6 Installation / Installation Diagram
CONNECTIONS AND CONTROLS - All connections to and
from the VM2860/VM2862 are made through the rear
panel. Figure 3 shows a typical two channel installation
using a typical satellite receiver as a signal source.
Additional channels can be added by using additional
VM2860/VM2862 modulators and either multi-port
combiners or combinations of two-port combiners.
INSTALLATION NOTES - Level adjustment provides
optimum performance in multichannel installations. The
modulator outputs should be checked periodically with a
spectrum analyzer to maintain a ±1 dB variation of
adjacent channel carriers. Aural/Visual (A/V) ratios should
be held to -15 dB or less. The 'Output Level' and 'A/V
Ratio' controls are used respectively to make these
adjustments. If an output level of less than +50 dBmV is
required from the VM2860/VM2862, add an attenuator of
the appropriate value to the modulator output.
Example: For an output level of +45 dBmV, add a 12 dB
attenuator pad to the modulator output and set the
VM2860/VM2862 output level to +57 dBmV ahead of
the pad.
RACK MOUNTING - Adequate ventilation is very important
in multichannel installations. Units should be spaced apart
by at least one panel height wherever possible, and some
air movement is advisable in enclosed rack cabinets.
Excessive heat will shorten component life and modulator
performance will be degraded without proper cooling.
FCC PART 76.612 - The VM2860/VM2862 synthesizer has
been programmed to comply with FCC requirements for
offsets on cable channel frequencies assigned to aviation
and navigation communications. The programmed offset
for each channel is listed in the following chart.
AUDIO
OUT
L R
SAP LEVEL
L R
VIDEO IN
AUDIO IN
EAS IN
RF OUTPUT
SAP
OVERMODULATION
SAP AUDIO IN
FUSE
.5 A / 250 V
SLO-BLO
115 VAC, 60 Hz
27 WATT
MADE IN THE U.S.A. BY
SERIAL #
CAUTION:-
RISK OF
FIRE-REPLACE FUSE AS
MARKED AFTER
DISCONNECTING
UNIT FROM AC LINE.
ATTENTION:
-RISQUE D'INCENIDE-
REMPLACEZ FUSIBLE DU
TYPE INDIQUÉ APRÉS
DEBRANCHER DU SECTEUR.
®
SAP LEVEL
L R
VIDEO IN
AUDIO IN
EAS IN
RF OUTPUT
SAP
OVERMODULATION
SAP AUDIO IN
FUSE
.5 A / 250 V
SLO-BLO
115 VAC, 60 Hz
27 WATT
MADE IN THE U.S.A. BY
SERIAL #
CAUTION:-
RISK OF
FIRE-REPLACE FUSE AS
MARKED AFTER
DISCONNECTING
UNIT FROM AC LINE.
ATTENTION:
-RISQUE D'INCENIDE-
REMPLACEZ FUSIBLE DU
TYPE INDIQUÉ APRÉS
DEBRANCHER DU SECTEUR.
®
Figure 3 - TYPICAL MULTIPLE MODULATOR INSTALLATION
H
V
VIDEO
OUT
TYPICAL SATELLITE RECEIVER
REAR PANEL
TYPICAL SATELLITE RECEIVER
REAR PANEL
AUDIO
RF OUT
COMBINER
VM2860/VM2862
VIDEO
AUDIO
VIDEO
H
V
VIDEO
OUT
AUDIO
OUT
VM2860/VM2862
L R
NOTE: When connecting the audio output of a stereo receiver to a VM2860, connect both
Left and Right channels. The VM2860 will sum these to make a complete mono audio
signal. When a mono source is used, either input of the VM2860 may be chosen.
