Technical Instruction

VSHD Exciter Technical Instruction Manual Page 2-11
Section 2 Installation Issue 2.0
2.3.3.1 ANALOG INPUTS:
The digital exciter accepts the following analog inputs:
2.3.3.1.1 Left and Right Inputs
An analog left/right or monaural input (left only) (30 Hz to 15 kHz, -12 dBu to +12 dBu) can
be applied to ANALOG AUDIO IN D-sub connector A1J5 [left (+ on pin 7, - on pin 8, shield
on pin 15), right (+ on pin 13, - on pin 14, shield on pin 6)]. The associated VS transmitter’s
front panel or remote AUI allows for configuration of the audio input mode (left, right or
stereo). Provision is made for adjustment of the input sensitivity and pre-emphasis. The input
impedance for each input is 600 Ω. Exciters are factory configured to provide 100%
modulation (± 75 kHz) with an analog L/R input level of precisely 1.24 V rms (4.7 dBu).
2.3.3.1.2 SCA Generator Input
Dual internal SCA generators can be interfaced via the ANALOG AUDIO IN D-sub connector
(A1J5) [SCA1 (+ on pin 4, - on pin 5, shield on pin 12), SCA2 (+ on pin 10, - on pin 11, shield
on pin 3)]. The input impedance is 600 Ω and the adjustment range is -12 dBu to +12 dBu.
Exciters are factory configured for a 1.24 V rms (4.7 dBu) SCA generator input level.
2.3.3.1.3 MPX Input
Balanced and unbalanced wideband MPX (composite) inputs (30 Hz to 100 kHz) are
provided on the BAL/UNBAL MPX BNC connector (A1J6). The UNBAL/BAL jumper (A1E1,
see Figure 7-11 of this manual) inside the exciter allows selection between balanced (jumper
installed between pins 2 and 3) and unbalanced (jumper installed between pins 1 and 2)
mode. The default setting of this jumper is in the BAL (balanced) position. The levels are
nominally 3.5 V pk-pk for 100% modulation (± 75 kHz) carrier deviation, and are adjustable
between 1.0 V and 5 V pk-pk. The input impedance for each input is 1210 Ω.
If you are using the BAL/UNBAL MPX IN connector (A1J6) for an unbalanced input, remove
the VSHD exciter’s top cover and change the jumper setting for E1 on the exciter/control
PWB (see Figure 7-11). Re-install the top cover.
2.3.3.1.4 MPX SCA Inputs
Two unbalanced inputs (20 kHz to 100 kHz) are provided on the MPX SCA1 (A1J7A) and
MPX SCA2 (A1J7B) BNC connectors, which accept pre-modulated SCA information. The
levels are nominally 2.8 V pk-pk for 10% modulation (± 7.5 kHz) carrier deviation, and are
adjustable between 1.0 V and 5 V pk-pk. The input impedance for each input is 10 kΩ.
NOTE
If the MPX Input is being used as the main audio source with the MPX SCA Input enabled as
well, the MPX SCA meter in the AUI and UI will display N/A.