Studio Technologies 45A - Manual (Page 5)

Model 45A User Guide Issue 2, November 2011
Studio Technologies, Inc. Page 5
Introduction
The Model 45A is designed to interface 2-
wire full-duplex party-line (PL) intercom cir-
cuits with 4-wire audio circuits associated
with matrix intercom systems. Applications
for the Model 45A include television sports
and live-event broadcasting, theme park
and theater installations, corporate AV,
and industrial testing environments. The
unit provides one full-featured two-chan-
nel 2-wire-to-4-wire interface. The inter-
face features hybrid circuitry that includes
automatic nulling capability. The analog
hybrids, under software control, provide
excellent audio quality and high return-
loss.
The Model 45A can be powered by an ex-
ternal source of 24 volts DC. The circuitry
is designed so that full isolation from the
connected party-line circuit is maintained.
The connected party-line intercom circuit
can also provide the Model 45A’s operat-
ing power. For maximum flexibility the unit
is capable of supplying 30 volt DC power
and AC terminations, thus creating a
2-wire party-line intercom circuit. This
allows direct support for devices such
as intercom belt packs.
Configuration settings allow the Model
45A’s performance to be optimized. Audio
level meters provide user confirmation
of system performance during setup and
operation. Standard audio connectors
are used for interfacing audio input, audio
output, party-line intercom, and DC power
signals. The Model 45A is housed in a
compact “1/2-rack” form factor that meets
the needs of broadcast “throw-down”
applications. Optional front panels allow
one or two Model 45A units to be mounted
in a single space of a standard 19-inch
rack enclosure or one unit can be mount-
ed in a special 10.5-inch rack.
Figure 1. Model 45A with standard “throw-down” front panel
Figure 2. Model 45A back panel