This project is a wireless Beat Frequency Oscillator (BFO) designed to let almost any shortwave radio receive single sideband (SSB) signals without internal modifications. Instead of injecting a signal electrically, this design uses a compact loop antenna to radiate a stable beat signal directly into the radio’s IF stage. The result is clean, accurate SSB demodulation on radios that were never built for it.

The BFO is generated using a microcontroller-driven frequency source, allowing precise tuning slightly above or below the IF frequency to select upper or lower sideband. An onboard encoder or tuning control gives smooth, fine adjustments, while the loop antenna ensures consistent coupling across a wide range of radios.

The PCB layout is simple, compact, and easy to assemble. Power requirements are minimal, and the board is ideal for portable use or bench setups. Because nothing connects electrically to the radio, there’s zero risk, no soldering inside the set, and full compatibility with both vintage and modern receivers.

This is an excellent project for builders, experimenters, and SW listeners who want to expand what their existing radios can do—especially older sets with great sensitivity but no SSB capability.

See the video here: https://youtu.be/oLG_kzfnzgM