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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
FRONT PANEL
ITEM NAME DESCRIPTION
1 RF IN
connector
(J2)
An RF video input is connected to this BNC connector.
2 VIDEO OUT
connector
(J3), 75 W
This BNC connector gives the composite video output that is
demodulated from the RF video input. The output impedance
is 75 W.
3 ADJUST-NORMAL
switch
· If this switch is set to ADJUST, the VMU turner goes into
an adjustment mode, in which you can adjust the receiving
frequency with the UP, DOWN, SET and RESET switches.
· If this switch is set to NORMAL, the VMU tuner goes into
a normal mode.
4 SET switch This switch sets the receiving frequency that you changed
with the UP or DOWN switch. To use this switch, the ADJUSTNORMAL
switch must be set to ADJUST and the EXT-INT switch
must be set to INT.
5 EXT-INT
switch
· If this switch is set to INT, the UP and DOWN switches
operate as the channel up and down switches in the normal
mode.
· If an external channel selector is connected to the EXT
CH connector (J1 on the rear panel) and this switch is
set to EXT, the external channel selector will operate.
6 CH display This display shows one of the channel numbers 01 thru 16.
It also shows the result of the power-on self-testing (refer
to POWER-ON SELF-TESTING below).
7 RESET switch · If this switch is quickly pushed and released in the
adjustment mode, the receiving frequency shown on the
FREQ display will go back to the default value (refer to
DEFAULT RECEIVING FREQUENCIES below).
· If this switch is pushed longer than one second in the
adjustment mode, the receiving frequencies of all
channels go back to their default values (refer to
DEFAULT RECEIVING FREQUENCIES below).
8 UP switch This switch operates as the channel up switch in the normal
mode, and as the channel/frequency up switch in the
adjustment mode.
RD-AX8308-01 VMU TUNER
Figure 102 (Sheet 2)
Page 110
Aug 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
FRONT PANEL (CONT'D)
ITEM NAME DESCRIPTION
9 DOWN switch This switch operates as the channel down switch in the
normal mode, and as the channel/frequency down switch in the
adjustment mode.
10 FREQ display This display shows one of the receiving frequencies in MHz,
080.25 thru 463.25 at intervals of 1. It also shows the
result of the power-on self-testing (refer to POWER-ON SELFTESTING
below).
11 POWER switch This switch controls the primary AC power of 115 V, 400 Hz
to the VMU tuner. The light in the switch comes on when
this switch is set to ON.
REAR PANEL
ITEM NAME DESCRIPTION
12 EXT CH
connector
(J1)
An external channel selector, which can be a personal
computer with a parallel output board or a 5-bit digital
switch, is connected here for remote control of the VMU
tester. The INT-EXT switch must be set to EXT for remote
control with the external channel selector.
13 Fuseholder,
T2A
This fuseholder holds a time-lag fuse of 2 A, 125 V for
protection of the VMU tuner's primary AC power circuit.
14 Power supply
cord
This three-conductor power supply cord is connected to an AC
power source of 115 V, 400 Hz.
DEFAULT RECEIVING FREQUENCIES
CH FREQ, MHz CH FREQ, MHz CH FREQ, MHz CH FREQ, MHz
1 151.25 5 199.25 9 247.25 13 295.25
2 163.25 6 211.25 10 259.25 14 307.25
3 175.25 7 223.25 11 271.25 15 319.25
4 187.25 8 235.25 12 283.25 16 331.25
RD-AX8308-01 VMU TUNER
Figure 102 (Sheet 3)
Page 111
Aug 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
POWER-ON SELF-TESTING
The VMU tuner does self-testing at the time of power-on:
· Display test - The CH display must show “88” and the FREQ display must show
“888.88” for approximately three seconds.
· EEPROM write/read test - The VMU tuner uses an EEPROM device to keep the
frequency data for each channel. This test makes sure that the EEPROM
device is serviceable.
· Tuner pack status check - The internal tuner pack is examined through data
communication.
· External channel selector input check - The VMU tuner makes this check if
the EXT-INT switch is set to EXT at the time of power-on. A minimum of one
channel selector input bit must be grounded.
The result of the power-on self-testing (POST) is shown on the CH and FREQ
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(28)
