Home KXPA100 100 Watt Linear Amplifier Firmware and Utility

KXPA100 100 Watt Linear Amplifier Firmware and Utility

 KXPA100 Current Production Firmware

MCU 1.39, 12-8-2016

All KXPA100’s ordered today will have Production Firmware loaded as they come out of the box. Monitor the Elecraft Email Reflector where announcements are made when new releases become available.

Elecraft delivers new features in firmware. As a result, you should consider the Release Notes as an extension of the Owner's Manual. Documentation for the new features will be found there and will not appear in the Owner's Manual until the next major manual revision is released.

Current Production KXPA100 Firmware Release Notes

  • Widen timing window to more reliably detect push button switch presses.
  • Enable PX3 image capture through KXPA100.
  • Requires updated PX3 Utility and PX3 firmware.
  • Change PC side RS-232 to 1 stop bit when transferring image.
  • Add manual switch to disable amplifier with ATU available:
  • MODE button HOLD now toggles power amplifier bypass.
  • Power ON LED blinks slowly when PA is bypassed.
  • See KXPA100 Firmware Release Notes for complete revision history.
  • Download the latest KXPA100 Firmware

These are the most Release Notes since the last Production firmware release. Please see your KXPA100 Utility → Help → Release Notes for all Release Notes listed in order of release.


Important - Please read before installing the latest Production Firmware

Production Firmware Installation Instructions are found in the Utility Help Facility

  • All Production Firmware is loaded with the KXPA100 Utility. It will take care of the download and installing Production Firmware
  • Before loading Production Firmware, please ensure you have installed the latest version of the KXPA100 Utility.
  • See the Help → Getting Started pull-down menu in the KXPA100 Utility for the steps to install firmware in your radio.

 Download and Install the KXPA100 Utility for your Operating System

Follow the links below to download and install the latest version of the Utility for your Operating System.

Minimum Operating System Requirements for Elecraft Utilities

Microsoft Windows: XP Service Pack 3 or later, including Vista, 7, 8, and 8.1 and 10.
Apple Mac: OS X 10.6 (Snow Leopard) or later



KXPA100 Utility for Windows (Version March 4, 2014

Note: This KXPA100 Utility version can be used to load KXPA100 Firmware versions 0.27 and above to your KXPA100.


KXPA100 Utility for 64bit MAC OSX (Version September 13, 2019

Note: This KXPA100 Utility version can be used to load KXPA100 Firmware versions 0.27 and above to your KXPA100.

X86 Linux

KXPA100 Utility for 64bit Linux (Version September 13, 2019

Note: This KXPA100 Utility version can be used to load KXPA100 Firmware versions 0.27 and above to your KXPA100.

Files are in TAR archive (gzip-compressed) format.


The following libraries and dependencies should be installed on your Linux distro:

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

Installing the FTDI driver

Follow this link to the FTDI Site for drivers: http://www.ftdichip.com/Drivers/VCP.htm

Depending on the Operating System you have, the driver needed for the Utility to communicate with the K3/K3S will need to be loaded.

All Elecraft products in production use the FTDI chipset for this function. The FTDI driver allows your computer to create a virtual COM port so that the Utility can communicate with the Elecraft product.

For K3, if your KUSB cable has a silver sheath on the wire, it is no longer supported.  Elecraft recommends that a KUSB cable be purchased for full support


KXPA100 Beta Firmware Installation and Release Notes

KXPA100 Beta Firmware Release Notes

None Right Now!

Beta Test Firmware Installation Procedures

NOTE: Beta test firmware may have new issues that we haven't caught during field testing. Please report them to support@elecraft.com.

A little more detail

We make it a little harder to load Beta firmware mainly because we want you to be sure you want to do this.  Beta firmware means that, while the KXPA100 engineering team has fully tested the firmware, it has not yet been deemed ready for Production status.   You can always return to the last firmware you have downloaded by following the steps in the KXPA100 Utility’s Help section.

To load Beta Firmware, follow the steps below:

1. Create a new folder for the beta firmware on your Desktop or some other easily found location. Use the a different folder than the default folder found in the Firmware tab of the Utility. In this way, you can revert to the last Production firmware easily.

2. Now, we will download the firmware in Zip file format. In a web browser, type in this URL:


If you do not see the correct version of the zip file, press the RELOAD/REFRESH button on our browser to update your browser cache.

3. Right-click on the .zip file containing the beta firmware (e.g. k3fwXrYZ.zip for revision MCU X.YZ and all associated files). Save the file to your beta folder you just created.

4. Unzip the files into the beta folder.

5. Enter the path to the beta folder in KXPA100 Utility → Firmware tab → "Local folder for firmware files".

6. After you have made the change in Step 5, make sure you *DO NOT* check the KXPA100 Utility box titled "Copy new files from Elecraft server". This will overwrite the Beta firmware if clicked.

7. Connect the KXPA100 to your computer and be sure it is turned on. Select the Firmware tab and Click on "Check versions now" button. 

8. Review the release notes. To find them, select the "Help" pull-down menu.

9. Click "Send all firmware to KXPA100." This will cause the firmware to be sent to the KXPA100. You will see that the KXPA100 appears to restart itself. Monitor the Activity Log until it is complete.

10. After completing a new software download to your product, please power cycle the KXPA100 OFF and then back ON before using it.

11. Please report any new firmware issues to support@elecraft.com