[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
OCXOs generally don’t require a lot of power. A small (portable size) UPS can keep the OCXO powered up while on the move. With an appropriate inverter, the UPS can be powered by a vehicle. Think “flying clock” of years ago. On Tue, Jun 28, 2022 at 3:59 PM Bob kb8tq via time-nuts < time-nuts@lists.febo.com> wrote: > Hi > > > > On Jun 28, 2022, at 12:15 PM, Hal Murray via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > > > Adrian Godwin said: > >> If you use the ovened oscillator for temporary use away from the home > GPSDO, > >> how good will the oscillator be with those interruptions to power / > >> temperature, and will it stabilise during the period you're using it > there ? > > > > You can solve that with a UPS and/or a gizmo that plugs into a car > accessory > > socket. > > You still power it down doing that. Power cycle generally isn’t a good > idea if you > are after good stability. > > > > > How much does the mechanical jostling as gear gets moved from bench to > car to > > table effect the frequency? > > If you flip it end for end you might be measuring the “2g tip” > acceleration sensitivity :). > That could be up in the 1 to 2 ppb range. Shock and vibe is very much a > “that depends” > sort of thing. You could (but probably won’t) see a couple of ppb. > > The biggest issue is going to be the changing temperature environment. > Thermal shock > is going to create a bigger change than simple temperature change. Going > from inside > to outside to car to outside to inside …. each one is a relatively fast > change. You might > have a device that held a ppb in a normal temp test and it changes 10X > that (or more) > when hit with a relatively modest “fast change”. > > Just what’s fast and how much of a change you get is very much a “that > depends” sort > of thing. Leave the cover off your OCXO mechanical trimmer and you could > find that it > is very sensitive to a gentle gust of wind from the wrong direction …. > > Bob > > > > > > > -- > > These are my opinions. I hate spam. > > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: too many two's
On Mon, Feb 21, 2022 at 5:24 PM Tom Van Baak wrote: > Get your cameras ready. Coming up in an hour: > > 2022-02-22 02:22:22 UTC = MJD 59632.098866 = time_t 1645496542 > > or second chance, 20 hours later: > > 2022-02-22 22:22:22 UTC = MJD 59632.932199 = time_t 1645568542 > > /tvb > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: My AC measurement project & question
A transformer may distort the waveform but that distortion should be constant, whereas a person monitoring line voltage at a particular location will be looking for changes with time. Effects of the transformer could be ignored, in that case. On Sun, Jan 23, 2022 at 8:33 AM Bob kb8tq wrote: > Hi > > On a similar note: > > If the transformer works well up to 600Hz, isn’t that high enough to > capture > anything that actually is grid related (as opposed to local to your home / > neighborhood )? > > One could easily argue that the other end is the pinch point. There may > well > be interesting things going on well below the main frequency. Of course > you > then get back to all those other transformers upstream of you … > > Bob > > > On Jan 23, 2022, at 5:55 AM, Andy Talbot wrote: > > > > But do you want to measure anything other than mains frequency? IF not, > > waveform distortion in immaterial. > > Or am I missing something here? > > > > My mains monitor uses an old wall wart with 9V rectified but unregulated > DC > > out - 5V regulator on the display board. I added an extra wire to one > side > > of the transformer winding which goes via a DC block capacitor and > resistor > > of a few kΩ to the Schmitt timer input of the PIC microcontroller. At > > several volts peak to peak, it's more than sufficient to take the Schmitt > > well beyond its two switching thresholds. Clamp diodes to Vdd and GND > > within the PIC keep it to safe limits. > > > > > > Andy > > www.g4jnt.com > > > > > > > > On Sun, 23 Jan 2022 at 10:44, Dave B via time-nuts < > time-nuts@lists.febo.com> > > wrote: > > > >> On 23/01/2022 08:30, time-nuts-requ...@lists.febo.com wrote: > >>> Stick with the transformer. The use of a capacitive divider is > >> predicated on the line waveform always being a sine wave. Dream on! All > it > >> takes is one good spike down the line, maybe only 20-30V amplitude, and > >> your capacitive divider passes it right on to that ADC that has a much > >> lower (3.3V?) limit. Guess what goes poof? > >>> > > >> > >> Transformers distort the waveform, unless specifically designed for that > >> need. > >> > >> > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: HP105B
Magnus is correct. One additional bit of trivia: HP’s last tube-based instrument was the 428B DC Milliameter. It was made for another year or so after the 200CD was finally dropped. So many military and industrial contracts were written specifying these instruments that customers insisted they stay in production, so the contractors didn’t have to re-qualify (or whatever the procedure was) their whole contract. HP said, hey, if you wanna pay… On Sun, Jan 16, 2022 at 2:35 PM Magnus Danielson via time-nuts < time-nuts@lists.febo.com> wrote: > Hi, > > No, not for HP. The HP200A through D products where separate products > for 8 years, then the 200A and 200B was merged to the 200AB and the 200C > and 200D merged into 200CD that was running for 37 years, totaling in 45 > years of continuous production. Not bad for a tube-based oscillator. The > numbers are from the top of my head, but was featured in an HP > PR-article, where they where proud of this fact, even after breaking out > Agilent. Someone can probably do the research and correct details, but I > distinctly recall the 45 total years. > > Cheers, > Magnus > > On 2022-01-16 22:18, Louis Taber wrote: > > Hi All, > > > > The HP 105B is in the HP catalogs for a 33 year period, 1968 through > > 2000. That is a 33 year run. Is this an HP/Agilent/Keysight record? > > Does anyone know how the newer units were fabricated? > > > > It is just barely mentioned in the year 2000 catalog. The price went up > > from $1800 to $9700 in 26 years. About 5.5 times the original price. I > > wonder what the price was in 2000. > > > > I was looking at the old HP catalogs at http://hparchive.com/hp_catalogs > > for the HP105B Quartz Oscillator. The 1967 catalog has the 106A and > > 107AR/BR on page 538, but no 105A/B > > > > 1968 $1800 p594-597 > > 1969 $1800 p648-651 > > 1970 $1800 p624 > > 1972 $1950 p237 > > 1973 $2145 p284 > > 1974 No catalog or supplement published > > 1975 $2470 p287 > > 1976 $2725 p276 > > 1977 $2950 p274 > > 1978 $3250 p300 > > 1979 $3500 p282 > > 1980 $3750 p284 > > 1981 Not listed > > 1982 $5750 p307 > > 1983 No price p281 > > 1984 No price p275 > > 1986 $5800 p257 > > 1987 $6400 p340 > > 1988 $6800 p467 > > 1989 $7500 p487 > > 1990 $8600 p491 > > 1991 $9000 p510 > > 1992 $9500 p556 > > 1993 $9700 p498 > > 1994/5/6 No catalog on the site. > > 1997 No price p493 > > 1998 No price p503 > > 1999 No price p508 > > 2000 "The HP 105B quartz frequency standard uses the HP 10811D and is > > available as a complete standalone instrument." p 491 > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Clock displays -- eye response
“ neat illusiions if you put a dark filter over one eye. “ The Exploratorium in San Francisco once has an example using an “inverted pendulum,” a ping-pong-sized ball on a rod that was waved back and forth by some mechanical means. Surrounding it were vertical strips of dark plastic (ND = perhaps 1?) with equal-sized empty spaces between. If you stood so you looked through the dark plastic with one eye and the empty space with the other, the pendulum appeared to trace out a cone in the air, going ‘round and ‘round instead of just back and forth. It made an impression that has stayed with me for 30 years. Jeremy On Sat, Dec 11, 2021 at 2:00 AM Hal Murray wrote: > > Erik E. Fair said: > > This apparently relevant paper is, alas, behind a paywall: > ... > > The magic (google-fu) word is "latency" ... > > Ah... Thanks. > > NIH should have a lot of papers on visual stuff, > so I fed >pubmed visual latency< to Google > That got a bunch of hits. Some are behind paywalls. > > This looks like more than I wanted to know: > > Event timing in human vision: Modulating factors and independent functions > https://pubmed.ncbi.nlm.nih.gov/32853238/ > > SOA is a magic TLA: Stimulus-onset asynchrony > https://en.wikipedia.org/wiki/Stimulus_onset_asynchrony > > The ballpark from the graphs is 30-50ms depending on accuracy. > > Along the way, I learned about Pulfrich > https://en.wikipedia.org/wiki/Pulfrich_effect > The latency depends on brightness. You get neat illusiions if you put a > dark > filter over one eye. > > From Wikipedia: > > The Pulfrich effect has typically been measured under full field > conditions > > with dark targets on a bright background, and yields about a 15 ms delay > for > > a factor of ten difference in average retinal illuminance.[7][8][9][10] > These > > delays increase monotonically with decreased luminance over a wide (> 6 > > log-units) range of luminance.[7][8] The effect is also seen with bright > > targets on a black background and exhibits the same luminance-to-latency > > > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: constructing a moon base
What will be the effect of the lunar ‘mascons’ on orbital time and position satellites? As I recall from Apollo, the effects were significant in hitting the targeted landing place—but the orbits were much lower, which increases the effect of each mascon. On Wed, Sep 29, 2021 at 7:54 AM Bob kb8tq wrote: > Hi > > My *guess* (and it’s only a guess) is that before you get to the “road > building” > phase, there will already be at least a basic set of satellites providing > coverage > for the moon. However much they cost today, they will be way cheaper then. > They also would be useful for a wide range of activities. > > Does that mean full GNSS on the moon? Who knows ….. It does mean that part > of the com / time transfer stuff could be offloaded. > > Bob > > > > On Sep 29, 2021, at 10:30 AM, Chris Howard wrote: > > > > My employment involves the design and manufacturing of construction > equipment. > > > > I had a conversation today about what will be needed for > time/positioning when GPS is not in sight, like road-building on the far > side of the moon. > > The context was timestamp coordination between multiple data sources in > the vehicle environment, ntpd, and similar things. > > > > No GPS probably means cesium on the road grader? > > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: in-ground clock room
Good point, Jared, regarding confined space protocols. When I was in
industry, the rule was “two people on any confined space job.” The second
person stays outside and watches. If the first person runs into trouble,
the second raises the alarm but does NOT enter the space until help is on
the scene.
