ad: Alphaant-1

Off Grid Raspberry Pi clock FT8, WSPR, JS8, ...

Discussion in 'Amateur Radio News' started by OH8STN, Oct 18, 2019.

ad: L-HROutlet
ad: l-rl
ad: Radclub22-2
ad: Left-2
ad: Left-3
ad: L-MFJ
ad: abrind-2
  1. OH8STN

    OH8STN Ham Member QRZ Page

     
    WL4T, PE0XJ, ON7TW and 10 others like this.
  2. OH8STN

    OH8STN Ham Member QRZ Page

    Hello Operators.
    If you've ever wanted to use a Raspberry Pi off grid & without internet, for ham radio data modes like WSPR, FT8, FT4, JS8, ... I've published a new tutorial for setting up a real-time clock in your Raspberry Pi.
    73
    Julian oh8stn
     
    N6EY, KQ6XA and K8XG like this.
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    Cool Beans.

    Thank You.
     
    OH8STN likes this.
  4. OH8STN

    OH8STN Ham Member QRZ Page

    You are very welcome.
    73
    Julian oh8stn
     
  5. N1FM

    N1FM Ham Member QRZ Page

    Excellent! Thanks Julian!
     
    OH8STN likes this.
  6. OH8STN

    OH8STN Ham Member QRZ Page

     
  7. K4BFH

    K4BFH Ham Member QRZ Page

    OH8STN likes this.
  8. VK6HIL

    VK6HIL Ham Member QRZ Page

    I've only quickly scanned through the video but did you use a GPS as well ? An RTC will eventually drift without constant time correction. It might only be .25 seconds per day but it will be too far out of sync quite quickly otherwise. A GPS is a good permanent solution as it can extract an accurate clock as long as it can see the satellites.

    I used PI's with RTC's in the past just to cover the gap when network time via NTP was not available.
     
  9. OH8STN

    OH8STN Ham Member QRZ Page

    Awesome.
    I've considered adding stratem
    Ok, perhaps not a very thorough scan. Augmenting the GPS with an RTC, was mentioned within the first minute of the video. The GPS is an excellent reference, but requires some time to acquire satellites before updating the clock. The real time clock provides accurate time instantaneously upon boot, augmentingthe HPS while waiting for acquisition. If it's out of sync, the GPS will update it, once satellite acquisition happens. They are definitely better in combination, than individually.
    Internet NTP is easy, but as mentioned in the video, getting operators to be less dependent on the grid, makes them better prepared for grid down scenarios as in California, or Manitoba.
    73
    Julian oh8stn
    GPS Tutorial
     
    WL4T, AJ4EM and N6EY like this.
  10. N6KZB

    N6KZB Premium Subscriber QRZ Page

    Very good tutorial OM.
    Keep up the good work.

    Adios
     
    OH8STN likes this.
  11. ON7TW

    ON7TW XML Subscriber QRZ Page

    Very nice job!
    Thanks a lot ;)
    Willy - on7tw
     
  12. VK6HIL

    VK6HIL Ham Member QRZ Page

    Thanks Julian - yes I admit I ran through it with no audio quickly - apologies for missing it.

    Very good point about mixing the GPS and the RTC.

    Good video - thanks.
     
  13. KJ4YQK

    KJ4YQK Premium Subscriber QRZ Page

    What if the GPS system went down?
     
  14. KV6O

    KV6O Ham Member QRZ Page

    A single satellite failure can happen, but a total system failure would be a pretty rare event. By using a more accurate RTC (they do exist), your drift could be such that you could go 30 days or so without a GPS lock to sync to, and still be within the FT8 (and others) timing requirements. Alternately, many GNSS receivers can pick up more that one system - GLOSNASS and Galileo are another 2 systems out there, so that could be used should there be a GPS system failure.

    However, a major solar storm could conceivably take out multiple satellite systems, but working HF probably wouldn't be in the cards anyway...
     

Share This Page

ad: elecraft