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75W 25-W resistor
100W 100-W resistor
2 Impedance
selector
switch
3 VIDEO OUT
connector
The composite video signal applied to the VIDEO IN connector
goes through the internal resistance and comes out from this
BNC connector. The output impedance is as set with the
selector switch.
RD-AM8285-01 IMPEDANCE SELECTOR
Figure 102B
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Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
3. VMU Tester Disk
A. General
The VMU tester disk (VMU tester software) contains a computer program to
set the picture carrier frequencies on the VMU. The name of this
computer program is "VMUTEST.EXE" (executable file). A number of changes
were made on this program. The history of changes is given below:
DISK P/N FREQ RANGE DESCRIPTION OF CHANGE
MD2HD256005 139.25
thru
295.25 MHz
Initial release (this initial version was replaced
with MD2HD256005A in the field).
MD2HD256005A 95.25
thru
320.25 MHz
The VMU's carrier range was expanded to 95.25 thru
320.25 MHz. Thus, the program was changed to
expand its setting range.
MD2HD256005B
(Ver. 1.0)
95.25
thru
320.25 MHz
The software version number was given to the
program. The program was changed to show this
version on the screen. There was no change in the
frequency range.
MD2HD256005C
(Ver. 1.01)
95.25
thru
320.25 MHz
The program was changed to send the delete channel
command, which sets the carrier frequency of 0 MHz
on the VMU (zero carrier condition). The
necessary frequency input for zero carrier is
"000".
MD2HD256005D
(Ver. 1.02)
90.25
thru
345.25 MHz
The program was changed to expand the setting
range because the older versions' setting range
does not agree with the VMU's carrier range of
90.25 thru 345.25 MHz. A two-digit frequency
input, such as "90" or "96", is also possible with
this version.
You can use MD2HD256005A, MD2HD256005B, MD2HD256005C or MD2HD256005D for
testing of the VMUs given in this manual.
Page 117
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
B. Preparation of VMU Test Disk
Do not use the supplied VMU tester disk for testing. Use it to make
copies only and with its write protect switch set to the WRITE PROTECT
position. Prepare a system disk on the personal computer (PC) and
install the program on the system disk as follows:
(1) Get a blank 1.44-MB formatted floppy disk and put it into the PC's
floppy disk drive (drive A).
(2) Copy the system files to the blank disk to make it a system disk
(bootable disk).
(3) Copy the VMUTEST.EXE program on the supplied VMU tester disk to the
system disk.
Usually, you must do this in two steps:
· Copy the program from the supplied VMU tester disk (drive A) to
drive C (the PC's hard disk drive).
· Then copy the program from drive C to the system disk (drive A).
(4) Make an AUTOEXEC.BAT file on the system disk, which contains a text
line as follows:
VMUTEST
(5) Identify the prepared system disk as "VMU Test Disk" or an
equivalent name.
NOTE: The procedure uses the name "VMU test disk" to show that it is
not the supplied VMU tester disk. You can use other names as
necessary.
(6) Keep the write protect switch of the VMU test disk in the WRITE
ENABLE position because log files will be made on it.
(7) If the VMU test disk becomes full with the log files, make a new VMU
test disk or erase the log files that are not necessary.
Page 118
Feb 20/2002
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COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
THIS PAGE IS
INTENTIONALLY
LEFT BLANK.
Page 119
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
4. Preparation for Functional Testing
A. RF Video Receiving Equipment
You can use a TV tuner or video cassette recorder or equivalent RF video
receiving equipment as an alternative to the RD-AX8308-01 VMU tuner if:
· It can make selection of 12 or more channels.
· It can tune to the normal set of VHF carrier frequencies (CH1 thru CH12
= 151.25 MHz thru 283.25 MHz at intervals of 12 MHz).
· It has a video output calibrated with a standard signal generator. The
　
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