Automatic antenna disconnected detection?

Here's one of those famous "how difficult could this possibly be to implement?" ideas 😀

How about automatic detection of when the antenna is disconnected (by looking at the A/D values and seeing they are all very small, maybe this would need to be set in the Admin panel) and display of a message to that effect for users (say on the waterfall or some other prominent location).

Yes, I know it's possible to manually take the KiwiSDR offline and set a message, but for those of us with multiple KiwiSDRs, it would be nice. Plus it would alert users to the case where the antenna got disconnected but the owner doesn't know it: a tree fell down snapping the coax feed, or in my most recent case this past week, the DC inserter to my active Crossed Parallel Loop antenna failed, so the pre-amp was not getting any power.


  • If an admin MOTD-style message field was implemented it would be great to have an auto antenna detect message or just automatically change the background color of the MOTD when it was disconnected. Just some thoughts that I'd like to see make it into a future update.

  • I did wonder if the existing SNR measurement could be used to produce not only an 'antenna broken' message but also a propagation prediction, especially on the HF bands.

    This example, grabbed using Chris's KiWi SDR monitor software

    It shows an antenna fault that occurred at around midday on 03/28/2022 and also the days when the upper HF bands were active. Night time propagation on the 10 to 20MHz bands can also be seen to vary slightly.



  • With an increasingly active sun, as we are now seeing, I wonder if it might be difficult to use S, N or SNR to determine antenna broken-ness. On a good receive system achieving ITU propagated noise floor, SIDs from X-ray emission induced absorption may make a system look broken when in fact it isn't, it's simply dropping to the the local noise floor approaching KTB. These event are becoming more and more common.

    Glenn n6gn

  • Another though of mine was to compare signal levels over a short time period and generate a delta value. A large change would indicate a fault.

    Plotting FFT bin changes over a 24 hour time period would give an interesting view of day / night propagation too.



  • Just had a minor event. Here's the noise at N6GN/K2

    It might have to be a pretty short time period to differentiate antenna fault from absorption increase!

Sign In or Register to comment.