MXD5U OPERATIONS AND MAINTENANCE
2 CONTROLLER
The control board (Assembly 31C1971) is a single-circuit assembly that provides all of the control functions
required for the transmitter on a single circuit board. This board can be configured for a number of different
transmitter types, power levels, transmission standards and options.
Figure 2 Controller Board
The control board provides local front panel interface via ON/OFF and RESET buttons. The board implements
controls/status/telemetry for remote control through a rear panel connector that will interface to a typical remote
control systems (such as Moseley or Gentner). An RS232 serial port is also provided to allow the operator to
access the transmitter through an external computer (with the appropriate software). The control board has RF
detectors for forward and reflected power and all the circuitry to support AGC/VSWR/Cutback functions. Circuitry
to control and monitor the +28V power supply is also included on this board.
Figure 3 Front Panel
2.1 C
ONTROL
B
OARD
A
SSEMBLY AND
J
UMPER SETTINGS
Figure 9 shows the assembly diagram for the control board (Part No 31C1897A2) that performs all the control,
monitoring, RF detection and communication functions.
There are a number of jumpers on this board that are factory set and should not be altered in the field without
consulting Larcan Technical Services first. Changing the jumper settings may result in improper operation of the
transmitter.
The factory jumper settings are given here in the case that either a jumper is dislodged during shipping or has
been removed for any other reason.
Note:
This circuit board is used for a number of transmitter models and a number of components and jumpers are
not installed or used for this transmitter model. We will only detail the jumpers that are used in the MXD5U.
E1 BDM
Enable
Allows connection of the BDM program cable to the board
Setting = NORM for all MXD5U transmitters
PUB09-03 Rev 0 April 16, 2009
09-03-2
MXD5U Operations and Maintenance
