Comtech EF Data KST-2000A/B - Manual (Page 57)

Ku-Band Satellite Transceiver Revision 9
Operation MN/KST2000AB.IOM
3–9
3.3.1 3.3.1 RJU-2000 Description
Refer to Figure 3-4 RJU-2000 block diagram.
TX A (J7)
TX IF ( J12)
TX B (J8)
M&C A (J4)
M&C (J6)
M&C B (J5)
RS-485/422
FAULT A
FAULT B
TX (J1) SW
1:1
(J3)
RX (J2) SW
IF SW STATUS / CONTROL
RX SW STATUS / CONTROL
TX SW STATUS / CONTROL RX A (J9)
RX IF J11
RX B (J10)
INTERNAL
TERMINATION
OFFLINE
UNIT
Figure 3-4. RJU-2000 Block Diagram
The RJU-2000 performs several functions vital to correct operation of the redundant
KST-2000A/B system. It performs IF splitting of the TX IF input for application to each
of the KST-2000A/B up converter inputs. Using an IF splitter on the uplink input main-
tains an IF input to each up converter, ensuring correct AGC operation in the offline up-
link.
The RJU-2000 houses an RX IF transfer switch that is used to select the proper down
converter output for application to the RX IF output port (J11). The offline down con-
verter output is internally terminated within the RJU-2000. This switch is not accessible
to the user. The redundant system always maintains the position of this switch to corre-
spond to the position of the RX waveguide switch. This ensures that the proper receive IF
output signal is always presented to the user at J11.
The RJU-2000 has four weatherproof switch position indicators on its front panel. This
enables the operator to quickly determine the online/offline status of each of the system’s
up and downlinks. The green ON LINE indicators illuminate when the corresponding
link is online, and extinguish when a link is offline. These LEDs are powered by diode
“OR’d” voltages supplied by the KST-2000A/Bs.