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GPS Synchronized Clock?

Discussion in 'General Technical Questions and Answers' started by KA2IRQ, Nov 6, 2019.

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  1. KA2IRQ

    KA2IRQ Ham Member QRZ Page

    Is there a station clock on the market that is synchronized to GPS instead of WWVB?

    I love WWVB as much as the next ham... but it would seem to me that GPS is an excellent time distribution system and would serve as a better time sync for consumer level clocks than WWVB would. At least to have the option...

    I know you can buy a USB GPS receiver and plug it into a computer, run some software, and voila! But I'm talking about a self-contained display clock.

    Just a thought.
  2. W9KEY

    W9KEY XML Subscriber QRZ Page

    I've not seen a GPS enabled "wall clock", but will be interested in what others have found.

    One big issue that detracts from their possible marketability: GPS reception inside buildings is spotty, at best -- and impractical for any multistory or high rise structure - unless you get the clock right next to a window where it could "see" a satellite or two. Or I suppose a clock with remote antenna could be designed, but then harder to compete on price with all the common $20 "Atomic Clocks" that are out there now.

    WWVB's 60 kHz signal offers better penetration into normal structures.
  3. W0KDT

    W0KDT XML Subscriber QRZ Page

    There are any number of used Android tablets out there below $100. GPSTest is the app I use but there are many of them. Another option is any cell phone or tablet's "clock" which gets its time from the cell phone system, also very accurate.
  4. VA3VF

    VA3VF Ham Member QRZ Page

    Another option, an old car GPS receiver. Some of them have grayline mapping, if I recall.
  5. KE0CAA

    KE0CAA XML Subscriber QRZ Page

    I havent seen any standard wall clock models specifically because of the gps signal propagation issues. I have however seen enterprise grade rack mounted gps time sources that have a time display on a front mounted lcd panel that also output an ntp time source. They are usually fairly expensive and significantly beyond what anyone typically would require.

    There are a few much more cost effective options available depending on how involved you want. A raspberry pi connected to a monitor syncing its time from ntp and displaying it as a screensaver clock would work but require some minor skills and not look all that clean.

    an echo dot with a built in clock display should also have a reasonably accurate ntp based timesource as well.
  6. KA2IRQ

    KA2IRQ Ham Member QRZ Page

    I was thinking that the signal itself would be an issue. But you could also put a WWVB receiver in there for times when there is no GPS signal. Additionally, you don't really need a full-fledged GPS signal, you just need one satellite to give you accurate-enough time. GPS systems are looking for a minimum of three satellites if memory serves correct. To get accurate time, you just need one.

    I think it should avoid using anything derived from the Internet/NTP, unless maybe that was a third option. But now it's starting to get expensive.
  7. KF5FEI

    KF5FEI Ham Member QRZ Page

    Arduino, LCD display and a GPS module. And with a bit more code, you can get it to calculate your grid square.
  8. W9GB

    W9GB Ham Member QRZ Page

    ADAFRUIT Project
    D57DD534-D140-4328-BB3F-E31F1B5A91E1.jpeg . 73B6954E-1B05-4131-B81E-13DF9133ADE4.jpeg
    This is a project to build a clock with an Arduino that sets itself using time broadcast from GPS satellites.
    Hardware Required

    Time-Nuts™ is a mailing list for amateurs who are interested in precise Time & Frequency.
    Topics include stability of quartz oscillators, measurements of rubidium and cesium atomic clocks, using WWVB, Loran-C, and GPS for long-term comparisons.

    Most of the members are hams or electronics hobbyists. Topics also include acquisition, repair, and operation of surplus electronic instruments related to precise time; nanoseconds; picoseconds; results of homebrew hardware and software T&F projects, etc.

    Please join if you have questions or expertise to add to the group.
    The time-nuts forum signup and archive is at:
    Last edited: Nov 6, 2019
    KD0CAC likes this.
  9. AG6QR

    AG6QR Premium Subscriber QRZ Page

    True, and it can be received using much less power. Two AA batteries can keep a clock running for many months while syncing a couple of times per day to WWVB. GPS requires the receiver to stay on for long periods to download almanac and ephemeris data.
  10. KA2IRQ

    KA2IRQ Ham Member QRZ Page

    Actually a very good option. I was thinking of rolling my own at some point, but I wanted to see if there was anything already on the market.

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