Sokkia R4S-BT External UHF Radio Modem

The Sokkia R4S-BT is a compact, rugged external UHF radio modem designed to expand the communication range of your RTK GNSS system—especially when used with the Sokkia GCX3 receiver line. Featuring built-in Bluetooth® 4.1 connectivity, internal battery power, and full IP67 protection, the R4S-BT delivers wireless freedom and long-lasting performance for demanding field conditions.

This modem is ideal for extending base-to-rover communication up to a full mile in environments where cellular or network coverage is unreliable or unavailable. Whether you're converting a SiteComm rover into a full UHF rover or building an affordable base-rover solution, the R4S-BT offers flexible, field-ready functionality with fast setup and low power consumption.

Key Features:

• Frequency Range: 403–473 MHz with software-selectable 12.5 / 25 kHz channel widths
• Adjustable Output Power: 0.1, 0.2, 0.5, or 1.0 W for flexible field performance
• Bluetooth® 4.1 Connectivity: Wireless configuration and data transfer from compatible field computers
• Internal 7200 mAh Battery: Provides up to 20 hours in receive mode or 6 hours in transmit mode (1 W)
• IP67-Rated Housing: Dustproof, waterproof, and built for rugged outdoor environments
• Lightweight and Portable: Weighs only 420 g (0.93 lb), easy to carry and mount
• Multiple Interface Options: RS-232, USB-to-Serial, M12 circular and TNC connectors
• Wide Compatibility: Works with Sokkia GCX3 and most third-party GNSS systems via open architecture

Applications:

• Extend RTK correction transmission from your base station
• Boost rover performance on large or obstructed job sites
• Convert network rovers into long-range UHF systems
• Reliable field communication in remote or rural areas