Re: [time-nuts] Tektronix FCA3103 ADEV measurement tau setting problem

On 5/28/2018 1:44 PM, Bob kb8tq wrote: Hi TimeLab will work with some counters and it will do most of the common plots. It is indeed free ….. Bob The TimeLab manual says it will support any counter that can dump data in Talk Only mode. The Tek manual doesn't mention Talk Only mode.

Re: [time-nuts] Tektronix FCA3103 ADEV measurement tau setting problem

On 5/29/2018 11:58 AM, gandalfg8--- via time-nuts wrote: Unfortunately, I can't help with your enquiry, and am also somewhat confused, as I don't recall seeing a settings entry window for "tau" as a settings option for the built in ADEV function. I take it you do mean the built in option

[time-nuts] Tektronix FCA3103 ADEV measurement tau setting problem

I have a Tek FCA3103 300 MHz counter that measures ADEV as a built in function. When I bring up the settings menu for the measurement, it has an entry window for "tau" (the averaging time, IE "sigma sub y of tau"). It defaults to 200 ms. I can enter larger values and ADEV gives reasonably

Re: [time-nuts] Improving ocxo temp control

In my experience, the oven temperature controller is rarely the determining factor for static oven performance. This article explains what the real determining factors are: http://www.karlquist.com/oven.pdf An analog oven temperature controller will be limited in its dynamics by how much

Re: [time-nuts] Traveling to the US west coast

I'm also interested if it can be arranged. It would be great to be able to meet Attila in person. Rick On 5/18/2018 9:36 AM, Jerry Hancock wrote: Are you going to be in San Francisco area? Maybe we could get a time-nuts breakfast together with a couple of us. Regards, Jerry On May 17,

Re: [time-nuts] Better quartz crystals with single isotope ?

On 4/22/2018 10:20 AM, Bob kb8tq wrote: Do we know anybody in the quartz business who needs a really cool research project ? You could put it on the list with the 1 Kg quartz resonator proposal ….. https://tf.nist.gov/general/pdf/2638.pdf Also an

[time-nuts] 1 kg standard (was:Re: Better quartz crystals with single isotope ?)

A neophyte question about this topic: Since we know that 0.001 cubic meter of water displaces 1 liter, and that it weighs 1 kg, and meters are based on wavelengths of light, why do we need a separate artifact of mass? Also, can we measure the mass of the artifact in Paris based on water

Re: [time-nuts] 4046 replacement

On 4/18/2018 3:15 PM, Magnus Danielson wrote: The real benefit of the 4044 and 4046 lies in that they where CMOS devices and integrated well with other CMOS devices, and could help to The original MC4044 is TTL, not CMOS. There is a CMOS "CD4044" but it is something completely different,

Re: [time-nuts] 4046 replacement

On 4/18/2018 6:27 AM, Bob kb8tq wrote: Hi If this is a new build, why use a 4046 in the first place? There are many newer parts that will do all sorts of things. If this is a repair of something that has been running for years, is it > 5V supply to the chips? If so, you are pretty much

Re: [time-nuts] 4046 replacement

On 4/18/2018 4:34 AM, John Miles wrote: Ulrich Rohde's book indicates that this problem was first documented in 1978 in an EDN article by some authors named Egan and Clark. Newer PFDs implement the 'antibacklash' logic that Rohde mentions. If you really must use a 4046, I'd look for a

Re: [time-nuts] Any guesses as to how Citizen is claiming ±1 second/year with using this AT-cut 8.4MHz XTAL?

The aging spec on the 10811 is 5 parts in 10^10 per day. After 60 days, it could be off 30 ppb. So what we have here is a non-ovenized AT cut that is better than an ovenized SC cut. I'm sure. I am reminded of the old Accutron ads. The headlines guaranteed so many seconds a day or whatever it

Re: [time-nuts] Weird Stuff Warehouse shutting down

On 4/7/2018 10:54 AM, Gary E. Miller wrote: Sad news. Weird Stuff, Haltek, and Halted were integral parts of the Silicon Valley ecosystem. Are you saying Halted is gone? Last I heard, Halted was for sale because the owners are retiring. It could well be the next domino to fall. They

Re: [time-nuts] Microsemi up for sale?

