: In USB or LSB mode, press the tuning knob to activate BFO. This allows for ultra-fine adjustments (often in 10Hz or 20Hz steps) to clarify "Donald Duck" voices in SSB transmissions. AGC (Auto Gain Control)
: Rotate the large Encoder Knob to change the frequency. Primary Controls & Functions ats-20 radio manual
| Problem | Likely Cause | Solution | |---------|--------------|----------| | Won’t turn on | Dead battery / reversed polarity | Charge 4+ hrs; check 18650 orientation | | No FM reception | Antenna not connected (for SMA version) | Attach stub antenna or wire | | Poor shortwave | No external antenna | Add 15–30 ft wire outdoors | | Display flickers | Low battery or USB noise | Charge battery; use battery power | | Menus stuck | Accidental long press | Short press B or cycle power | : In USB or LSB mode, press the tuning knob to activate BFO