ATS-20+ SI4732 All-Band Radio Receiver Kit with SSB, RDS, USB-C & More

What is it?

The ATS-20+ is a fully assembled all-band radio receiver built around the powerful SI4732 chip, featuring FM, AM (MW/LW), SW, and full SSB (LSB & USB) reception. This upgraded DIY electronics kit is a portable yet highly capable shortwave radio for amateur radio enthusiasts, RF tinkerers, and signal explorers. It includes a rechargeable lithium battery, telescopic BNC antenna, speaker, USB-C charging, and an intuitive OLED interface – all packed in a solid case with protective rubber feet.

This is not just another off-the-shelf radio – it’s a highly functional, hackable, and hobby-grade radio receiver, perfect for DIYers, ham radio beginners, shortwave listeners (SWL), and electronics experimenters alike.

Why did you make it?

We built the ATS-20+ to give radio and RF hobbyists a better, more refined tool for signal exploration – all in one compact form. While basic versions of the SI4732 receivers exist, they often lack usability, durability, and modern interface convenience.

By adopting features from the popular ATS-25 line (like its encoder and knob design), and integrating USB-C charging, an onboard FM amplifier, BFO (Beat Frequency Oscillator) control, and selectable bandwidth filters, this upgrade delivers a dramatically improved user experience.

The result is a feature-rich, portable all-band receiver that feels good in hand, responds accurately, and supports both casual scanning and more technical amateur radio activities.

Comprehensive Band Coverage

FM Band (84–108 MHz) Longwave (100–510 kHz) Medium Wave AM (520–1720 kHz) Shortwave SW Bands (1720–30000 kHz) Full SSB Support (LSB & USB for ham radio) CB Band, Ham Bands (160m, 80m, 40m, 20m, 10m, etc.) preconfigured RDS support on FM

Improved Hardware & Design

Based on SI4732-RDS chip for enhanced signal clarity and decoding Durable encoder from ATS-25 for better tuning feel and longevity Enlarged tuning knob for smoother control High-contrast OLED screen for better outdoor visibility USB-C interface for faster, more universal charging Includes high-gain telescopic BNC antenna

Audio & Interface Features

3.5mm stereo headphone jack Built-in 1W 8-ohm speaker Audio output support for external speakers or amplifiers Bandwidth filters: 0.5, 1, 1.2, 2.2, 3, and 4 kHz BFO control for fine SSB tuning Step tuning in 1/5/10 kHz increments 22 preconfigured commercial and ham frequency presets

DIY-Friendly and Hackable

PCB includes SI4735-compatible footprint – swap the chip if desired Software compatible with SI4732 and SI4735 control libraries Preloaded firmware with SI4732-RDS-ALL-IN-ONE-OLED project support Easily modifiable for those who love to tweak

Battery & Power

3.6V 1000mAh lithium battery (included) USB charging via Type-C port (cable included) Long-lasting battery life suitable for outdoor listening

Compatibility & Expansion

Compatible with all standard 3.5mm stereo headphones External audio output for line-in recording or amplification Standard BNC antenna jack for external or directional antennas Compatible with community firmware for SI4732-based devices Users can upgrade or modify firmware via UART if needed

Note

This product is shipped fully assembled and tested. It’s not a kit to solder, but rather a ready-to-use, DIY-grade gadget meant to explore the world of RF with the flexibility hobbyists expect. You don’t need to be an electrical engineer to enjoy this receiver – but if you are, you’ll definitely appreciate what’s under the hood.

This is perfect for

Ham radio beginners and licensed amateurs Shortwave and broadcast listeners RF tinkerers and DIY hardware hackers Educational labs and portable test benches Field kits for emergency radio use