K4/0 SOFTWARE RELEASE NOTES =============================================================== ====================== R3 (PRODUCTION) ======================= =============================================================== June 17, 2026 This release is functionally identical to R3.BETA2, which has been tested and promoted to production status. See below for details. FSK RTTY BUG NOTE: At present, FSK RTTY transmissions from a K4/0 (or from a K4 used as a client) will not work unless TEXT DECODE is enabled. This will be addressed in a future release. (When operating a K4 standalone, FSK RTTY transmit will work with or without text decode enabled.) ======================================================== ====================== R3.BETA2 ======================== ======================================================== May 31, 2026 ------------ NEW FEATURES ------------ - RX AUDIO GAIN BOOST RANGE NOW -10 TO +6 DB: Previously, the RX Audio Gain Boost menu entry's range was 0 to +6 dB. The range has now been extended _downward_ (to -10 dB) for the benefit of operators with exceptionally sensitive headphones. In addition to reducing overall gain, this change can move the AF GAIN knob away from its minimum setting, improving granularity. --------- BUG FIXES --------- - NOISE REDUCTION TYPE LAST USED IS PRESERVED BETWEEN POWER CYCLES: The last type of NR selected, SSNR (new) vs. LMS (original) will appear on power-up. - TRANSMIT MONITOR AUDIO PRESERVED IN FSKD & PSKD MODES: Previously, TX monitor audio was lost in some cases, e.g. when using DTR for keying. -------------- FOR DEVELOPERS -------------- - The ME113 command (RX Audio Gain Boost) now takes negative numbers, e.g. "ME113.-10;". ME113.+; and ME113.-; also work as expected, with range -10 to +6. ======================================================= ====================== R3.BETA1 ======================= ======================================================= May 11, 2026 ------------ NEW FEATURES ------------ - ADDED SPECTRAL SUBTRACTION NOISE REDUCTION (SSNR): SSNR is a major enhancement to the K4's receivers, often suppressing background noise to nearly inaudible levels. In addition to making reception more pleasant, SSNR can often clarify signals near the noise floor that were highly degraded. SSNR works in all modes but is especially effect on speech signals. TO USE SSNR: Hold the NR LEVEL switch, change the algorithm from "LMS" (least mean squares, the original NR algorithm) to "SSNR", and select a level from 1-20. Higher level values will suppress noise to a greater degree, at the expense of some erosion of weak signals. As with all NR algorithms, the lowest effective value should be used. NOTE: In CW mode where weak or tightly packed signals are present, LMS NR may be preferred. Also, CW copy may be better enhanced by narrowing filter bandwidths or using APF rather than using NR. Filtering and APF can also be combined with NR and NB for maximum benefit. - RIT/XIT OFFSET KNOB SPEED REDUCED: The RIT/XIT offset knob's steps per turn rate is now set to 50 when VFO A is set for 100, and 100 if VFO A is set for 200 or 400. This makes fine-tuning of signals easier. - CLIENT FREQUENCY MEMORIES: The K4/0 (and K4 when used as a remote client) store their own set of GP and Quick memories internally. Those memories now apply to every server K4 to which the client connects. Any changes remain local to the client. Client activity never changes memories stored on the server. If two clients connect concurrently to the same server, they will each have their own set of GP and Quick memories. NOTE: When you first install this update, your *most recent* per-Server Quick Memories will be saved. Any memories that you save from now on will apply to ALL servers. As a one-time side effect, GP memories may be replaced by factory defaults, mostly blank except for 60 m presets. - NOW PRESERVING STATES OF SPLIT, TEST, VFO LINK, AND VFO LOCK: The new STARTUP macro (see below) allows full customization of the K4's power-up state, so we no longer automatically turn these settings off. - STARTUP MACRO: You can now automatically set up initial conditions each time the K4 is turned on, if desired, by editing the STARTUP MACRO. Tap Fn, then select MACROS. Scroll to STARTUP (at the top of the list). To bring up a text keyboard, tap the empty field at the right end of this selected line on the screen. You can bypass execution of the startup macro by holding the REV switch during power-on. For example, if you want SPLIT to be turned OFF on power-up, enter the command "ft0;" as the macro command. (A semicolon is required at the end of each command in the list.) Another typical use of the startup macro is to jump to a preferred frequency and/or mode. The command "fa14250;md2;" in the STARTUP macro would set the K4 to 14.250.000, USB mode. Refer to the K4 Programmer's Reference for full details on available control commands. --------- BUG FIXES --------- - ANT and RX ANT button configuration tracks server ANT CFG correctly upon connection. Changes made to ANT CFG while connected do not modify the ANT CFG of the Server, only the Client, and only temporarily for the duration of the connection. (Host commands RS2, ACM and ACT may be used to change Server ANT CFG while remote, if required.) - DVR message play can now be interrupted via PTT or