Ats20 Firmware Link -

Many stock units struggle with Single Side Band. Custom firmware optimized for the SI4732 chip provides much clearer SSB reception for ham radio monitoring.

Many ATS20 units use the chip, but the stock firmware sometimes misidentifies it as an Si4735. This causes band limits to be incorrect. Custom firmware correctly identifies the hardware. ats20 firmware

Because the community contributes to the code, you may encounter different firmware "flavors": Many stock units struggle with Single Side Band