When I was working on fiber optic communication test, I remember hearing about lasers that were "tuned" with variable Peltier coolers. Power consumption is critical in a cesium standard that can run on batteries. Maybe the power consumption of the coolers is a deal breaker. Rick On 3/3/2018

Re: [time-nuts] LT1016 as a pulse shaper...

In the 5071A, we squared up an 80 MHz clock with a 74AC04 gate capacitively coupled with resistive bias to set it at half the supply current; not a resistor from input to output as you often see. Ever since the LT1016 came out, it has been the "easy" way to square up a sine wave. Easy != high

Re: [time-nuts] Output impedance of MC74VHC logic?

It's not just that you need to have small signal Thevenin source impedance << 50 ohms, you also need to be able to deliver sufficient current, at the rated logic voltage swing of the device. If the device is swinging rail to rail, and you drive a 50 ohm load through a 50 ohm resistor in series

Re: [time-nuts] Microsemi up for sale?

I asked the CBT manager at Microsemi about this rumor and he disavowed any knowledge of this. He told me they were making 8 a week (not clear if this is just 5071A's, or includes replacement CBT's). I don't remember the production ever being anywhere near this level. The reason for the

Re: [time-nuts] question about HP 5601a harmonic generator

I extensively studied the 5061 harmonic generator when I was designing the harmonic generator in the 5071A. We are now going on 30 years since that work. The diode had some HP part number. Even if you knew this part number, you would need to have the Part Information Report microfiche that gave

Re: [time-nuts] Recently acquired 53132A

I worked in the HP Santa Clara Division frequency counter section at the time of the development of the 53132A series, which had the internal code name of "Major League Baseball". IIRC, the external reference circuit in it was designed by a couple of engineers who had no background in time

Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

(Rick) Karlquist < rich...@karlquist.com> wrote: I need a very simple controller to tune a DDS with up/down switches (imagine setting the time on a clock). A DDS chip, such as an AD9836 would go on a PC board and a couple of pushbuttons would tell the controller to tune up or down.

Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

suggested? On 13 Dec 2017 20:03, "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: I need a very simple controller to tune a DDS with up/down switches (imagine setting the time on a clock). A DDS chip, such as an AD9836 would go on a PC board and a couple of pushbuttons would t

[time-nuts] Simple open source microcontroller solution to tune DDS needed

I need a very simple controller to tune a DDS with up/down switches (imagine setting the time on a clock). A DDS chip, such as an AD9836 would go on a PC board and a couple of pushbuttons would tell the controller to tune up or down. Before reinventing this wheel, I thought I would see if

Re: [time-nuts] Oscillators and Ovens

On 11/1/2017 3:44 PM, Dana Whitlow wrote: Bob, This discussion is getting really interesting. In thinking about the crystal Q versus tuning range conundrum, two (presumably-overlapping) concerns come to mind: 1. The motional parameters of a high-Q crystal are such that the external network

Re: [time-nuts] Spice simulation of PSRR and phase noise

On 10/24/2017 11:10 AM, Hal Murray wrote: aph...@comcast.net said: My applications were broadband. If I remember correctly, aggressive bandwidth limiting can cause phase shift problems due to temperature changes unless one is careful in the design of the filter. Does anybody ovenize

[time-nuts] HP 3048 question: how to export graphs?

I am running an HP 3048 under HTBasic and I have a nice looking phase noise graph on the screen. I want to export the graph to the world outside of RMB. Using the "Hard Copy" or "Plot" function keys does nothing, probably because I don't have an HP-IB printer or plotter connected. (I actually

Re: [time-nuts] 5071A Reference Oscillator ?

