FlexRadio FLEX-6600M firmware v3.9.18

Page 1 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.18 Release Notes SmartSDR™ for Windows v3.9.18 Release Notes May 28, 2025 SmartSDR™ v3.9.18 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 v3.9.18, 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 v3.9.18 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 required to ensure the firmware update installs successfully.

New Features in SmartSDR v3.9.18 Introducing SmartSignal™ (Beta): FlexRadio is pleased to announce the beta release of SmartSignal, our new automatic adaptive pre-distortion (APD) feature designed to significantly reduce intermodulation products at the transmitter output.

SmartSignal for the FLEX-8000 actively analyzes and compensates for amplifier non-linearity in real time, improving spectral cleanliness and transmitter performance.

Important: Please refer to the Caveats and Known Issues section below for information regarding the SmartSignal Beta limitations in SmartSDR v3.9.18.

To enable SmartSignal, first check to see if the APD status shows AVAIL, indicating the APD meets the requirements for use.

Next, simply enable SmartSignal in the SmartSDR software by clicking/enabling the APD button.

The APD status will change to CAL indicating SmartSignal is ready for calibration.

The last step is calibrating or training SmartSignal for optimal signal quality by keying the mic while speaking ​when in SSB Page 2 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.18 Release Notes mode.

When training is complete, usually taking less than a second you will see the APD status change to ACTIVE.

If at any time you see the status change to CAL, simply transmitting in SSB mode will reactivate SmartSignal.

For additional information, please refer to the SmartSignal FAQ available from the HelpDesk: SmartSignal™ (automatic adaptive pre-distortion) FAQ.

As a beta feature release, this version is not intended to be perfect, and it is being released to gather feedback and generate data for future improvements to the underlying algorithm.

We encourage you to share this information with users and support teams via the HelpDesk to help manage expectations and provide clarity on the current state of SmartSignal.

We look forward to your feedback and suggestions for further development.

Analog Meter Display: SmartSDR v3.9.18 now provides a combo analog meter option in addition to the standard bar meters.

The feature is enabled in the right-hand side applet bar by clicking on the ANLG tab located at the top of the applet bar.

You can select either the normal or peak reading version of the meter.

When receiving, the meter displays the signal level in S units.

The available transmit meters are Power, SWR, Level (audio input), and Compression.

USB Cable Serial Pass-Through Feature: With SmartSDR v3.9.18 and above, FlexRadio introduces Serial Pass-Through, a USB Cable feature that allows you to connect and control RS-232 serial devices, such as antenna rotators and amplifiers, directly through your radio.

This feature works locally and over the internet using SmartLink.

For additional information and instructions on how to use and configure the Serial Pass-Through feature, please refer to the HelpDesk article SmartSDR Serial Pass-Through Feature.

The Automatic Profile Save Feature can be disabled: There are certain circumstances where the profile (microphone and TX) auto-save feature may not be ideally suited for your operating workflow.

In these instances, SmartSDR now provides the ability to disable the profile auto-save action.

Enabling and disabling the profile auto-save capability is located in the top option bar in the SmartSDR Profile Manager.

When disabled, if a change is made to a Microphone or TX Profile parameter, a small floppy disk icon is shown to the right of the Microphone and TX profileselection drop-down box on the Phone/CW (p/cw) sidebar indicating a parameter has been changed.

Clicking on the icon will save the changed profile.

Two-Tone Signal Generator: A two-tone signal generator has been added to SmartSDR.

To utilize the two-tone generator, you must select between the single and two-tone signal generation options in the Transmit settings.

To activate the two-tone generator, simply click or press the Tune button.

TGXL Integration into SmartSDR for Windows and Maestro: As a companion to the PGXL integration, you can now control the basic functions of the TGXL directly from SmartSDR.

Please note that to utilize this feature, the TGXL must be running version 1.2.17 or greater of the TGXL Utility.

The TGXL Utility can be downloaded from the 4O3A website.

Page 3 | Copyright 2025 FlexRadio, Inc. | SmartSDR v3.9.18 Release Notes Bug Fix Highlights in SmartSDR v3.9.18 Please refer to the SmartSDR v3 Changelog for a complete listing of changes. [SMART-10697] 8000 Radios: Receive Audio goes silent after transmitting with NR and ANF enabled [SMART-10633] SmartSDR CAT f​requency no longer gets out of sync following direct Frequency input from a SmartSDR client [SMART-11048] Improvements to SmartLink connection security [SMART-10698] SmartSDR will now display 'GNSS' vs 'GPS' on the status indicator of the main view [SMART-10785] Enabled 10MHz output when GPSDO is installed on the 8000 Series Radios [SMART-10998] 8000 Series Radios with GPSDO now show the correct GPS status [SMART-10757] Changed wording in Frequency Offset menu to show 'GNSS is installed' for 8000 radios with the stock option and 'GPS is installed' for radios with the optional GPSDO upgrade. [SMART-10463] Frequency Offset is now available for external 10 MHz and TXCO.

Values are saved uniquely for each source; Frequency Offset is not offered for GPSDO or GNSS. [SMART-10969] Fixed an issue with panadapter resizing that incorrectly reported a UHE: Out of Memory errors [SMART-10437] Fixed an issue where DAX channels intermittently get out-of-sync following a sequence of events and Band changes.

Related to SMART-10640 [SMART-10672] Improvements to network disconnect handling on both radio and clients [SMART-10734] 8000 radios can now use SmartLink when the radio is assigned a Static IP [SMART-9562] Fixed an issue where the subnet mask value was incorrectly displayed after entering a static IP address [SMART-9226] Various improvements to meter ballistics for existing digital meters. [SMART-10903] Fixed an issue in PROC that made compression less effective on 8000 Series Radios [SMART-11001] Moved AGC to just before modulation in the audio signal chain [SMART-10649] Fixed an issue with 8000 Series Radios that caused low RF power out levels on XVTR B [SMART-10074] Fixed a memory leak caused by loading a specific profile [SMART-9650] Changed Maestro and M Model error handling forcing a reboot if a fatal error has occurred [SMART-10740] Improved M Model and Maestro notifications and handling of PIC software updates [SMART-10113] Fixed a UHE and incorrect Warning Messages when changing the network with a Maestro connected to a