Orban OPTIMOD-FM 8700, Operating Manual

Page: 73 / 390

OPTIMOD-FM DIGITAL INSTALLATION
2-11
drawing on page 6-37. The schematic diagram showing J400 is on page 6-
55.
Connect your subcarrier generator(s) to the 8700i’s subcarrier input(s)
with coaxial cable terminated with BNC connectors.
The subcarrier inputs have greater than 600

load impedance and are
unbalanced. Their sensitivity is variable from 220 mV p-p to > 10 V p-p to
produce 10% injection via trimmers that are accessible for screwdriver
adjustment through holes in the rear panel.
Using the P
ILOT
R
EFERENCE
control (in the I
NPUT
/O
UTPUT
> C
OMPOSITE
screen), you can set the phase of the reference to 0

, 90

, 180

, or 270

with respect to the pilot tone appearing at the composite output.
You can use the
19K R
EF
control in
S
ETUP
to determine whether the 19 kHz pilot
reference output will be in-phase (
0 DEG
) with the pilot tone present in the compo-
site output or will lead it by 90 degrees (
90 DEG
).
0 DEG
is correct for most installa-
tions. Use
90 DEG
only if your RDS/RBDS generator’s 19 kHz reference input specifi-
cally requires this phase relationship.
Digital Composite Outputs
The 8700i provides an AES3 digital composite output at 192 kHz sample rate. Its
output level is set in the Input/Output 5 screen titled Composite 2. At the PC remote,
it is located in the
I/O S
ETUP
S
CREEN
with the tab D
IGITAL
E
NCODER
.
This output appears on a male XLR-type connector on the rear panel. This output is
fully compatible with and interoperable with the de-facto industry standard digital
connection being implemented by transmitter manufacturers and others.
Digitized Subcarrier Inputs
Two additional subcarrier inputs are provided on the rear panel. These are digitized
and are summed only into the digital composite output.
Their mix level is set in the Input/Output 5 screen titled Composite 2. At the PC re-
mote, they are located in the
I/O S
ETUP
S
CREEN
with the tab
D
IGITAL
E
NCODER
.
If you need to use both the digital and analog composite outputs, you must split the
outputs of your SCA generators with tee connectors so that each generator output
drives one digitized SCA input and one non-digitized SCA input.
Wordclock/10 MHz Sync Reference Input
The sync reference input (labeled R
EF
I
N
) appears on a female BNC jack on the rear
panel. It accepts a 1x 5V p-p squarewave wordclock signal at 32, 44.1, 48, 88.2, or 96
kHz, or a 10 MHz sinewave or squarewave signal, 0.5 to 5 V peak. 10 MHz is a com-
mon output frequency produced by GPS and rubidium frequency standards. You can
configure the 8700i to lock its 19 kHz pilot tone and output sample frequency to this
input.
When a valid reference signal is applied to this input, it locks the Optimod’s Internal
DSP clock to this input, so if a given AES3 L/R output’s sync source is set to
I
NTERNAL
,
the sample frequency at that output will be locked to this reference signal.