Related articles: Proper Single Transistor LNA for HF A Sustainable Radio Design? We are finally going to build a QSD RX! Here is the rough schematic I am thinking about: References: https://www.n6qw.com/MC1496.html https://github.com/steve-m/hsdaoh-rp2350 (see internal_adc section) This way we can continue using RP2350 instead of moving to something like STM32H5 immediately https://github.com/dawsonjon/PicoRX/tree/master/simulations (also for DSP code)
Future radio receiver design ideas (from Ismo, Pete and other folks): Antenna ➔ (BPF) ➔ BFR93A based pre-amp from mcHF project ➔ MC1496 (Mixer) ➔ 455 kHz IF ➔ Ceramic filter SMD (HCI) ➔ 'IF amplifier' (20-40 dB gain?) ➔ Overclocked Pico 2's ADC (3+ MSPS) ➔ Digital down-conversion and processing in digital domain ➔ Expose the processed audio samples over USB (Pico 2 acts as a sound card). Benefits: This enables reception of SSB and CW signals! The 455 kHz IF with digital processing gives us the best of both analog selectivity (ceramic filter) and digital flexibility. ...