Phase Cancellation in Diversity Receiption for Dual SCU Radios

I bought my 6700's in 2016 explicitly because a Flex employee at the Yuma Hamfest said that they would be doing just that.

Still waiting!!

73,

Bill AB7AA

Neil,

You are exactly correct!! There are a few things that they could improve on by the way they implement diversity reception, like being able to view both antenna spectrums simultaneously. There is much that you can tell by viewing as well as hearing.

73,

Bill AB7AA

See this thread from 2017. Quoting Steve-N5AC...."In other words, the two channels will provide a constant phase separation between the two outputs that will be random, but constant and stable after each tune. Changing this to a coherent tune has always been in our playbook and not hard to do -- the chief challenge is how to represent that you want this from the GUI. We have also had this request from the HF side."

7 years later.....I guess other more important things got in the way or it was harder to do than originally thought.

https://community.flexradio.com/discussion/comment/13770928#Comment_13770928?utm_source=community-search&utm_medium=organic-search&utm_term=eme+phase

SmartSDR has Diversity Reception available for dual SCU radios. What it doesn't have is Phase Cancelation like they had ( and still have) in PowerSDR for the legacy radios. So, Diversity Reception is only half baked. As for an effective Noise Blanker, including the Wide Noise Blanker, it depends on the nature of your noise source. When it comes to noise blanking, there is no, one size fits all, noise blanker. What works for one noise source may not work for another. For my particular area and the noise I experience, the WNB works great. At our previous QTH, there were some noise sources that the WNB couldn't touch. It is simply impossible to have one that works well for everyone.

James

WD5GWY

I can understand your frustration. My 6600M , currently visiting the Flex Radio hospital for an unrelated issue, is a first production run Radio from 2017. ( I received it February 2018 when they finally started shipping the M model radios) The WNB has worked well here. It surprises me that the problem you are experiencing is because it is a late production model. As far as I know, all of the DSP processing takes place in the radio. I would think Flex Radio's developers could write code that should take into account any differences between the older generation of hardware and the newer generation. I hope they get this sorted for you and others, sooner than later. And should my 6600M prove to be too ill to repair fully, I may have to think long and hard before purchasing a new radio if it cannot handle my local noise as well as my current 6600M does ( or did, if it's unrepairable )

James

WD5GWY

Phase Cancelation is something I wish Flex Radio would add to Diversity Reception in SmartSDR for the dual SCU radios. It still surprises me that they stopped short of having Phase Cancelation since it was present and working great in PowerSDR for the legacy Flex Radios. I have yet to understand why they didn't include it in Diversity Reception to begin with. They should know that anyone who has used it in PowerSDR would expect the same functions in SmartSDR. Maybe one day someone at Flex Radio will wake up and realize that there are features in their older generation of software that many of their customers expect to be in the current generation of software. Automatic Notch Filter, Noise Reduction, Phase Cancelation in Diversity Reception, an All Mode Squelch, all should be included in SmartSDR and working as good as, or better than, it did in the previous generation of software.

They hope people will be willing to pay for new features. But, if they cannot or will not, improve the existing features they shouldn't expect people to line up and pay more money only to be disappointed that features common to all modern radios don't work as well as their previous generation of radios and software.

James

WD5GWY

Neil, the front panel and the SmartSDR display are simply interfaces. The real magic takes place in the radio. The displays can easily be updated to add the necessary visual part.

James

WD5GWY

Since this thread is still active I will comment….

I agree with the general tone of this thread that Flex Radio has dropped the ball on including amplitude and phase control for radios with two or more SCUs. This is kind of the whole point of having two phase locked SCUs and multiple antennas. The absence of the of phase/amplitude control on SmartSDR is a major shortcoming of what is otherwise a state-of-the-art radio.

Having phase/amplitude control is why I keep my Flex 5000a going. I just spent some $$ with Troy radio to keep my 5000 alive. I also have the DXE NCC-1. The NCC-2 is a bit mor refined than the first version but they are basically the same - the 2 has more features internal that are otherwise external on the 1.

The effectiveness of noise cancellation regardless of how it is done is highly dependent on the what signal you are working with - noise cancellation and/or signal enhancement - along with the type of antennas being used. In the latter case polarization matters a lot!

I have two Beverage antennas I use on RX for 160-40. These are vertically polarized. When I use my horizontal 40m yagi as the second antenna noise cancellation is very limited. However, signal enhancement can be big - almost entirely eliminating QSB on very weak signals and knocking down random noise. When the two vertically polarized Beverages are used together I can routinely get nearly perfect noise cancelation on local line and solar noise. I also get fairly effective beam pattern steering. When I combine a Beverage with my 160m vertical I get similar results. It is all just physics…

Back to the topic… If you are watching Flex Radio… The community is begging you implement phase/amplitude control in SmartSDR for multi-SCU radios. Do this ASAP to still be considered "state-of-the-art". Other SDRs are out ahead…

Best 73s,

Chuck
de NJ6D / N7KU