Theory of Operation
3-70 2715 Spectrum Analyzer Service Manual
Table3 -20: Microprocessor Counter Section Connector Signal Names and
Definitions
Signal Name Description Source Module
CFC Center Frequency (J180):Si gnal from the CFC
board to be counted
Center Frequency Control
OPTION Optional Input (J185): Signal from an installed
option to be counted
InstalledOption
IF IF Input (J190): IF Signal from the Log board to
be counted
Log Board
100MHZ 100MHZCalibrator (J195): Reference Si gnal from
the ReferenceOscillator to be counted
ReferenceOscillator
Tables3 --21 through 3--24 give the pinout foreach connector on the Micropro-
cessor board.
Frequency Counter Connectors. There are four SMB connectors that provide the
required signals to the FrequencyCounter section of the Microprocessor board.
These four connectorsare listed in Figure 3--21 with the associatedinput name.
Table3 -21: Connectors and Signal Names for the
Frequency Counter Section
Connector Signal Name
J180 CFC
J185 OPTION
J190 IF
J195 100MHZ
Power Supply Interface. The Microprocessor board requires only the +5 V supply.
A single 0.1 F capacitor is placed near th e power supply pins for each digital
integrated circuit on theboard to reduce the noise. In addition there are several
220 F electrolytic capacitors placed near sectio ns of the board that require extra
filtering.
Connector Pinouts