On 10/6/2017 9:32 PM, Artek Manuals wrote: One of the few things I dont have a manual for Can anyone tell me if there is an HP model number for the Reference Oscillator Assembly (A19) in the 5071A? Might be a  a 10544A ? Thanks, It was a 10811 that I modified to get more tuning range by

Re: [time-nuts] Phase Noise Test Set For Sale

Just wanted to say hi, I didn't know you read this group. Are you retired from Keysight? I retired from Agilent as a Keysight retiree in 2014 but got hired back to Agilent (not Keysight) last year in the Mass Spectrometer division. Does Keysight still have the frequency synthesis COT? How much

Re: [time-nuts] DAC performance

On 7/17/2017 1:41 PM, Attila Kinali wrote: On Mon, 17 Jul 2017 12:07:29 -0700 "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: On 7/17/2017 10:54 AM, Azelio Boriani wrote: This implies that in a Rb or Cs there is not a voltage reference source? Y

Re: [time-nuts] DAC performance [WAS: Papers on timing for lunar laser ranging]

On 7/17/2017 10:54 AM, Azelio Boriani wrote: This implies that in a Rb or Cs there is not a voltage reference source? Yes, that's right, there is no voltage reference with a material effect on stability or accuracy. Rick N6RK ___ time-nuts

Re: [time-nuts] DAC performance [WAS: Papers on timing for lunar laser ranging]

On 7/16/2017 1:51 PM, Bob kb8tq wrote: Hi One gotcha with any ADC or DAC is going to be the reference. There, you are in the same “get what you pay for” dilemma. Stable and noisy, can do. Quiet and not very stable, can do. Both stable and quiet, not so easy if you want it cheap. Noise can

Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

No one has brought up the issue of hermaphrodicity, so I will. Only PP's are hermaphroditic. Why does this matter? It matters in the case of a battery. A battery is both a power source and a power sink. In the PP system, you can make a 3 way connection between a power source, a power sink,

[time-nuts] HP 4815 Vector Impedance Analyzer repair

I have a non-functional HP 4815, don't know if it is the probe or the box. A long time ago, there was a fellow named George Standford (something like that) who repaired these. My old contact information for him is no good. Does anyone know if he is still in business, or if there is any other

Re: [time-nuts] uC ADC resolution (was: Poor man's oven)

On 6/11/2017 6:09 AM, Magnus Danielson wrote: Hi, What papers would you recommend reading? One of the things that we experimented on and improved was the passive wall to prohibit quick cooling of oven. A puff of air or the forced convection (fans) needed for other electronics would tie the

Re: [time-nuts] E1938 oven design

On 6/11/2017 8:59 AM, Attila Kinali wrote: The exact insulation is relatively unimportant. We even tried still air using a knife edge cradle. Didn't make much difference. What is a knife edge cradle? We wanted to test still air as insulation. We couldn't just replace the insulation

Re: [time-nuts] backfill

On 6/8/2017 5:08 PM, Bob kb8tq wrote: Hi In this case hydrogen + oxygen (like from oxidized metal) goes to H20. You very much do not want water running around inside your crystal holder… Helium is inert. Bob Exactly right Bob. The 10811 guys used to go nuts about keeping water out of

Re: [time-nuts] backfill

Bob is exactly right. Read up on "mean free path" physics. Just a little air will take care of conduction. Full atmospheric pressure would drop the Q something like a factor of 2. In any event, conduction through the crystal mounts is plenty adequate for the tiny thermal mass of the crystal

Re: [time-nuts] E1938 oven design

The exact insulation is relatively unimportant. We even tried still air using a knife edge cradle. Didn't make much difference. Rick N6RK On 6/8/2017 1:27 PM, Attila Kinali wrote: On Wed, 7 Jun 2017 14:21:52 -0700 "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote:

Re: [time-nuts] Poor man's oven

On 6/7/2017 1:09 PM, Attila Kinali wrote: makes the PI loop better behaved. Also the thermal mass of the crystal holder is quite small. Especially compared ot the 10811. Actually, the oven mass of the E1938A is much heavier than the 10811 and is made of copper to boot. Due to the flat

Re: [time-nuts] MCXO and dual mode

On 6/6/2017 3:16 PM, Bob kb8tq wrote: Hi If you do the classic MCXO with two oscillator circuits and one resonator, the issue is pretty simple. You have a load capacitance on the fundamental. You have a load capacitance on the third overtone. Even if it is the exact same capacitor, the