On Mon, Sep 13, 2021 at 3:24 PM Jared Cabot via time-nuts <
time-nuts@lists.febo.com> wrote:
> Also, don't forget about ventilation if you will be entering the
> underground space.
> This sort of thing is classed as a 'confined space' and there should be
> oxygen monitoring in place while inside to prevent asphyxiation.
> Ventilation may work against the thermal isolation goals, but it's better
> than being found laying at the bottom of a pit..
>
>
> Jared.
>
>
>
>
>
>
> \ Original Message
> On Sep 9, 2021, 9:38 PM, Dana Whitlow < k8yumdoo...@gmail.com> wrote:
>
> >
> >
> >
> > Tom,
> >
> > Andy brings up good points, especially about water leaks.
> > Are you familiar with "Whitlow's 5th law" (which can be summarized
> > as "everything leaks")?
> >
> > Dana Whitlow
> >
> >
> > On Thu, Sep 9, 2021 at 7:29 AM Andy Gardner, ZL3AG via time-nuts <
> > time-nuts@lists.febo.com> wrote:
> >
> > >
> > >
> > > So the 2 things you're after are thermal insulation and vibration
> > > insulation?
> > >
> > > Digging can be expensive, and you have to worry about water table in
> many
> > > locations.
> > >
> > > How about the thickest concrete water tank you can find, plonk it in a
> > > nice location, spray layers of polyurethane foam over the top and
> sides for
> > > thermal insulation, then build a wind shield ("shed") around it. The
> shed
> > > could be an old coolstore, adding more insulation.
> > >
> > > Concrete water tanks are out of fashion these days due to plastics, so
> if
> > > you shop around you can find a cheap used one, and then it's just the
> > > trucking/crane charges.
> > >
> > >
> > >
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
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> send
> > > an email to time-nuts-le...@lists.febo.com
> > > To unsubscribe, go to and follow the instructions there.
> > >
> >
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
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> >___
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> an email to time-nuts-le...@lists.febo.com
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--
Jeremy Nichols
Sent from my iPad 6.
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[time-nuts] Re: UltrAtomic - Analog Wall Clock
I’ve not had any issues with mine other than replacing batteries a time or two. Jeremy On Mon, Aug 23, 2021 at 8:55 AM Dan Kemppainen wrote: > Hi, > > Has anyone else here had trouble with any of the LaCrosse UltrAtomic > clocks? > > I personally purchased one new around early 2017 it worked well until > early this summer. At that point it suffered a mechanical failure where > the minute hand would just swing around the 6 'o clock mark. > Occasionally the gears would hit, and the hand would swing to and fro a > bit. (Yes, we did replace batteries as a test). So, we ordered another > one, and replaced it. > > When I pulled the clock down from the wall, there was a lot of white > 'plastic' dust everywhere between the glass and clock face. Looks like > these are prone to wearing out quickly. Unfortunately the wife threw out > the dead one without me knowing, so no serous diagnostic surgery was > performed. > > > Then the clock we bought for work had the second hand quit. We tried a > set of batteries in this one also, which did not help. (Eco mode was > off). This one died a month out of warranty. > > I took that one home and did some digging. It appears the ID of the > pinion with the magnets (Part of stepper motor mechanism) is wearing. > It's brown plastic part, and there is a lot of brown plastic dust on the > fixed pin it rides on. > > In an effort to rejuvenate that clock, some cleaning was done, and small > bit of light oil was applied to the pinion shaft. (I did note, that one > of the other pinion/wheel shafts came from the factory with a bit of > oil). The second hand did start to move again after this cleaning and > lubrication. > > I've played with the supply voltage on that clock, and as long as > everything is above 3.0V it seems to operate correctly. Below that it > will sporadically miss steps, and eventually do it's automatic setting > routine. (Maybe drag from the oil applied, or drag from wear, etc...) > > Just curious if anyone else has noticed issues with these. > > Thanks, > Dan > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Help ID'ing Frequency Standard
Ahh, the HP-5110A was the driver for the 5100 Synthesizer, a monstrously heavy beast from the 1960s. See this link: https://www.prc68.com/I/HP5100.shtml On Sun, Jun 6, 2021 at 10:28 AM Poul-Henning Kamp wrote: > > Magne Mæhre writes: > > On 6/6/21 4:22 PM, John Ackermann N8UR wrote: > > > Looking through the junk box I came upon a metal box labeled: > > > > > > Frequency Standard > > > 05110-6014 > > > Series 330 > > > > This eBay listing lists it as a 1 MHz HP frequency standard > > HP 5110 was the driver HP's first "cash-register" synthesizer. > > According to the HP5110A manual: > > 05110-6014 is "A2 Frequency Standard" > > And: > > 05110-6081 is "A3 Crystal Filter" > > https://bama.edebris.com/manuals/hp/5110a/ > > > > -- > 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 send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Help ID'ing Frequency Standard
None of my older HP counters, standards, etc., have 5110 part numbers. A 1 MHz standard would date from the early 60s—the 5245L counter was introduced in ‘63, I believe, with a 1 MHz standard. HP shifted to 5 MHz standards later in the 1960s. A 5110 number definitely puts it in the Frequency and Time (02) division, probably before the division moved to Santa Clara from Palo Alto. Jeremy On Sun, Jun 6, 2021 at 10:06 AM John Ackermann N8UR wrote: > Thanks for doing that digging, Magne! The eBay pics exactly match what > I have. I wonder what HP product it was used in... the parts list > doesn't help with that, unfortunately. I did a quick search for > 05110-6030 which is what it replaces, and that didn't turn up anything > on Google. > > John > > > On 6/6/21 11:39 AM, Magne Mæhre wrote: > > On 6/6/21 4:22 PM, John Ackermann N8UR wrote: > >> Looking through the junk box I came upon a metal box labeled: > >> > >> Frequency Standard > >> 05110-6014 > >> Series 330 > > > > This eBay listing lists it as a 1 MHz HP frequency standard > > > > > https://www.ebay.de/itm/133759143331?mkevt=1&mkcid=1&mkrid=707-53477-19255-0&campid=5338722076&toolid=10001 > > > > > > > > This list refers to it as a replacement > > > > http://hparchive.com/PARTS/HP-Parts-List-1973-74.pdf > > > > I couldn't get a solid URL for these outdated ebay pics, so I did a > > screenshot: > > http://ixocarpa.hytra.org/pub/2021-06-06-zSYSQQhalxs/hp05110-6014.png > > > > --Magne / LA1BFA > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
Re: [time-nuts] Historical question
Magnus, the first HP oscillator has been studied about as much as is possible. That is not my interest. I am looking at the HP-100 family of frequency standards. On Mon, Mar 1, 2021 at 12:36 AM Magnus Danielson wrote: > Hi, > > On 2021-03-01 00:17, Jeremy Nichols wrote: > > Does anyone know how many of its “first family” of frequency standards HP > > made? That would be the HP-100A (starting in 1943) through HP-100E > (ending > > 1967). Just curious—I have a 100E, made in or after 1961. > > As I recall it, the HP200A was the first product. A handy audio > frequency oscillator. Variants came along for 200B, 200C, 200D and those > where made for 8 years, when they was revamped into the 200AB and 200CD > products that ran for another 35 years of production. Pretty amazing. > The 100 series was started later as I recall it. > > Rather than trusting my memory, there is a number of HP history-sites, > and the HP Journal may have relevant articles that shed light on it, I > would trust that way more than my memory, but at least I got you pointed > towards that. > > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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.
