Assorted ramblings from the developer

Release: 3.0.11

Download here [Link].

What's new / changed in 3.0.11:


  • CW Skimmer interface updated, minor bugs fixed. [Link]
  • Audio - minor change in WASAPI feed/output logic, buffers padded with zeros.
  • More intelligent buffering of unprocessed data in the FFT threads, improves resillience when main thread is interrupted.
  • Installation kit appearance updated.
  • Very minor enhancements to the processing behind the matrix display. I spent some time working out how I would get 48 receivers running smoothly – I haven’t done this, but at least I now know what I would have to do (multi-threaded Direct2D). I was running 20 receivers at once to test the above audio driver logic and wasn’t 100% happy with the performance.
  • NR3 – slight increase in sensitivity.

CTCSS squelch

  • CTCSS is an addition to the normal squelch.
  • Signal level is measured for each CTCSS frequency using Goertzel’s algorithm (the standard for this sort of thing).
  • Selected frequency level must be 5dB or more that the average measured across CTCSS tone range.
  • Once CTCSS frequency is detected the squelch stays open until the signal is lost. This will change in a future kit, CTCSS must be detected at least every two seconds (an over modulated transmission can affect the CTCSS tone).

Data Recording

As I use this a lot I attacked a few features which I didn’t like very much:

  • Recording Selection
    • Added [_] Reload on open which reloads the current folder when the Select Recording window is opened, rather than displaying the previous values which are stored in an XML file. As I use SSDs for the recordings the reload is fast, but an aged HDD may not be, hence the default which is to restore the previous values from a cache.
  • Playback
    • Added Gain (main toolbar only).
    • Slight change to the logic used to determine the display bandwidth when a file is opened.
    • Change to the layout of the Navigator window.
    • Added Show/Hide time button.
    • Dynamic positioning of the navigation grid based on available room in the window.


  • Fixed error displaying waterfall, spectrum and receiver markers where the radio was tuned close to 0 Hz.
  • Corrected redraw issues if the spectrum high value is automatic (Ribbon Bar, View,  Spectrum Scale, High) and the colour scale (right of display) is adjusted.
  • Tuning Bar
    o    Clicking the mouse in the unused area to the side of the tuning bar (bottom of display) now centres the tuning indicator at the click position, previously there was no action.
    o    Clicking << or >> at either end of the tuning bar now increments the offset by the zoom factor – 1 (was just zoom factor).
  • The new smoothing algorithm (One Euro Filter) now made symmetric.


  • Updated Favourites Organiser:
    • Tree is collapsed by default,
    • Added Expand and Collapse buttons.
  • When a Favourite is added a default title is suggested.
  • Tooltips now show the frequency and mode for the first three receivers.


  • Airspy HF+ update API library. Recommended that the latest firmware is installed, this is 3.0.0 or newer.
  • Airspy R2 small change in decimation processing.
  • Added initial support for WiNRADiO Sigma.
  • Lime:
    • Calibration updated:
      • Rx Calibration and TX Calibration buttons have icons which show whether the RX / TX is calibrated.
      • TX Calibration prompts to disable any PA before the calibration proceeds. Calibration must use the current TX antenna at a relatively high gain.
      • Calibration values are stored in XML files for each band.
      • Calibration always performed at the recommended internal gain of 64dB.
    • Logfile optionally sent to the system debugger (DebugView).

Spectrum Markers

  • Initial implementation: Ribbon Bar, View, Spectrum, Markers.
  • Intergration with DX Clusters will be the main focus of 3.0.12.


  • Only one definition per server.
    • When you select the server a list of available radios is displayed.
    • If the remote server is using this kit you will see ‘ X In use’ if the SDR is in use. Earlier servers will always assume it is available.
    • Your list of server definitions should upgrade automatically.
    • Test with my server: port 50101 .


  • When starting the console / applying a favourite only one receiver opens the audio output device at a time. Although there shouldn’t be a problem with multiple threads simultaneously opening an audio output at the same time it’s just better to do it this way, it’s cleaner and places less stress on the Windows mixer / driver logic.
  • Sanity improved when starting the program:
    • Ensure any floating panes are actually visible and not off the screen.
    • Rewrote some of the code for easier maintenance in the future (replaced fixed tables with dynamic logic).

Comments are closed.

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