Re: [time-nuts] Poor man's oven

On Jun 6, 2017, at 7:10 PM, Chris Albertson wrote: There are more sophisticated control loop designs that can handle this better, eg by using two temperature sensors, one at the crystal and one at the heater. But designing them correctly is more difficult than

Re: [time-nuts] Poor man's oven

On 6/6/2017 4:26 AM, Poul-Henning Kamp wrote: But I cant imagine the ovens used are so perfect that they have the same regulation performance at all temperatures. I can choose the exterior temperature, which I should prefer ? Disregard aging of electronics and materials, we all know that

[time-nuts] HP 3048 NI GP-IB cards help requested

I am trying to set up an HP 3048 system and have read the KE5FX web page on the software. I have successfully installed both PN3048 and the HT Basic port of RMB. The programs basically appear to run correctly on my Windows 7 desktop. HOWEVER, I don't have a GP-IB card. According to KE5FX, both

Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

exists. πθ°μΩω±√·Γλ WB0KV -- Forwarded message -- From: Richard (Rick) Karlquist <rich...@karlquist.com> Date: Thu, Jun 1, 2017 at 10:01 PM Subject: Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies To: Discussion of precise time and frequency measurement <

Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

Direct multiplication to 9192 MHz isn't used by any manufacturer of any atomic clock that I know of, due to its well known disadvantages. I can state for a fact that it was summarily rejected by the designers of the 5060/5061 (Cutler, et al). In the 5071, I (being the RF designer) also summarily

Re: [time-nuts] Fwd: HP5061B Versus HP5071 Cesium Line Frequencies

On 5/27/2017 2:08 PM, Donald E. Pauly wrote: I am investigating the total redesign of the HP5061B lock system for vastly improved performance. It looks like the performance of the HP5071A can be beaten by 10 to 1 for averaging times on the order of a few seconds. πθ°μΩω±√·Γλ WB0KV That's

Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

Wow Tom, great posting. All I can add is that in the 5061 there is a tradeoff that the higher the C field is, the more sensitive it is to errors. That tempered the decision in the past. With the 5071, we have Zeeman line sampling so that the C field can be measured by physics, not by precision

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

On 5/11/2017 4:25 AM, Bob kb8tq wrote: Ultimately it all came to no good. The energy conservation rules simply took over. Shutting down everything during off hours became the way a lot of outfits did things. Don’t turn off all A couple of comments on this, probably no surprise to many time

Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

The view from inside HP when I worked with the people who designed and built the 10811 some 35-40 years ago was that: 1. 10811 ovens rarely fail. 2. When they do fail, it is rarely because the oven runs away. I know I have never encountered a runaway. No one at HP had a "trophy" on their

Re: [time-nuts] Counter Internal Oscillator Importance with External Reference?

On 5/9/2017 12:05 AM, Poul-Henning Kamp wrote: I'm sure that modern counters like 53230 are better at this than The 53230 oven oscillator option in an inferior oscillator to the 10811, by an order of magnitude. So in this case, modern != better. Rick

Re: [time-nuts] HP E1938A question

I know that it will run on Windows 2000. It was originally written on Windows NT4. Rick On 4/24/2017 11:06 PM, gandal...@aol.com wrote: Thanks Rick, I understand better now. The turn over label is still on the crystal but not the matching label on the PCB. So far I've not been able to get

Re: [time-nuts] HP E1938A question

The main issue is that the oven will no longer be at the crystal turnover temperature. If you are using it in a benign environment, you might not need the extreme thermal performance enabled by being dead nuts on the turnover. You still have an oven with thermal gain in the 100's of thousands.

