FlexRadio FLEX-6400 firmware v3.10.10

Page 1 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.10.10 Release Notes SmartSDR™ for Windows v3.10.10 Release Notes September 3, 2025 SmartSDR™ v3.10.10 is a general 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 v3.10.10, 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 v3.10.10 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 v3.10.10 Multiple SmartSignal (APD) improvements.

Incremental improvements on SmartSignal performance consistency and removed RF Gain in Sampler Path to improve SmartSignal performance.

SMART-11290 Implemented CWX Remote Sidetone .

This feature allows the operator to hear sidetone generated by N1MM and other programs that use the virtual Winkeyer interface.

Note: Sidetone levels can vary depending on the source keying CW and the client in use.

Take caution to protect your hearing and familiarize yourself with the audio levels for your particular setup and use case.

Sidetone levels will be more balanced in a future release.

SMART-11151

WinKeyer Emulation Enhancement.

Added spacing character 0x7C hex.

SMART-11052 Page 2 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.10.10 Release Notes TGXL Meters are now available in Maestro and M-Models.

The meters are available when the radio is connected to the TGXL.

SMART-11356 Added New Assignable Function Keys to Maestro.

The functions added are: (a) Tuner ​Change State, (b) Tuner Tune, and (c) Amp Change State.

SMART-10943 Bug Fix Highlights in SmartSDR v3.10.10 Please refer to the SmartSDR v3 Changelog for a complete listing of changes.

SMART-11569 Updated SmartSDR Installers/Executables with the FlexRadio, Inc. name

SMART-10967

Fixed the inaccurate error message "No TX Slice" when PTT is held during boot up.

SMART-11496

Fixed an issue where a software update failed to start correctly

SMART-11132

Improved reliability of VOX in multiFLEX

SMART-10346

• Improved trailing edge of CW waveform envelope
• SMART-11403 Analog-style meter now has tick marks to mirror the digital bar meter scale

SMART-10822

Fixed an issue where ATU changes affect the CW delay setting

SMART-10720

Fixed issue with 8000M Models where the front panel and the radio could be powered on out of sync.

SMART-8099

Improved performance when deleting multiple Spots

SMART-11601

Fixed a small memory leak in CW

SMART-11213

• Fixed an issue where SmartSDR for Windows didn't allow navigation to the
• Select Radio screen after setting a fixed IP

SMART-11477

Fixed an SO2R interlock issue with CW and setups with the PGXL

SMART-11267

Fixed TGXL problem that could result in timing errors with SO2R config and intermittent High SWR warnings on PGXL. Also related to SMART-11523

SMART-11272

Fixed an issue with the ATU and ATU LED hanging after TGXL connection dropped SMART-11422 Changed the Two Tone Test frequency pairing from 1900/700 Hz to 1900/710 Hz for improved performance SMART-11166 When set to Two Tone mode and a mode that does not support two -tone Tuning, the single tone is now used

SMART-11224

Fixed an issue on Maestro that prevented re-adding meters.

SMART-11365

Fixed an issue with the 6000 series radios that would cause band persistence issues (Slice/Pan off frequency, not present, etc.)

SMART-11435

Fixed an issue where the SO2R Default profile was not loading correctly after reboot on M Models

SMART-11257

Fixed the Tool Tip wording when hovering over the disabled ATU button with TGXL inline Page 3 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.10.10 Release Notes Important Release Details There are minimum versions of SmartSDR needed for certain FLEX-6000, FLEX-8000, and Maestro 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 or the radio’s Power button LED remains illuminated purple after 10 minutes?

If ten (10) minutes have elapsed when the software 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 radio’s power button LED stays illuminated purple or the radio will not shut down when pressing the power button, momentarily remove DC power from the radio to shut it down.

The radio should restart using the power button, and the firmware update should have completed successfully.

What to do if the FLEX-8000/6000 fails to boot after upgrading to SmartSDR 3.10.10: 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​.10.10, 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 4 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.10.10 Release Notes Best Practices for Installing / Uninstalling SmartSDR Best Practices for Installing a New Version of SmartSDR 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 v3.10.10.

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.

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