Jaw-Dropping Atomic Clock Build

You could cruise the Internet bazaars for a talking clock but you’ll never find one as awesome as this. Just look at it… even if it didn’t work it would be awesome.

[Art] certainly lives up to his username. His Rubidium-standard atomic real-time clock is surely an example of hardware art. The substrate is a collection of point-to-point soldered perfboard modules. Each laid out meticulously. What does such layout call for? A gorgeous enclosure which doesn’t obscure your view of the components. For this he went with a copper tube frame and a custom fabricated aluminum chassis pan.

For the circuit itself [Art] tells us he wanted to build something akin to the old HP nixie frequency counters so he went with logic chips. The pictures and a few video annotations are the only clues we have for how this works. Hopefully your encouragement in the comments will help prompt him to share more about that.

Oh, and the talking clock part that we referred to earlier? Every minute you get a readout of the time thanks to a PIC playing back audio using [Roman Black’s] BTc sound compression algorithm.

44 thoughts on “Jaw-Dropping Atomic Clock Build

      1. The HP Nixie frequency counters are full of boards with discrete logic for the counting, triggering, etc. circuits. That was the only way to do it in the 60s when the equipment was built. I have one here. Weighs a fricken ton.

  1. Wonderful, can’t think of a more wasteful application of a FE-5680A. Not even a 10MHz output. Please just give me that FE-5680A, I’ll give you a nice OCXO, which is still a waste but you probably won’t notice it.
    Hackaday now is ugly and full of lamerz.

      1. Yes I’m king lamerz. Because if I’d become lame enough to build something as useless as this, I’d make it especially lame, so I’d at least win the lamerz award and not just being unwillingly lame.

        Like using 1pps output, coding a crap PLL in software using a f****ng Arduino just get 32.768 kHz with extra lame phase noise and feeding that crap into the quarz input of an analog clock pulled out of the Walmart dumpster

        1. You know something, a whole lot of us learned invaluable lessons building useless devices. The more complex the useless device, the more we learned. If I got discouraged and scrapped an idea every time I encountered someone like you, I never would have learned anything. Please stop putting people down.

        2. 1pps output into a quartz clock movement?….

          OK, I’m down with that! I will purchase the parts and send in my results, if only just to see your head explode! I would consider that money well spent. :) Seriously, I like the idea!

  2. Nice build, duly xposted to 4HV :-)
    Also I see that there are now single chip rubidium sources, this is pretty amazing and as a result all the “old” non-single-chip ones are likely to show up surplus pretty soon as seen here.

    Re. OCXO, I’ve run into these in old 2G baseband boards and some old frequency counters (ie mine) use them.
    The 10 MHz should be broken out to a pin though as this can be very handy for calibrating counting instruments and with a F-V converter for calibrating voltmeters as well.

  3. See that waveguide? Brings up memories. I was being shown a mutiplexed receiver system and the tech showing me around explained the tubes as air tubes that you have to make sure are tight otherwise the air leaks and then that one channel won’t work.

    Thanks for spurring the memory…. and a good laugh.

    Pity is, these young kids coming up aren’t getting that great an education.

    Very nice work by the way! I very much appreciate you showing it to us. Thank you very much for posting it on the web.

    And thank you hackaday for reposting the author’s work so we could see it!

  4. After very nice build, my first thought; don’t try to transport via carry-on luggage, your explanations of a rubidium frequency standard based clock will be reciprocated with lobotomized stares, a cavity search, and admission to the no-fly club. Second thought; I like the copper pipe frame but why hide it? polished, lacquered, copper would add a touch of steampunk.
    Agree with Zaprodk, nixie tubes!! or some stepper based analog dials maybe?
    Anyway, keep doing!!

    1. Hi, It’s not irrelevant, but for bargraphs I thought it looked odd MSB first, and more logical in logic order. If it had have been nixies I’d have arranged them in order. For the HF radio work though, the MSDs are already known and only a few LSDs are needed.

  5. That’s the most blinkenlights per square inch EVER. I LIKE. And don’t listen to that guy about arranging the counters the other way – they’re beautiful just as they are. Just one suggestion, though: add some bling to the audio, like a “tick, tick, tick” at one-second intervals, culminating at 55 seconds with “At the tone, zero hours, seven minutes, Universal Coordinated Time – deeep”. I mean, it’s only software, and the current implementation has the time hack at the beginning of the announcement, which is kind of backward.

    1. It would be easier just to finish the radio and receive WWV on 10MHz!
      For the finished project you request the time on a mark, you don’t wait for it.
      Think DTMF over VHF and real time announced back to you.

      1. If you don’t KNOW what time it is, you need the time before the hack. That’s why WWV puts it there. That, and it gives you plenty of warning just how close you are to the hack.

  6. I love you Hackaday, just when I was in need of a neat way to cram shitloads of audio samples to be played with the least clock cycles effort, there you come with a uberneat project of this blinky blinky rubidium clock that uses the neatest of algorithms to encode and playback audio using 1-bit compression!!!

  7. It’s not the same chip running the clock as playing the sound Michele. I doubt you would get away with any time splitting to run another program on the audio player (16F628A). It waits for a five bit control signal from the main chip to signal one “digit word” or syllable (i.e.. To speak “Thirty-Five” is the “Thir” from “Thirteen”, the “ty” from” Twenty”, and the “Five” is an entire word sample).
    Having said all that this is only mid range pics because I’m in the 80’s-90’s right now. If you could time split looking up display lookup tables with reading i2c hardware and shifting bits for sound then I think it could be done with one chip now.

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