Dawnco PCMA860-HQ Installations- und Betriebshandbuch - Seite 7
Blättern Sie online oder laden Sie pdf Installations- und Betriebshandbuch für Modulator Dawnco PCMA860-HQ herunter. Dawnco PCMA860-HQ 7 Seiten. A/v mini-modulator
Seite druckenUse a small plastic screwdriver to make required selection of switches
and buttons
1. If module is to be used in an HRC or IRC CATV frequency assignment,
slide the format assignment switch inside the side of module to HRC or
IRC. (Unit is shipped with this switch in the STD position)
2. If the audio source is BTSC stereo, slide the preemphasis switch inside the
side of module to off. (Unit is shipped with this switch in the on position)
3. Align the top and bottom edge of module with the guide channel in chassis.
4. Slide module into chassis.
5. Connect the 3 pin molex power supply connector.
6. Connect a cable between the module RF output connection and the
channel-combining network.
7. Connect cables from the programming source baseband output to the
audio and video input connectors of module.
8. If needed, press the CATV/ANT button to select between cable TV and off-
air channel assignments.
9. Select the desired channel by pressing either channel button adjacent to
the arrows on front panel.
10. When the desired channel is displayed, press the set button to lock channel.
11. Connect a signal level meter or spectrum analyzer to a common port of
the channel combiner network.
12. Adjust RF output control on the front of modulator until the RF video
carrier level matches the RF video level of adjacent channels.
13. Adjust the A/V ratio control on the front panel until the RF audio carrier
level is between 13 and 17dB below the RF video carrier level.
14. Connect a television set to a common port of the channel combiner network.
15. Analyze the brightness of channel compared to adjacent channels.
16. If needed, adjust video control on the front of modulator until the bright-
ness level matches the brightness of adjacent channels.
17. Analyze the sound level of channel compared to adjacent channels.
18. If needed, adjust audio control on the front of modulator until the sound
level matches the sound of adjacent channels.
Installation Procedure
PCMA860-HQ
MODULE REPLACEMENT
1. Disconnect the 3 pin molex connector from module.
2. Disconnect the audio, video, and RF connectors from back of module.
3. Remove module by sliding the unit out the front of the chassis.
4. Insert replacement module into chassis.
5. Reconnect the 3 pin molex connector and audio, video, and RF connec-
tors to the rear of module.
6. Set Channel Frequency, level and deviation controls as described in
installation procedures.
OPERATION AND CARE
Do's & Don'ts
•
Always operate in a cool well-ventilated environment.
•
Always provide a stable, conditioned power source..
•
Heed all safety warnings and obey all environmental and electrical oper-
ating requirements.
•
To clean, use a damp cloth only and clean only with mild soap.
•
Do not use solvents or harsh detergents.
•
Do not use this product for purposes other than intended.
HEADEND/DISTRIBUTION INTERFACE
We recommend connecting the headend components in
the following manner:
Each of the modulators, signal processors or strip amplifiers output are
connected to a combining network. Either a head-
end combiner may be used to accomplish this purpose.
The passive headend combiner consists of two rows
of directional couplers combined by a hybrid splitter. Normally, the odd chan-
nels are combined on one row while even channels are combined on the
other row of directional couplers for maximum isolation. The output of the
combiners
input of a launch amplifier
amplifier
distribution line.
A 24 channel system hook-up is shown. (The
same combining result may be accomplished
by using a single #____). The two #____
outputs are combined via a two-way split-
ter, which is connected to a
launch amplifier. The input levels to the com-
biner, whether from a modulator, signal
processor or a strip amplifier, must be at the
same amplitude.
may
be
connected
The output of the
is
connected
to
the
to
the
main