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K4 High Performance Direct Sampling SDR Software

 Current K4 Production Software

K4 Production Software (Release 32)  December 13, 2022

K4 Production Software - General Information
  • K4 software updates are handled at the radio itself.  An ethernet connection is required to obtain new software. It is also possible to load (or re-load) software from a USB flash drive. For further information on that topic, please refer to the K4 Operating Manual.
  • The K4 provides new features via software. As a result, you should consider the Release Notes as an extension of the Owners Manual. Documentation for the new features will be found there and will not appear in the Owner’s Manual until the next manual revision is released.
  • K4 production software release notes appear below, followed by release notes for the present beta release.
Current K4 Production Software Release Notes


==================== RELEASE R32 =====================

December 13, 2022


- SSB/ESSB TRANSMIT AUDIO LOW-FREQUENCY RESPONSE IMPROVED: The nominal SSB transmit audio low-frequency rolloff can now be moved down from about 200 Hz to 100 Hz. (Amplitude at 100 Hz then increases by nearly 20 dB.) This selection is made using the new "TX Audio LF Cutoff, SSB" menu entry. IMPORTANT NOTES: (1) The 100 Hz selection is *always* applied in ESSB mode. (2) In addition to using this new SSB setting, you can control the transmit passband in all modes using TX EQ. (3) If you use USB or LSB for audio DATA modes such as PACTOR that require fast turnaround times, you should not use the 100 Hz SSB setting, because it slows turnaround by about 20 milliseconds. (The high-performance digital filter required to obtain a lower passband has additional "taps," resulting in greater delay.)


- KPA1500 / KPA500 LOSS OF BUTTON PRESSES: In previous releases, some amp front panel button presses could be missed by the K4 due to the concurrent handling of other band-change activity.

- RADIO LOCKUP DURING VFO MOVEMENT AT ~5600 KHZ: One operator discovered a radio lockup when moving the VFO in the vicinity of 5600-5620 kHz. This was due to incorrect lookup of ATU LC segment data, which has now been corrected.


- The "TQX;" command now bypasses other command processing delays to provide a more real-time response during "TX;" / "RX;" command transitions.


  • See K4 Software Release Notes for complete revision history.


    K4 BETA Software Release Notes


    None at this time.


    See K4 Beta Software Release Notes for revision updates.


    K4 Production BETA Software Installation Procedures

    To install the beta software, make sure you have an ethernet connection, then:

    1. Tap Fn, then hold UPDATE

    2. Use the pulldown menu at the top of the screen to select Beta Release (if you didn't have this selected already).

    3. Tap Check for Updates. This downloads the new code but does not do the installation. This gives you an opportunity to optionally tap "Release Notes" and read the notes first.

    4. When you're ready to do the installation, tap "Install".

    NOTE: If the status area shows error messages of any kind, try doing the install a second time. You may have had an older version of the update app itself, in which case a second install should complete the process.