Re: [time-nuts] HP E1938

It's been 20 years, but I will try to recap what I remember about this connector. I believe there were 3 customers, and one of them required the DB connector with coax inserts for reasons of backward compatibility. I think this vendor was Motorola. We did not actually use the coax inserts, but

Re: [time-nuts] OCXO Soft-Start

10.9 MHz is likely the B-mode of the SC cut. (It's a different mode, not a different overtone). This mode has a tempco of 20 ppm and is used to do thermometry. IMHO, there is NO excuse for the oscillator designer to design an oscillator that doesn't oscillate unconditionally in the right mode.

Re: [time-nuts] Re. DIY atomic "resonator"

Many decades ago, QST had an article about the "Monode" RF noise generator. No it wasn't an April Fools joke; the Monode is simply a light bulb. You can probably download the article from the arrl.org web site. HP used to sell a fluorescent tube embedded in a waveguide as a noise source.

Re: [time-nuts] Re. DIY atomic "resonator" 6GHz synthesizer from ADI

You always want two frequency sources. One generates a carrier frequency offset many MHz from 6.834 GHz and the other frequency source modulates the carrier with a sideband that is at the exact ~6.834 GHz frequency that finds the atomic line. The sideband is in turn modulated with audio to find

Re: [time-nuts] a link to a explanation of Rb vs Cs?

The "magic" of Rb in a gas cell standard is that you can make an optical filter cell out of radioactive Rb87 isotope that allows you to selectively optically pump to the quantum level you need. It is just "luck" that the absorption line falls where you need it. And the RF pumping is at a doable

Re: [time-nuts] Re. DIY atomic "resonator"

On 4/11/2017 12:31 AM, Andre wrote: Has anyone else either built an atomic clock around a bare Rb lamp module "core" or attempted Not a DIY project, but I was the RF designer on the HP 10816 rubidium standard, which never made it to product introduction (a half dozen working pilot run

Re: [time-nuts] The ultraAtomic clock for home

, Richard (Rick) Karlquist <rich...@karlquist.com> wrote: On 4/4/2017 3:19 PM, Bob kb8tq wrote: Hi Based on their web site, the model you saw is the one and only version that does the new modulation. One very useful feature is the ability to set it to any time zone world wide. I guess I

Re: [time-nuts] The ultraAtomic clock for home

Why? oh why? is this only available as an analog clock?? I am wondering if Lacrosse only has the rights to an analog version and that a higher priced digital version will show up in some "professional" line from another vendor. This is at least a plausible theory because this is a well known

Re: [time-nuts] The ultraAtomic clock for home

On 4/4/2017 3:19 PM, Bob kb8tq wrote: Hi Based on their web site, the model you saw is the one and only version that does the new modulation. One very useful feature is the ability to set it to any time zone world wide. I guess I missed the note on the WWVB coverage area expanding to cover

Re: [time-nuts] Time Dilation tinkering

On 3/21/2017 7:12 PM, Chris Albertson wrote: "flight" there is the word.Why drive up a mountain? Take the clock with you inside the pressurized cabin of a commercial airliner next time you are on one of those 10 hour trans=pacific flights. You be taller then any mountain and it is

Re: [time-nuts] Optical Cesium or maybe Cesium "light"!

On 3/18/2017 3:13 AM, Magnus Danielson wrote: The NIST-7 was a optically pumped cesium beam, and a pre-cursor to the fountain clocks. There should be a bunch of papers on it. I am however somewhat wondering about if we will see this coming out of Oscilloquartz. We will see. NIST-7 has a

Re: [time-nuts] Optical Cesium or maybe Cesium "light"!

Len Cutler was all set to build an optically pumped Cs beam 20 years ago. Even then, he could get the lasers. He was only missing one thing: money. HP management never agreed to fund it. The paper conspicuously omits any spec on absolute accuracy. The optical pumping does nothing to improve

Re: [time-nuts] Bye-Bye Crystals

On 3/15/2017 4:45 AM, Bob Camp wrote: Hi Where do you plan on getting an OCXO grade crystal at an odd frequency like that? Much of the performance of a good OCXO is in the crystal. Doing a proper design on one is a lot of work. You *might* think that having a design for 5.00 MHz would

