Re: [time-nuts] Long life products, obsolete components, and code 4 parts. RE: HP Cesium Standards in the International Atomic Time Scale, the legend of Felix Lazarus, and the "top cover
Hugh, On 12/30/2018 10:19 PM, Rice, Hugh (IPH Writing Systems) wrote: > This email chain has unleashed a flood of memories from 30 years ago. > Hopefully a few of you find this walk down memory lane interesting. I > have a few more stories in the que if any of you are still interested. I enjoy these stories very much. I was an HP VAR during that time period and would love to hear more. Cheers, Dan ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Long life products, obsolete components, and code 4 parts.
> This email chain has unleashed a flood of memories from 30 years ago. > Hopefully a few of you find this walk down memory lane interesting. > I have a few more stories in the que if any of you are still interested. > > Hugh Rice Somewhere in my library I have an internal hp document describing all the changes between the 5061 A and B. I remember a number of the changes were influenced by feedback from the repair group. So the design was driven not only by manufacturability, but also serviceability. By the time the 5061B came out there was a decade or two of field experience with portable cesium clocks and this was put to good use. If you have this document it would be worth scanning. If not, I'll try to find the box where my copy is hiding. Yes, keep the stories coming. They are very much appreciated. Thanks, /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Long life products, obsolete components, and code 4 parts. RE: HP Cesium Standards in the International Atomic Time Scale, the legend of Felix Lazarus, and the "top cover
I’ll add a bit to Rick’s story, from my manufacturing engineering perspective. I was hired into PFS manufacturing engineering in 1984, specifically to work with Roberto (Robert) Montesi on the 5061B product. Roberto was the production engineer on the 5061A, and acting “project manager” of our little two man development team. We were funded by manufacturing, as Rick noted, but sat in the R lab for about 18 months as we redesigned (updated) a bunch of stuff on the 5061A. As I mentioned a few weeks ago, Roberto was a very good engineer (compared to me at least), and a great mentor. One story he told me about himself that I recall: He was originally from Nicaragua, and somehow wound up in the US Army during Vietnam, spending some time in combat there as a GI. At one point the Army wanted to send him to officers candidate school, since he scored so well on all the tests. He was a smart guy, with perfect English. Well into the process, they finally realized that he wasn’t a US citizen, and thus couldn’t be an officer.He seemed to make it through the whole Vietnam experience with minimal PTSD (as far as I could tell), and would tell an interesting (and likely cynical) war story now an then. Like Rick said, Roberto kept his head down, and we sat in a shared work area and did our 5061B thing, surrounded by the team working on the new 5350,51,52 microwave counters, led by their very energetic project manager Bob Renner. The real R guys treated us well, even though we were 2nd class production guys. (Not too many years before this, R engineers and production engineers were not on the same pay scale, and really were second class in HP eyes. The feeling of not being a “full” engineer still lingered in 1984.) As Rick said, PFS products like the cesium standards were cash cow products, and didn’t have a R staff at all. All the “upgrades” were funded by manufacturing, to keep this product line viable.The whole development effort was about extending the production life of the 5061A. We were selling about 15/month, with an average price of about $35K. The gross margins were very high (sales price – material costs), and the product line delivered 4 or 5 million in gross profits to the division a year.It was well worth having a couple of manufacturing engineers freshen things up to keep this cow healthy. And Roberto was still the production engineer for the 5061A during this time, so kinda doing double duty. My job on the 5061B was to redesign the clock display and the battery charger. These were both part of the popular time-keeping option 003, which was primarily the 1pps output circuit. The battery backup was to prevent the 1PPS signal from losing syc. If there was a power interruption. I recall the battery charger had a huge mica capacitor that couldn’t be purchased any more, and a crazy design with obscure TTL counters. The clock display was even crazier. Not nixie tubes, but two or three circular PC boards driving LED displays, and again obscure ICs that were hard to procure. Hard to build, and really expensive. (More on these in another story on another day.) Roberto redesigned the frequency divider module (5MHz in; 10MHz, 1MHz, 100kHz out – another odd design rooted in 5060 history), the A3 power regulator board, and some stuff internal to one (both?) of the high voltage power supplies, used for the Ion Pump and Electron Multiplier. Maybe some other things too. For all of these, obsolete components was the driving force. By 1984 standards, there were some really crazy circuits still in the instrument (still another story for another day), but as Rick said, in low volume manufacturing, if it isn’t broken, don’t fix it. In the case of the 5061, don’t even think about touching it. Rick’s memory of the management dynamics are similar to mine. A 5061A to 5061B “upgrade”, particularly if funded by manufacturing, was easy to get approved.Entire new developments were hard to justify.The division was under a lot of financial stress in the 1980s. Peace was breaking out as the cold war was winding down, and DOD spending, which drove a lot of instrumentation sales, was shrinking. Digital oscilloscopes and synthesized frequency generators were obsoleting the need for frequency counters, the majority of the divisions revenue.PFS was profitable, but zero growth. We also build laser interferometers, which did amazing high precision displacement measurements, but they weren’t growing either. While profitable, the division revenue was shrinking maybe 10% per year.In the 8 years I was there, headcount went from about 1500 to 500 people. Management was desperate to fund new products that would lead to growth. I recall the general manager at the time (Jim Horner), having a metric for every new development on how much growth it would contribute to the division. It was never enough.
