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KPA500 Software Page

See the bottom of this page to get the latest KPA500 f/w downloader - KPA Utility,  and KUSB Drivers.

Beta Firmware Revisions

MCU 1.47    November 15, 2015

Beta releases will not be recognized by the KPA500 Utility automatically.

Download: KPA_firmware_beta
Extract ZIP contents to your KPA500 Utility Firmware folder.

  • Updated Radio PC serial port handler to properly support Kenwood format. This version now supports memory operation and issues the correct polling sequence for Kenwood radios.

Current KPA500 Firmware Revisions

MCU 1.47  October 27, 2016

Production Release (shipped with new KPA500s)

This release will automatically be recognized by KPA500 Utility.

Please use latest KPA500 Utility to load.

Note: For KPAK3AUX cable use between the KPA500 and K3, K3 Firmware Version 4.36 or later must be loaded.
*Required by KPA500-Remote Software

New Features and Changes:

  • Updated Radio PC serial port handler to properly support Kenwood format. This version now supports memory operation and issues the correct polling sequence for Kenwood radios.
  • Enhanced operation with no BAND lines connected and RADIO=K3 or BCD. With POWER-ON set to OPER and RADIO=K3, on power-up the KPA will now go to operate mode when the K3 enables its band lines or if the band lines stay at all 1s for 4 seconds. If RADIO=BCD, it will go to OPER immediately after the power-on self tests have completed.
  • Serial commands received and processed during startup could cause strange behavior. Processing of commands during startup are now disallowed. They will still be received and will be processed after the startup state completes. Serial ports are now disabled at the beginning of shutdown so they cannot affect the process.
  • Added ^FS; serial command which returns the current fan speed. The format of the command is: ^FS; - gets the current fan speed. This is a get-only command. The response is: ^FSn; where n indicates the current fan speed from 0 (off) - 6 (full speed)
  • Corrected a situation where some parameter changes from serial port commands were not being properly saved.
  • Tweaked the Hi Reflected Power attenuation indication.
  • Corrected a HI REFL Fault bug.  



KPA500 Utilities and Drivers

Use this software to load the latest firmware into your K3.


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, and cURL. 64-bit Linux requires 32-bit compatibility libraries.


KPA Utility:



Elecraft KUSB Serial to USB Cable

Elecraft offers the KUSB serial-to-USB cable for USB only computers etc.   Our cable was originally provided using a Prolific chip set but since approximately July of 2010 we have been shipping KUSB cables which use the FTDI chip set.

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

Although both of these cables shipped with a mini CD, the drivers on this mini CD are not up to date.  Please follow the links below for the latest versions of the drivers.  Be sure to select the correct Operating System version.



Connecting the KPA500 to a Computer

The KPA500 uses a standard RS232 port implemented via a female DB9 for interfacing to external devices and programs.

If your computer has a standard serial port, all you will need is a straight through serial cable with a male DB9 on one end and the proper connector (usually a female DB9 or DB25) on the other end to plug into your computer's serial port and you are all set.

Many modern computers no longer have serial ports but instead use USB (Universal Serial Bus) ports for connecting to external devices. Elecraft provides the KUSB - USB to Serial adapter to connect the K3 to these computers. See above for the KUSB Drivers