Re: [time-nuts] Bye-Bye Crystals

On 3/14/2017 4:03 AM, Bruce Griffiths wrote: Looking at oscillator circuits like the HP10811A will give some idea of some of the additional complexity required for a overtone operation. Dissecting a few ocxos may also be helpful. Some start with a 10MHz crystal and a Colpitts sustaining

Re: [time-nuts] Bye-Bye Crystals

. About all you can buy now are SAW oscillators. Rick N6RK On 3/13/2017 12:07 AM, Bryan _ wrote: sorry, what do you mean by "complete oscillator" have outnumbered loose crystals? -=Bryan=- From: time-nuts <time-nuts-boun...@febo.com> on behalf

Re: [time-nuts] Bye-Bye Crystals

I got a job in 1975 to design Konel's first synthesized radio, which was to obsolete their crystal controlled radios. That's over 40 years ago. The other trend (not mentioned) is that since 20 years ago or so, complete oscillator sales have vastly outnumbered sales of loose crystals. Rick N6RK

Re: [time-nuts] Have done some more cutting on the Cs beam tube

On 2/18/2017 7:43 PM, Tom Van Baak wrote: Unless yours is a high-perf 5061 tube I wonder if the degaussing coil even exists. Did you pull it from an option /004 frame? Check if there's a separate pair of degaussing wires coming from the tube and heading to the rear panel of the instrument.

Re: [time-nuts] Optimal oscillator topology for diffrent frequency range

Agreed, for low phase noise FLOOR, it is imperative to take the signal out through the crystal. However, for close in noise (say ADEV at t=1), the Driscoll has worked well for me. I have been able to reach ADEV = 10^-11 at 100 MHz at using suitable resonators. Rick On 2/6/2017 4:35 AM,

Re: [time-nuts] Optimal oscillator topology for diffrent frequency range

I would say the 2 stage "Driscoll" oscillator is the way to go. I have had good luck with it up to 100 MHz. The first stage has the crystal in series with the emitter, but is otherwise a grounded emitter stage. The second stage is in cascode as a grounded base. The important operating condition

Re: [time-nuts] What interrupts aging?

On 2/5/2017 4:19 PM, Peter Reilley wrote: I am curious: is the quartz in a high quality quartz crystal perfect? That is; is the crystalline lattice perfect, without flaws or impurities? I assume that the quartz is grown in a furnace, can we grow perfect quartz crystals? Pete. Even a

Re: [time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

I downloaded the following: eagle-win64.exe eagle-win64-7.7.0.exe eagle-win64-7.7.0.exe.INF What is the difference between these files in terms of installing this version? Which file do I run? Do I need the other ones to go along with it? (Similarly, for LINUX, there is the same set of

[time-nuts] OT: Eagle PC CAD now Autodesk, $500/year

Off topic, but probably a lot of disgrunted Eagle users on this list. Its official, you will now have to pay $500 per year for a professional license from Autodesk. The spin meistering of the announcement would make George Orwell proud. I don't see any way they can keep me from just using the

Re: [time-nuts] 10MHz to 25MHz

On 1/19/2017 5:40 AM, David wrote: oscillator. In some applications I would also be concerned about the phase of a narrow bandpass filter changing with temperature. The 5061 has tuned bandpass filter multipliers which have exactly this problem. A temperature ramp causes a phase ramp

Re: [time-nuts] 10MHz to 25MHz

On 1/18/2017 6:34 PM, David wrote: An alternative very simple design I might try is a variation of the active frequency multiplier where the 5th harmonic is filtered directly from the output of the digital divide by two stage. That's a useful trick to reduce the filtering burden. Having

Re: [time-nuts] 10MHz to 25MHz

A better and easier way is to phase lock a crystal oscillator. I would use a 50 MHz VCXO and divide the output by 2 to get a 25 MHz square wave. Rick N6RK On 1/18/2017 10:28 AM, Loren Moline WA7SKT wrote: Hello, I am looking for a good X5 multiplier to use to generate a 25MHz signal from my

[time-nuts] HP counter basic oscillators

On 12/27/2016 11:48 AM, GandalfG8--- via time-nuts wrote: All the 5313x counter basic oscillators are indeed extraordinarily poor, and I've always assumed that their only purpose was to demonstrate that the unit was basically functional. I don't know exactly what is in the 5313X counters,

Re: [time-nuts] Totally unrelated, but..

