Comtech EF Data CST-5000 - Manual (Page 120)

Rev. 9 A–1
Appendix A.
OPTIONS
This appendix describes the 140 MHz IF and Multi-Carrier System options.
A.1 140 MHz Option
This section describes the 140 MHz IF option, which enables the user to double the
available band width. Specifically, instead of the standard 70 MHz,
± 18 MHz IF, this
option allows a 140 MHz, ± 36 MHz IF.
A.1.1 IF 1112.5 MHz Local Oscillator
The IF Local Oscillator (IFLO) contains:
• Voltage-Controlled Oscillator (VCO)
• Loop filter
• Divide-down chain
The IFLO provides a fixed frequency of 1112.5 MHz to both the up and down
converters. The loop tracking voltage is sent to the M&C board, where it is monitored
along with the lock detect fault.
Refer to Figure Appendix A-1 for a block diagram of the 1112.5 MHz IFLO.