[time-nuts] Historical question
Does anyone know how many of its “first family” of frequency standards HP made? That would be the HP-100A (starting in 1943) through HP-100E (ending 1967). Just curious—I have a 100E, made in or after 1961. Jeremy -- Jeremy Nichols Sent from my iPad 6. ___ 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] The need for quartz crystals and mains frequency
Interesting comment about non-self-starting clocks. I have an old “FDR” clock with a synchronous motor; it has to be started by spinning a knob on the back. The case has molded into it the words, “F.D.R., The Man of the Hour.” I suppose it dates from just after 1933 when Roosevelt became President. A couple of my HP quartz frequency standards use non-self-starting dividers to take 1 MHz down to 100 KHz. Failure of either power or signal causes the divider to stop; a manual restart button is used to start the divider. Loss of the 100 KHz output is thus a signal there has been an interruption. J On Sat, Feb 13, 2021 at 12:55 PM Thomas D. Erb wrote: > My firm has electrictime.com - sold power station master clock as part > of Telechron - now we just make big tower and street clocks. > > We have a bunch of master clocks in our museum - two in our on-line > exhibit - I'm hoping to get a small article in IEEE Spectrum. One master > clock was made in an vacuum chamber with an invar pendulum. > > My clocks are shown > https://electricclock.omeka.net/items/show/6 > https://electricclock.omeka.net/items/show/12 > > Mark Frank has some restored units at > > http://www.my-time-machines.net/master_clocks.ht > > In the 1970's we made a cheap power station clock for some islands - it > consisted of a synchronous wall clock next to a quartz battery power clock > - the operator keep the synchronous clock in phase with the quart clock. > > BTW the little red flag was a part of a patent fight - Telechron had a > patent on self-starting synchronous motor the non-self-starting clock > companies got a law or regulation that a clock had to had a notification > power had been off - they thought they had him - but he came up with a > creative solution. > > > > Thomas D. Erb > p:508-359-4396 > f:508-359-4482 > a:97 West Street, Medfield, MA 02052 USA > e: t...@electrictime.com > w:www.electrictime.com > Tower & Street Clocks Since 1928 > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] Mains Frequency
The joke in USA at that time was that the power companies adjusted their frequency by calling the local telephone company (which was ATT/Bell Telephone almost everywhere). In that era, you could call a local number and get the time. The power companies used that time number, it was joked, to adjust their frequency. The telephone companies, of course, just had an electric clock that ran on the power line. Jeremy On Fri, Feb 12, 2021 at 1:38 PM Alex Pummer wrote: > at the time I grew up in Eastern Europe -- "communist time" -- they kept > he clocks using the line frequency as reference -- by counting the > periods during the day and week and for longer time for equal time > interval the "provided" equal number of line frequency periods, as > longer the time interval was as more precise was the time. That way the > clocks were relative accurate. They could do it since everything was > "central governed". > > On 2/12/2021 9:24 AM, Lux, Jim wrote: > > On 2/12/21 8:23 AM, Thomas D. Erb wrote: > >> "I would think they try to hold it over 1 day, so that mains driven > >> > >> clocks don't run slow or fast.? That being said, I wonder how many > >> > >> clocks are still being built using a synchronous motor drive? Given that > >> > >> all the clocks on appliances in my kitchen have drifted apart, I'll bet > >> > >> they use their internal microcontroller crystal as a reference." > >> > >> Actually I think all of my kitchen appliances use line frequency for > >> time reference - it's so easy to count. > > > > > > Maybe.. you've got to condition the AC from the secondary side of the > > transformer and use a pin to bring it in on, which requires at least 2 > > or 3 passive components, and you already have a crystal for the > > microcontroller (thinking here of oven timers and the like, which have > > a numeric display). These applications are super price sensitive, and > > those 2 or 3 components cost money, in components, in board space, and > > in assembly costs. Pennies to be sure, but... > > > > And the fact that my appliances drift on the order of a minute in a > > month, differently. So maybe some count cycles and some have a rock. > > > > > > > > ___ > > 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. > > > > > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] US Line Frequency - Time Correction
See http://fnetpublic.utk.edu. The University of Tennessee monitors the grid from places all over the world (most in USA). I have one of their monitor stations. It monitors voltage and frequency, gets timing from a GPS antenna, and sends it all to U of T via the Internet. You can see my location on their map, in Santa Rosa, California, USA (near the Pacific coast and north of San Francisco). Jeremy On Mon, Feb 8, 2021 at 3:05 PM Thomas D. Erb wrote: > I was wondering if anyone could describe how the US power gird sets it's > line frequency. > > I know there is a standard somewhere, a local operator just told me - he > just synchs with the grid - but obviously that standard is set somewhere. > > > > Thomas D. Erb > o:508-359-9684 > p:508-359-4396 x 1700 > f:508-359-4482 > a:97 West Street, Medfield, MA 02052 USA > e: t...@electrictime.com > w:www.electrictime.com<http://www.electrictime.com> > Tower & Street Clocks Since 1928 > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] La Crosse Clocks -
When I bought my LaCrosse clock a couple of years ago, I thought they offered 24 hours as an option. Jeremy On Sat, Dec 26, 2020 at 9:40 AM Mike Feher wrote: > Are any of you aware of any La Crosse Ultra Atomic clocks with a 24 hour > format? Hope all had a great Christmas. Regards - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] Voyager space probe question
As the RTGs aged, the Voyagers were commanded to shed parts of their load. Did the RTG voltage drop, was it the current-supplying capability (or both) and how did that affect the oscillators, if at all? Jeremy N6WFO On Sun, Nov 29, 2020 at 10:11 AM jimlux wrote: > For those interested in a "typical" (hah!) TCXO spec for a space radio, > generically similar to the Electra UHF radios on and orbiting Mars, it's > attached. > > The excessively precise frequency (49.244. MHz) is because it > matched a particular channel assignment for S-band, and the idea was to > have the PN code (which is about 3 MHz, proportional to the carrier) be > exactly 16 samples long. > > This is in pre "we can trust an NCO/DDS" days. When it takes years to > build your spacecraft, ordering a crystal with a 24 month lead time to > get the frequency "just right" isn't considered a problem. Historically, > the SDST used a VCXO with a crystal at the frequency at 8*f0, where f0 > is about 9.xx MHz, and multiplies up by 880 to the transmit frequency > between 8.4-8.45 GHz. > > Today, we use 50 or 100 MHz oscillators (Electra uses 24 MHz, but it's > an older design) and synthesize the carrier with a DDS feeding a PLL. > For instance, the Iris cube-sat transponder uses a 50 MHz oscillator, > and that drives a DDS running at 20 MHz, which is multiplied up in an > integer N PLL to the carrier frequency. > > This is because the missions are shorter development time, and we don't > want to have to know the frequency until after the radios are built (or > at least, the oscillators are ordered). For Iris, there were 7 of them > built for the Artemis-1 mission, and the frequencies are all over the > space science X-band allocation. > > The SDST and older used a DRO as the microwave oscillator, and they just > don't have the tuning range needed to cover 50-100 MHz tuning range (and > lordy, we tried a bunch of techniques) - not do mention that DROs have > noticeable microphonics because the physical cavity is part of the > resonator. > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] Assistance needed to understand some V_OCXO stability concepts.
> > Yes this is a whole bunch of rabbit holes to go chasing down. Indeed the > > > bench setup > > > to do all this is pretty massive. Sorry about that ….. > > > > > > The “normal” outcome of testing the part is that you spot issues. You > then > > > get into > > > a tweak / test / tweak / test loop. The normal design process is to spend > > > >5X the > > > time in that loop compared to the time to get the device up and running. > > > That sounds > > > a bit nuts, it turns out to be just as true on your 20th GPSDO design as > > > on your first one ... > > > > > > Bob > > > > > > > > > > > > > > > > > > > > > On Thu, Oct 1, 2020 at 10:33 AM Joe & Gisela Noci > > > wrote: > > > > > > > >> Good Morning all. > > > >> I am new to the group, very green as to how the group/mailing, etc > > > works, > > > >> so if I mess up, please put me straight, gently...! > > > >> I do not have much experience or knowledge in this field, but have > spent > > > >> the last year or so building a GPDSO and need some help in > understanding > > > >> the results I get - they seem to good to be true, so I suspect it's > not > > > >> true! > > > >> I have built the unit based on the Brooks Shera concept, with some > > > changes > > > >> in collaboration with Jeff, K6JCA. > > > >> To describe it would be best done by means of a block diagram ( can I > > > just > > > >> add a PDF as an attachment to this mail and will everyone then see > > > it?). In > > > >> essence - a UBLOX M7N GPS provides a 1PPS signal which controls a > pulse > > > >> width detector, fed from the HP_00105-6013 OCXO ( pulled from a > defunct > > > >> HP-5061A) . This pulse width is converted to a DC level, into a D/A. A > > > uP > > > >> then drives a 16bit DAC to control the Varicap drive to the OCXO. > > > >> I have measured the KV of the OCXO to be close to 0.03Hz/volt. > > > >> > > > >> The DAC drive is derived for a set of software filters, first is a > 32tap > > > >> FIR, for initial stabilization, then into IIR filters of increasing > time > > > >> constants, 30sec, 100sec, 200sec, 400sec. > > > >> > > > >> I log plots of the pulse width detector, DAC voltage, Oven temp, and > > > many > > > >> other parameters. > > > >> I do not have any fancy equipment to measure Adev, etc, nor any > accurate > > > >> frequency counters... > > > >> NOTE - The OCXO is a 5MHz unit, but I double to 10MHz and the ref > clock > > > to > > > >> the pulse width detector is 10MHz/10 = 1MHz. So the pulse counter has > a > > > max > > > >> period of 1us. > > > >> > > > >> I understand the KV of the OCXO works out to 3ppt / millivolt (from > the > > > >> 0.03 Hz/volt). > > > >> When I run the unit, it locks very well, and while running with IIR4 > > > >> active ( 400sec) is observe the following: > > > >> The DAC output voltage curve shapes closely resembles the temp control > > > >> voltage to the oven - as I would expect. > > > >> Over a 24hour period the oven control voltage varied by 0.5 volts. The > > > >> total DAC voltage during this varies by 36millivolts ( Is that > 0.108ppb > > > in > > > >> delta freq?) > > > >> Over a specific period of 3 hours ( afternoon), where the temp control > > > >> voltage varied by less than 200millivolts, the DAC output varied by > > > >> 10millivolts ( is that 30ppt ??) > > > >> > > > >> Please forgive my questions - I lack the knowledge to know if I am > > > asking > > > >> the right questions! > > > >> > > > >> I can post some plots if it will help folk explain what I should be > > > asking! > > > >> > > > >> Thank You > > > >> Joe > > > >> V51JN, Swakopmund > > > >> Over a > > > >> > > > >> > > > > <15hour > > > plot.jpg> OCXO.jpg> > > Page.jpg>___ > > > > 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. > > > > > > > > > ___ > > > 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. > > > > > ___ > > 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. > > -- Jeremy Nichols Sent from my iPad 6. ___ 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] What do people use for measuring temperature?
I checked my 3456A with a Beckman resistance standard box. A 5000 Ohm resistor is measured as 25.02 degrees Celsius, which is good considering neither the 3456A or the Beckman have been calibrated in ages. I have 10 of the Ametherm ACC-003s on order from DigiKey. When they show up (and if we survive the Shady Fire) I’ll report how they do. On Mon, Sep 28, 2020 at 3:48 AM Hal Murray wrote: > > > > Answered my own question: Ametherm ACC-003 from Tim Hughes’ 2-02-2019 > post to > > > the HPAK Equipment group (thanks, Tim!). > > > > Thanks. > > > > I poked around a bit. Ametherm's data sheet shows that they make them in > > various resistances and also various accuracies. 003 and friends are 5K. > > ACC-003 is 0.2C $3.19 at Mouser > > ACC-013 is 0,5C > > ACC-023 is 1.0C > > ACC-103 is 0.1C $3.00 at Mouser > > > > > > > > -- > > These are my opinions. I hate spam. > > > > > > > > > > ___ > > 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. > > -- Jeremy Nichols Sent from my iPad 6. ___ 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] What do people use for measuring temperature?
