Re: [time-nuts] China, GCJ-02 & cartography

I live at the edge of Boston Harbor, in the Charlestown Navy Yard. Tide stations, such as this one at Boston Harbor’s Fort Point Channel , report their tides against a locally-defined datum

[time-nuts] China, GCJ-02 & cartography

The following was published on an email list to which I subscribe. Can others on this list can shed more light on CGJ-02 vs WGS-84, and some of the representations made in this article? — Eric The Problem with Chinese GPS If you’re in a foreign country and try to read a map, you may find it

[time-nuts] Hat Creek observatory

Hi — Does anyone here have contacts with the Hat Creek Observatory? My partner and I will be in the area Jun 15 Fri afternoon through Jun 18 Mon morning. While reports state the site has a few kiosks for self-tourism, we’re geeky time/frequency, radio & astrophysics types that want to

Re: [time-nuts] unidentified HF time pips

This is a numbers station . — Eric K3NA > In a message dated 2/5/2018 12:34:36 PM Eastern Standard Time, > je...@hanler.com writes: > > > Ha, so I was jumping around looking for the same and found a guy on 15.016Mhz >

Re: [time-nuts] Some HP 10811 05071-60219 info!

“Wavy lockwashers” are actually a form of spring washer known as a — wait for it — “wave washer”. General design considerations and information here. Grainger and many others carry stock. — Eric > On 2018 Jan

Re: [time-nuts] General Radio Model 723D Precision Oscillator (Tuning Fork)

Another fascinating tuning-fork standard was used together with a Synchronome to govern the timing of pulses of Morse code on undersea telegraph cables in the British empire’s globe-girdling telegraph network. Timing was derived electromagnetically from incoming Morse code signals (a bi-polar

[time-nuts] Jefferts & Campbell recent papers

These may be of interest, if the papers have not been circulated here before. — Eric ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

[time-nuts] Fwd: A talk on Atomic Clocks by Steve Jefferts NIST Boulder Wed 11/15

For time-nuts in the Washington/Baltimore area... > > http://www.aps.org/units/maspg/ > November 2017 Event > > Date: November 15, 2017 > Speaker: Steven R. Jefferts > Topic: Primary Frequency References at NIST: Atomic Clocks > Time and Location: 1:00 p.m., with Q to follow in a 1st floor

[time-nuts] MIT flea meet-up for time-nuts

The MIT Flea occurs this Sunday (May 21) from 09:00–14:00. Come join us for a bite at Flour Café at the end of the block (190 Mass Ave) at 11:30. I’d love to hear about your time projects & lab, see your

[time-nuts] removing sidereal correlation

What other patterns, if any, are uncovered if one removes a smoothed sidereal variation? — Eric > Begin forwarded message: > > From: Jim Harman > Subject: Re: [time-nuts] Three-cornered hat on timelab? > Date: 2017 Apr 29 Sat at 10:14:58 EDT > To: Bob Stewart

Re: [time-nuts] Time-nut going England!

Do not neglect a visit to the Clockworks museum. Examples of the most accurate pendulum clocks ever put into production e.g., (LeRoy, Riefler, Shortt-Synchronome and Fedchenko) are among the collection there. Free — and the staff are very friendly and extremely

[time-nuts] Apr 16 MIT flea gathering of time-nuts

Are any other time-nuts planning to visit the MIT Flea market on April 16 Sunday? (So far I know of at least 3.) Contact me off-list, as we’re planning to meet for coffee/sandwiches at the nearby Flour café at noon. Even if you can’t make it, I’d like to meet you in person. Hopefully

Re: [time-nuts] Sinlge ADC multi-band receiver

This approach is known as “security through obscurity”, and is deprecated in the professional of information security. What one invents, another can discover. The most secure systems use well-documented algorithms with open-source software — widely scrutinized for bugs or implants, and

Re: [time-nuts] Antique precision timing device without electronics

On British submarine telegraph cable systems, repeater stations and receiving sites employed tuning forks. Repeater sites were at cable traffic junctions or islands; e.g., Ascension and St Helena Islands in the Atlantic, Cocos Keeling in the Indian Ocean, Norfolk Island (junction) and

Re: [time-nuts] HP 115CR Clock Powerup / Documentation

Hello Hugh & Luciano — Luciano: Hugh said his clock was a 115CR, not BR. The CR has the mechanical digital display. I have a 115BR that I want to bring back on the air after about 30 years of power-off in my father’s lab. The state of any electrolytic and tantalum capacitors after that

Re: [time-nuts] 1PPS users?

