[Elecraft] New K4 & K4/0 Beta releases: Spectral Subtraction Noise Reduction and other features

Mon May 11 18:07:49 EDT 2026

Nope, the K3 available programming memory is full and the hardware used 
is not the same (it's less capable).

The K3, while still eminently still a great rig (in my storage bin), 
won't be updated again (in part because the programming cost for a past 
End Of Life rig and which firmware is always given out for free, returns 
no investment; there is no budget for K3 development and programmers are 
NOT cheap).

73,
Rick nk7i

On 5/11/2026 3:01 PM, Dave Sublette via Elecraft wrote:
> Speaking of back porting to the KX3, what about the K3?  Any hope that this
> might end up on the K3 also?
>
> K4TO
>
> On Mon, May 11, 2026 at 3:37 PM Wayne Burdick via Elecraft <
> elecraft at mailman.qth.net> wrote:
>
>> The latest beta release for the K4 and K4/0 software includes the
>> long-awaited Spectral Subtraction Noise Reduction feature (SSNR). Our Field
>> Testers have found our SSNR algorithm to work very well in all modes,
>> especially SSB and CW, with many commenting it's the best NR they've used.
>>
>> We've also implemented a new STARTUP macro capability. This allow users to
>> customize the K4's power-up behavior. For example, you can have SPLIT
>> always default to OFF if desired.
>>
>> This beta release is recommended for all K4 users. Please test using all
>> bands, modes, and features you normally use, while also giving SSNR a good
>> workout. For full details see release notes below.
>>
>> IMPORTANT: If you have both a K4 (or K4D) and K4/0, you'll need to install
>> new software on both. This is necessary to coordinate access to new
>> features between the two units.
>>
>> 73,
>> Wayne
>> N6KR
>>
>>
>> ===========================================================
>> ====================== K4 R38.BETA3  ======================
>> ====================== K4/0 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.
>>
>> - Internal storage for frequency memories now based on Client (K4/0) serial
>> number.
>>
>> --------------
>> 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.
>>
>> --
>> Elecraft, Inc.
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