How would you create a SDR type transceiver without using a computer. Is that really possible to do?
I won't put you on the spot and expect any answers, but it does raise the specter of a better, well maybe not better but alternative mouse trap.
Many rodent traps simply kill the rodent either with poison or by mechanical means. Then there are the kinder, more gentler approaches such as trapping the vermin and releasing same in your neighbor's yard. A gift to your obnoxious, loud, uncaring and self-indulgent next-door neighbor. (Remember my Italian heritage -- we don't get mad we get even!)
Iowa Hills Software ~ 100 Coefficients 3.75kHz Fc and 2.5 kHz Wide
The ZL2CTM Teensy SDR. If I don't post a picture then no views.
Over the past several years I have repeatedly asked myself that question initially posed. Now with a tip of the cap to Charlie Morris, ZL1CTM, he did create a SSB transceiver using the Teensy Micro-Controller Unit and the companion audio board. The Teensy has embedded in the code the Hilbert Transforms with the Iowa Hills Filter constants (see 1st Chart). Yes, this was all done inside the Teensy (available from PJRC and sold from the USA).
In fact, I built two versions of Charlie's design, but I could not get the two rigs to have significant opposite sideband suppression on both receive and transmit. On Receive, it was really obvious on very strong signals. Reports from QSO's told me my signal was more DSB than SSB.
I firmly believe it was a problem on my end and not with Charlie's design. I did battle with the Iowa Hills software to get a narrower filter than the stock code that was in his design. I think that is the issue with the two I built.
So that certainly would be one way although I would need to really roll up my sleeves and figure out exactly what I did wrong in the code. For those who are software adverse and loathe to follow detailed programming nuances -- don't even start.
Then there are the uSDX radios that are being sold by the hundreds (maybe thousands) on eBay and Amazon. I scratch built one starting with just the plain circuit board.
My build was a flat out a piece of crap on both transmitting and receiving. Even some You Tube videos from other builders early on, showed the naked truth about use on SSB. On CW it might have been OK but not SSB. It was so bad that I did not even place it on the Shame Shelf.
In my opinion the Arduino is ill suited for the job! The Xiao RP2040 might have enough large sized cojones to do it with its 8X faster processor and 2MB of program storage However, I will forever forget that track.
So, put on your thinking caps and conduct an omphaloskepsis process about some simple way to do it. There has to be a better mousetrap out there!
73's
Pete N6QW