Studio Technologies MODEL-46
Dual 2-Wire to 4-Wire Interface

MODEL-46

The Model 46 is designed to interface 2-wire full-duplex party-line intercom circuits with 4-wire audio circuits associated with matrix intercom systems. Other specialized audio system interfacing applications can also be supported. The Model 46 provides two independent full-featured 2-channel interfaces. Each interface contains two hybrid circuits which include automatic nulling capability. The analog circuitry, under software control, provides excellent audio quality and high return-loss. The interfaces are compatible with powered and unpowered 2-wire party-line circuits. They are capable of supplying DC power, allowing direct operation of devices such as user belt packs. Configuration settings allow the 2-wire and 4-wire interface circuitry to be compatible with a range of nominal signal levels. Audio level meters provide user confirmation of system performance during setup and operation.

The Model 46 uses standard 3-pin XLR-type connectors to allow convenient interconnection in most broadcast and general audio environments. For flexibility, access to the 2-wire party-line intercom interfaces can be made using the connectors provided on both the front and back panels. In permanent installations the back-panel connectors will typically be utilized. In other settings, such as field television production, front-panel-access allows intercom belt packs to be rapidly connected, without requiring access to the inside of a rack enclosure or necessitating the use of a secondary input/output (I/O) panel.

Applications for the Model 46 include television sports and special event broadcasting, theme park and theater installations, corporate events, and industrial testing environments. Standard audio connectors are used for all input and output signals. The Model 46 mounts in one space of a standard 19-inch rack enclosure and requires 100-240 volts, 50/60 Hz for operation.

Features:

• Two 2-channel party-line intercom interfaces
• Four analog hybrids with auto null capability
• Input and output level metering
• Excellent audio quality
• Integrated intercom power sources
• Standard audio connectors
• Transformer-coupled 4-wire inputs and outputs
• "Universal input" mains powered

Specifications:

General Audio:
Frequency Response: ±2 dB 100 Hz to 8 kHz
Distortion (THD+N): <0.5%, measured at 1 kHz, 4-wire input to 2-wire interface pin 2
Signal-to-Noise Ratio: >55 dB, measured at 1 kHz, 4-wire input to 2-wire interface pin 2

Connectors:
Inputs from 4-Wire: 3-pin female XLR-type
Outputs to 4-Wire: 3-pin male XLR-type
2-Wire Party-Line Intercom: 3-pin male XLR-type
Remote Control: 10-pin header, requires optional 10-pin ribbon connector assembly
AC Mains: 3-blade, IEC 320 C14-type (mates with IEC 320 C13)

2-Wire Party-Line Intercom Interfaces: 2
Type: 2-channel party-line (PL), unbalanced (pin 1 common; pin 2 DC with channel 1 audio; pin 3 channel 2 audio)
Compatibility: single- and dual-channel intercom systems such as from Telex®/RTS® and Clear-Com®
Impedance, External Power Mode: >10 k ohms
Impedance, Internal Power Mode: 200 ohms
Nominal Level: –10 or –14 dBu, selectable
"Mic Kill" Signal: square wave, 24 kHz, ±1%
Internal Power Source: 30 volts DC nominal, 300 milliamperes maximum

Hybrids: 4, 2 per interface
Topology: 3-section analog circuitry compensates for resistive, inductive, and capacitive 2-wire party-line loads
Nulling Method: automatic upon user initiation, processor implements digital control of analog circuitry; null settings stored in non-volatile memory
Nulling Line Impedance Range: 120-350 ohms
Nulling Cable Length Range: 0-3500 feet, typical
Trans-Hybrid Loss: >40 dB, typical at 800 Hz

4-Wire Inputs: 4, 2 per interface
Type: transformer-coupled, capacitor isolated
Impedance: 13 k ohms
Nominal Level: 0, +4, +6, or +8 dBu, selectable in tandem with nominal output level
Maximum Level: +22 dBu

4-Wire Outputs: 4, 2 per interface
Type: transformer-coupled, capacitor isolated
Impedance: 50 ohms nominal
Nominal Level: 0, +4, +6, or +8 dBu, selectable in tandem with nominal input level
Maximum Level: +20 dBu into 2 k ohms

Meters: 8
Function: displays level of 4-wire inputs and outputs
Type: 5-segment LED, modified VU ballistics

Remote Control Inputs: 3
Type: optically coupled
Input: 3-32 volts DC; 2 milliamperes minimum for operation, 20 milliamperes maximum
Functions: auto null interface 1, auto null interface 2, and "mic kill"

AC Mains Requirement: 100-240 volts (–15/+10%), 50/60 Hz, 0.7 A maximum @ 100 volts, 0.4 amperes maximum @ 240 volts

Dimensions (Overall):
19.0 inches wide (48.3 cm)
1.72 inches high (8.9 cm)
8.5 inches deep (21.6 cm)

Mounting: one space in a standard 19-inch rack

Weight: 7.75 pounds (3.5 kg)

Our Part #  MODEL-46