APD demo ,v3.9.x.x - what's been added, when it should be released

Mike VE3CKO

After watching from Steve Hicks presentation from the Orlando Hamcation 2025, there is new information I thought I'd share in the community.

There is actually a video of Michael Walker (VA3MW) demonstrating Adaptive PreDistortion. For a transmitter Michael used the FlexRadio 8600 with an alpha version of SSDR that has APD, and to receive he used a 6000 series radio. I took some screen shots from that video, see below. With APD off you can see the spurs, I've added red squiggly lines to highlight the spurs, then when APD is turned on, the spurs are gone which means APD has cleaned up and reduced the IMD as intended.

Michael APD turns on/off several times with a button in the TX pane and a display box indicates if APD is "available" or "activated. Everything else seems as intended, automatic. No levels to tweak, or elmering from gurus to get it to work.

Steve mentions SSDR v3.9.xx is in Alpha testing and is targeted to be released before Dayton, so sometime in April 2025. These features were highlighted and safe to assume will be in the next release:

• TGXL/PGXL integration with SmartSDR/Maestro
• Analog meters - RX and TX (power/swr)
• USB cable pass thru - allows USB or any serial device like a rotator control to be passed thru so control software can be used remotely via SmartLink
• Adaptive Predistortion (for FLEX-8000 series only)
• Integrated two-tone testing- like what was in PowerSDR

I keep getting asked besides Adaptive PreDistortion what is the advantage of upgrading from a 6xxx to an 8xxx. I refer to what Steve Hicks said, that with the extra capability of the 8000 series, FlexRadio will add many new features over time and that some of which will not be possible on the FLEX-6000. 

Some announced features to be added:

FT8 Amateur Wideband - Currently FT8 is in a crowded 3kHz window, this feature will allow to transmit and receive over 40kHz bandwidth, multiple carriers at once with a single radio, mulitple transmit channels, you'll be able to run FT8 and FT4 at the same time. FlexRadio will release this portion as open source code so other vendors can make their radios compatible. 

Spectrum Overview - Visibility of all HF/6m bands in a single, unified panadapter window to provide awareness of bands to spot openings easier, DX stations moving between bands. All this with greatly reduced noise floor than it is today. You'll be able to setup multiple bands next to each other so if you want to watch 10, 15 and 20m you can keep an eye on them in a single panadapter window, as compared to now where you would need to have 3 receivers open to do that. 

Internal GNSS reciever -  provides source for time standard, accuracy of 0.5 Hz at 50 mHz. Provides NTP service that can be sent on local network, this is so if working POTA or remotely, apps like WJST which are timing-critical can get timing source from the GNSS in the FlexRadio.

Additional noise reduction techniques for greater noise mitigation (improved NR, new NR capabilities, AND and NB)

Again I just took some highlights you should watch the video yourself.

Trucker

I watched the video. It provided a lot of good information.

James

WD5GWY

John K3MA

It would be better to see the two displays with only a 2 tone injected signal so that the drop in the 3rd and 5th order could be clearly seen and the amount of reduction determined.

W2PP

right I can’t hardly tell the difference between APD on or off on those pictures. I’ve seen others use it and the results were much more impressive

km9r.mike

Mike thanks for the info. I have been waiting for a thread on "smart signal" aka APD to hopefully learn what modes besides SSB will this feature be beneficial.

I appreciate all the effort FRS has put into this feature because some users / ex users have basically wigged out or lost their minds about not having this feature available. I find that odd but do appreciate FRS's effort to give the customer what they want in addition to meeting the ARRL's clean signal initiative. However, I seldom use SSB voice and this feature appears to be geared only towards cleaning up dirty SSB voice transmissions.

I did notice however in Mr Hick's presentation , specifically "dynamic APD " that values will be adjusted or compensated according to temp, freq, volt and "mode" giving me hope that this feature may be beneficial for modes besides SSB voice.

Doe anyone know for certain if this feature "smart signal" can be used beyond just cleaning up dirty SSB signals ?