KX3 Software Page

KX3 Beta Firmware Revision

MCU 2.30 / DSP 1.32, 12-03-2014

Please read KX3 Beta Firmware Instructions for installing beta firmware.
Only the current production firmware releases can be downloaded by KX3 Utility automatically.

  • SPEECH COMPRESSION IMPROVED: Corrected internal DSP stage gain, resulting in higher output levels with compression turned on.
  • 2-M/4-M SSB POWER OUTPUT IMPROVED: Max power output improved with and without speech compression turned on. Note: The KX3 will automatically reduce 2-m/4-m power output if safe levels of SWR, current, or temperature are exceeded. (You’ll see HI SWR, HI CUR, or HI TEMP flashed on the VFO B display.) This is more likely to happen when heavy speech compression is used, or when using a whip connected directly to the radio. We recommend reducing power to 2 to 2.5 W as required in this case to avoid the automatic power rollbacks or RFI problems.
  • 2-M/4-M CW TIMING IMPROVED: Dot length is now more consistent.
  • 4-M/6-M DIRECT FREQ ENTRY FIXED: Direct frequency entry to 6 or 4 meters now works correctly with a KX3-4M module installed.


KX3 Production Firmware Revision

MCU 2.27 / DSP 1.30, 11-10-2014

See KX3 Firmware Release Notes for a complete revision history.
This release can be automatically downloaded by KX3 Utility.

  • RX I/Q PORT TURNED ON AUTOMATICALLY WITH PX3 ATTACHED: The KX3 now turns on the RX I/Q output whenever it detects an attached PX3. This eliminates the problem of image signals in the PX3 display due to RX I/Q being off.
  • IMPROVED FIRMWARE LOADING: Now handling case where new MCU firmware is incompatible with old DSP firmware in the middle of a full firmware load sequence. An error message may still appear in this case, but load timing will not be affected, allowing the new DSP firmware to be loaded correctly.
  • PX3 NOW DISPLAYS VFO B PASSBAND CORRECTLY: The PX3 was showing the wrong VFO B filter bandwidth or passband location when using DATA modes or DUAL RX (dual watch).
  • DUAL RX DOES NOT FORCE OFS/B KNOB TO BE USED AS VFO B: The operator’s OFS/B knob assignment is no longer lost when DUAL RX is in effect.
  • FAST-PLAY DISPLAY ERROR FIXED: With fast-play enabled (1-touch message play using BAND+/- and FREQ ENT.), a band change originating from a PC application no longer flashes “END” on VFO B.
  • CW SPEED DISPLAY TIME INCREASED WHEN TEXT DECODE IS ON: In CW mode, speed is now displayed for 1.0 sec. In FSK-D and PSK-D modes, it's .5 sec. The time is shorter for DATA modes because character transmission rates are usually faster, and the operator might miss important text due to the speed display.
  • PA BYPASS METERING FIXED: If the KXPA100 goes to bypass because of an error condition, the KX3 drops to 5 W. The RF meter is now correctly set to low range.
  • TEXT DECODE LOCKOUT FIX: Adjustment of NR, NB, NTCH, etc. no longer causes loss of CW/DATA text decode on the VFO B display.
  • HOST COMMANDS “UP”, “DN”, and “DT”: These are now working with the PX3.
  • SUPPORT FOR PX3 TEXT DISPLAY: To enable text decode on the PX3, hold LABELS switch to switch to text-decode mode (requires PX3 rev. 1.12 or later). Text decode must also be enabled at the KX3.


KX3 Archived Firmware Revisions

Please browse our KX3 Firmware Archive FTP Folder for obtaining archived KX3 firmware revisions.
Only the current production firmware releases can be downloaded by KX3 Utility automatically.


KX3 Utility and Drivers for Windows, Mac and Linux


Minimum Operating System Requirements for Elecraft Utilities:

Microsoft Windows: XP Service Pack 3 or later, including Vista, 7, 8, and 8.1.

Apple Mac: OS X 10.6 (Snow Leopard) or later

X86-based Linux: GTK+ 2.8 or later, glibc-2.4, libstdc++.so.6 and cURL. 64-bit Linux requires 32-bit compatibility libraries.


Elecraft KXUSB Cable for the KX3

Elecraft offers the KXUSB cable for USB only computers etc.  It uses the FTDI chip set.

Before plugging in this cable to any of your computer's USB ports, you may need to install the correct FTDI USB drivers for your computer's operating system.   Drivers are available for most Windows, Mac, and Linux OS's.  Note that most of the latest Windows 7 operating systems already have the proper drivers for the FTDI chip set and will automatically install them if you just plug the KXUSB cable into a USB port.

Connecting the KX3 to a Computer

If your computer has a standard serial port, all you will need is our KXSER cable for the KX3. .

Most modern computers no longer have serial ports but instead use USB (Universal Serial Bus) ports for connecting to external devices. Elecraft provides the KXUSB cable to connect the KX3 to these computers.

KX3 Utility Download


KX3 Tools and Application Notes