TH-K20A / TH-K20E / TH-K40A / TH-K40E
Firmware update information
Last updated : December 9, 2015
The TH-K20/K40 firmware has been updated from Version 1.20 to Version 1.21 as follows.
We are offering the firmware updating program to the TH-K20/K40 owners.
You can update the TH-K20/K40 firmware by connecting the TH-K20/K40 to the PC by using an optional Programming Cable KPG-22U.
Updated item : (Version 1.20 1.21)
  Revises the following symptom.
1. When the Lock function is ON, PTT or VOX operation may not work correctly under certain conditions.
Updated item : (Version 1.19 1.20)
  Revises the following symptom.
1. S meter might temporarily show an incorrect reading when the [MONI] key is pressed.
Updated item : (Version 1.18 1.19)
  Revises the following symptom.
1. Memory Scan may not work correctly when Weather Alert is ON.(TH-K20A K-type only)
Updated item : (Version 1.17 1.18)
  Revises the following symptom.
1. When the radio is tuned off/on while scanning, the scan resume method may change to [TO](Time Operated mode) despite setting to [CO](Carrier Operated mode) or [SEEK](Seek mode).
Updated item : (Version 1.15 1.17)
  Revises the following symptom.
1. The radio might lock up under certain conditions.
Updated item : (Version 1.10 1.15)
  Revises the following symptom.
1. The radio might not store the status of Auto-Repeater-Offset correctly.
Updated items : (Version 1.00 1.10)
  Updates the following features.
1. Adds the UHF models TH-K40A/E.
2. Enables modulation from an external microphone when the main PTT is pressed as well as the external microphone's PTT.
Applicable models/units :
The firmware updating program is applicable to the following models/units.
Models: TH-K20A, TH-K20E, TH-K40A, TH-K40E
Serial numbers: From S/NO.B1Bxxxxx through S/NO.B5Bxxxxx approx.
Notes : You can find the serial number imprinted on the rear panel after removing the battery.; It consists of an 8-digit number beginning with "S/NO."
: You can check the firmware version of your TH-K20/K40 by pressing #[ENT] + Power ON.
The firmware version appears in the LCD display.
Operating Environments
1. Operating System (OS)
  Windows Vista® (Service Pack 2 or later)(32-bit or 64-bit)
Windows® 7 (Service Pack 1 or later) (32-bit or 64-bit)
Windows® 8 (RTM or later) (32-bit or 64-bit)
Windows® 8.1 (RTM or later) (32-bit or 64-bit)
This software is designed to run on the above operating systems.
This software also runs on Windows® 10 and Windows® 11. (Noted on June 23, 2022)
Applicable operating systems are subject to change without notice due to the end of the technical support by Microsoft Corporation or change of the product specifications.
2. Processor
  Faster than the recommended CPU for each OS.
3. System Memory (RAM)
  Larger than the recommended System Memory for each OS.
4. Free Hard Drive Space
  Larger than the system Hard Drive Space for each OS.
5. Runtime
  Microsoft .NET Framework 3.5 (includes .NET 2.0 and 3.0).
6. Peripheral Devices
A display with resolutions higher than VGA (640 x 480).
A keyboard and a mouse, or other pointing devices.
A USB 2.0 interface.
7. Programming Cable
An optional Programming Cable KPG-22U.
A Virtual COM port driver needs to be installed onto the PC to use the KPG-22U programming cable.
If you do not want to lose user data, save the data using the Memory Control Program MCP-5A before updating the firmware and write the data back after updating the firmware.
Turn the transceiver OFF before connecting it to a PC.
Notes on usage
Users are required to obtain an approval from JVC KENWOOD Corporation, in writing, prior to redistributing this software on a personal web page or packet radio.
Users are prohibited to assign, rent, lease, or resell the software.
Users are prohibited to revise, change, translate, merge, de-compile, or reverse engineer the software.
JVC KENWOOD Corporation does not warrant that quality and functions of this software comply with each user's purpose of use of this software, and unless specifically described in this document, JVC KENWOOD Corporation shall be free from any responsibilities to any defects and indemnities to any damages or losses. Selection and installation of this software shall be done by the user's own designation. The user shall take full responsibility for the use and effects of this software.
JVC KENWOOD Corporation shall be free from any responsibilities for any incidental losses or damages, such as missing communications or a call opportunity, caused by a failure or performance error of this software.
JVC KENWOOD Corporation shall own all copyrights and other intellectual properties for the software and all manuals and documents attached to the software. The user shall be allowed to use, not to resell, the software by obtaining a license from JVC KENWOOD Corporation. While the media on which the software is stored is possessed by the user, the ownership for the software itself shall be reserved for JVC KENWOOD Corporation.
Extract the downloaded file "" into a designated folder.
In the designated folder, a folder labeled "TH-K20_K40_V121E" will be created.
In the folder labeled "TH-K20_K40_V121E", two files "TH-K20_K40_V121_e.exe" and "TH-K20_K40_e.chm" are automatically created.
1) Start the program by double-clicking "TH-K20_K40_V121_e.exe" icon. 
2) Connect the transceiver to a PC by using an optional programming cable, and select the COM port you will use by following the Help file.
3) Proceed firmware updating by following the explanations in the dialog boxes.
Delete the folder labeled "TH-K20_K40_V121E" manually using the Explorer or an alternative method.
This software does not modify the system registry parameters or system folder.
If you agree with the details listed above, click the following link to download the firmware updating program.
(The latest version includes all previous updates.)
TH-K20/K40 Firmware Update Version 1.21 (December / 2015) : 670KB download
Microsoft, Windows, Windows Vista, and Windows logo are registered trademarks of Microsoft Corporation in the United States and other countries.
.NET Framework is a registered trademark or trademark of Microsoft Corporation in the United States and other countries.