Speaking as an owner of a well-behaved mechanical clock: Clock rate performance over time can be done based on time interval measurements anchored to a solid frequency standard. No 1pps needed per se. Bring a clock to time is simplified with a timescale-accurate 1pps source. > On 2016 Dec 18, at

Re: [time-nuts] Time math libraries

I should clarify my intended application for “time math”. My company is deep in development of a system that, in part, records events on a blockchain. For various reasons a precise and accurate representation of time of the event can be important. How precise and accurate depends on the

[time-nuts] Time math libraries

(Apologies if this question has been addressed before. Archive search is rather cumbersome on a month-by-month basis.) Few people will be surprised to learn that MS Excel does not account for leap seconds when doing time math. See below for an example. This is just an example of many

Re: [time-nuts] HP Z3801A

Hi Joe — I’ll take the HP-58516A splitter, if you’re willing to see it separately. — Eric K3NA > On 2016 Nov 27, at 14:15 , Joseph Gray wrote: > > I'm selling my remaining Z3801A. Months ago, I replaced the original > GPS module with a more sensitive Oncore VP. At that

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

Kickstarter? > On 2016 Nov 03, at 16:07 , Bert Kehren via time-nuts > wrote: > > > Over the past there has been talk about building from scratch high > performance references. I think consensus was that it is out of reach. In > the mean > time Corby is reworking an

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

a few years 1978-1981 on international data networking problems. I think the Scace family has the record for maximum number of family members employed at NIST. — Eric Scace > On 2016 Oct 27, at 13:32 , William H. Fite <omni...@gmail.com> wrote: > > Just for the fun of it, here

[time-nuts] Ig Nobel ceremonies & time

I had the happy fortune to attend this year’s Ig Nobel award ceremonies, the agenda of which is found here . This was the 26th First Annual Ig Novel Prize Ceremony This year’s program featured “time”, including: a mini-opera “The Last Second”, whose plot

Re: [time-nuts] GPS antenna selection — lightning

Unfortunately, an antenna, cable, or piece of electronics located indoors is just as susceptible to lightning surges as one that is outdoors. Lightning-induced surges couple into these systems electromagnetically across a wide range (VLF to SHF) of frequencies. When you think about your home

Re: [time-nuts] Visiting Greenwich

Also in London, and not to be missed, is James Nye’s Clockworks Museum of precision astronomical regulators and electro-mechanical clocks, including working examples of each of the successive generations of top-accuracy pendulum clocks (Riefler,

[time-nuts] O-451A/u 5 MHz oscillator: more photos

I added some more photos of the O-451A/U to a Dropbox folder . There are no obvious manufacturer marks beyond the Western Electric contractor cited on the Coast Guard nameplate on the front panel. Note that the large

Re: [time-nuts] Mystery hp Ovens For Sale

http://www.loran-history.info/Johnston_Island/Johnston%20-%20OSC%20Msg%20221416Z%20Oct%2064.pdf states than an O-451/U oscillator was shipped to the Johnston Island LORAN station in 1967. We are getting closer... I am the owner of O-451A/U serial number 11. I would appreciate any documentation

Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV), with 5071A cesium clocks

For those of us who do not have TVs, pointers to an Internet source for viewing the show would be welcomed. Thanks! signature.asc Description: Message signed with OpenPGP using GPGMail ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

Re: [time-nuts] Western Electric O-451A/U double-oven XO

> On 2016 Apr 26, at 16:25 , paul swed wrote: > > Tom, > Thanks for sharing the photos. > > Comments > It looks like most of the items will clean up very well with a bit of TLC. Agree. That won’t be hard. Mostly sawdust from cellar storage at my parents’ home. > Tom

[time-nuts] Western Electric O-451A/U double-oven XO

Hi — I have finally retrieved from my parents’ home my original time & frequency standards lab, to which will be added my more recent HP Z3805A. The assembly contains: HP-113BR frequency divider/clock homebrew WWVB receiver & frequency comparator, with its own internal OCXO standard, that

[time-nuts] Western Electric O-451A/U double-oven XO

Hi — I have finally retrieved from my parents’ home my original time & frequency standards lab, to which will be added my more recent HP Z3805A. The assembly contains: HP-113BR frequency divider/clock homebrew WWVB receiver & frequency comparator, with its own internal OCXO standard, that

Re: [time-nuts] GPS jumps of -13.7 us?

I have an idle curiosity as to whether the erroneous UTC correction propagated into any high-speed trading platforms in the financial markets in a what that caused a disruption. signature.asc Description: Message signed with OpenPGP using GPGMail

Re: [time-nuts] "Selective availability" af accurate time for Appleusers?

Warning: the following may be apocryphal. I was once told: Sprint PCS networks distributed very accurate time to cell phones because GPSDO & accurate time was essential to the multiplexing technology then in use. In contrast, time of day at an AT GSM cell site depending on the accuracy of the

Re: [time-nuts] UPS for my time rack

I’ve used Anderson PowerPoles in mixed voltage environments successfully. A visual indication can be obtained by using other colors for the connector shell; e.g., red for +13 Vdc and blue for +25 Vdc… One can also re-orient one of the connectors in each pair by 90º or 180º to create a physical