> > > > > We used three thermistors and averaged them. > > I assume they were spread around in case one side of the package was > warmer than the other. > > Could one do an analog “average” by using a set of, for example, four ‘identical’ (there’s a risky word!) thermistors in series-parallel? Jeremy -- Jeremy Nichols Sent from my iPad 6. ___ 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] What do people use for measuring temperature?
Do we know what this “Long Term Aging Process” is or is it proprietary? On Sat, Sep 26, 2020 at 5:03 PM Bruce Griffiths wrote: > Drift ~1-2mK per year for suitably conditioned thermistors at 25C: > > > https://www.littelfuse.com/technical-resources/technical-centers/temperature-sensors/thermistor-info/thermistor-terminology/stability.aspx > > > > Bruce > > > On 27 September 2020 at 11:15 Bob kb8tq wrote: > > > > > > > > > Hi > > > > > > Roughly speaking 99.9% of all OCXO’s use thermistors as temperature > sensors. > > > The normal evaluation process on a new one *probably* would catch > something < 0.01C > > > over a few months. You may do it a couple different ways depending on > the target > > > OCXO. The net result is still in the “golly gee wiz low” sort of range. > If you can detect a > > > drift / shift, you disqualify that part and move on to another one. Very > few glass bead > > > parts seem to get tossed out ….. > > > > > > Bob > > > > > > > > > > > > > On Sep 26, 2020, at 4:23 PM, John Ponsonby > wrote: > > > > > > > > Have any time-nuts got any data on the long term stability or drift > rates/ageing characteristics of thermistors? I am concerned with ability > of holding temperature constant at the milliK level for years. I reckon > that if one can measure it one can control it. Conversely if one can't > measure it, because of the instability of the sensor, one can't control it. > > > > John Ponsonby > > > > ___ > > > > 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. > > > > > > > > > ___ > > > 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. > > > > ___ > > 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. > > -- Jeremy Nichols Sent from my iPad 6. ___ 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] What do people use for measuring temperature?
Answered my own question: Ametherm ACC-003 from Tim Hughes’ 2-02-2019 post to the HPAK Equipment group (thanks, Tim!). On Sat, Sep 26, 2020 at 10:25 AM Jeremy Nichols wrote: > The HP-3456A DVM was mentioned as one way to measure temperature with > thermistors. Does anyone know the specs for the thermistor that the 3456 > can use? All my manual gives is an HP part number. > > Jeremy > > > -- > Jeremy Nichols > Sent from my iPad 6. > > > -- Jeremy Nichols Sent from my iPad 6. ___ 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] What do people use for measuring temperature?
The HP-3456A DVM was mentioned as one way to measure temperature with thermistors. Does anyone know the specs for the thermistor that the 3456 can use? All my manual gives is an HP part number. Jeremy -- Jeremy Nichols Sent from my iPad 6. ___ 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] time sync by moonbounce
My 2001 copy of Uplink-Downlink was printed by GPO and is 674 pages of 10-point type. I would not want to scan it! Anyway, it was only $25 from an Abebooks seller including tax and shipping and is in near-new condition including a plastic-wrapped dust jacket. Jeremy On Mon, Jun 8, 2020 at 1:01 PM jimlux wrote: > On 6/5/20 3:43 PM, Wannes Sels wrote: > > I bought a used copy of Uplink-Downlink on Ebay. > > Unfortunately the quality is downright bad. Printed on what looks like > > bright white copy paper with a laser printer. > > All the images and illustrations are rasterized, the text is low > > resolution. The photo on the cover shows compression artifacts. > > The pdf on the NASA site is of similar quality, and probably what the > "print to order" version is printed from. > > I don't know where one would go about getting a copy of the GPO printed > version - perhaps a used book dealer. > Conceivably, someone could get a good copy from a library that happens > to have it and spend the time to scan it. > > > > > > > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > > " > > A quick search shows similar experiences with other print on demand books > > from Amazon. > > > > Unfortunately there's no way to tell if a book was printed on demand, > most > > listings just show the cover image instead of a photo of the actual book. > > > > I will try to return it, if I don't have to cover shipping costs. > > > > Buyer beware... > > > > Wannes > > > > On Mon, May 25, 2020 at 4:46 PM EB4APL wrote: > > > >> Hi Jim, > >> > >> This explains a lot of things. As an old time user of the Moon Bounce > >> time synchronization in the Madrid Space Complex, I can say that the > >> system was never popular among the users, it was cumbersome to use and > >> there were already other systems with better accuracy and availability, > >> such as VLBI and Loran-C. We used Loran-C as our daily reference > >> because we had a station at a distance of 650 Km and the signal was very > >> good, even with an old receiver who needed manual estimation of the > >> delay the results were very good. Maybe the aliens who designed the > >> system were not very aware of the humans idiosyncrasies > >> > >> I think that the idea was good, but the implementation was not so good. > >> I can summarize the "peculiarities" as I remember them: > >> > >> - The transmissions had to be scheduled for a period of common moon > >> view. The receiving station was manned 7/24 but the transmitting station > >> (DSS13, if I remember it correctly) had to be manned specially for the > >> event by a crew probably from Barstow, some 40 miles away. > >> > >> - Normally there were not provisions for voice communications between > >> the two end points, so if we did not got correlations we didn't know if > >> the transmitting station was working ok or even if it was not manned due > >> to some problem. > >> > >> - There were not monitoring aids in the receiver, so if we did not have > >> correlations, we has to climb to the roof, verify the pointing of the > >> antenna (there were a rifle scope for that), and if it was, tried to > >> contact DSS13 by phone and pray. > >> > >> - As you can figure it out, the antenna was not remotely controlled. One > >> had to climb to the roof, set the moon declination for that day using a > >> handwheel, slew the hour angle with a switch and select the hour angle > >> rate with another switch. The moon position and rate was obtained from a > >> nautical almanac and when the sky was clear we used the above mentioned > >> rifle scope. > >> > >> The receiver was quite dumb, all intelligence was on the transmitter > >> site. The TX equipment generated a PN code that lasted about 1s, and a > >> full observation cycle lasted about a minute, I don't remember the exact > >> figures. The code was sent advanced to take care of the round trip light > >> time but an additional time bias of 30 us was also introduced which was > >> the basis of the measurement. The bias was decreased 1us/s, so > >> theoretically it was received just on time in the second 30. > >> > >> The receiver generated the same PN using the station timing reference > >> (from a HP 5065A Rb) and it was correlated with the received code. The > >> output of the correlator was integrated and sent to a strip chart > >> recorder. The graph consisted in one trace with a quite noisy ramp and > >> the other trace with 1PPS from the station reference. Now the weird > >> thing: after finishing an observation, we put the graph in a desk and > >> using a drafting rule we draw a straight line that tried to be the "best > >> fit" to the noisy ramp. Were the line crossed the zero we read the PPS > >> mark there and counting back to the start of the minute we got the PPS > >> offset with respect to the transmitting station. Of course we averaged > >> the values obtained from several minutes, after discarding the noisiest > >> ones. > >> > >> Since we didn'
Re: [time-nuts] time sync by moonbounce
I didn't even notice the fold-out. Thanks, Hal! Looks like mine has never been folded out. On Mon, Jun 8, 2020 at 4:49 PM Hal Murray wrote: > > Abe Books has several copies of the hardcopy. > https://www.abebooks.com/ > $30. Check the fine print. At least one says print on demand. > > My copy is in near perfect condition. Page 127/8 is a 3 page fold out > diagram. > > It's 650 pages, way more than I will ever read, but if somebody sends a > note > with a page number, I'll probably look it up. > > It's also the sort of thing that I can easily get sucked into. Just open > to a > random page and start reading. For example, page 525 is Orbiting VLBI, > clearly time-nuts bait. > > > > The last page reveals the culprit: "Printed in Great Britain by > Amazon.co.uk > > " A quick search shows similar experiences with other print on demand > books > > from Amazon. > > Print on Demand doesn't have to be crap quality. > > A friend wrote a college level physics text. The story he told was that > the > college book store would put in an order with the publisher. The > publisher > would send it to the nearest Fed-Ex print shop. (I forget what they were > called back then.) They would print and deliver the next day. > > Xerographic printers can be really good. > > > -- > These are my opinions. I hate spam. > > > > > ___ > 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. > ___ 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] time sync by moonbounce
> improvements or improve it ourselves. A good one could be to use a > > computer program to perform the best fit analytically, but this would > > mean to type the hundreds of points manually from the graph and we never > > tried this. There were not a digital version of the output, we also > > could use a digital voltmeter for acquiring it. We suggested or > > implemented a lot of improvements to other operational things, but this > > contraption was felt as a dead horse from the beginning and its > > operational life was short. Later it was replaced with a GPS based one: > > 2 full height racks filled with equipment and an antenna made from a 10 > > or 20 gallon hermetic paint drum for housing the front end electronics, > > topped with a fiberglass radome about 1 1/2 ' in diameter. It was > > painted white, but the cylinder origin was discovered during a > > maintenance. It was a beautiful prototype that worked very well during > > its shot life. > > > > I don't keep pictures of this equipment, but I have one with the same > > antenna used for other purposes. > > > > Sorry for the bandwidth, but the thread brought me old memories. > > > > Best regards, > > > > Ignacio > > > > > > El 23/05/2020 a las 19:17, jimlux escribió: > > > On 5/23/20 9:18 AM, Mike Millen wrote: > > >> Probably a good idea... there are two page 19s and no page 20 in the > > >> pdf. :-( > > >> > > > > > > > > > That's the page where the aliens came and told us how to build the > > > DSN, then the story resumes with 26m antenna design and operation. > > > > > > (If anyone's interested, I can probably ask the librarians to find it > > > at JPL - correcting the pdf/microfilm is probably beyond scope) > > > > > > > > > > -- > > El software de antivirus Avast ha analizado este correo electrónico en > > busca de virus. > > https://www.avast.com/antivirus > > > > > > ___ > > 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. > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] time sync by moonbounce