Re: [time-nuts] Long life products, obsolete components, and code 4 parts. RE: HP Cesium Standards in the International Atomic Time Scale, the legend of Felix Lazarus, and the "top cover
On 12/28/2018 8:36 PM, Rice, Hugh (IPH Writing Systems) wrote: Well, I can’t prove that Bob would lose this bet (Maybe Rick K could), and I didn’t work on the 5071. But for PFS products, in production engineering, we had been building and selling these instruments for decades, with no end in sight. Volumes were low, so they didn’t get redesigned very often. I’ll bet the same six pack that the 5071 team felt it would be a VERY long time before HP designed a replacement for the 5071. Rick – any memories you can share? Happy New Year, Hugh Rice Even in the late 1980's when the 5071A project started, the handwriting was on the wall with respect to GPS. It seemed like cesium was going to be a niche product. OTOH, Len's vision was that after the 5071A we would do an optically pumped version. So it could be said that no one expected the 5071A to last 25 years. What changed was: 1. Len never got permission to do an optically pumped version. The people at Microchip tell me that even now, they can't get reliable laser diodes. Optical pumping is limited to laboratory standards, not COTS ones. 2. I am shocked! to report that GPS can be spoofed or jammed :-). Now every military commander wants his own cesium. An anecdote about life time buys: When I designed the 5071A, HP had their own SAW fab. This was when HP made their own coax, transformers, etc. They already had a 640 MHz SAWR that was used in the 11729, so I designed it into the 5071A and phase locked it to the 10811. Then we got the news about the SAW fab. The managers patted themselves on the back for arranging with SAWTEK to support the SAW products. However, that referred to SAWTEK selling us only complete oscillators for $300. Not loose resonators. BTW, Jack Kusters developed the original SAW technology. So I started work on a new RF module without a SAW, and meanwhile purchasing made a life time buy. Long before the inventory was used up, I released a new RF module that was one PC board that replaced the old on with two PC boards and had a factory cost that was $100 lower. The production engineers loved the module because it just worked from the get go. It contained five cascaded doublers that went from 10 MHz to 320 MHz. Previous multiplier chains going from 10 MHz to 90 MHz constituted a full employment program for production engineers. With the 5071A design, I never heard from production about any problems. I assumed that they would immediately implement this change because they were basically shipping a $100 bill with each instrument. But they said, no, they would have to write off the life time buy inventory and "lose" money. I tried to explain "sunk cost" to them to no avail. So they kept shipping the old design until the last SAWR was used up. Go figure. Robin Gifford of 5071A fame used to talk about his professor who had a very old tank of helium that was acquired when helium was very expensive. It was carried on the books at its "book" price which was the historical cost. The professor would order new helium tanks to avoid using up the "expensive" helium. Robin loved debunking nonsense. He had a subtle but devastating English sense of humor. Rick ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Long life products, obsolete components, and code 4 parts. RE: HP Cesium Standards in the International Atomic Time Scale, the legend of Felix Lazarus, and the "top cover
Dear Hugh, Many thanks for another nice post from the good old times. Was a nice morning reading. I didn't know that the 5061B was rebuilt with removing odd parts in mind, but it makes sense. Interesting system with Code 1 to Code 4. Cheers, Magnus On 12/29/18 5:36 AM, Rice, Hugh (IPH Writing Systems) wrote: > My “Test and Measurement” days with HP, from 1984 to 1992, were all in > manufacturing (a.k.a. production) engineering. A major task was dealing > with the endless list of obsoleted components, since many of our products had > designs dating back 10 or 20 years, into the wild west early days of > semiconductors and integrated circuits. > > In addition to Frequency and Time products (which we called “PFS” – Precision > Frequency Sources), HP’s Santa Clara Division (SCD) also had the frequency > counter product line. I managed the production engineering team for counters > from 1988 to 1992; the job that I had to pass the R engineering new hire > interview to qualify for. This technology was invented in the 1950s and > even with many new models and upgrades, we still were shipping “classics” > products from the early 1970s in low