Comtech EF Data HPCST-5000 - Manual (Page 171)

Rev. 0 A–1
A
Appendix A.
CONFIGURATIONS
This appendix describes the 140 MHz IF configuration.
A.1 140 MHz Configuration
This section describes the 140 MHz IF configuration, which enables the user to double the
available band width. Specifically, instead of the standard 70
! 18 MHz IF, this
configuration allows a 140
! 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 A-1 for a block diagram of the 1112.5 MHz IFLO.