Grass Valley 8900 Frames Gecko 2009 - Manual (Page 39)

Gecko Frames — Instruction Manual 39
Rear Connectors
Loop-through Input Connectors
Input signals are routed through the rear of the frame. There is one loop-
through input for each module cell refer to
Figure 10 and Figure 11 on
page 38 .
Note No more than five digital modules should be looped. Use cables less than
two meters in length, and an input cable of less than 200 meters of Belden
8281 (or equivalent).
If not used for looping, the unused loop-through connector must be exter-
nally terminated. The recommended termination for serial digital signals is
CONARE BCP-TA (or equivalent).
Performance of looping inputs to equipment other than 8900 modules has
not been verified; monitor signal quality carefully when configuring such a
system.
Serial digital video is a wideband RF signal. Be sure to protect the data from
environmental noise. The serial digital signal is attenuated by as much as
30 dB after traveling through 1000 feet of 8281 cable. An equalizer must be
used to restore the signal so data can be recovered. The equalizer boosts the
serial digital video signal and any environmental noise on the line. Data
corruption takes place if the environmental noise is large enough to cause
pick-off errors in the equalizer.
When connecting serial digital video signals to and from the 8900 Series
frame:
• Use high quality BNC connectors to ensure continuous shield connec-
tions.
• Use high quality cable (8281 or 1694A).
• Use one continuous cable for long cable runs. Avoid using patch panels
or BNC barrel connectors.
Note These recommendations become even more important in noisy environ-
ments (subject to radio frequencies and static) with long cable runs.
Direct Input/Output Connectors
In the video frame (refer to Figure 12 ) there are eight direct (not looping)
input/output BNC connectors provided for each module slot (J1 – J8).
Refer to the Instruction Manual for the specific module for input/output
connector information.
Note If 8500 modules are used in the frame, there are six outputs provided for each
module, J1 through J6.