That’s it! And Author Mudgway turns out to be from Sonoma, a town in my county just a few miles east of me. I wonder if I can get him to sign my copy when it comes out? On Sat, May 23, 2020 at 3:52 PM Adam Kumiszcza wrote: > I think this is available here: > https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020033033.pdf and > here: > > https://books.google.pl/books?id=vn5TMAAJ&printsec=frontcover&hl=pl&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false > > Best regards, > Adam Kumiszcza > > On Sat, May 23, 2020 at 5:20 PM Jeremy Nichols wrote: > > > Sufficiently interesting that I bought a paper copy through Abebooks. > Looks > > like a somewhat later version, author given as Douglas Mudgway, title > > “ Uplink-Downlink: > > A History of the Deep Space Network 1957-1997.” “Oversized,” 674 > > pages. Abebooks > > lists a couple dozen copies in both hardback and paperback at prices from > > reasonable to ridiculous, as is usual for bookstores. > > > > Jeremy > > > > > > On Sat, May 23, 2020 at 3:47 AM ew via time-nuts < > time-nuts@lists.febo.com > > > > > wrote: > > > > > This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did > > > learn a lot at the same time fascinating > > > Bert Kehren > > > In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, > > > jim...@earthlink.net writes: > > > > > > Apparently, they used moonbounce between DSN stations to synchronize > to 5 > > > microseconds in 1968. It was easier and cheaper than flying cesium > clocks > > > around. (And the Rb standards weren't good enough). > > > https://ntrs.nasa.gov/search.jsp?R=19770007245 > > > History of DSN - mostly about politics, history, transmitters and > > > receivers, but a whole section on timekeeping, phase measurements, etc. > > > starting around page 133 (The DSN Inherent accuracy project), and the > > > discovery during Mariner that UTC and UTI were different enough to > cause > > > nav errors. > > > ___time-nuts mailing list > -- > > > time-n...@lists.febo.comTo unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand > > follow > > > the instructions there. > > > ___ > > > 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. > > > > > -- > > Jeremy Nichols > > Sent from my iPad 6. > > ___ > > 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. > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] NYTimes: New geoid soon
In a similar vein I recommend “The Measure of All Things,” by Ken Alder, the story of Méchain and Delambre and the history of the meter. (Published by The Free Press in 2002.) On Sat, May 23, 2020 at 1:07 PM Steve Allen wrote: > On Sat 2020-05-23T12:21:17-0700 jimlux hath writ: > > > So fiendishly difficult that the first time the task was completed was > > > not until 1899 > > > > And how long did Mr. Schott and the team work on it? > > The reason that this report was in the Lick library is that the > observatory hosted one of the sites in 1888. google will reveal scans > of a lot of the preliminary reports for the traverse in parts farther > east. > > -- > Steve Allen WGS-84 (GPS) > UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat > +36.99855 > 1156 High Street Voice: +1 831 459 3046 Lng > -122.06015 > Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] time nuttery in Space Communications
Some of the stories of deep space communication are really interesting. Round-trip light times measured in hours, data rates measured in bits per minute, remote transmitters with only a few watts. The knowledge is limited to just a handful of people, I suppose. On Sat, May 23, 2020 at 10:44 AM jimlux wrote: > One thing in all these DSN histories is that they don't make very much > of the essential thing that separates Deep Space radio links from Near > Earth radio links, and that's the timing: specifically the coherent link > between the received signal and transmitted signal. I suspect that's > just because it's an "of course it's coherent" for everyone who does > deep space comm, so it's of no great notice. > > > One thing I find in folks building and using ground stations (and > spacecraft) for LEO (vs beyond GEO) is that they essentially treat the > communications path to the spacecraft (telecommand, in the lingo) as > entirely separate from the communications path from the spacecraft > (telemetry, in the lingo). > > This is also found in textbooks on communications systems at whatever > level - you have a sender, you have a propagation path, you have a > receiver. > If there's a "connection" between the two directions, it's usually > handled as a "network" thing (in the sense of ARQ or ACK/NAK, perhaps). > > Things like Doppler and oscillator stability are "nuisances to be > compensated for" so that the receiver can be tuned to the right frequency. > > More than one ground station system for Earth orbit has no idea how long > it takes for the signals to propagate through the chain - it doesn't > matter - I put bits in at one end, and not too long (milliseconds, maybe > seconds) the bits come out the other end. > > > However, for those of us using the radio signals to track and navigate, > or to do science, that "round trip light time" or "phase difference > between receiving the signal at two different stations" is really, > really important. > > And, a bit of codger, "get off my grass" sense (and I'm a relative > newbie, having only done this for 20 years) - all those folks who are > excited about going to the Moon are having to learn this all again. > There's no GPS to give you your position, an omni antenna won't close > the link, etc. > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] time sync by moonbounce
Sufficiently interesting that I bought a paper copy through Abebooks. Looks like a somewhat later version, author given as Douglas Mudgway, title “ Uplink-Downlink: A History of the Deep Space Network 1957-1997.” “Oversized,” 674 pages. Abebooks lists a couple dozen copies in both hardback and paperback at prices from reasonable to ridiculous, as is usual for bookstores. Jeremy On Sat, May 23, 2020 at 3:47 AM ew via time-nuts wrote: > This is a must read. Could not put it down, JPL, NASA, Eisenhowe,r did > learn a lot at the same time fascinating > Bert Kehren > In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, > jim...@earthlink.net writes: > > Apparently, they used moonbounce between DSN stations to synchronize to 5 > microseconds in 1968. It was easier and cheaper than flying cesium clocks > around. (And the Rb standards weren't good enough). > https://ntrs.nasa.gov/search.jsp?R=19770007245 > History of DSN - mostly about politics, history, transmitters and > receivers, but a whole section on timekeeping, phase measurements, etc. > starting around page 133 (The DSN Inherent accuracy project), and the > discovery during Mariner that UTC and UTI were different enough to cause > nav errors. > ___time-nuts mailing list -- > time-n...@lists.febo.comTo unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow > the instructions there. > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] HP 106B on Ebay
I would be concerned the xtal has drifted so far it can’t be adjusted to 5 MHz any more. My 103AR has such a problem. On Fri, Mar 20, 2020 at 12:17 PM Taka Kamiya via time-nuts < time-nuts@lists.febo.com> wrote: > I saw this one. > What scares me is that the seller appears to be competent in testing his > frequency counter, oscilloscope plugin, and other equipment, but on this > one he says, "not sure how to operate". My alarm went off and I didn't bid. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > > On Friday, March 20, 2020, 2:49:34 PM EDT, Bob kb8tq > wrote: > > Hi > > I’m guessing that it is a dewar based OCXO. If so, the *big* question is: > Can the boys at UPS / Fed Ex / DHL / USPS (your pick) get it to you > without cracking the glass bottle? I’ve had reasonable success at shipping > them ( = dewar based OCXO’s not HP106’s) in, but not 100% > success. Replacing dewars is generally not an easy task. > > Bob > > > On Mar 20, 2020, at 12:49 PM, Perry Sandeen via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > Gents, > > This is the only one I've ever seen on ebay in 15+ years. Sold as parts > only but it has a clean 5Mhz output. No bids so far at $499. Auction ends > Sat 1:52 PDST. (I'd buy it if my discretionary financial situation was > better). > > Regards, > > Perrier > > ___ > > 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. > > > ___ > 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. > > ___________ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] HP5065A on ebay
OK, that makes sense. Maybe they had responsibility for keeping all their state’s radio gear tuned up and on frequency. On Wed, Jan 1, 2020 at 2:42 PM jimlux wrote: > On 1/1/20 1:27 PM, Jeremy Nichols wrote: > > Wonder why a highway department would have a rubidium standard? > > I'm not sure about one like that, but a frequency standard in the radio > shop wouldn't be surprising for checking radio frequencies, calibrating > electronic distance measuring equipment, etc. > > Of course, today, they'd buy a SR725 or some GPSDO. > > > And it might well have been purchased by the ebay vendor as part of a > lot of surplus gear sold essentially by the pound/ton. > > (of course, the seller has only been on ebay for a few months) > > > > > > > > On Wed, Jan 1, 2020 at 8:18 AM ew via time-nuts < > time-nuts@lists.febo.com> > > wrote: > > > >> There is a HP5065A with date code 28 on ebay looks like new 12 hours to > go > >> > >> Bert Kehren > >> ___ > >> 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. > >> > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] HP5065A on ebay
Wonder why a highway department would have a rubidium standard? On Wed, Jan 1, 2020 at 8:18 AM ew via time-nuts wrote: > There is a HP5065A with date code 28 on ebay looks like new 12 hours to go > > Bert Kehren > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] Effects on GPS antenna performance due to installation proximity of second antenna
I have two identical GPS antennas mounted side by side about a foot apart feeding two different receivers with no observed problems. Jeremy On Sat, Nov 23, 2019 at 4:12 PM JAMES ROBBINS wrote: > I would appreciate feedback on the question of the ill effects (if any) of > mounting two GPS antennas in proximity to one another. I am intending to > mount a 58532A L1 antenna and a L1/L2 antenna on the same mast on my roof > separated by around 1-2 feet. I have attached a photo to show the intended > installation. (Mast is clamped into the right side aluminum channel.) My > concern is “shading” of one antenna over the other. Thanks for the consult. > > Jim Robbins > N1JR > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] HP105B HP 105B 1 amp fuse blowing
