AOR SDU5500 Manual page 18

Section 4-2
Note: Although the earlier AR3000 (not AR3000A) may be modified to provide a 10.7 MHz IF
output, the microprocessor is not capable of communicating with the SDU5500, this limits its
effectiveness.
The RS232 baud rate of the AR3000A is set to 4800bps at the factory. However a 'dip switch' is
provided on the reverse of the AR3000A microprocessor / display PCB, tucked in the corner directly
behind the x10 TUNING button. There are two switches in this PCB area, the momentary action switch
is for CPU reset (do not touch it), the slide switch is for baud rate control. Remove the lower case of the
AR3000A (2 screws next to the front feet and 2 screws on the rear cabinet, use the correct size cross-
head screwdriver). The switch will currently be pushed toward the edge of the PCB (4800bps), slide it
toward the centre of the PCB (9600bps). The AR3000A will need to be switched off / on for the change
to take effect.
Note: Although the AR3000A will operate satisfactorily with the SDU5500, stable operation of the
AR3000A at 9600bps is not guaranteed.
•
Connect a suitable power supply using the d.c. lead provided. Ensure the correct polarity is
observed, the stripe signifies positive. (In certain market areas, a suitable power supply may be
provided).
•
Connect the 9-pin to 9-pin connection lead between the RX CTR socket of the SDU5500 and
REMOTE socket of the AR3000A, an RS232 adapter from 9-pin to 25-pin will be required or procure
/ make up a suitable lead (see section 2-2 item 2 of this manual for pin-out information).
•
Connect a 50 OHM BNC patch lead between the RF IN socket of the SDU5500 and the IF OUT
socket of the AR3000A (following modification of the receiver).
Cold start
It is important that the AR3000A is switched on FIRST, press the POWER switch of the AR3000A so
that the display appears on the radio.
Place the AR3000A into REMOTE mode by sliding the rear REMOTE switch upward, the legend "RMT"
confirms operation on the front panel of the AR3000A receiver.
Now switch on the SDU5500. The first time the SDU5500 is switched on, or whenever power is
removed from the SDU5500, a COLD START sequence needs to be followed. This involves selecting
the required receiver via the SDU5500 companion radio configuration menu. As long as power is not
removed from the SDU5500 (even though it may be switched off with the power feed still connected), the
SDU5500 will remember which companion radio is in use.
Note: The SDU5500 CPU draws a very small current for backup purposes even though the
SDU5500 power switch is off.
The SDU5500 LCD will display various details. Under the item "RX" (third line down from the top left of
the LCD), "Other" radio will be displayed with the CF (centre frequency) of 10.7 MHz. Ensure that
menu item "1" is displayed in the lower left corner of the LCD, if not use the PREV (previous) and
NEXT keys. Press RX to display the COMPANION RADIO configuration menu.
18