volume in about 1990. The 5340 microwave > counter and 5328 universal counters come to mind. We kept raising the > prices, because we had newer, better, cheaper counters for sale. But the > old ones kept selling because they were designed into some DOD test system, > and the hassle of designing in a new instrument was more expensive than > buying an new (but obsolete) counter for our customers.The parade of > obsolete components seemed to never end on these old units.I recall > talking to the marketing manager, Murli Thurmali (sp?) about obsoleting some > of these products, and he would wisely respond: “Tell me how you are going > to replace the million dollars of lost revenue.” The manufacturing manager, > Chuck Taubman, would likewise say: “Our margins are well over 50% on these > products, that money pays overhead, which is our salaries. Show me $500K in > cost savings before we obsolete them.” Turns out that even though they were > a hassle, it was relatively easy money, so we kept building and selling them. > > The PFS products were similar in this regard. The product line had largely > been developed in the 1960s and 1970s, volumes were low, but prices and > margins were high.Yeah, they took some effort to keep in production, but > the development was done, and it was good money. HP was a business after > all, and if we didn’t make money, we didn’t have jobs.The was a great > education for me, brand new to management, learning that HP may be a cool > technology company, but we only had jobs as long as the business was > profitable, and preferably growing. Nothing was guaranteed. > > HP instituted a system of “Codes” for parts, to measure how well we were > designing our products for long production lives and low materials management > overhead costs. Code 1 was best. Industry standard parts available from > many sources cheaply.Code 2 were OK to use. Code 3 was something really > special, and needed a good reason to include. Code 4 brought the scorn of > procurement engineers, and brought significant management review. > > The easy way out for production engineering to deal with obsoleted component > was a life time buy. The Materials group hated this, because they had > hundreds of other parts already on life time buys. What if they get lost or > damaged, or the last batch was defective, or the product lasted longer than > we expected?A product like the 5061A, at ~200 build per year, was a > typical challenge. 10 more years of life? Buy 2400 parts? Perhaps > double it to 5000 parts. The response from component buyers was easy to > predict: “But VendorX wants $2.31 for this ancient transistor. We’re not > tying up $10K in one part.We have dozens of parts like this, we can’t > afford all this inventory.”So we would try harder. Maybe a 2N222A, or a > 2N3904 will work. Procurements loves these parts. We’d try them out, and > hope we didn’t miss something in the qualification. New parts never had the > same specs at the old parts, and the original designer was long gone, and > design intent documentation non-existent. I bet half the time the old > transistor just happened to be on the engineers bench back in 1969, worked > fine, and he just used it. The Code 1,2,3,4 process was designed to > discourage this kind of design thinking. > > When we upgraded the 5061A Cesium Standard to the 5061B in 1984-85, the > primary objective was to eliminate all the code 3 and code 4 parts. > Designing out all the old stuff wound up being a fantastic education in > component technologies, reading and interpreting data sheets, dealing with > vendors, worrying about inventory control and so on. Our attitude was > trying to make a product we
Re: [time-nuts] TIC Characterization
In message , Magnus D anielson writes: >Hi Gilles, > >On 12/29/18 11:28 PM, Club-Internet Clemgill wrote: >> Hi, >> Looking to testing my HP53132A in TIC mode. >> I considered the Time Interval measurement technique: >> The start channel is connected to a 1 PPS signal, and to the stop channel >> though a coax cable (constant delay line). > >Fair enough setup. This is a static test setup which works as long as >you do not lock the counter up to a 10 MHz of the same source as the >PPS, and for all maters not accurate enough, so it's best for the test >for it to be free-running. Here is another test-setup, which is very revealing about non-white noise in TIC counters: You need a signal generator which can be locked to an external frequency and control the phase of the output signal relative to that external frequency. The HP3336 is a good cancidate. Lock both the counter under investigation and the siggen to the same house standard. Set the siggen to output same frequency as house standard. measure (start=house_std, stop=siggen) and (start=siggen, stop=house_std) for as many siggen phase settings as you have patience for. Plot results, and wonder why you don't get a straight line... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] TIC Characterization