The 105A was built without a battery. The 105B has a battery and charger. I have a 105B that had the failed battery removed before I bought it. It works fine. I have it on a UPS; it survived our just-finished NorCal power shutdown just fine. Jeremy On Fri, Oct 11, 2019 at 7:01 AM Scott McGrath wrote: > As one who owns a 105 i had the battery properly rebuilt and basically > have it on low rate charge and periodically discharge the battery > > When rebuilding a 105 battery it’s important to replicate its > characteristics > > Remember HP also intended I believe that the battery would also serve as a > filter for the power supply. As I dont recall any version of the 105 > without a battery. > > > > On Oct 10, 2019, at 4:50 PM, Taka Kamiya via time-nuts < > time-nuts@lists.febo.com> wrote: > > The fact that 25V supply is dropping to 23.4V shows it is drawing far more > current than it is rated. I am assuming this is a regulated power supply. > Does the power brick actually shuts down at 500mA or does it let the the > voltage drop and try to supply what it can? Maybe one or more Nicad has an > internal short? That will cause and over-voltage situation per battery and > thus over-current. I've recently seen a brick power supply go into > oscillation and produce 3x rated voltage when too much current was drawn. > (and blew the circuit) > > Also, different batteries has different charging rates. As far as 105B > document goes, it says 24V 0.5Amp supply but that is for default > configuration. Designed charge rate is 390mA (page 3-4) and is current > controlled by A5Q3. > > I would actually measure how much current is drawn there. Since the fuse > is already blown, just put an am-meter across the fuse and see > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle < > roy.this...@mail.utoronto.ca> wrote: > > Hi All: > A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 > hour. > The fuse appears to have just melted (not a black mark as the result of a > flash, in the case of a high current short.)… just looks like the fuse wire > (inside the glass capsule) melted into some little blobs, for about 1/4 > the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... > just the normal kind. > I think the unit is drawing just a little too much current, as the result > of the batteries needing charging (I had the fast charge option on when the > fuse blew.) And so, the fuse heated up, and finally melted. Not sure why > the batteries were not charging normally... but 20.1 volts is what I > measured across the pack, initially, and 23.4 V after about 45 min of > charging. > I am charging the batters, from a power cube, at 510 ma, and dropping > (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in > series... that of course is a retrofit. > I don't want to put another fuse in, and blow that too, without some > reasonable explanation of why the first one failed! > Please, any comments, or hints/suggestions... much appreciated. > ___ > 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. > ___ > 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. > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] DC distribution
;>>>> hoping for a long COTS pcb with fusing and maybe holes for plugs. > >>>>> > >>>>> Any insights? > >>>>> > >>>>> Bill > >>>>> > >>>>> Bill Dailey > >>>>> > >>>>> Negativity always wins the short game. But positivity wins the long > >>>> game. > >>>>> - Gary Vaynerchuk > >>>>> > >>>>> Don’t be easy to understand, > >>>>> Be impossible to misunderstand > >>>>> - Steve Sims > >>>>> ___ > >>>>> 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. > >>>>> > >>>>> ___ > >>>>> 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. > >>>>> > >>>> ___ > >>>> 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. > >>>> > >>>> ___ > >>>> 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. > >>> ___ > >>> 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. > >>> > >> ___ > >> 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. > >> > > > > > > ___ > > 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. > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] 60 Hz frequency and phase measurement
It gets time from GPS and frequency from the power line at my house. I suspect a certain amount of frequency wobble due to inductive loads somewhere upstream of my home. On Wed, Jul 3, 2019 at 8:01 PM jimlux wrote: > On 7/3/19 3:20 PM, Jeremy Nichols wrote: > > The station at Santa Rosa, California (#853 in the Western > Interconnection) > > is mine. Have had their receiver for several years. Only downside is > that i > > can't record the data directly from the supplied receiver. > > > > Jeremy > > > > > > but what can you tell us about the receiver - I assume it's line > connected. How does it get time hacks? GPS? Maybe it takes a feed from > the de-rigueur Hydrogen maser, Cs fountain, or cryogenic sapphire > oscillator that time-nuts just happen to have around? > > > -- Jeremy Nichols Sent from my iPad 6. ___ 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] 60 Hz frequency and phase measurement
The station at Santa Rosa, California (#853 in the Western Interconnection) is mine. Have had their receiver for several years. Only downside is that i can't record the data directly from the supplied receiver. Jeremy On Wed, Jul 3, 2019 at 12:01 PM Paul Theodoropoulos via time-nuts < time-nuts@lists.febo.com> wrote: > This stuff is fascinating to a time-nut-level:Novice such as myself. > While falling down the rabbit-hole searching on all the various bits of > the info below, I ran across this - not sure if you're aware of it, or > if it's old news, but it seems at least peripherally interesting: > > http://fnetpublic.utk.edu > > > On 7/3/19 08:56, Tom Van Baak wrote: > > Bob, > > > > Several of us do long-term measurement of mains frequency. We tend to > > time-stamp cycles and then compute period or frequency, rather than > > measuring frequency or period directly. Traditional counters in gated > > frequency or time interval mode have dead time and this will skew > > results. > > > > In my case I just run a 5 VAC wall-wart through a 10k resistor > > directly to the input pin of a PIC. No scaling, no filtering, no opto, > > no ZCD, no nothing. If I measure every cycle I get 155 million samples > > per month. If I extract one cycle each second (decimate by 60) it's > > only 2.5 million samples a month. Many months there is not a single > > glitch in the data in spite of all the FUD about power line noise. > > Once in a while a month contains an extra or missing sample but the > > beauty of timestamp data is that this can be detected and repaired as > > part of data processing with no loss of phase. > > > > Here's a page where Kevin (in New Mexico) and I (in Seattle) both used > > picPET's to measure mains for a few days and then we compared the > > results. Although thousands of miles apart, we're both on the same > > grid so the agreement was astonishing. It was milliseconds in time and > > ADEV down to e-8 over a day: > > > > http://leapsecond.com/pages/mains-cv/ > > > > See also: http://leapsecond.com/pic/mains-adev-mdev-gnuplot-g4.png > > > > /tvb > > > > > > On 7/2/2019 10:09 PM, Bob Albert via time-nuts wrote: > >> I have tried to measure the power line frequency with spotty > >> success. My best results came from a period measurement, as many > >> periods as the counter can accumulate. Due to noise, one is never > >> sure at quite what point the source is measured. Perhaps a brick > >> wall filter would clean it up for a more reliable measurement. > >> Of course, at 60 Hz the period is 16-2/3 milliseconds. So the > >> counter should properly show a 1 followed by a row of 6s, with the > >> last digit bouncing between 6 and 7 most of the time. > >> If there is a filter used, it will not only remove noise but also > >> short term variations. But generatlly speaking you don't want to > >> measure those, unless you are trying to evaluate a rotary generator. > >> Getting this reading can be a challenge. > >> On Tuesday, July 2, 2019, 10:01:03 PM PDT, jimlux > >> wrote: > >> On 7/2/19 4:09 PM, Dana Whitlow wrote: > >>> I've always noted that casual attempts to pick up 60 Hz with small > >>> antennas > >>> etc see more harmonics and other trash than actual line frequency. > >>> But if > >>> you're in an office environment, why not plug something in? It's > >>> quite easy > >>> to build a simple passive diode clipper/filter that will plug into a > >>> wall > >>> outlet and > >>> which will provide a sort of soft (but clean) squarewave at a > >>> voltage level > >>> convenient for lab instruments and with good protection against big > >>> spikes > >>> and > >>> other trash riding on the line. > >> > >> Safety approvals are one obstacle (of course one could use a AC wall > >> wart). > >> > >> Actually, it's because someone asked me about a science experiment where > >> you'd place them in a neighborhood outdoors. > >> > >> > >> > >> ___ > >> 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. > >>___ > >> 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. > > > > > > ___ > > 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. > > -- > Paul Theodoropoulos > www.anastrophe.com > > ___ > 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. > ___ time-nut
Re: [time-nuts] 60 Hz frequency and phase measurement
I built a 6 Volt filament transformer into a small metal box and connected the secondary to a couple of 5-way banana jacks. In addition to the 6 Volt output, I put a 100KΩ pot across the terminals with the wiper connected to a third jack. That way, I can have any voltage from 0 to 6 VAC, avoiding possible damage to sensitive front ends. Jeremy On Tue, Jul 2, 2019 at 8:00 PM Gerhard Hoffmann wrote: > > Am 03.07.19 um 01:25 schrieb Tim Shoppa: > > Jim, most of us are satisfied to use a 6.3VAC filament transformer to > step down from 120VAC and isolate from the power line. > > Exactly. I used an old 6 or 9V AC wall wart and a resistive 1:3 divider > last year when the European grid frequency was low because of some > trouble in the distant south-east. That gave a really stable reading. > > < > > https://www.flickr.com/photos/137684711@N07/38870750440/in/dateposted-public/ >> > > > regards, Gerhard > > > > > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] Chuck Little (of HP Cesium fame) just passed away
