D&R Dual Telephone Hybrid-2 Broadcast Telephone Interface

D&R Dual Telephone Hybrid-2 Broadcast Telephone Interface combines two active hybrid circuits in one 19-inch rackmount enclosure. It connects two conventional analogue telephone lines to professional studio audio equipment, providing separate send and receive audio paths for each line. This arrangement supports telephone interviews, audience calls and production communications without relying on acoustic coupling to a handset.

Two Independent Telephone Interfaces

Each hybrid provides an interface between a two-wire telephone circuit and the separate audio paths used by a broadcast mixer. Two channels allow the studio to manage separate callers through one unit, with individual audio connections for routing and level management. The product is intended for analogue telephone connections; it should not be connected directly to Ethernet, an ISDN circuit or a digital proprietary telephone extension.

Balanced Audio and Adjustable Filtering

D&R Dual Telephone Hybrid-2 uses active balanced audio interfacing for connection to compatible broadcast equipment. Adjustable high-cut and low-cut filters help shape caller audio, while external resistance and capacitance balance adjustments optimise separation between the outgoing studio feed and incoming telephone audio. The published separation figure exceeds 35 dB, with actual performance dependent on the connected line and balance settings.

Broadcast Control and Studio Integration

D&R Dual Telephone Hybrid-2 remote-control and GPIO facilities support integration with compatible mixing consoles and studio control systems. Plan each channel’s return feed so the caller receives the required programme sources without their own delayed voice being routed back. Confirm remote connector wiring, telephone connections and mains configuration against the manual supplied with the dual-channel unit before commissioning. The shared rackmount format keeps both telephone interfaces together within the studio installation.

Basic Product Specifications

• Manufacturer: D&R.
• Product designation: Dual Telephone Hybrid-2.
• Hybrid circuits: two active analogue telephone interfaces.
• Telephone lines: two independent analogue connections.
• Audio routing: separate send and receive paths per channel.
• Audio interface: balanced line-level connections.
• Filtering: adjustable high-cut and low-cut filters.
• Line balance: external resistance and capacitance adjustment.
• Published separation: greater than 35 dB.
• Control: remote operation and GPIO integration.
• Installation format: 19-inch rackmount, 1U.
• Electrical ratings, chassis depth and shipping measurements: confirmation required.