/HP-10811AB-Manual.pdf In section 2.20 on the page numbered 8 (actually the sixteenth page in the PDF), a 15-pin Cinch connector is described.

Re: [time-nuts] International time meridian

Certainly we use UTC in Britain, although the Government are keen to try and keep the Greenwich link, so the term GMT is erroniously used more often than not (especially by the BBC!). Yes, there are people who want to stop this irritating leap second business until well after they are dead,

[time-nuts] Datum Efratom LPRO Rubidium Lamp removal

Hi all, does anybody out there have any experience in replacing the lamp on an LPRO rubidium oscillator? I have two LPROs, one working and another which reads lamp volt = zero. I feel it is not a matter of lamp, as the lamp housing doesn't heat (it should). I would try swapping the lamps

[time-nuts] Is this archive searchable?

Hi all, I've just joined this list today, and have found that the archive is full of interesting stuff. So I would ask, is there any possibility to search the archive by keywords? Thanks in advance. Antonio I8IOV ___ time-nuts mailing list --

Re: [time-nuts] Datum Efratom LPRO Rubidium Lamp removal

Hi Frank, in fact Symmetricom states that LPRO is not field-repairable, and I suspect that disassembly would be destructive of the delicate mechanical/thermal coupling between the lamp assembly and the outer case. Anyway, as my unit doesn't work, I will try to repair it, and even in the case of

[time-nuts] Qualcomm RF/SYNTH W/GPS question

Hi all, I have some Qualcomm RF/SYNTH W/GPS boards which are programmable synthesizers for the 750-1000 MHz band. They bear a 10 MHz TCXO as a reference. Based on the above mentioned lettering on the PCB, I guess the oscillator could be GPS disciplined supplying some GPS derived signal somewhere

[time-nuts] HP10811 problem - wrong frequency

. Can anyone help me ? Thanks a lot... Best regards [EMAIL PROTECTED] ___ 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] HP10811 problem - wrong frequency

. The power consumtion is about 3W and the unit is gettuing warm on the outside. I guess this is okay ? [EMAIL PROTECTED] ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow

[time-nuts] FW: [Fwd: [Fwd: HP10811 pr oblem - wrong frequency]]

Bernd DK1AG Original-Nachricht Betreff: [time-nuts] HP10811 problem - wrong frequency Datum: Sun, 13 Jan 2008 19:37:48 +0100 Von: [EMAIL PROTECTED] [EMAIL PROTECTED] Antwort an: Discussion of precise time and frequency measurement time-nuts@febo.com

Re: [time-nuts] 10811 clones

Just speaking of 10811 clones, I have one made by Piezo Systems, model # 2810007-1. It fits electrically and mechanically HP boards, and looks like a 10811. But I miss the specs. Does anybody have any info? Thanks, Antonio Geoff Blake wrote: Hi, I know this has been asked before - but I

Re: [time-nuts] Clock Powers of Ten

Tom, for your archive of tuning fork oscillators pictures, look at my Bryans Aeroquipment (later a Negretti Zambra division) 50 Hz fork at http://xoomer.alice.it/iovane and click on fork.htm - This appeared to be quite stable. Antonio ___ time-nuts

[time-nuts] Eclipses and atomic clocks

Whether or not the rate of atomic clocks may be affected by a solar eclipse is a controversial matter. NATURE magazine published the article Chronometry: Effect of the 1999 solar eclipse on atomic clocks, see: http://www.nature.com/nature/journal/v402/n6763/abs/402749a0.html but the full text

[time-nuts] HP58450A

It should be 58540A, not 58450A. Look at: http://www.leapsecond.com/museum/hp58540a/ds-58540a.pdf Antonio I8IOV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow

Re: [time-nuts] Rubidium Oscillators and Racal 1992

I purchased on ebay four rubidium LPRO and I'm quite satisfied with them. The lamp-Volt parameter (which is an indication of the lamp's health) was respectively 8.4, 7.95, 6.8 and 5.1 Volt. When an LPRO leaves the factory its lamp-V is around 12V. A drop of up to 3 V would be expected in the