On 12/7/2016 12:16 PM, Clint Jay wrote: I was looking for a low noise regulator to power a log amp/detector earlier this year and was rather surprised to find the 78xx regulators were considerably better than many of the "low noise" devices. Are you kidding me? Check out the Linear

Re: [time-nuts] Excel logarithmic function (was Thermal impact on OCXO)

On 11/24/2016 5:16 AM, Bob Camp wrote: The biggest challenge is to take out the “early stuff”. One approach is to fit the same equation twice with the time constant restricted to a range on each. For most OCXO’s (90%) the equation when fit early represents an upper limit to the drift. You

Re: [time-nuts] HP 55300A

When I was testing the E1938A I used to run the environmental test chamber up to 85 degrees C, let the unit stabilize for a while, and then dump liquid nitrogen into the chamber to go to -55 degrees C in something like 2 minutes. The temperature inside the crystal oven fluctuated maybe a

Re: [time-nuts] Question about AD9832 "I out Full Scale" (what does it mean?)

n 11/17/16 11:09 PM, Richard (Rick) Karlquist wrote: Trying to figure out what "Iout Full Scale" means on the AD9832. Some time nuts may have used this one. On page 7 of this doc: http://www.analog.com/media/en/technical-documentation/user-guides/UG-313.pdf It shows the AD9832 o

Re: [time-nuts] Need for a document comparing time interval counters

On 11/21/2016 1:10 PM, Bob Camp wrote: Hi With both counters running on the same external standard (and no internal OCXO), the 53230 beats the 53132 both on frequency and time. It also has slightly better isolation of the 10 MHz internals so the “dead zone” at 10 MHz is not quite as bad. I

Re: [time-nuts] Need for a document comparing time interval counters

I had a 53230 the last few years I worked for Agilent. The oven oscillator in it is inferior to a 10811. Its only claim to fame IMHO is that it can measure Allan Deviation. Turns out that we really needed Hadamard, but it doesn't do that. It is very expensive. The old Santa Clara Division with

[time-nuts] Question about AD9832 "I out Full Scale" (what does it mean?)

Trying to figure out what "Iout Full Scale" means on the AD9832. Some time nuts may have used this one. On page 7 of this doc: http://www.analog.com/media/en/technical-documentation/user-guides/UG-313.pdf It shows the AD9832 output as 572 mV peak to peak across 300 ohms. This works out to 1.9

Re: [time-nuts] Do the HP 5334A & 5335A counter/timers take the same oven oscillator?

In general, any 10811 with an edge card type connector in interchangeable in any instrument, in terms of basic functionality. The only differences are that various part numbers in the 10811 family are selected for certain critical specs. Certainly, between the 5334 and 5335, they are

Re: [time-nuts] Sapphire oscillators

A lot of hype has been coming out of the left coast down under for many years, with this being the latest example. This technology tends to produce the world's most sensitive microphone. It's also a fairly sensitive thermometer, too, which the helium bath tends to mask. The prices asked have

Re: [time-nuts] 5071A with ATTENTION flashing

Regarding error codes in the 5071A. This "feature" was an afterthought. All of us hardware designers brought out test points that were easy to implement and then the microcontroller polled them and software was written to give error reports. We did what was easy on already finished board

Re: [time-nuts] Thinking outside the box a super reference

ough. Rick On 11/5/2016 7:39 AM, Attila Kinali wrote: Hoi Rick, On Sat, 5 Nov 2016 07:17:21 -0700 "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: I think this is all described in the 1992 FCS papers, but the executive summary is that a direct synthesizer on 91

Re: [time-nuts] Thinking outside the box a super reference

On 11/5/2016 12:18 AM, Poul-Henning Kamp wrote: In message <768ee5a7-1c53-06cf-cf36-ec75e2901...@karlquist.com>, "Richard (Rick) Karlquist" w rites: Reminds me of an interesting Jack Kusters story. There was some customer who was having problems with his atomic cl

