Wide-band WebSDR

Find your own numbers stations!

On this page you can listen to and control a short-wave receiver located at the amateur radio club ETGD at the University of Twente. In contrast to other web-controlled receivers, this receiver can be tuned by multiple users simultaneously, thanks to the use of Software-Defined Radio.

The system is currently composed of a "Mini-Whip" antenna, a homebuilt SDR board which samples the entire shortwave spectrum and sends all of this via a gigabit ethernet link to a PC, where a special version of the WebSDR server software processes it.

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6 Responses:

  1. The Mini-Whip is the latest in a long line of "small" HF antennas that simply turn the coax feedline into the antenna. Oldest trick in the book.

    "The demonstration supports the analysis above, the performance of the system without a significant length of feed line common mode conductor is seriously degraded, the feed line common mode conductor is a significant part of the antenna system."


  2. James C. says:

    The SDR.hu site lets you pick from a huge number of similar WebSDRs. Many are actually the KiwiSDR which is a little self-contained Linux box with a custom FPGA for the radio hardware that is controlled by a web-based UI.

    • James C. says:

      Also, Priyom.org has a Google Calendar schedule of numbers stations that you can use to find the next predicted broadcast in your target area. This combined with the plethora of KiwiSDRs means that you can listen to numbers stations live from their best broadcast regions all day long.

      A consequence of the widespread installation of KiwiSDRs, which have GPS-disciplined clocks, is that they can be used for remote radio direction finding and geolocation of signals. The work on this is still preliminary and ongoing, but we may in the near future be able to precisely geolocate numbers stations and other weird broadcasts using just WebSDR data.

  3. robert_ says:

    This Dutch one can pick up a number of UK AM stations. For example, 198KHz (BBC Radio 4) comes in quite clearly.

    • Nick Lamb says:

      Note that 198kHz is Radio 4 _Long Wave_ and at times may be broadcasting something quite different from "normal" FM Radio 4, listings may mark such divergence LW or might ignore this older frequency altogether, it's core listeners know where to find it anyway.

  4. Ray says:

    UVB-76 can be heard at 4625kHz most of the time. The russian station is also know as the Buzzer.

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