Re: [time-nuts] Rubidium Oscillators and Racal 1992

Antonio I8IOV ([EMAIL PROTECTED]) wrote: The unconvenience with the 02M version is that it uses a military GPIB language (MATE/CIIL), and I had to get familiar with it. The Racal units that I have (with no button problems) have a jumper for military or standard GPIB. They do have

Re: [time-nuts] Rubidium Oscillators and Racal 1992 (gpib jumper)

Dan Rae wrote: In my original copy of the 1992 manual, there is only one jumper indicated on the GPIB board. It is at the front of the board. Pages 7-34 and 7-35 show it. On the first page it says : Make certain the jumper plug is installed in the upper two pins of SK4 as shown. On

Re: [time-nuts] Rubidium Oscillators and Racal 1992

Ulrich Bangert, DF6JB wrote: So a better phrase would be that the lamps voltage is an indicator of the lamp's health IF and ONLY IF everything else is sane. Don't blame the lamp before you have checked the temperature and the exciting field's frequency. Agreed completely. I'm not yet

Re: [time-nuts] Racal Dana 1992 - GPIB interface

I have 2 different Racal Dana 1992 frequency counters: The first one (kept for spares because the display is broken) has a GPIB interface of type 19-1146: this interface has NOT the SK4 jumper (see RACAL-DANA-1991-1992-ServiceManualSch.pdf pages 16/17 in my archive). The other one, in

Re: [time-nuts] Power supply for Thunderbolt

Alternatively since you only need 25mA @ +12V, 25mA @ -12V and 300mA @+5V (if I'm reading the right datasheet) you can use a much lower voltage output transformer suited to the 5V regulator and use a pair of voltage doublers or triplers to feed your 12V regulators. A 7.5- 0 - 7.5V

[time-nuts] Disciplining Rubidium

Does it make any sense GPS disciplining a rubidium oscillator? In such a case we have a chain made of GPS - Rubidium - XTAL as opposed to the simpler case of GPS - XTAL (assume that XTALs are of the same quality, and so the control loops). Does the addition of Rb in the middle of the chain add

Re: [time-nuts] Disciplining Rubidium

Tom Duckworth wrote: Antonio, Absolutely! With a good XTAL you have parts in the 9th, short term. With a XTAL controlled by a Rubidium, in the phase-lock feedback loop, you have parts in the 12th, short term. With the Rubidium disciplined by the GPS, with its on-board Rubidium/Cesium

Re: [time-nuts] Disciplining Rubidium

More precisely, if I had two black boxes, one containing a GPS-Rb-XTAL setup and another containing GPS-XTAL, what measurement would you make from outside the boxes to distinguish from one another? Antonio I8IOV Tom Duckworth wrote: Antonio, Absolutely! With a good XTAL you have

Re: [time-nuts] Disciplining Rubidium

Thanks to all for the interesting discussion. I understand that, having a thunderbolt, I might feel free to delay a bit (or even cancel) my Rb disciplining project. A last question to tvb. You said that 6) Turn-over -- if you flip the black box upside down, the Rb version will show little or no

Re: [time-nuts] Power Consumption Trimble Thunderbolt

Rainer, I presume your Power Supply has a fan which may absorb 2 to 4 Watt. Given the low consumption of Thunderbolt, you could try disconnecting the fan to save a few Watts. The Meanwell T-30B has no fan. I' ve not yet measured its idling consumption (no load), but to answer your question it

[time-nuts] LPRO repair

Any sources for an MRF160 power mosfet? Or any suggestions for a replacement? Thanks in advance. Antonio I8IOV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow

Re: [time-nuts] Thunderbolt Group Buy, part 1

I want one. Where to send the request? Antonio I8IOV 2) Those of you newcomers to Time-Nuts should expect to wait until the first batch has been shipped and TAPR is ready for you. There should be enough for everyone; so don't panic.