ADPRO FastTx by Xtralis
Installation and User Manual
Doc 11949_06
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3.4.1 Video Input Requirements
To ensure high quality images, the ADPRO FastTx must synchronise correctly to the incoming
video signal for the selected video standard. For synchronisation to occur the following
conditions must be met:
•
the synchronisation pulse amplitude at each video input must be within the range of
0.2 volts to 0.4 volts,
•
the peak video amplitude with reference to the black level (ie. not including the
synchronisation pulses) at each video input must be within the range of 0.5 volt to 1.0 volt,
and
•
for colour cameras, the minimum colour burst level at each video input must be at least
100 mV.
If the video level is low, cable compensators or video line drivers should be installed at the video
source. They should be adjusted to boost the video signal to within the voltage limits given
above.
Maximum Camera Input Cable Length
The maximum cable length that can be used from a camera before cable compensators are
required is dictated by the desired quality of the video picture.
Generally, the shorter the cable
between the camera and the ADPRO FastTx the better the video picture quality.
Use the following information as a guide for RG59 type coaxial cable (75 ohm nominal
impedance):
•
In a monochrome system, depending on the resolution required, the cable length should be
restricted to 500 metres (1600 feet) before cable compensators are installed.
Signal degradation due to the coaxial cables characteristics has a far greater effect on colour
video. In a colour system, the coaxial cable length should be limited to 250 metres (800 feet)
before cable compensators are installed. Again the length is dependent on the required picture
quality.
3.5
Video Output
The video output of the ADPRO FastTx is normally connected to a colour or monochrome
monitor capable of receiving composite video signal to the required TV standard (PAL/CCIR or
NTSC/RS170). The composite video output is designed to drive a 75ohm load.
Figure 41: Video Output Configuration
