The ATS-20 is open-source hardware. The community has written superior firmware that the original manual never mentions. The most famous is SI4735 Arduino firmware (ported to ATS-20).
Benefits of updating:
To update (you will need a USB-to-TTL adapter):
Warning: This voids any warranty and requires moderate technical skill.
Forget the tiny pamphlet. Print this quick reference and tape it to the back of your ATS-20: ats-20 radio manual
POWER ON: Long-press VF
SELECT MODE: Long-press Filter (AM > LSB > USB)
SAVE MEMORY: VFO mode > Long-press VM > Long-press VF
RECALL MEMORY: Short-press VM > Rotate Encoder
SSB TUNING: 10 Hz steps (press encoder to change step speed)
RESET DEVICE: Pinhole reset button next to USB port (paperclip)
HIDDEN MENU: Power off > Hold VOL + Power
The original manual is notoriously bad at explaining battery installation.
Step 1 – Open the back: Use a small Phillips screwdriver. Do not strip the tiny screws. Step 2 – Battery orientation: Insert an unprotected flat-top 18650 lithium-ion battery. Positive (+) terminal goes towards the top of the radio (near the SMA antenna connector). Negative goes towards the bottom. Step 3 – Power on: Long press the Power/VF button for 1.5 seconds. If the screen flashes and dies, your battery is low or inserted backward. Step 4 – Antenna: The SMA connector is fragile. Do not over-tighten. For SW/HF, a 5-7 meter long wire is best. For FM, use the included telescopic whip.
Warning: Do not transmit on this radio—it is a receiver only. Applying transmit power from another radio into the ATS-20's antenna jack will destroy the Si4732 chip instantly.
Before diving into the button sequences, let's identify which model you have. The ATS-20 is open-source hardware
What’s in the box (usually):
First Impression: The ATS-20 feels premium. The rotary encoder (knob) is the primary control. It has a bright 1.8-inch or 2.0-inch TFT color display. Do not lose the tiny reset button pinhole—you will need it.
Controls how "wide" the receiver listens. This is a DSP filter simulation.
To enter the Setup Menu, press and hold the Encoder Button (or sometimes a dedicated "Menu" button depending on firmware) for 2 seconds. To update (you will need a USB-to-TTL adapter):
Hold the Light/Display button to enter the settings menu. Rotate tuning knob to adjust:
| Menu Item | Function | |-----------|----------| | MW SW STEP | Tuning step (1/5/9/10 kHz for MW; 1/5 kHz for SW) | | FM STEP | FM step (50/100 kHz) | | FM DE | De-emphasis (50 µs for Europe, 75 µs for US) | | BEEP | Keypress beep on/off | | LCD BACKLIGHT | Backlight timeout (1–30 seconds / always on) | | BATTERY TYPE | Li-ion / NiMH (affects voltage display) |
Press S to save setting, then B to exit.