On Mon, May 31, 2021, at 09:33 PM, Ashhar Farhan wrote:
When someone finishes the usdx build, I would like them to measure the opposite sideband and the audio distortion. I am curious how well it works.
I too would be interested in actual performance data, most importantly the efficiency data.? Efficient portable SSB operation was the original goal of the ?SDX, gaining the Class E power efficiency for SSB use.? I have not seen this data for any of the kits offered, nor is the ongoing effort to constantly improve on the efficiency while maintaining reasonable signal quality.? Since it is the efficiency of power use as the goal, as long as the signal is intelligible and within legal requirements, then the goal is met if it has better power efficiency than similar SSB transceivers.? That would be total power for operation, not just the finals.
I do not mean to criticize the effort.? It is amazing what has been done.? I am just not sure that the original goals are still the focus of the group.
At the same time, while interesting, I can say that I will not be building one.? If there were a Teensy or another better-specified microcontroller I might be.? One reason for my interest in the sBITX that Ashhar Farhan is working on now.? Based on data from him so far, portable operation would not be one of the major goals.? The Raspberry Pi is a real power hog, up to 10 watts just to run it, and that does not include the display.?
So far the superheterodyne seems to be the most efficient for SSB use.? That is NOT the case for CW as Hans Summers has proven with the QCX Mini.? I could be wrong about this, as it is not based on any real data that I have analyzed.? SDR is the trend as Icom and Elecraft are showing with their QRP portable rigs.? They still have a standard PA and are being driven by features more than power efficiency.
The above are my thoughts, others will be different, and that is OK.? I am always open to new data to change my view.
73
Evan
AC9TU
