Ah, you've hit on it
Yup, good suggestions and interesting discussion.
But my point of this project is how little does it take for $100 or less. The point isn't about spending more and more money for half-dB or tenth-dB performance increments.
What can be done with less and with mostly software ... I haven't needed to find a hardware 9600 baud pin without low pass filtering all week either ;-)
My main station with the multi-core laptop, RSP2 running with SDR Uno, yagi, etc. has uploaded about 600 frames this week with casual use whenever I'm in the shack. The Raspberry Pi, SDR-RTL dongle, and 2M vertical has accomplished around 60 frames in a week just as experiment with mostly spare parts.
It will be interesting to hear how much less might have worked ... with appropriately scaled expectations, of course.
-- 73 de JoAnne K9JKM k9jkm@amsat.org