FlexRadio FLEX-6400M firmware v3.9.19

Page 1 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.19 Release Notes SmartSDR™ for Windows v3.9.19 Release Notes July 8, 2025 SmartSDR™ v3.9.19 is a maintenance release for all FLEX-8000 and FLEX-6000 series software-defined radios, and the Maestro™.

This version supersedes all previous versions of SmartSDR v3.x.

This document covers changes to client software (SmartSDR for Windows, SmartSDR for the “M” radios, and Maestro).

Changes to clients or utilities produced by 3rd parties are not addressed.

Please consult the SmartSDR Software User Guide v3 for details on using features and an optimal operating experience.

Before upgrading, please read all sections marked as IMPORTANT for upgrade prerequisites and other important information.

Failure to follow these instructions may create problems requiring FlexRadio support or service staff assistance.

Note: Recent versions of SmartSDR v3 address several critical software defects identified in previous versions of SmartSDR.

After upgrading to SmartSDR v3.9.19, downgrading to previous versions of SmartSDR v3 will result in the reoccurrence of critical issues resolved in this software release.

Important Notice: After upgrading the v3.9.19 firmware in all FLEX-8000s and FLEX-6000s, a hardware power cycle, which includes shutting down the radio, cycling the DC power, and restarting the radio, is recommended to ensure the firmware update installs successfully.

New Features in SmartSDR v3.9.19 There are no new features in this release of SmartSDR.

SmartSignal is still designated as a beta feature.

Bug Fix Highlights in SmartSDR v3.9.19 Please refer to the SmartSDR v3 Changelog for a complete listing of changes. [SMART-11274] Fixed SmartControl display issues when anything other than a single Panadapter is in use [SMART-11280] CAT: Frequency tracking no longer fails on band change [SMART-11300] Fixed incorrect 'Interlock is preventing transmission' message appearing immediately after connecting FLEX-8000s to SmartSDR [SMART-11378] SmartSignal (APD): Improved handling of TX Slice removal Page 2 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.19 Release Notes Important Release Details There are minimum versions of SmartSDR needed for certain FLEX-6000, FLEX-8000, and Ma​estro models due to hardware revision levels.

The table below indicates the minimum required version of SmartSDR based on hardware ship dates.

Using the latest version of SmartSDR will prevent any issues you may encounter by running firmware below the minimum version for your radio.

Product Hardware Ship Date Minimum Version Maestro C, FLEX-8400M

FLEX-8600M

• 17-February-2025 3.8.23
• FLEX-8400M, FLEX-8600M 2-January-2025 3.8.21
• FLEX-8400, FLEX-8600 9-October-2024 3.8.19

FLEX-6400, FLEX-6400M,

FLEX-6600, FLEX-6600M

24-March-2023 3.4.23 What to do if the SmartSDR software update does not finish after 10 minutes?

If ten (10) minutes have elapsed when the upgrade indicator is no longer moving and the radio has not rebooted to complete the upgrade, power off the radio by pressing the power button.

If the power button is unresponsive, momentarily remove DC power from the radio to shut it down.

The radio should restart, and the firmware update should have been completed successfully.

What to do if the FLEX-8000/6000 fails to boot after upgrading to SmartSDR 3.9.19: If the radio fails to boot after performing a firmware upgrade, please open a HelpDesk support ticket to get the issue resolved.

Upgrading an M-model Radio Front Panel: If you are upgrading an M-model radio using SmartSDR for Windows, the upgrade will not be applied to the software for the Front Panel (display).

Use the information below to upgrade the front panel.  The radio must first be connected to your network and can access the Internet to download the necessary software to update the front panel.  After the radio firmware updates from your PC, shut down SmartSDR for Windows and connect to your radio using the M-model Front Panel.

The Version Select screen should display SmartSDR v3.9.19, showing a download icon.

Selecting that version will start the final portion of the upgrade process.

For a detailed description of the SmartSDR for Windows software upgrade process, please refer to the SmartSDR Software Users Guide v3 Upgrading the radio firmware over a SmartLink connection is not supported.

Since Internet connections can be inherently unreliable, and it is paramount that the firmware upgrade process proceeds uninterrupted to prevent the FLEX-8000/6000 from becoming inoperable, upgrading the radio firmware is only supported using a LAN or network- connected SmartSDR client.

Page 3 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.19 Release Notes Best Practices for Installing / Uninstalling SmartSDR Best Practices for Installing a New Version of Smart​SDR for Windows Always back up your Global, TX (transmit), and Microphone Profiles.

For detailed instructions on exporting your profiles to a file on your PC, refer to the SmartSDR for Windows Software User’s Guide.

It is recommended to export all profiles before upgrading to v3.9.19.

Maintaining a good set of profile exports as backups is always a best practice.

Moving back and forth between different versions of SmartSDR may result in data loss unless you have a backup (export) of your Profiles.

Power cycle the radio before installing a new version of SmartSDR for Windows.

To ensure a seamless upgrade, it is recommended that you power cycle your radio before installing the SmartSDR for Windows software on your PC and updating the radio firmware.

Ensure your Windows operating system is up to date before installing SmartSDR for Windows.

The proper operation of SmartSDR for Windows and its associated drivers relies on having an up-to-date and supported Windows operating system, including the root security certificates.

It is strongly recommended that you run Windows Update and install all mandatory and optional updates before installing SmartSDR for Windows.

Managing SmartSDR installed on other devices.

If using Maestro or other PCs running SmartSDR for Windows, update all devices at the same time to ensure a consistent operating experience and to avoid radio firmware upgrade/downgrade delays. “Cold Boot” the radio after upgrading the radio firmware.

Using the power button, shut down the radio, then disconnect it from DC power for approximately 30 seconds.

This procedure “cold boots” the radio and helps ensure proper operation.

Once DC power is restored to the radio, wait 2 minutes to ensure all internal processors have booted up completely before booting your radio.

Always perform a Factory Reset of your Radio when Downgrading the Radio Firmware: In general, downgrading to a previous version of SmartSDR is not recommended.

The database in the FLEX-8000/6000 is NOT backward compatible.

This means if you downgrade the firmware in your radio, you must perform a Factory Reset to ensure the internal database is consistent with the version of SmartSDR firmware that is running on the radio.

The procedure for performing a Factory Reset is described in the Best Practices for Installing a New Version of SmartSDR for Windows section below.

In addition to performing a Factory Reset on the radio, you mustn't import a database using a profile export that is greater than the version you are using with the FLEX-6000.

In later versions of SmartSDR, the profile export file name contains the version of SmartSDR that was running when the export was saved to your PC for easy version identification.

Page 4 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.19 Release Notes How to Factory Reset a FLEX-8000/FLEX-6000 There may be situations where a factory reset of the radio is needed to ensure that the radio is working properly.

If instructed to perform a Factory Reset of the radio, use the procedure below.

Perform a Comprehensive Cold Boot and Factory Reset of your radio.

NOTE: Before starting, shut down all programs that may interface with the radio, such as log