Network Router User Manual

Model 46 User Guide Issue 2, September 2007
Studio Technologies, Inc. Page 17
power supply is providing power to the
intercom circuit. In addition to power, it’s
expected that the external power supply
will also provide the required 200 ohm ter-
minating impedance to both pins 2 and 3.
When switch 1 is in its on (up) position the
Model 46 will provide a 30 volt, 300 mil-
liamperes maximum source of DC power
to pin 2 of the 2-wire PL intercom connec-
tors. The Model 46 will also provide 200
ohm terminating impedances for both pin
2 and pin 3 of the party-line connectors.
The DC power and termination capabili-
ties allow direct powering of dual-chan-
nel intercom belt packs, such as the RTS
BP325. In addition, listen-only belt packs,
such as the Model 34 from Studio Tech-
nologies, Inc. can be directly connected.
There’s also no problem connecting
single-channel intercom belt packs or user
stations.
2-Wire Nominal Audio Level
DIP switch 2 allows adjustment of the
nominal audio level for the two 2-wire
party-line channels associated with inter-
face 1. When the switch is in its off (down)
position the nominal level is –14 dBu.
This level is compatible with intercom belt
packs from manufacturers such as Clear-
Com. When the switch is in its on (up)
position the nominal level is –10 dBu. This
setting is appropriate when belt packs
from RTS, such as the BP325, or listen-
only talent amplifier units from Studio
Technologies, Inc. are connected. For best
Model 46 performance it’s important that
the 2-wire nominal level selection be made
correctly.
4-Wire Nominal Audio Level
DIP switches 3 and 4 are used to config-
ure the nominal level of the input and out-
put circuitry associated with interface 1’s
two 4-wire input and output connections.
Four level settings are available: 0, +4,
+6, and +8 dBu. Prior to setting these DIP
switches it’s important to determine the
nominal audio level of the equipment con-
nected to the Model 46’s 4-wire input and
outputs. This may take a little investigation
but is important for obtaining the best pos-
sible Model 46 performance.
The 0 dBu setting is provided specifically
for use when a Model 46 is interconnected
with a Clear-Com matrix intercom system.
The +4 dBu setting is appropriate when
standard audio lines with “+4” nominal
levels are interconnected. The +6 dBu
setting can be appropriate when intercon-
necting with equipment manufactured in
Europe, such as the digital matrix intercom
systems from Riedel. The +8 dBu setting
is provided specifically when interconnect-
ing the Model 46 with audio signals asso-
ciated with an RTS ADAM-series of matrix
intercom system. This includes the related
RVON-I/O unit.
When DIP switches 3 and 4 are in their
off (down) position the nominal level is
set for 0 dBu. When switch 3 is on (up)
and switch 4 is off (down) the nominal
level is +4 dBu. When switch 3 is off
(down) and switch 4 is on (up) the nomi-
nal level is +6 dBu. When both switches
3 and 4 are in their on (up) position the
nominal level is configured for +8 dBu.