My wife (Laura Cline) worked for Chuck for a time at HP. Jeremy Nichols On Mon, Jul 1, 2019 at 3:05 PM Richard (Rick) Karlquist < rich...@karlquist.com> wrote: > Hugh Rice posted a very nice write up on Chuck Little > earlier this year on this reflector. I just heard > about his passing. He started work at HP in 1956! > > Rick Karlquist > > ___ > 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. > -- Jeremy Nichols Sent from my iPad 6. ___ 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] time-nuts Digest, Vol 177, Issue 29
That's what I do. My 105B came with the dead battery pack already removed. Since I didn't plan on moving mine around, I installed it in a rack and connected it to my UPS. On Wed, Apr 24, 2019 at 3:29 PM Bob kb8tq wrote: > Hi > > My advice: Pull out the nicads and run the device on a normal UPS if you > actually need > power backup. When the UPS bites the dust … replace it. Much easier than > keeping > the batteries in these devices happy. > > Bob > > > On Apr 24, 2019, at 11:53 AM, Roy Thistle > wrote: > > > > Hi Time Nuts: > > > > I've been lurking for a while now... reading the posts. > > > > I have just got an HP 105B, which is in good shape, and has a > new/replaced NiCad battery pack, and was calibrated against a rubidium > oscillator (standard?). > > > > NiCads don't like me... does anyone have recommendations/commiserations, > concerning their care. > > > > Best regards and wishes. > > > > Roy > > > > > > From: time-nuts on behalf of > time-nuts-requ...@lists.febo.com > > Sent: April 24, 2019 12:00:02 PM > > To: time-nuts@lists.febo.com > > Subject: time-nuts Digest, Vol 177, Issue 29 > > > > Send time-nuts mailing list submissions to > >time-nuts@lists.febo.com > > > > To subscribe or unsubscribe via the World Wide Web, visit > >http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > or, via email, send a message with subject or body 'help' to > >time-nuts-requ...@lists.febo.com > > > > You can reach the person managing the list at > >time-nuts-ow...@lists.febo.com > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of time-nuts digest..." > > > > > > Today's Topics: > > > > 1. OSC value with Lady Heather (Giuseppe Marullo) > > 2. Re: Z3801 Power Supply Schematic (RICHARD GOLDING) > > > > > > -- > > > > Message: 1 > > Date: Wed, 24 Apr 2019 08:51:44 +0200 > > From: Giuseppe Marullo > > To: time-nuts@lists.febo.com > > Subject: [time-nuts] OSC value with Lady Heather > > Message-ID: <0a87064f-23f6-926a-671c-ccefba0c0...@marullo.it> > > Content-Type: text/plain; charset=utf-8; format=flowed > > > > Is it possible to display the actual OSC value instead of ppt? I tried > > /tx but surely I am doing something wrong. > > > > Yes, I am European, lol. > > > > TIA. > > > > Giuseppe Marullo > > IW2JWW - JN45RQ > > > > > > > > > > > > -- > > > > Message: 2 > > Date: Wed, 24 Apr 2019 14:46:06 + (UTC) > > From: RICHARD GOLDING > > To: time-nuts@lists.febo.com > > Subject: Re: [time-nuts] Z3801 Power Supply Schematic > > Message-ID: <1237404332.3862013.1556117166...@mail.yahoo.com> > > Content-Type: text/plain; charset=UTF-8 > > > > Many thanks to those who took the trouble to send me schematics of the > Z3801a PSU. > > I'm pleased to report that, using, the schematic, I was able to trace > and fix the fault and that GPS lock led is glowing again. > > The problem was a faulty regulator IC (U2 LM317) that had decided to > produce 1.8V instead of 2.5V, which resulted in the PSU thinking that the > input supply voltage was out of range. > > It does seem a very complicated circuit for what could be > straightforward voltage window comparator. i.e. 24R's, 8 Diodes, 3 > regulators, a comparator and logic IC + a handful of Mosfets! > > Thanks again for those that helped. > > 73 Richard, G3VZG > > ? ?? > > > > -- > > > > Subject: Digest Footer > > > > ___ > > time-nuts mailing list > > time-nuts@lists.febo.com > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > > > > > -- > > > > End of time-nuts Digest, Vol 177, Issue 29 > > ** > > ___ > > 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. > > > ___ > 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. > -- Sent from my iPad 4. ___ 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] Part 2: Atomic Clocks: It is important that they keep good time.
I think those are backup power supplies. On Fri, Jan 4, 2019 at 8:48 PM Hal Murray wrote: > > hugh.r...@hp.com said: > > ersal Time. This was done in our standards lab where we kept a rack of > > several HP Cesium standards. Hopefully the attached picture of the lab > > comes through for some of you. > > What are the units on the lower right with pairs of analog meters? > > Thanks for all the wonderful stories. > > > -- > These are my opinions. I hate spam. > > > > > ___ > 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. > ___ 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] Noisy clocks [Was: Atomic Clocks]
Bill, I've done much the same thing, putting the 113AR in a small rack cabinet stuffed full of Fiberglas® house insulation. I also lined the 113AR cabinet with rubber insulation designed for high-end auto sound system. The rubber absorbs high frequency vibrations and the Fiberglas® absorbs lower frequencies. I'm now working on installing the rack cabinet into an old kitchen cabinet lined with styrofoam and Fiberglas®. That should knock the noise down even further. Multiple plexiglas windows will allow the clock face to be seen; I'll add some LEDs inside the 113AR cabinet to illuminate the clock. Jeremy On Fri, Jan 4, 2019 at 7:56 PM Bill Hawkins wrote: > Well, your first clue should be the heavy box that contains the hardware. > Don't recall any other HP gear built that way. The box could have been an > aluminum casting. > > I had two of them with about the same noise, many years ago (but not > new). I used standard fiberglass wall insulation to line a wooden cabinet > that also contained the 103 crystal standard. That made the noise bearable > and kept the 103 temperature stable. Of course, you had to open the front > insulated door to see the clock. > > Never found out if it was the 1 KC stepper motor or the gearbox making the > noise. Should have tried heavy grease on the motor gears, but that would > make a mess of the chassis. Too late now. > > Bill Hawkins > > On Fri, Jan 4, 2019, at 4:01 PM, Jeremy Nichols wrote: > > Does anyone know how loud the mechanical analog clock in the HP-113AR > > Frequency Divider/Clock is supposed to be? Mine is loud to the point of > > being annoying. I've surrounded it with insulation, which helps, but it's > > not really quiet. I never saw one of these things when new (1960) so I've > > no idea whether the noise is simply a function of design and construction > > or if mine is worn after 50+ years of use. [The noise is mechanical > > gear-type noise, not 1000 Hz whine from the driving frequency.] > > > > Jeremy > > > > On Fri, Jan 4, 2019 at 2:11 PM paul swed wrote: > > > > > > > > On Fri, Jan 4, 2019 at 4:28 PM Mark Sims wrote: > > > > > > > My 5065A has the Patek clock. Those suckers are LOUD. You can hear > > > them > > > > ticking two counties away... hence mine is always disabled. Once > > > started, > > > > you have to power cycle the machine to get it to shut up. > > > > ___ > > > > > > > > > ___ > > 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. > > ___ > 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. > ___ 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] Noisy clocks [Was: Atomic Clocks]
I am fortunate that my 113AR came to me in excellent condition from an eBay seller and worked immediately. The noise is the only concern. On Fri, Jan 4, 2019 at 7:06 PM paul swed wrote: > Well don't know that anyone had one new. But they do have them and some > have shared pix of the cleanup they did. Has my respect. > Regards > > On Fri, Jan 4, 2019 at 9:51 PM Jeremy Nichols wrote: > > > Thanks, Paul. I have and there was. Unfortunately, there isn't much real > > information, no data one can use, just vague descriptions. Next time I > have > > the clock running I'll make a video, put it on YouTube, post a link here. > > Perhaps someone else has one and can compare. What would be nice would be > > to find someone who had a 113AR when it was new and could comment on the > > noise level out of the box. > > > > Jeremy > > N6WFO > > > > > > On Fri, Jan 4, 2019 at 5:38 PM paul swed wrote: > > > > > Do a search on time-nuts. I would swear some 3 years ago this was > > discussed > > > and they are annoying loud. It wouldn't have mattered im many > > environments > > > as there were other peices of equipment that had fans and such. But at > > home > > > we tend to hear lots of things. > > > Good luck. > > > Regards > > > Paul > > > WB8TSL > > > > > > On Fri, Jan 4, 2019 at 7:02 PM Jeremy Nichols > wrote: > > > > > > > Does anyone know how loud the mechanical analog clock in the HP-113AR > > > > Frequency Divider/Clock is supposed to be? Mine is loud to the point > of > > > > being annoying. I've surrounded it with insulation, which helps, but > > it's > > > > not really quiet. I never saw one of these things when new (1960) so > > I've > > > > no idea whether the noise is simply a function of design and > > construction > > > > or if mine is worn after 50+ years of use. [The noise is mechanical > > > > gear-type noise, not 1000 Hz whine from the driving frequency.] > > > > > > > > Jeremy > > > > > > > > On Fri, Jan 4, 2019 at 2:11 PM paul swed > wrote: > > > > > > > > > > > > > > On Fri, Jan 4, 2019 at 4:28 PM Mark Sims > wrote: > > > > > > > > > > > My 5065A has the Patek clock. Those suckers are LOUD. You can > > hear > > > > > them > > > > > > ticking two counties away... hence mine is always disabled. > Once > > > > > started, > > > > > > you have to power cycle the machine to get it to shut up. > > > > > > ___ > > > > > > > > > > > > > > > ___ > > > > 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. > > > > > > > ___ > > > 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. > > > > > ___ > > 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. > > > ___ > 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. > ___ 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] Noisy clocks [Was: Atomic Clocks]
