FlexRadio FLEX-6600M firmware v4.0.1

Page 1 | Copyright 2025 FlexRadio, Inc. | SmartSDR v4.0.1 Release Notes | SmartSDR+ v4.0.1 Release Notes Version Release Date Release Theme/Title 4.0.1 2025-10-30 Noise Mitigation, DVK, CW Auto Tune & Panadapter Enhancement SmartSDR Basic™ and SmartSDR+™ v4.0.1 is a software and firmware release for Aurora, FLEX-8000, and FLEX-6000 series of software defined radios (SDRs), and the Maestro™.

This version supersedes all previous versions of SmartSDR.

Description of SmartSDR Basic, SmartSDR+, and SmartSDR+ Early Access Feature License Tiers: SmartSDR v4 Basic is available free of charge and includes all bug fixes and select minor feature enhancements for all radio models.

We strongly encourage all customers to upgrade to SmartSDR v4 Basic.

If you are currently running SmartSDR v2 and upgrade to SmartSDR v4 Basic, you will receive all prior bug fixes and minor enhancements from previous versions.

However, please note that MultiFlex—the major feature introduced in SmartSDR v3—is not included in SmartSDR v4 Basic for radios licensed for SmartSDR v2.

For radios licensed for SmartSDR v1, the SmartLink feature introduced in SmartSDR v2, along with the MultiFl​ex feature from SmartSDR v3, are not included in SmartSDR v4 Basic.

SmartSDR+ is an optional one-year new feature license.

When you purchase a SmartSDR+ feature license, you gain or retain access to all prior SmartSDR v2 and v3 major features, as well as all new SmartSDR v4 major features released during your one-year license period.

All new SmartSDR v4 features are only available immediately for SmartSDR+ Early Access feature license radios.

Radios that have a SmartSDR+ feature license will gain access to the new features ~30 days later with a subsequent software release.

To get the features immediately, a SmartSDR+ Early Access license is required.

When your one-year feature license expires, you retain all features received during that period—you never lose them.

To gain access to any new features introduced after your license period ends, simply renew your SmartSDR+ license for an additional year.

SmartSDR+ Early Access is an optional one-year SmartSDR+ feature license that provides all the benefits of SmartSDR+, with the added advantage of early access to new features 30 days before they are available for standard SmartSDR+ license holders by a subsequent software release.

As part of the Early Access Program, participants are invited to share feedback with the software engineering and product management teams based on their experience with the preview software.

This collaboration helps shape and refine future SmartSDR releases.

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

Important Notice: Beginning with SmartSDR v3.10.10, the SmartSDR hardware license installed on your radio must be revalidated by connecting to the SmartSDR License Server.

To complete this process, ensure that your radio is connected to a network with Internet access.

Once your SmartSDR license has been successfully validated, the radio will not need to reconnect to the License Server unless you purchase a new SmartSDR+ feature license.

Page 2 | Copyright 2025 FlexRadio, Inc. | SmartSDR v4.0.1 Release Notes | SmartSDR+ v4.0.1

New Features

As noted above, radios licensed for SmartSDR+ have new features automatically activated 30 days after each new SmartSDR version is released.

However, for the initial release of SmartSDR v4, the following features have been activated immediately for radios licensed for SmartSDR+.

Radios licensed for SmartSDR+ Early Access will have all new features activated immediately upon release.  Relative Noise Floor Scaling  Enhanced Signal Clarity (ESC) Feature Description Supported Radio Models

SMART-11431

New DSP Noise Mitigation: We have updated and added a variety of new noise reduction/mitigation algorithms to the Aurora, FLEX-8000 and FLEX-8000 series radios.

The new noise mitigation features are designed to cater to different types of noises, environments, and setups.

Multiple Noise Mitigation functions can be used simultaneously.

Toggle the various noise mitigation functions on and off to taste.

NRF

1

• Spectral Subtraction Filtering Algorithm

NRS

1

• Spectral Subtraction with Voice Detection

RNN

1

• AI Noise Reduction

NRL

1,2

• NR algorithm using LMS (Least Mean Squares)

ANFL

1,2

• ANF algorithm using LMS

ANFT

1,2

• ANF algorithm using FFT (Fast Fourier Transform) 1 Aurora 1 FLEX-8000s 2 FLEX-6000s

SMART-3985

Digital Voice Keyer: Digital Voice Keyer (DVK) allows recording, playback, and transmission of up to 12 voice recordings stored on the radio. Aurora FLEX-8000s FLEX-6000s

SMART-10570

Enhanced Signal Clarity (ESC): ESC is a unique diversity reception feature that is only available on dual SCU radios.

Enhanced Signal Clarity (ESC) in diversity.

ESC combines signals from multiple antennas to optimize audio receive capabilities via beamforming/nullforming.

Used to accentuate desired signals (constructive interference patterns) or to remove undesired signals (destructive interference patterns) to improve signal quality.

This does not affect the displayed panadapter or waterfall, but metering will be affected.

AU-520(M)

FLEX-8600(M)

FLEX-6700

FLEX-6600(M)

SMART-9958

Relative Noise Floor Scaling: This feature automatically adjusts the displayed noise floor to maintain a visually consistent reference level as you operate on different bands and antennas.

This feature makes it easier to compare signal strengths and visually interpret band conditions.

Aurora FLEX-8000s

SMART-11332

CW Auto Tune: Introducing CW Auto Tune.

CW Auto Tune automatically tunes the active slice receiver to CW signals within the passband, simplifying the process of locking onto CW transmissions.

There are two modes of operation: One-Shot or Intermittent Mode.  One Shot - Autotunes once to the highest signal on the click of the AUTOTUNE button  Intermittent – Continuously autotunes to the highest signal every two seconds while the AUTOTUNE button remains enabled.

Aurora FLEX-8000s FLEX-6000s Page 3 | Copyright 2025 FlexRadio, Inc. | SmartSDR v4.0.1 Release Notes | How To Use SmartSDR+ v4.0.1 Features: DSP - Noise Mitigation Features SmartSDR offers a variety of noise mitigation features to cater to different types of noises, environments, and setups.

Multiple Noise Mitigation functions can be used simultaneously.

Toggle the various noise mitigation functions on and off to taste.

The user interface has been simplified to on/off buttons for eas​e of use.

Noise Mitigation features available in previous versions of SmartSDR are available with the SmartSDR Basic license.

New Noise Mitigation features require SmartSDR+ or SmartSDR+ Early access.

In SmartSDR for Windows, Noise Mitigation features are available in the Slice’s DSP drop-down menu.

In Maestro/M-Model, Noise Mitigation features are available in the Slice menu.

SmartSDR Basic

• NR (Noise Reduction) - Same NR as before, but the algorithm has been improved - Useful for reducing uncorrelated “white” noise.
• NB (Noise Blanking) - Same NB as before - Useful for reducing fast rise time noise from sparks and other pulse-type sources
• ANF (Automatic Notch Filter) - Same ANF as before, but the algorithm is improved - Attenuates persistent unwanted signals.
• WNB (Wide Noise Blanker) - Same WNB as before, but this function is now only located in the Antenna menus.

SmartSDR+

• NRF - A Spectral Subtraction Filtering Algorithm - This algorithm continuously computes the probability of speech and noise for each frequency in the passband, along with a corresponding gain to remove the possible noise. This algorithm is intended for stationary noise that does not change rapidly. Only available on 8000 Series Radios.
• NRS - Spectral subtraction with Voice Activity Detection. Only available on 8000 Series Radios
• RNN - Noise suppression using a recurrent neural network, to remove noise