Orban Optimod-AM 9400, Operating Manual

Page: 58 / 295

2-6
INSTALLATION ORBAN MODEL 9400
OPTIMOD-AM. The amount of rolloff is adjustable with the filter's high
frequency ROLLOFF control to complement the setting of the
HF G
AIN
control on OPTIMOD-AM.
B) Change the jumpers to the desired rolloff. See Figure 2-4 on page 2-5.
C) Connect the output of your modulation monitor to the Input terminals of the
Monitor Rolloff Filter.

If the output impedance of the source is between 0 and 35 ohms (such as
the output of an opamp), connect the source between the
0 OHM
SOURCE and COM terminals on the rolloff filter chassis.

If the output impedance of the source is 600 ohms, connect the source
between the
600-OHM SOURCE
and
COM
terminals.

If the output impedance is some value in between, connect a resistor be-
tween the source's output and the Monitor Rolloff Filter's
600-OHM
SOURCE
terminal so that the total source impedance seen by the Moni-
tor Rolloff Filter is 600
Ω
(external re output impedance of source
= 600
Ω
).

If your console monitor or monitor amplifier input is bridging (like virtu-
ally all modern amplifiers), set the
TERMINATION
switches on the Rolloff
Filter to ON.

If the console monitor or monitor amplifier input impedance is a true
600
Ω
, set the TERMINATION switch on the Rolloff Filter to OFF.
D) Connect the input of your console monitor or monitor amplifier to the
OUTPUT terminals on the Monitor Rolloff Filter.
Figure 2-5: Frequency Response Curves as Function of
R
OLLOFF
Control,
Monitor Rolloff Filter Strapped for 18 dB/Octave