d. Downconverter. The downconverter unit per-
Frequency synthesizer, A1.
forms single or double downconversion from an SHF
70-MHz channel, A2.
input to a 70/700 MHz modem interface. Tuning is
adjustable in 1-kHz intervals over a frequency range of
700-MHz channel, A3.
7250 MHz to 7750 MHz by the use of direct-reading,
Power supply, PS1.
decade, front-panel switches. No tuning is required in
700 MHz WB filter, FL1.
the terminal for signal reception other than in this unit.
700 MHz NB filter, FL2.
generated in a frequency synthesizer subassembly
located in the downconverter. It is a separate removable
downconverter unit. The modules within the frequency
unit and is identical to the one used in the upconverter.
synthesizer are not shown. Figure 3-3 shows the front
(1) The downconverter is a completely
panel layout of the downconverter.
independent operating unit requiring only 115-volt line
power for its operation.
It consists of six major