First PCB project — civil airband scanner, looking for feedback before printing
Hey everyone,
This is my first PCB design and before I send it to PCBWay I want to make sure I'm not missing anything obvious and see if there are any improvements I can make.
I'm building a standalone civil airband scanner (118–137 MHz) with 6 parallel receiver chains so it can scan fast. The basic idea is antenna → LNA → attenuator → 6x TA2003 mixers (each with their own Si5351A generated local oscillator) → 21.4MHz IF → Si4732 demodulator → audio out.
Control is handled by an ESP32 with a TCA9548A I²C multiplexer to talk to all 6 chips. Power comes from 2x 18650 batteries with a TP4056 charger and AMS1117-3.3 regulator.
Main things I'm unsure about:
- The crystal filter between TA2003 AM_MIX and Si4732 AMI — I have a reference schematic but can't read the values clearly. What does a proper 21.4MHz IF filter circuit look like here?
- Does the overall superhet architecture make sense for this use case?
- Any improvements you'd suggest?
- Anything obviously wrong that would stop it working?
Not looking for perfection, just want to know if it's worth printing and what I could do better. Happy to share the schematic.
Thanks