Studio Technologies 2A 2013 - Manual (Page 19)

Model 2A User Guide Issue 1, October 2013
Studio Technologies, Inc. Page 19
An input level trim pot allows signals with
a nominal level range of –15 to +10 dBu to
be correctly interfaced. When connecting a
balanced audio signal it should be connect-
ed to the terminal strip’s + and – terminals.
The shield wire can be connected to the
SHLD screw terminal associated with the
mic input. Unbalanced signals may require
a bit more attention for correct operation.
The signal high lead should be connected
to the + terminal. The signal low/shield wire
should connect to both the – terminal and
the SHLD terminal. Failure to make this dual
connection can result is large amounts of
hum being induced into the interrupt signal.
Selecting the Operating Modes
Two slide switches are used to select the
Model 22’s operating modes. The input
select switch allows either the mic input or
the line input terminals of the 5-position
terminal strip to be active. In most cases a
Studio Technologies’ Model 11A gooseneck
microphone has been connected. In this
case the switch should be set to its MIC
position. If you have connected a signal to
the line input terminals, set the switch to its
LINE position. When the Model 22 is using
the line input as its interrupt audio source
an audio trim pot is active. Adjust that
trim pot only after installing the entire IFB
system. Refer to the Configuration section
of this guide for details on how to set the
trim pot.
The Model 22 contains a monitor mute func-
tion which is intended to prevent acoustical
feedback from a loudspeaker associated
with the Model 2A’s monitor output. When
the monitor mute switch is set to its ON
position, the monitor output will be muted
whenever an interrupt (one or both of the
IFB buttons is pressed) on that access
station. When the switch is set to its OFF
position an interrupt from that specific Model
22 will not cause the monitor output to mute.
Model 24 Access Stations
Up to four Model 24 Access Stations can
be connected to two Model 2A units. In this
way the Model 24 units can provide remote
access to the four IFB channels associated
with the two Model 2As. One cable, terminat-
ed with a male 9-pin D-subminiature connec-
tor (DE-9M) on each end, links the Model 24
with the Model 2A designated to provide IFB
channels 1 and 2. A second identical cable
links the Model 24 with the Model 2A desig-
nated to provide IFB channels 3 and 4. Each
Model 24 has an unbalanced microphone
input, a balanced line-level input, five lighted
pushbutton switches, and related circuitry
to access the four IFB channels. Power is
provided by the Model 2A units; an external
power source is not required. A 5-position
screw terminal strip allows connection of
an optional Studio Technologies’ Model 11A
Gooseneck Microphone or a line-level signal.
The Model 24 can be mounted using
either the Model 27A 19-Inch Rack Adapter
or a custom panel cutout. The Model 27A
19-Inch Rack Adapter allows convenient
installation of a Model 24 and a Model 11A
Gooseneck Microphone into one space
of a standard rack enclosure. Refer to the
mechanical drawing in Appendix A for de-
tails. Plenty of room remains on the right
side of the rack adapter panel, allowing
the addition of custom switches, lights, or
connectors as the specific installation may
require.
A custom Model 24 installation is defined
as any installation where you devise the
mounting method! Refer to Appendix A for
a mechanical drawing showing the dimen-
sions of the Model 24. This will assist you