Hi Gilles, On 12/29/18 11:28 PM, Club-Internet Clemgill wrote: > Hi, > Looking to testing my HP53132A in TIC mode. > I considered the Time Interval measurement technique: > The start channel is connected to a 1 PPS signal, and to the stop channel > though a coax cable (constant delay line). Fair enough setup. This is a static test setup which works as long as you do not lock the counter up to a 10 MHz of the same source as the PPS, and for all maters not accurate enough, so it's best for the test for it to be free-running. When you lock it up, you get a very static behavior of the systematic noise of quantization resolution, and you will be hitting essentially the same bin all the time, and well, you are not that lucky on real-life signals since the phase relationship glides ever so slightly that you want to make sure you do that. So, either you use the time-base offset to cause the quantization of the counter glide relative to the PPS reference or you use an offset oscillator for your signal, both achieve the same goal. The difference lies in wither you have both start and stop channels glide, as for internal reference offset, or you have only the stop channel glide, as you do with an offset oscillator but have time-base and start channel being synchronous. The jitter for the later one is expected lower, because it will have the start-channel banging the same bin more or less each time since the time-base of the counter, steering the phase of the quantization is synchronous to the start-channel, thus essentially removing the noise of the start-channel. While you get an ADEV slope of -1 and it looks like white phase modulation noise, the counters resolution is a very systematic noise and you should not forget that, rather, you can use this fact in your tests to learn more about it. You will find that it is not perfectly linear slope either, so for an average performance you want to average over the full set of phase-relationships between time-base and start/stop channels. > I found some references on the web, but no one with the associated maths. The counter resolution and slope is somewhat of a white spot. It is "known" but not very well researched. I did one presentation on it with associated paper, but I need to redo that one because it does not present it properly. > So I tried the following : > > 1/ AVAR = (1/2*Tau^2) * < [(Xi+2 - Xi+1) - (Xi+1 - Xi)]^2 > > with (Xi+1 - Xi) = phase difference = time interval > > 2/ Phase difference = To + Ti > where To is the constant delay between start and stop (coax line) > and Ti is the counter's resolution at time i > > 3/ Assuming that Ti is a Central Gaussian distribution then: > mean = < Ti > = 0 and variance = < Ti ^2> = SigmaTIC^2 It will not be completely true, but a dominant feature. Turns out that the quantization staircase is a very systematic property, but then offset by the white phase modulation and flicker phase modulation that you can expect. However, the staircase quantization will dominate for these short taus and it is only for longer taus you go into the flicker part. > 4/ [(Xi+2 - Xi+1) - (Xi+1 - Xi)]^2 = [(To + Ti+1) - (To + Ti)]^2 = (Ti+1 - > Ti)^2 > = (Ti+1)^2 + (Ti)^2 - 2(Ti+1 * Ti) > > 5/ <(Ti+1)^2> # < (Ti)^2> for large samples and > <2(Ti+1 * Ti)> = 0 because Ti+1 and Ti are independent > Then AVAR = (1/2Tau^2) * 2< (Ti)^2> = (1/Tau^2) * SigmaTIC^2 > > 6/ Hence ADEV = SigmaTIC / Tau > > So ADEV (log log) is a straight line with -1 slope > And ADEV(Tau=1) provides the standard deviation = SigmaTIC of the Time > Interval Counter's resolution > > Is this right ? > Thanks to point me at related articles or web pages if you know any. You do indeed get an ADEV -1 slope for the counter quantization, I've done essentially the same analysis. I've then done a paper showing how noise and quantization interacts and somewhat shifts this around in, ehm, interesting ways. Unfortunately the paper as presented was not all that good, but I should do work on that, because there is some further insights to present more thoroughly as well as making the real point go through better. I have only seen an Agilent app-note which addresses some of this, but then with the focus on frequency measurements. Others seems to have treated the subject as a fact of life and moved on. So, thank you for reminding me about this property, it is indeed somewhat of a white spot. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
