The Rohde & Schwarz GB4000V Audio Unit is a compact interface device that routes audio, Push-to-Talk (PTT), and squelch signals between operator consoles and remote radio systems. It supports both analog 4-wire E & M signaling and VoIP connections compliant with EUROCAE ED137-1, enabling professional-grade voice communications in civil and military environments, particularly for air traffic control systems where centralized voice switching is unavailable.
Technical Specifications
The unit operates on external DC power from +19 V to +32 V with dual independent connections for redundant supply architecture. Audio frequency response at 600 Ω impedance spans 300 Hz to 3.4 kHz with ±1 dB variation at 1 kHz nominal.
Signaling uses 4-wire E & M lines for PTT and squelch. In-band tone signaling employs 2040 Hz for PTT and 2440 Hz for squelch.
– Key Features
• Compact 19″ × 3 HU form factor for rack mounting or operator console integration
• Built-in loudspeaker with adjustable and configurable minimum volume for safety
• Splash-proof front panel
• LED status indicators for PTT, squelch, and VoIP activity
• Web browser configuration interface
• Optional headset connector supporting instructor operation
• External loudspeaker connection for distributed monitoring
• Dual DC supply inputs enabling redundant power architecture
– Typical Applications
Primary deployment in air traffic control (ATC) facilities, civil aviation, and military command centers requiring long-distance voice monitoring and operator control without dedicated voice switch infrastructure.
– Compatibility & Integration
Fully compatible with Rohde & Schwarz Series4200, Series4400, and Series4100 radios via EUROCAE ED137-1 compliant SIP/RTP over LAN/WAN. Analog interface supports all Rohde & Schwarz radio platforms via 4-wire E & M connections. Front and rear panel connectors vary by model variant (VAR02, VAR03, VAR12); detailed pinout specifications are provided in the User Manual.
