4. HARDWARE
CONNECTIONS
a. The CT-SAW860 is designed for installation in a standard 19” ELA rack.
b. Connect a 75ohm coaxial cable with F-connectors from the video source’s Audio
Output port to the CT-SAW860’s Audio Input port.
c. Connect a 75ohm coaxial cable with F-connectors from the video source’s Video
Output port to the CT-SAW860’s Video Input port.
d. Connect a 75ohm coaxial cable with F-connectors from the CT-SAW860’s RF Output
port to the headend combiner.
e. Connect the CT-SAW860 to an appropriate power source capable of powering this
device. Be certain that power source is capable of handling the load if the CT-
SAW860 and other equipment are being powered by it.
5. CHANNEL
SELECTION
The CT-SAW860 is a fixed frequency modulator and units are pre-programmed for a single
given channel at the factory. No channel selection is available from the unit.
6. ADJUSTMENT
a. After installation and completing all hardware connections power the unit and wait 20
minutes before making the following adjustments.
b. For testing purposes no more than 15dB from the
RF Output
should be going to a
TV or RF input monitor. Use an attenuator to reduce the signal level if testing with an
RF Input monitor. Individual CT-SAW860 setup and level settings can be tested from
the
RF Output
port. However, system level testing should be done from the
combiner.
c. With a nominal 1 Vp-p video source connected, adjust the
VIDEO LEVEL
control fully
clockwise. The circuit will automatically set the unit for 87.5% modulation over an
input level of 0.5 to 1.5 volts peak-to-peak. If the video input is greater than 1.5Vp-p,
adjust the
VIDEO LEVEL
for correct percentage of modulation (87.5%). If test
equipment is not available then adjust for proper picture contrast when viewed on a
TV monitor and compare with known Off-Air broadcast picture quality.
d. With audio source connected, adjust
AUDIO LEVEL
control on the front panel for 25
KHz deviation. Instead of an audio modulation meter, use a TV set and adjust for
equal volume as compared to a known Off-Air broadcast. Monitor for a few minutes
to assure the maximum volume does not over modulate, which can cause picture
distortion.
e. During field maintenance of the headend the CT-SAW860’s
Output Test
port can be
used for taking unit measurements. However, note the output from the port is
padded down -30 dB and must be taken into consideration when adjusting levels.
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