Re: [time-nuts] Thinking outside the box a super reference

I think this is all described in the 1992 FCS papers, but the executive summary is that a direct synthesizer on 9192.63177 is to be avoided at all costs because of the danger of it leaking into the CBT cavity. This is also the reason why you don't multiply up a subharmonic of this frequency. It

Re: [time-nuts] Thinking outside the box a super reference

On 11/4/2016 5:24 PM, Poul-Henning Kamp wrote: Yes, that sounds about right for an isotope with a 40 billion years half-life. The problem with the half life number is that the cylinder still was marked "radioactive" complex with the radiation symbol. Radioactivity (for legal purposes) is a

Re: [time-nuts] Thinking outside the box a super reference

On 11/4/2016 4:04 PM, Poul-Henning Kamp wrote: Historically resonance cavities were used so that step/avalance diode multipliers had enough power to excite them. Today we have semiconductors which work at those frequencies. A great deal of complexity in the 5061 went into exciting an SRD at

Re: [time-nuts] Satellite TV messed up, how is GPS time

On 11/4/2016 2:51 PM, Don Murray via time-nuts wrote: DirecTV and DishNetwork are on Ku-Band platforms. Ku-Band is not affected by sun outage. Don W4WJ The backhaul on C band might be affected. Rick ___ time-nuts mailing list -- time-nuts@febo.com

Re: [time-nuts] Thinking outside the box a super reference

On 11/3/2016 1:07 PM, Bert Kehren via time-nuts wrote: Over the past there has been talk about building from scratch high performance references. I think consensus was that it is out of reach. In the mean I was on the design team for the HP 10816 mini rubidium which leveraged the

Re: [time-nuts] So what’s inside that Cs Beam Tube anyway?

On 11/2/2016 10:23 AM, Tom Van Baak wrote: Hi Rick, You know the famous 1971 Hafele-Keating experiment with four 5061 cesium clocks flying around the world. Several years later, a more precise measurement was made by Carroll Alley using better clocks. What I read is that he got Len

Re: [time-nuts] So what’s inside that Cs Beam Tube anyway?

This has probably been covered here before, but, at least going to the 5071A, now 25 years ago!, all CBT's, whether high performance or not, have the same amount of cesium inside. This means that the standard performance (never call it "low" performance) CBT has enough cesium to last 30 years!

Re: [time-nuts] Cs tube pics

On 10/31/2016 10:18 PM, Tom Van Baak wrote: So if you keep hacking on your tube(s) you should get to the same point as they did. If nothing else, you can use my photos of hp's display as a hint of where and where not to cut! Note that the shinny copper will look fantastic at first but may

Re: [time-nuts] So what’s inside that Cs Beam Tube anyway?

I remember when they made tubes in Santa Clara, they would assemble them and do some tests without breaking the Cs ampule. A fair percentage would fail and would go to a machinist using a big lathe to cut them open to be rebuilt. It was very important that the Cs had not been released yet.

Re: [time-nuts] So what’s inside that Cs Beam Tube anyway?

The ghost of Jack Kusters is now spinning in his grave on this Halloween night. Jack was a fairly opinionated guy and it didn't take much to get him excited. Jack used to rail against people who asked this naive question. There are any number of reasons why this doesn't make sense. One major

Re: [time-nuts] Difference in manufacturing for fundamental tone, 3rd, and 5th overtone crystals

On 10/27/2016 4:50 PM, Bob Camp wrote: Hi Crystals are highly optimized for the specific overtone they are intended to operate on. In fact, you can fiddle them to the point that they no longer have a “fundamental” response. Bob That's interesting. Every overtone crystal I have played

Re: [time-nuts] Temp/Humidity control systems?

On 10/26/2016 8:59 AM, John Ackermann N8UR wrote: I may have the opportunity to build a small "clock room" and am considering whether I could make it an environmentally controlled space. I'd like to learn about the options for doing this. The space would probably be 6x8 feet or so, in a

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