While not a hardware mod, one exclusive firmware branch repurposes the headphone jack's digital signal path. By toggling a hidden menu (Encoder press + Hold for 10 seconds), the audio out becomes a 455kHz IF (Intermediate Frequency) stream.
You plug this into a PC sound card, and suddenly your $40 ATS20 becomes a $400 panadapter for software like HDSDR or SDR#. This "soft-mod" effectively turns the radio into an upconverter using only firmware. The manufacturer never intended this; it was a reverse-engineered exploit of the DSP's data stream. ats20 firmware exclusive
Is it legal? Absolutely. The ATS20 is open hardware to an extent. However, "exclusive" often means closed source. You must trust the developer. A malicious binary could theoretically damage the Si4732 chip by sending incorrect I2C commands (though rare). While not a hardware mod, one exclusive firmware
The Golden Rule: Only download from reputable forums where the source code has been audited by at least three other members. This "soft-mod" effectively turns the radio into an
The ATS-20 hardware is capable of much more than the factory settings allow. Installing an "Exclusive" custom firmware build is highly recommended for users who want a modern interface, waterfall displays, and better SSB performance.
Recommendation: If you are a beginner, stick to the stock firmware until you are familiar with the radio's operation. If you are an intermediate user, search for the latest "ATS-20E Custom Firmware" on GitHub to unlock your device's full potential.