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K4 High Performance Direct Sampling SDR Software

 Current K4 Production Software

K4 Production Software (Release 34)  September 15, 2023

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 

====================== R34 (PRODUCTION) ====================

Sept. 15, 2023


The release notes below are a merge of all R33 beta 1/2/3/4 release notes, showing everything that has changed since the R33 production release.


- SUPPLY OVER-VOLTAGE MEASUREMENT: If the K4's supply voltage is found to be excessive, an alert will be displayed. If the condition persists, the radio will be powered off for safety purposes. Note: Max supply voltage is specified as 15 V.

- ADDED "TX MONITOR METHOD, VOICE" menu entry: When this menu entry is set to "Fast", all speech processing effects and delays are removed from the voice monitor.

- UPDATED BUILT-IN OPERATING MANUAL TO REV C29: This edition includes a number of corrections suggested by K4 users.

- AGC SPEED SETTINGS: AGC speed (slow/fast) is now correctly stored per-mode rather than per-VFO or per-band. (Also see related bug fix below.)

- NEW APF BANDWIDTH: The CW audio peaking filter now has three settings: 30, 50, and 150 Hz. The new 150 Hz setting allows APF to be used with faster code speeds.

- THREE QSK METHODS: The TX QSK Method menu entry now has three settings. Method 1 is unchanged from the last production release; it uses slightly longer mute times to create the cleanest possible QSK. Method 2 is the same as the original, except that it uses a new DSP algorithm that results in a bit more recovered audio. Method 3 is is the same as Method 2, except that some users report that it provides reduced artifacts (as compared to Method 2) when using the internal keyer at speeds of 47 WPM or higher. NOTE: With all three settings, the primary goal is to eliminate "clicks," "thumps," or other artifacts that may occur when operating near very strong signals (S9+). Such a signal must be present within +/- 2 kHz of the K4's VFO setting in order to evaluate the various QSK methods. Otherwise there are no artifacts at all.


- "NO RECORDED MESSAGE" BUG: When doing AF RECord, this message would be displayed if the recording filled the 90-second buffer.

- MESSAGE CHAIN/REPEAT FIX: CW/FSK/PSK chained and repeated messages are now correctly spaced.

- DETECTION OF ESC ON LOCAL KEYBOARD: With a local keyboard plugged into the K4 for TX text entry, the ESC key now properly terminates messages.

- DIV LED now turns on if diversity is in effect at power-on.

- SOFTWARE UPDATE FIX: 'Check for Updates' now correctly updates all release selections with the latest revision numbers.

- TRANSMIT STATUS INFORMATION FIXED: Previously, in some cases power output would be displayed incorrectly, e.g. showing a nonzero value during receive.

- MSG REPEAT TRUNCATION FIXED: Previously, repeating a message with more than 24 characters would result in truncation of some portion of the message. Messages can now be up to 60 characters.

- ELIMINATED "MOTORBOATING" (4 Hz cycling of transmitter when MIC gain = 80).

- ELIMINATED VOICE MODE POWER SPIKES: Previously, asserting PTT could lead to a brief spike in output power ahead of normal transmit audio.

- XVTR CONFIGURATION: Transverter configurations are now correctly maintained after software updates.

- XVTR QUICK MEMORIES: These now function correctly.


- DVR VOICE MESSAGE PLAYBACK CLICKS: The beginning and ending of buffers are now truncated by 21 ms to help mask any mic clicks recorded in the message.

- DVR CHAINING: Sometimes when chaining multiple messages, one of them may not have played, but the radio would have stay keyed up for the remaining time as if it were playing.

- AGC SETTINGS: A/B VFO swaps and copies no longer result in loss of the operator's AGC speed setting. Similarly, settings are no longer lost when the text decoder is used.

- TX ANTENNA SELECTION: TX ANT settings that are invalid, such as XV OUT on an HF band, are no longer allowed. Previously, it was possible to inadvertently get into this state with a remote-control command.

- TX GAIN SETTINGS: In rare cases, per-band transmit gain calibration data was becoming altered as a side-effect of a band change, swap, etc. This should no longer occur.


- RU/RD COMMANDS: These encoder up/down simulation commands now work when the RIT/XIT offset knob is assigned to an alternate function.

- ADDED FC COMMAND VARIANT: The existing "FC;" command centers the panadapter. You can now provide an offset of up to +/- 99999 Hz, e.g. "FC-5000;". This might be useful when optimizing the panadapter presentation for a given band segment. NOTE: Nonzero panadapter offsets do not apply to tracking mode.

- KY command no longer inserts spaces unexpectedly (example: KY A;KY A; now sends AA not A A). RELATED NOTE: The KY command has a 60 character limit. Any KYR command used for MSG RPT operation has a 60 character limit for repeat. If your message is longer than 60 characters, then MSG RPT may not behave as expected.

- KYW command now always waits before processing the next command (example: KS10;KYW A;KS20;KYW B;FT1;).

- RX; command can now kill TX during a KYW wait command.

- Added support for MENU toggle,incr,decr commands ( MEnnn./; MEnnn.-; MEnnn.+; ) Toggle command behaves the same as decrement on non-binary menu entries.

- UP/DN command: Encoder simulation/emulation performance improved.

- External command performance improved: May help resolve "lag" that appeared in R34.B1 compared to R33 with external host applications.

- Added RD/RU command alternate set format RD0nnnn; RU0nnnn; for direct Hz adjustment.

- Properly implemented RD/RU commands.

- Finished XVP command implementation.


  • See K4 Software Release Notes for complete revision history.


    K4 BETA Software Release Notes


    No BETA Updates 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.