Studio Technologies 200 - Manual (Page 11)

Issue 3, August 2004 Model 200 User Guide
Page 12 Studio Technologies, Inc.
The Model 200 can be directly connected
to, and function correctly with, one of these
circuits. For reliable operation, especially
when using lengthy cable runs, it’s strongly
recommended that no other device be
connected to a 4000-series IFB circuit that
is specified for connection to a Model 200.
This requirement is due to the current-
limited DC source that is supplied by the
4010 IFB Controller.
With 4000-series IFB circuits channel 1
(XLR pin 2) provides program audio that
is “interrupted” with cue signals. This
channel is sometimes referred to as “pro-
gram-with-interrupt.” It’s important to note
that the program audio source fully mutes
whenever directors or producers are com-
municating with on-air talent. Channel 2
(XLR pin 3) of the IFB circuit provides a
“program-only” audio feed. It is never inter-
rupted with cue signals.
While the Model 200’s IFB input was
designed for connection to a “wet” IFB
circuit, it’s also possible to connect line-
level audio sources. Please refer to the
Technical Notes section of this user guide
for details.
External Power Input
An external source of 24 volt DC power
can be connected to the Model 200 by way
of a 2.1 x 5.5 mm coaxial power jack which
is located on the unit’s back panel. The
center pin of the jack is the positive (+)
connection. While the requirement for the
external source is nominally 24 volts, cor-
rect operation will take place over a 20 to
30 volt range. The Model 200 requires 50
milliamperes maximum for correct opera-
tion. Included with each Model 200 is a
24 volt DC external power supply. The
power supply’s DC output cable has
been terminated with a Switchcraft®
S760K coaxial power plug. This “lock-
ing” type of plug correctly mates with the
Model 200’s DC input jack. The locking
feature is important, allowing the external
power supply to be securely attached to
the Model 200.
As previously discussed in this user
guide, an IFB circuit connected to the
IFB input can serve as the Model 200’s
power source. Alternately, an external 24
volt source can be connected. For redun-
dancy, both the IFB circuit and the exter-
nal source can be connected at the same
time. If one or the other becomes inopera-
tive, the remaining source will provide all
Model 200 power.
Note that if both an IFB circuit and an
external 24 volt DC source are connected,
power will be drawn only from the exter-
nal source. This minimizes the chance
that lengthy cable runs or other IFB circuit
issues will impact Model 200 operation.
Whatever device is providing power, audio
signals from the IFB circuit will continue to
serve as the audio source(s) for the head-
phone output.
Pushbutton Labeling
The two pushbutton switches used in
the Model 200 were selected for several
reasons. Foremost was the fact that they
were highly reliable, using gold-plated
contacts for long life in less-than-ideal
environments. A second reason was that
applying customized labels to the button
caps would be very simple. The labels,
text printed on clear material, are placed
under the clear caps that are on the top
of the buttons. From the factory the left
button is labeled COUGH and the right
button is labeled TALKBACK. This was