Comtech EF Data HPCST-5000 - Manual (Page 180)

Configurations High-Power C-Band Satellite Terminal
A–10 Rev. 0
A.1.4.2 Theory of Operation
The RF-500 up converter utilizes a dual conversion process to convert from a baseband
140 MHz IF signal to the output frequency band.
The first conversion requires an IFLO frequency at 1112.5 MHz from the IFLO module.
The output of the first mixing process is at a frequency of 1252.5 MHz. The 1252.5 MHz
output is applied to the second mixer which mixes the synthesizer frequency input. The
M&C board controls the frequency selection of the synthesizer. The output frequency is
from 4592.5 to 5172.5 MHz, in 2.5 MHz steps.
The output frequency of the second mixer is the desired RF frequency band of 5845 to
6425 MHz.
The M&C board interpolates the factory present compensation data that is stored in an
EEPROM inside the up converter. This data allows the M&C board to command and
compensate the up converter’s output power, ensuring proper output levels over the entire
frequency and temperature range.
The M&C also controls the up converter attenuator.