There's a good chance that anyone who reads this has at least heard of Tony Parks and his Softrock SDR kits (www.fivedash.com). If not, check 'em out - they're fun to build and an inexpensive way to wet your beak in the world of SDR.
I've got a number of his older (V6.2) transceiver kits built for different bands and can't say enough good things about them, so this is, by no means, a criticism: While they work fine and do everything well, the operating experience is, as Bill, N2CQR would say: Very appliancy.
This got the wheels turning: Why not use the SDR as the "back end" (modulation/demodulation and audio) of a "traditional" transceiver? The idea's been festering in my mind for a few years now, I suppose it's time to lance that boil.
As with any other project, if you want any chance at bringing it to a successful conclusion, you need to start with a plan. At this stage, I know what I want:
- 80 - 10 Meter coverage.
- Power output > 20 Watts.
- Front panel touchscreen display.
- Rotary controls for audio and tuning.
- Integral processor (Rasp. Pi) for SDR.
- Arduino Pro-Mini for user interface and system control.
So, I took those requirements and drew the above block diagram to use as a road-map. As I said before, the only way to eat an elephant is one bite at a time. This is the basic recipe I'll use for making elephant sandwiches.
Moving forward, I'll determine the specs for each block, which will lead to more noodling before I even think about melting any solder. Sure, it's fun to just jump in and make shi... stuff up as you go, the problem is that projects started that way tend to either go unfinished or don't work right when they are.