VOX activation. RF switching artifacts eliminated from DVR message play. - Eliminated ALC/CMP metering glitch at start of remote transmission. Also eliminated false triggering of VOX. - TX Inhibit status on client now passed correctly. - RX EQ adjustments on client now adjusting server properly. - REV button now functions correctly when activated from a K4/0. - RX command now clears client streaming DVR message. -------------- FOR DEVELOPERS -------------- - DARS (start voice recording of speaker audio) is now allowed in the STARTUP macro. - Updated RS (Remote Set) command: * Added '2' as a new parameter for experimental mode command tunnel. RS2; enables a remote set command tunnel which, when enabled, causes commands to be forwarded to the server radio. For example, RS2;MG0;RS0; will set MIC GAIN on the server radio to 0 without affecting the client radio. - Added NRS command for SSNR configuration. Associated change to NR command (for LMS). - RX; command interrupts DVR messages sent to server. - RX; command interrupts KZ commands in progress on server. - TXPARAMS in status area no longer flickers between 0 and current value. =================================================================== ========================== R2 (PRODUCTION) ======================== =================================================================== April 2, 2026 -------- FEATURES -------- - NEW BATTERY STATUS INDICTOR IN STATUS AREA. --------- BUG FIXES --------- - ELIMINATED RESIDUAL CURRENT DRAIN ON BATTERY: Previously there was a persistent 16 mA current drain on the battery when the K4/0 was turned off and a battery installed. - AF GAIN ADJUSTMENT FIXED: Volume is now set correctly with SUB AF=BAL when connected to a server. -------------- FOR DEVELOPERS -------------- - PO command auto-info responses were sent to clients not in auto-info mode. - DARC; command now forces the DAP idle. Emit blank commands (DARS000..., DAPS000...) to clear display timers. - RX command was not terminating the DVR message when connected to a server. ======================================================== ======================== R1.FT5 ======================== ======================================================== Dec. 19, 2025 -------- FEATURES -------- - IMPROVED BATTERY STATUS MONITORING. K4/0 battery parameters are shown in the All Params display. (Tap LCD in status area, then hold All Params.) - LOCAL AND REMOTE SYSTEM PARAMETERS NOW AVAILABLE: When viewing the All Params list, tap the LOCAL/REMOTE switch to select client K4 ("LOCAL") or server K4 ("REMOTE") system voltages/currents/temperatures. -------------- FOR DEVELOPERS -------------- - The SI command now supports both local and remote system information updates: use "SI" for client info; use "SISI" for server info. - Added RROn; command to control display of "Remote" dialogs. RRO/; toggle display, RRO0; hide dialog, RRO1; display dialog. ========================================================== ======================== R1.BETA1 ======================== ========================================================== Dec. 4, 2025 - "mDNS" is now enabled, so you can connect to the K4/0 by its fixed host name K4Z-SN000xx.local instead of only by its numerical local IP address, which is subject to change. --------- BUG FIXES --------- - MONitor level no longer defaults to 5 when the K4/0 makes a remote connection. - Keyer/Paddle now enabled prior to making a Remote connection. - Cleaned up an audio keying artifact resulting from audio buffer management. - Eliminated DVR message delay (~200 ms) on transition from TX back to RX. - K4/0 no longer reboots or shuts off when battery is fully charged. - Radio keying via a host computer's DTR signal is no longer locked out after keyer paddle is used. - Improved hotel/business captive portal interfacing. - VOX gain and mic gain settings should match those on the K4. - SSB Monitor gain now responds correctly to MENU: Tx monitor level. - Sidetone/monitor audio is now present in both LineOut channels. - Both sound card channels have artifact-free TX monitor audio. - Built-in Help Text FIND and SCROLL are now usable. - MON level value is now remembered between local and terminal states. IE, if MENU is not set to =MON, changing the MON value while connected will be preserved when disconnected. - Cleaned up the "all params" voltage report to make it more readable. - While using the built-in manual, tapping "?" again exits. - Mic now functions correctly fter sending CW in SSB mode. - Cleaned up pops/clicks during TX -> RX transition, as well as when playing DVR messages on K4/0 client. - DVR messages can now be recorded and played on the K4/0 client when connected or stand-alone (not connected, and can be played back on the client. - LCD brightness settings now match the K4. - AUTO SPOT indicator now functions correctly. - K4/0 Charge Enable menu setting now initialized to "Always charge", the default. NOTE: The BATT STAT LED will be on while charging is in effect, then will turn off. You can use this to determine when charge has completed. -------------- FOR DEVELOPERS -------------- - SQ+/- commands now working correctly. SQ- command does not wrap. - EC (accessory echo command), when sent to the K4/0, is now forwarded to remote server. - MO command (menu open) now correctly opens menu on local client.