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FiberLink 1900 Series User’s Manual
FiberLink 1900 Series
Operating Pointers
Driving Signal:
The input to the XA-1900 is an AC coupled 600 ohm impedance . It can be
driven by any source including lines with DC levels (below 4 volts) present . The signal return
is connected to case ground and power ground .
The XA-1903 may be switched between the 600 ohm impedance level and a high imped-
ance level . The high impedance level is used to connect additional XA-1903 units to form
a distribution system . When this feature is desired, connect the original IRIG signal to the
input BNC connector of the first XA-1903 and the output BNC connector of that unit to the
input BNC connector of the second XA-1903 and so on until all XA-1903 units have been
connected . Then set all impedance switches to the high impedance position except for the
last XA-1903, which should be set for 600 ohms .
Power Supplies:
The power input to the XA-1900 box is designed to accept AC or DC
voltages . In order for proper operation, the AC level should not drop below 14 volts rms or
the DC level, below 15 volts DC . As long as this criteria is met, unregulated sources may be
used . To prevent damage, voltages higher than 18 volts AC or 25 volts DC should not be
applied . Suitable voltages can be obtained from various low voltage transformers or from a
FiberLink XP-1000A, 115 to 14 VAC plug-in adapter .
Note that one side of the DC input or AC input is connected to the case .
The XA-1900 and RA-1900 card versions derive their power from the 6000A chassis .
The XA-1903 operates from 115/239 VAC 50/60 Hz internal power supply .
Optical Fiber:
Versions of the XA-1900 and XA-1903 are available to drive most multimode
(MM) and single-mode (SM) optical fibers . The specific models are identified by a suffix at
the end of the model number as follows:
Fiber Size
Connector
850nm
1310nm
50u, 62 .5u MM
ST
-1
-3
8/10u SM
ST or FCPC
-
-7
