CESSB And Pure Audio

[ka7niq]

It has come to my attention that HPSDR, the group that does the ANAN Open Source Software has come out with their version of Power SDR and it will allow us FLEX Legacy Guys to get both CESSB and Pure Audio! The N9IZ Blog is where I read this, here is an excerpt.

The developers at HPSDR are doing a great job with their version of PowerSDR as well. It’s actually based on older source code, but they have been able to implement some great features. Two of which are CESSB and PureSignal active pre-distortion. The CESSB cleans up the audio on the mic side of the rig and actually results in higher average power output. PureSignal cleans up the output side generating a signal with much lower IMD and harmonic suppression. Hopefully some of the features can be shared between these two. For now I’m glad that there are hams like Darrin who continue to develop PowerSDR for legacy Flex radios such as my Flex-5000A. He’s currently up to Ver. 2.7.2 R12.

I was wondering if KE9NS has any plans to incorporate these features into his software as well ?

[ka7niq]

Yesterday, I actually downloaded and installed this software, to see if it would find my FLEX 5000A. It did not, and it asked me to choose what radio I was using by giving me a list of radios. Most of the radios it will work with are ANAN, and a Hermes. There were no FLEX Products on the list, so I uninstalled the program.
I never ever thought of selling my FLEX 5000A until now. I really want ECSSB and Pure Signal, and if I have to buy an ANAN to make it happen, that is what I will do.

[ke9ns]

That version of PowerSDR was forked over many years ago (long before v2.7.2), and then they swapped out the "DttSP" code for Dr. Warren Pratt's "wdsp". The GUI console code at the time, was kept.
I am sure its possible to port over the "wdsp" code back to "DttSP" code to get more features, but its very time consuming, and I do this in my spare time, usually very late night. And this assumes Dr. Pratt is OK with porting over his code.

Darrin

[N4JGO]

Hi Darrin ( two big If's )

I for one, am very appreciative of the time that you put into this software. I am sure there have been a few sleepless nights thinking through an issue or trying to break out of a loop that is worse than ground hog day. If (the first big IF) Dr. Pratt's would approve the porting over of his code I would be interested in hearing from the forum of how many users would be interested in these audio features. (then the second big IF) if you would be willing to plug in the hours to do the heart transplant of your software. I myself am interested in these audio features, as well as being ready to donate more to you monetarily for this endeavor, any others ?

Bob

[w2jon]

To achieve pre distortion / linearization functionality would require hardware modifications to the 5000 TRX board.
Anan radios that have pre distortion / linearization ability already have the linearization circuitry baked in from the factory.

This has been done in the past by AC2IQ and was a marvelous proof of concept.

The tasks would require not only a delicate operation on the radio to add a pair of sample ports for output and input, but require also additional external hardware such as a directional coupler and linearization board to both sample and modify the input to the PA.



Not many folks have the proper tools to perform such a modification.

I for one would love to replicate AC2IQ's efforts on my 5k, but I cannot seem to be able to locate a suitable linearization board to round up the BOM.

The one thing we do have going for us is that the 5k is fairly clean already and if driven properly, will rarely exhibit the type of IMD that would spread into neighboring QSO's
73 de W2JON

[ke9ns]

Jonathan,

I think I looked at that many years ago...
I wasn't sure it was real or something else, but I thought that AC2IQ achieved this using an all hardware solution?

FYI...
I looked into a hardware only possibilities a very long time ago, and found that there actually are Chips designed to achieve pre-distortion / linearization out to the amplifier, but I could only find them dedicated to cell phone designs.

The Flex-5000 itself just fine, and in my opinion better than most, but where pre-distortion can come in handy is when running legal limit.

If AC2IQ did any software mods to make this work, I would very much like to see them?

Anyway...
You definitely need an external RF pickup sampler to go on the output of your Amp, since there is no need at all to run pre-distortion on just the Flex-5000 PA.

Darrin
ke9ns

[w2jon]

Yeah, it was an all hardware setup.. I know he had produced linearization boards, but that may have been a short run or a one-off.
The one shown on his qrz page is a homebrew hand-soldered unit that appears to have been used in another role prior to its transplant into the 5k.

I agree that the Flex PA is one of the cleanest PA's I've ever heard/watched.

It would still be neat to do the mod just for that extra bump at the elite Anan crowd.

[HB9DDS]

CESSB, the future?

So, is it now possible to implement CESSB into PowerSDR? Does it require hardware modifications?

Also for older Flexradios?

73 de Daniel
HB9DDS

[ke9ns]

CESSB is just software. So It would be possible to add that. Years ago I was looking into adding it until I heard what it sounded like.
I didn't notice a difference from just using the DX (compressor) feature already in PowerSDR?
I may add it at some point.

Darrin
ke9ns