BTW, does anyone have an HP-113AR manual they could copy and sell to me? I have a PDF of a 113BR manual, which is similar but not identical. Jeremy On Fri, Jan 4, 2019 at 6:50 PM Jeremy Nichols wrote: > Thanks, Paul. I have and there was. Unfortunately, there isn't much real > information, no data one can use, just vague descriptions. Next time I have > the clock running I'll make a video, put it on YouTube, post a link here. > Perhaps someone else has one and can compare. What would be nice would be > to find someone who had a 113AR when it was new and could comment on the > noise level out of the box. > > Jeremy > N6WFO > > > On Fri, Jan 4, 2019 at 5:38 PM paul swed wrote: > >> Do a search on time-nuts. I would swear some 3 years ago this was >> discussed >> and they are annoying loud. It wouldn't have mattered im many environments >> as there were other peices of equipment that had fans and such. But at >> home >> we tend to hear lots of things. >> Good luck. >> Regards >> Paul >> WB8TSL >> >> On Fri, Jan 4, 2019 at 7:02 PM Jeremy Nichols wrote: >> >> > Does anyone know how loud the mechanical analog clock in the HP-113AR >> > Frequency Divider/Clock is supposed to be? Mine is loud to the point of >> > being annoying. I've surrounded it with insulation, which helps, but >> it's >> > not really quiet. I never saw one of these things when new (1960) so >> I've >> > no idea whether the noise is simply a function of design and >> construction >> > or if mine is worn after 50+ years of use. [The noise is mechanical >> > gear-type noise, not 1000 Hz whine from the driving frequency.] >> > >> > Jeremy >> > >> > On Fri, Jan 4, 2019 at 2:11 PM paul swed wrote: >> > >> > > >> > > On Fri, Jan 4, 2019 at 4:28 PM Mark Sims wrote: >> > > >> > > > My 5065A has the Patek clock. Those suckers are LOUD. You can >> hear >> > > them >> > > > ticking two counties away... hence mine is always disabled. Once >> > > started, >> > > > you have to power cycle the machine to get it to shut up. >> > > > ___ >> > > > >> > > >> > ___ >> > 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. >> > >> ___ >> 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. >> > ___ 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] Noisy clocks [Was: Atomic Clocks]
Thanks, Paul. I have and there was. Unfortunately, there isn't much real information, no data one can use, just vague descriptions. Next time I have the clock running I'll make a video, put it on YouTube, post a link here. Perhaps someone else has one and can compare. What would be nice would be to find someone who had a 113AR when it was new and could comment on the noise level out of the box. Jeremy N6WFO On Fri, Jan 4, 2019 at 5:38 PM paul swed wrote: > Do a search on time-nuts. I would swear some 3 years ago this was discussed > and they are annoying loud. It wouldn't have mattered im many environments > as there were other peices of equipment that had fans and such. But at home > we tend to hear lots of things. > Good luck. > Regards > Paul > WB8TSL > > On Fri, Jan 4, 2019 at 7:02 PM Jeremy Nichols wrote: > > > Does anyone know how loud the mechanical analog clock in the HP-113AR > > Frequency Divider/Clock is supposed to be? Mine is loud to the point of > > being annoying. I've surrounded it with insulation, which helps, but it's > > not really quiet. I never saw one of these things when new (1960) so I've > > no idea whether the noise is simply a function of design and construction > > or if mine is worn after 50+ years of use. [The noise is mechanical > > gear-type noise, not 1000 Hz whine from the driving frequency.] > > > > Jeremy > > > > On Fri, Jan 4, 2019 at 2:11 PM paul swed wrote: > > > > > > > > On Fri, Jan 4, 2019 at 4:28 PM Mark Sims wrote: > > > > > > > My 5065A has the Patek clock. Those suckers are LOUD. You can hear > > > them > > > > ticking two counties away... hence mine is always disabled. Once > > > started, > > > > you have to power cycle the machine to get it to shut up. > > > > ___ > > > > > > > > > ___ > > 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. > > > ___ > 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. > ___ 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.
[time-nuts] Noisy clocks [Was: Atomic Clocks]
Does anyone know how loud the mechanical analog clock in the HP-113AR Frequency Divider/Clock is supposed to be? Mine is loud to the point of being annoying. I've surrounded it with insulation, which helps, but it's not really quiet. I never saw one of these things when new (1960) so I've no idea whether the noise is simply a function of design and construction or if mine is worn after 50+ years of use. [The noise is mechanical gear-type noise, not 1000 Hz whine from the driving frequency.] Jeremy On Fri, Jan 4, 2019 at 2:11 PM paul swed wrote: > > On Fri, Jan 4, 2019 at 4:28 PM Mark Sims wrote: > > > My 5065A has the Patek clock. Those suckers are LOUD. You can hear > them > > ticking two counties away... hence mine is always disabled. Once > started, > > you have to power cycle the machine to get it to shut up. > > ___ > > > ___ 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] 10 MHz -> 16 MHz
How about three doublers: 10 MHz -> 20 -> 40 -> 80 MHz and then divide by 5 -> 16 MHz? Jeremy N6WFO On Sat, Sep 29, 2018 at 9:17 PM Hal Murray wrote: > > > > What's a clever, simple, reliable (pick 2 of 3) way to get 16 MHz out of 10 > > MHz? Low phase noise isn't a big requirement and jitter doesn't need to be > > sub-nanosecond. The main requirement is perfect cycle count accuracy. This > > is > > for driving a 16 MHz microcontroller from a 10 MHz Rb/Cs/GPSDO. 10 MHz input > > is likely sine; 16 MHz output is 3v3 or 5v CMOS. > > There should be a PLL chip that includes the M and N dividers, but I'm not > familiar with that area. > > Some/many ARM chips include PLLs so you can use a convenient Xtal and run the > CPU at a higher speed. You might look for low cost break out boards for an > SoC ARM. Remove their Xtal, feed your 10 MHz into the right pad. Program it > to setup one of the counter/timers to do the right divide. > > > -- > These are my opinions. I hate spam. > > > > > ___ > 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. ___ 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] News
Congratulations, Magnus! J. On Thu, Aug 30, 2018 at 1:40 PM Magnus Danielson wrote: > Hi Bob, > > On 08/30/2018 10:33 PM, Bob kb8tq wrote: > > Hi > > > > Magnus … do you have some news you might want to share with the group? > > Oh, well, sure: > > Today I received a nice email from IEEE starting with: > "It is a great pleasure to congratulate you on your elevation to the > grade of IEEE Senior member. IEEE Senior Membership is an honor bestowed > only to those who have made significant contributions to the profession." > > I'm humbled by these words, but proud of the achievement and happy for > the distinction. This has been a process that has been going on since > spring when IEEE approached me and pointed out that I should be able to > become senior member, writing up a modern CV and then being interviewed > by three Senior Members was interesting, sharing the room with very > senior engineers, PhDs and professors all seeking to reach the IEEE > Senior member elevation. > > 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. > -- Sent from my iPad 4. ___ 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] Remembering Al Bagley
I am sorry to read of the death of Al Bagley, for whom I worked at HP in the 1970s, my first job after finishing school, at the Santa Clara plant, Division 02, the old Frequency and Time Division. Those were good times, when we were young and could do anything. Thanks, Tom, for providing this history lesson. Jeremy Nichols Santa Rosa, Cal. On Mon, Jul 16, 2018 at 11:34 PM Tom Van Baak wrote: > Some of you met, worked for, or at least know of Al Bagley. He was one of > the early guys at hp and very involved with time & frequency. > > (1) Here is recent news via https://www.seti.org/remembering-al-bagley > " > Al Bagley, one of the transformational engineers in Hewlett-Packard's > early days and a long-time member of the SETI Institute's Board of > Trustees, passed away on 24 June at the age of 94. > > At the SETI Institute, Bagley was known as a generally taciturn and > occasionally flinty board member with a deep background in technical > innovation and management. A graduate of Caltech and Stanford, Al had > decades of experience solving problems in the pressure cooker world of > high-tech - experience that prompted insightful comments on the development > of equipment for the Allen Telescope Array, an instrument that was being > planned and constructed during his Board tenure. > > Al (known to colleagues as "Bags") was one of the handful of HP pioneers > who established the company's impressive reputation for solidly-built > measuring equipment during its first few decades, eventually heading up > what became known as the Frequency and Time Division. The cesium atomic > clock developed under Bagley's leadership became the forerunner to > equipment that proved the tenets of Special Relativity and also made > applications such as GPS feasible. Without doubt, Al was part of the team > that ushered in Hewlett-Packard's Golden Age. > > Bagley's presence on the SETI Institute's Board was part of a small parade > of H-P luminaries who guided the research organization in its formative > years. Al was an exceptional talent and singular personality - one that > all who knew him will miss. > " > - > > (2) Here are some hp journal articles by Al Bagley that I remember: > > "The High-Speed Frequency Counter - A New Solution to Old Problems", 1951 > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1951-01.pdf > > "A New Performance of the "Flying Clock" Experiment", 1964 > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1964-07.pdf > > > > (3) Here's a very recent, detailed, delightful article that any hp test > equipment user or time nut should read: > > "MY LONG AND SATISFYING CAREER AT HEWLETT-PACKARD", by Alan Bagley, 2014 > http://hpmemoryproject.org/timeline/alan_bagley/career_00.htm > > which is summarized here: > > "Our Finest Hour," the Cesium Atomic Clock, circa 1964 > http://hpmemoryproject.org/news/flying_clock/celebration_01.htm > > In his HP Memoir chapter titled "Our Finest Hour," the Cesium Atomic > Clock, circa 1964, Alan Bagley, manager of the HP Time-Frequency Division > during more than 25 years, recalls: > > "That's a takeoff on the Winston Churchill WWII pronouncement, but the > technology which led HP to dominate the world of time keeping was based on > our best product to that time, literally our finest and most accurate hour. > By using the atomic resonance of the element Cesium, we created a time > standard based on atomic physics, and not the resonance of a quartz > crystal. This product was also in line with our stated product and business > strategy of providing extremely precise RF signals. > > Using this standard "Atomic Clock," our promotional department created a > well-publicized world tour, which was dubbed the "Flying Clock." The > chair-sized instrument usually occupied a first class airline seat, with > standby power supplied from the baby bottle warmer outlet in the galley. > The idea was to visit global standards labs including our U.S. National > Standard at the U.S. Naval Observatory in Washington, D.C. Then further > comparisons were made at Swiss Observatory in Neuchatel. The clock was > designed to maintain accuracy for 3000 years within only one second of > error, a truly remarkable leap ahead for time keeping. Just in time for the > Apollo Moon mission which required precise timing to carry out the critical > navigation and communications. > > The HP line of Cesium standards came to completely dominate the standards > world, with most large and aerospace companies buying their own resident > standard. And for decades, as the communications technology m
