My recent receiver design (circa 2011), which has neither been built nor tested, was to have the following features:
- Single 5V d.c. supply.
- Gyrator tuning and second stage amplifier gain adjustment by means of digital potentiometers.
- Zero-crossing detector, precision full-wave rectifier, peak detector and d.c. level shifter.
- Micro-controller (Freescale MC9S08SH8).
- RS-232 serial port.
You can download the circuit diagrams here and try out the circuit if you wish, at your own risk. The circuit comes with no guarantees:Download
I now have other, more ambitious ideas for a receiver. But more about this later.