SDRGEEK ATS25 Max-Decoder II Si4732 Full Band Radio Receiver User Manual

1. Introduction

This manual provides detailed instructions for the operation and maintenance of your SDRGEEK ATS25 Max-Decoder II Si4732 Full Band Radio Receiver. Please read this manual thoroughly before using the device to ensure proper functionality and to maximize your listening experience.

Front view of the SDRGEEK ATS25 Max-Decoder II radio receiver, showing the display, tuning knob, and two antennas (telescopic and whip) attached.

2. Product Overview

2.1 Key Features

• Full band reception: FM, LW, MW, SW, SSB.
• Enhanced modes: LSB, AM, USB, CW, DIGI (PSK/FT4/FT8/RTTY L/RTTY U/HELL), CWR, SYNC L, SYNC U.
• High impedance (Hi-Z) antenna input mode and Low Noise Amplifier (LNA) function.
• Integrated bandpass filter circuit for interference reduction.
• Built-in 4000mAh rechargeable battery with USB-C charging.
• 2.4-inch touch screen display with adjustable brightness.
• WiFi connectivity for firmware updates and PSK mode in DIGI function.
• Built-in full-frequency stereo speaker and 3.5mm headphone jack.
• Robust metal casing and multi-function tuning knob.

This image details the functional upgrades of the ATS25 Max-Decoder II, including LNA function, Hi-Z antenna input impedance, built-in bandpass filter circuit, WiFi function, 50-Ohm mode support, CW decoding functions, PSK mode in WiFi and Digi functions, and support for subsequent updates.

2.2 Package Contents

The following items are included in your package:

• ATS25 Max-Decoder II Host
• Antenna (telescopic)
• Touch Stylus
• USB-C Charging Data Cable
• English User Manual

3. Setup

3.1 Initial Charging

Before first use, fully charge the device using the provided USB-C cable. Connect the cable to the USB-C port on the receiver and a compatible USB power adapter (not included). The LED indicator will show charging status.

The ATS25 Max-Decoder II radio receiver connected to a power outlet via a USB-C cable for charging. The image highlights the built-in 4000mAh rechargeable battery and an estimated 8 hours of working time.

3.2 Antenna Connection

Attach the provided telescopic antenna to the ANT connector on the device. For optimal shortwave reception, consider connecting an external active antenna, loop antenna, or magnetic antenna to the BNC interface.

This image highlights the robust aluminum casing of the ATS25 Max-Decoder II, its BNC antenna interface on the rear panel, and the large multi-function tuning knob on the front.

4. Operating Instructions

4.1 Power On/Off

Press and hold the power button to turn the device on or off.

4.2 Frequency Range and Modes

The receiver supports the following frequency ranges and modes:

• FM: 64-108 MHz (with RDS)
• LW: 153-500 kHz
• MW: 520-1710 kHz
• SW: 1730-30000 kHz
• SSB: 17030 kHz

Available modes include: LSB, AM, USB, CW, DIGI (PSK/FT4/FT8/RTTY L/RTTY U/HELL), CWR, SYNC L, SYNC U.

This image illustrates the various reception modes and frequency ranges supported by the ATS25 Max-Decoder II.

4.3 Tuning and Navigation

• Use the large tuning knob to adjust the frequency.
• The touch screen allows for direct frequency input and navigation through menus.
• The device features a memory function to store frequently used frequencies.
• Spectral scanning function is available for identifying active frequencies.

A close-up of the ATS25 Max-Decoder II's high-resolution display showing various radio parameters, alongside an illustration of its adjustable brightness feature.

4.4 WiFi Connection

To connect to WiFi:

1. Ensure both the receiving antenna and the WiFi antenna are mounted.
2. Connect to a local radio station (turn off LNA/Hi-Z before connecting).
3. Go to SETUP > WIRELESS ON > SELECT AP > ENTER PIN CODE.
4. The decoder must first search for a radio station before connecting to WiFi; otherwise, the connection will not work.

Screenshots from the ATS25 Max-Decoder II display showing the setup menu for decoder functions, various DIGI modes, firmware version, and the WiFi connection settings.

4.5 Audio Output

The device features a built-in wideband speaker for clear audio. For private listening, connect headphones to the 3.5mm headphone jack.

Two scenarios of using the ATS25 Max-Decoder II: one person listening to the built-in speaker while relaxing, and another person listening privately with headphones.

5. Maintenance

• Keep the device clean and free from dust. Use a soft, dry cloth for cleaning.
• Avoid exposing the device to extreme temperatures, humidity, or direct sunlight.
• Charge the battery regularly, even if not in use, to maintain battery health.
• Do not attempt to disassemble or repair the device yourself. Refer to qualified service personnel.

6. Troubleshooting

• Poor Shortwave Reception: If reception is weak, especially on shortwave bands, consider using an external active antenna. The built-in telescopic antenna is primarily for FM broadcast and stronger shortwave signals.
• WiFi Connection Failure: Ensure both antennas are connected and that you have tuned to a radio station before attempting to connect to WiFi. Verify the PIN code and network selection.
• No Audio: Check the volume level. If using headphones, ensure they are properly plugged into the 3.5mm jack.
• Device Not Powering On: Ensure the battery is sufficiently charged. Connect the device to a power source using the USB-C cable.

7. Specifications

8. Warranty and Support

For warranty information and technical support, please refer to the documentation provided with your purchase or contact SDRGEEK customer service. Keep your proof of purchase for any warranty claims.