Studio Technologies 47 - Manual (Page 5)

Model 47 User Guide Issue 1, August 2010
Studio Technologies, Inc. Page 5
Introduction
The Model 47 is designed to interface
2-wire full-duplex party-line intercom cir-
cuits with 4-wire audio circuits associated
with matrix intercom systems. Other spe-
cialized audio system interfacing applica-
tions can also be supported. The Model
47 provides two independent full-featured
2-channel interfaces. Each interface con-
tains 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 to devices such as user belt packs
and user stations. Independent power
sources are provided for both channels
(pins 2 and 3) of each interface, allowing
direct support for broadcast source
assignment panel (SAP) applications.
Configuration settings allow the 2-wire and
4-wire interface circuitry to be compat-
ible with a range of nominal signal levels.
Audio level meters provide user confirma-
tion of system performance during setup
and operation. Applications for the Model
Model 47 Back Panel
Model 47 Front Panel
47 include mobile and fixed television
facilities, theme park and theater installa-
tions, and industrial testing environments.
Standard audio connectors are used for
all input and output signals. The Model 47
mounts in one space (1U) of a standard
19-inch rack enclosure and requires 100-
240 volts, 50/60 Hz for operation.
2-Wire Interfaces
The Model 47’s 2-wire interfaces are
optimized for direct connection with dual-
channel party-line (PL) intercom circuits.
In addition, single-channel party-line inter-
com circuits can also be connected.
Many broadcast applications use the
dual-channel TW-series from RTS®, includ-
ing their popular BP325 belt pack. Other
industry-standard single- and dual-channel
PL intercom systems, including those from
Clear-Com®, are also directly compatible.
To provide optimal signal matching and
interface performance the nominal level
of the Model 47’s 2-wire interfaces can be
selected. Using DIP switches, accessible
on the front panel, the nominal levels can
be selected to be either –10 or –14 dBu,
settings that should allow compatibility
with virtually all party-line systems.